The Driving Forces of Cultural Complexity : Neanderthals, Modern Humans, and the Question of Population Size.

PubMed

Fogarty, Laurel; Wakano, Joe Yuichiro; Feldman, Marcus W; Aoki, Kenichi

2017-03-01

The forces driving cultural accumulation in human populations, both modern and ancient, are hotly debated. Did genetic, demographic, or cognitive features of behaviorally modern humans (as opposed to, say, early modern humans or Neanderthals) allow culture to accumulate to its current, unprecedented levels of complexity? Theoretical explanations for patterns of accumulation often invoke demographic factors such as population size or density, whereas statistical analyses of variation in cultural complexity often point to the importance of environmental factors such as food stability, in determining cultural complexity. Here we use both an analytical model and an agent-based simulation model to show that a full understanding of the emergence of behavioral modernity, and the cultural evolution that has followed, depends on understanding and untangling the complex relationships among culture, genetically determined cognitive ability, and demographic history. For example, we show that a small but growing population could have a different number of cultural traits from a shrinking population with the same absolute number of individuals in some circumstances.

The demographic components of population aging in China.

PubMed

Grigsby, J S; Olshansky, S J

1989-01-01

"In this paper we examine measures of population aging in China from 1953 to 1982, and then project population aging to the year 2050 using a cohort-components methodology.... Results indicate that China's population will age at an unprecedented rate over the next 70 years, both in terms of the absolute size of the elderly population and their proportion of the total population. At least 50 percent of the projected increase in population aging in China between 1980 and 2050 will be a product of the momentum for aging that is already built into the present age structure and vital rates. However, prospective trends in the measures of population aging become increasingly more sensitive to varying assumptions about fertility and mortality with time, and as older age groups are considered." excerpt

Impact and cratering rates onto Pluto

NASA Astrophysics Data System (ADS)

Greenstreet, Sarah; Gladman, Brett; McKinnon, William B.

2015-09-01

The New Horizons spacecraft fly-through of the Pluto system in July 2015 will provide humanity's first data for the crater populations on Pluto and its binary companion, Charon. In principle, these surfaces could be dated in an absolute sense, using the observed surface crater density (# craters/km2 larger than some threshold crater diameter D). Success, however, requires an understanding of both the cratering physics and absolute impactor flux. The Canada-France Ecliptic Plane Survey (CFEPS) L7 synthetic model of classical and resonant Kuiper belt populations (Petit, J.M. et al. [2011]. Astron. J. 142, 131-155; Gladman, B. et al. [2012]. Astron. J. 144, 23-47) and the scattering object model of Kaib et al. (Kaib, N., Roškar, R., Quinn, T. [2011]. Icarus 215, 491-507) calibrated by Shankman et al. (Shankman, C. et al. [2013]. Astrophys. J. 764, L2-L5) provide such impact fluxes and thus current primary cratering rates for each dynamical sub-population. We find that four sub-populations (the q < 42AU hot and stirred main classicals, the classical outers, and the plutinos) dominate Pluto's impact flux, each providing ≈ 15- 25 % of the total rate. Due to the uncertainty in how the well-characterized size distribution for Kuiper belt objects (with impactor diameter d > 100km) connects to smaller projectiles, we compute cratering rates using five model impactor size distributions: a single power-law, a power-law with a knee, a power-law with a divot, as well as the "wavy" size distributions described in Minton et al. (Minton, D.A. et al. [2012]. Asteroids Comets Meteors Conf. 1667, 6348) and Schlichting et al. (Schlichting, H.E., Fuentes, C.I., Trilling, D.E. [2013]. Astron. J. 146, 36-42). We find that there is only a small chance that Pluto has been hit in the past 4 Gyr by even one impactor with a diameter larger than the known break in the projectile size distribution (d ≈ 100km) which would create a basin on Pluto (D ⩾ 400km in diameter). We show that due to present uncertainties in the impactor size distribution between d = 1- 100km , computing absolute ages for the surface of Pluto is entirely dependent on the extrapolation to small sizes and thus fraught with uncertainty. We show, however, what the ages would be for several cases and illustrate the relative importance of each Kuiper belt sub-population to the cratering rate, both now and integrated into the past. In addition, we compute the largest "fresh" crater expected to have formed in 1 Gyr on the surface of Pluto and in 3 Gyr on Charon (to 95% confidence) and use the "wavy" size distribution models to predict whether these largest "fresh" craters will provide surfaces for which portions of the crater production function can be measured should most of the target's surface appear saturated. The fly-through results coupled with telescopic surveys that bridge current uncertainties in the d = 10- 100km regime should eventually result in the population estimate uncertainties for the Kuiper belt sub-populations, and thus the impact fluxes onto Pluto and Charon, dipping to < 30 % . We also compute "disruption timescales" (to a factor of three accuracy) for Pluto's smaller satellites: Styx, Nix, Kerberos, and Hydra. We find that none of the four satellites have likely undergone a catastrophic disruption and reassembly event in the past ≈ 4Gyr . In addition, we find that for a knee size distribution with αfaint ⩽ 0.4 (down to sub-km diameters), satellites of all sizes are able to survive catastrophic disruption over the past 4 Gyr.

OSSOS. II. A Sharp Transition in the Absolute Magnitude Distribution of the Kuiper Belt’s Scattering Population

NASA Astrophysics Data System (ADS)

Shankman, C.; Kavelaars, JJ.; Gladman, B. J.; Alexandersen, M.; Kaib, N.; Petit, J.-M.; Bannister, M. T.; Chen, Y.-T.; Gwyn, S.; Jakubik, M.; Volk, K.

2016-02-01

We measure the absolute magnitude, H, distribution, dN(H) ∝ 10 αH , of the scattering Trans-Neptunian Objects (TNOs) as a proxy for their size-frequency distribution. We show that the H-distribution of the scattering TNOs is not consistent with a single-slope distribution, but must transition around H g ˜ 9 to either a knee with a shallow slope or to a divot, which is a differential drop followed by second exponential distribution. Our analysis is based on a sample of 22 scattering TNOs drawn from three different TNO surveys—the Canada-France Ecliptic Plane Survey, Alexandersen et al., and the Outer Solar System Origins Survey, all of which provide well-characterized detection thresholds—combined with a cosmogonic model for the formation of the scattering TNO population. Our measured absolute magnitude distribution result is independent of the choice of cosmogonic model. Based on our analysis, we estimate that the number of scattering TNOs is (2.4-8.3) × 105 for H r < 12. A divot H-distribution is seen in a variety of formation scenarios and may explain several puzzles in Kuiper Belt science. We find that a divot H-distribution simultaneously explains the observed scattering TNO, Neptune Trojan, Plutino, and Centaur H-distributions while simultaneously predicting a large enough scattering TNO population to act as the sole supply of the Jupiter-Family Comets.

Introducing the Mean Absolute Deviation "Effect" Size

ERIC Educational Resources Information Center

Gorard, Stephen

2015-01-01

This paper revisits the use of effect sizes in the analysis of experimental and similar results, and reminds readers of the relative advantages of the mean absolute deviation as a measure of variation, as opposed to the more complex standard deviation. The mean absolute deviation is easier to use and understand, and more tolerant of extreme…

Comparative adoption of cone beam computed tomography and panoramic radiography machines across Australia.

PubMed

Zhang, A; Critchley, S; Monsour, P A

2016-12-01

The aim of the present study was to assess the current adoption of cone beam computed tomography (CBCT) and panoramic radiography (PR) machines across Australia. Information regarding registered CBCT and PR machines was obtained from radiation regulators across Australia. The number of X-ray machines was correlated with the population size, the number of dentists, and the gross state product (GSP) per capita, to determine the best fitting regression model(s). In 2014, there were 232 CBCT and 1681 PR machines registered in Australia. Based on absolute counts, Queensland had the largest number of CBCT and PR machines whereas the Northern Territory had the smallest number. However, when based on accessibility in terms of the population size and the number of dentists, the Australian Capital Territory had the most CBCT machines and Western Australia had the most PR machines. The number of X-ray machines correlated strongly with both the population size and the number of dentists, but not with the GSP per capita. In 2014, the ratio of PR to CBCT machines was approximately 7:1. Projected increases in either the population size or the number of dentists could positively impact on the adoption of PR and CBCT machines in Australia. © 2016 Australian Dental Association.

Evidence for self-secondary cratering of Copernican-age continuous ejecta deposits on the Moon

NASA Astrophysics Data System (ADS)

Zanetti, M.; Stadermann, A.; Jolliff, B.; Hiesinger, H.; van der Bogert, C. H.; Plescia, J.

2017-12-01

Crater size-frequency distributions on the ejecta blankets of Aristarchus and Tycho Craters are highly variable, resulting in apparent absolute model age differences despite ejecta being emplaced in a geologic instant. Crater populations on impact melt ponds are a factor of 4 less than on the ejecta, and crater density increases with distance from the parent crater rim. Although target material properties may affect crater diameters and in turn crater size-frequency distribution (CSFD) results, they cannot completely reconcile crater density and population differences observed within the ejecta blanket. We infer from the data that self-secondary cratering, the formation of impact craters immediately following the emplacement of the continuous ejecta blanket by ejecta from the parent crater, contributed to the population of small craters (< 300 m diameter) on ejecta blankets and must be taken into account if small craters and small count areas are to be used for relative and absolute model age determinations on the Moon. Our results indicate that the cumulative number of craters larger than 1 km in diameter per unit area, N(1), on the continuous ejecta blanket at Tycho Crater, ranges between 2.17 × 10-5 and 1.0 × 10-4, with impact melt ponds most accurately reflecting the primary crater flux (N(1) = 3.4 × 10-5). Using the cratering flux recorded on Tycho impact melt deposits calibrated to accepted exposure age (109 ± 1.5 Ma) as ground truth, and using similar crater distribution analyses on impact melt at Aristarchus Crater, we infer the age of Aristarchus Crater to be ∼280 Ma. The broader implications of this work suggest that the measured cratering rate on ejecta blankets throughout the Solar System may be overestimated, and caution should be exercised when using small crater diameters (i.e. < 300 m on the Moon) for absolute model age determination.

Superslow relaxation in identical phase oscillators with random and frustrated interactions

NASA Astrophysics Data System (ADS)

Daido, H.

2018-04-01

This paper is concerned with the relaxation dynamics of a large population of identical phase oscillators, each of which interacts with all the others through random couplings whose parameters obey the same Gaussian distribution with the average equal to zero and are mutually independent. The results obtained by numerical simulation suggest that for the infinite-size system, the absolute value of Kuramoto's order parameter exhibits superslow relaxation, i.e., 1/ln t as time t increases. Moreover, the statistics on both the transient time T for the system to reach a fixed point and the absolute value of Kuramoto's order parameter at t = T are also presented together with their distribution densities over many realizations of the coupling parameters.

Primary care and health inequality: Difference-in-difference study comparing England and Ontario

PubMed Central

Cookson, Richard; Mondor, Luke; Kringos, Dionne S.; Klazinga, Niek S.

2017-01-01

Background It is not known whether equity-oriented primary care investment that seeks to scale up the delivery of effective care in disadvantaged communities can reduce health inequality within high-income settings that have pre-existing universal primary care systems. We provide some non-randomised controlled evidence by comparing health inequality trends between two similar jurisdictions–one of which implemented equity-oriented primary care investment in the mid-to-late 2000s as part of a cross-government strategy for reducing health inequality (England), and one which invested in primary care without any explicit equity objective (Ontario, Canada). Methods We analysed whole-population data on 32,482 neighbourhoods (with mean population size of approximately 1,500 people) in England, and 18,961 neighbourhoods (with mean population size of approximately 700 people) in Ontario. We examined trends in mortality amenable to healthcare by decile groups of neighbourhood deprivation within each jurisdiction. We used linear models to estimate absolute and relative gaps in amenable mortality between most and least deprived groups, considering the gradient between these extremes, and evaluated difference-in-difference comparisons between the two jurisdictions. Results Inequality trends were comparable in both jurisdictions from 2004–6 but diverged from 2007–11. Compared with Ontario, the absolute gap in amenable mortality in England fell between 2004–6 and 2007–11 by 19.8 per 100,000 population (95% CI: 4.8 to 34.9); and the relative gap in amenable mortality fell by 10 percentage points (95% CI: 1 to 19). The biggest divergence occurred in the most deprived decile group of neighbourhoods. Discussion In comparison to Ontario, England succeeded in reducing absolute socioeconomic gaps in mortality amenable to healthcare from 2007 to 2011, and preventing them from growing in relative terms. Equity-oriented primary care reform in England in the mid-to-late 2000s may have helped to reduce socioeconomic inequality in health, though other explanations for this divergence are possible and further research is needed on the specific causal mechanisms. PMID:29182652

Size of thyroid carcinoma by histotype and variants: A population-based study in a mildly iodine-deficient area.

PubMed

Marina, Michela; Ceda, Gian Paolo; Corcione, Luigi; Sgargi, Paolo; Michiara, Maria; Silini, Enrico Maria; Ceresini, Graziano

2017-10-01

Data relating the size of thyroid cancer with histological types and variants are scarce. All incident thyroid cancer diagnosed between 2003 and 2012 in a mildly iodine-deficient area were derived from a population-based tumor registry. Undifferentiated/anaplastic thyroid cancer and incidental cases were excluded. Major diameter of thyroid cancer, as assessed by pathological examination, was stratified in classes: ≤10 mm; 11-20 mm; 21-40 mm; and >40 mm. For each class, absolute and relative frequencies of histological types were calculated. Tumors >20 mm were more frequent among follicular thyroid carcinoma (FTC) and Hürthle cell carcinoma than in other histotypes, with median size of 22.50 mm (95% confidence interval [CI] 16.71-28.29) and 25.00 mm (95% CI 17.04-32.96) in FTC and Hürthle cell carcinoma, respectively. Odds ratio for tumors >20 mm was significant for FTC and Hürthle cell carcinoma only (P < .0001). Among the histotypes and variants of differentiated thyroid cancer, FTC and Hürthle cell carcinoma are characterized by the largest size. © 2017 Wiley Periodicals, Inc.

Parker's sneak-guard model revisited: why do reproductively parasitic males heavily invest in testes?

PubMed

Ota, Kazutaka; Kohda, Masanori; Hori, Michio; Sato, Tetsu

2011-10-01

Alternative reproductive tactics are widespread in males and may cause intraspecific differences in testes investment. Parker's sneak-guard model predicts that sneaker males, who mate under sperm competition risk, invest in testes relatively more than bourgeois conspecifics that have lower risk. Given that sneakers are much smaller than bourgeois males, sneakers may increase testes investment to overcome their limited sperm productivity because of their small body sizes. In this study, we examined the mechanism that mediates differential testes investment across tactics in the Lake Tanganyika cichlid fish Lamprologus callipterus. In the Rumonge population of Burundi, bourgeois males are small compared with those in other populations and have a body size close to sneaky dwarf males. Therefore, if differences in relative testis investment depend on sperm competition, the rank order of relative testis investment should be dwarf males > bourgeois males in Rumonge = bourgeois males in the other populations. If differences in relative testis investment depend on body size, the rank order of relative testes investment should be dwarf males > bourgeois males in Rumonge > bourgeois males in the other populations. Comparisons of relative testis investment among the three male groups supported the role of sperm competition, as predicted by the sneak-guard model. Nevertheless, the effects of absolute body size on testes investment should be considered to understand the mechanisms underlying intraspecific variation in testes investment caused by alternative reproductive tactics.

Parker's sneak-guard model revisited: why do reproductively parasitic males heavily invest in testes?

NASA Astrophysics Data System (ADS)

Ota, Kazutaka; Kohda, Masanori; Hori, Michio; Sato, Tetsu

2011-10-01

Alternative reproductive tactics are widespread in males and may cause intraspecific differences in testes investment. Parker's sneak-guard model predicts that sneaker males, who mate under sperm competition risk, invest in testes relatively more than bourgeois conspecifics that have lower risk. Given that sneakers are much smaller than bourgeois males, sneakers may increase testes investment to overcome their limited sperm productivity because of their small body sizes. In this study, we examined the mechanism that mediates differential testes investment across tactics in the Lake Tanganyika cichlid fish Lamprologus callipterus. In the Rumonge population of Burundi, bourgeois males are small compared with those in other populations and have a body size close to sneaky dwarf males. Therefore, if differences in relative testis investment depend on sperm competition, the rank order of relative testis investment should be dwarf males > bourgeois males in Rumonge = bourgeois males in the other populations. If differences in relative testis investment depend on body size, the rank order of relative testes investment should be dwarf males > bourgeois males in Rumonge > bourgeois males in the other populations. Comparisons of relative testis investment among the three male groups supported the role of sperm competition, as predicted by the sneak-guard model. Nevertheless, the effects of absolute body size on testes investment should be considered to understand the mechanisms underlying intraspecific variation in testes investment caused by alternative reproductive tactics.

Anticipatory flexibility: larval population density in moths determines male investment in antennae, wings and testes.

PubMed

Johnson, Tamara L; Symonds, Matthew R E; Elgar, Mark A

2017-11-15

Developmental plasticity provides individuals with a distinct advantage when the reproductive environment changes dramatically. Variation in population density, in particular, can have profound effects on male reproductive success. Females may be easier to locate in dense populations, but there may be a greater risk of sperm competition. Thus, males should invest in traits that enhance fertilization success over traits that enhance mate location. Conversely, males in less dense populations should invest more in structures that will facilitate mate location. In Lepidoptera, this may result in the development of larger antennae to increase the likelihood of detecting female sex pheromones, and larger wings to fly more efficiently. We explored the effects of larval density on adult morphology in the gum-leaf skeletonizer moth, Uraba lugens , by manipulating both the number of larvae and the size of the rearing container. This experimental arrangement allowed us to reveal the cues used by larvae to assess whether absolute number or density influences adult responses. Male investment in testes size depended on the number of individuals, while male investment in wings and antennae depended upon larval density. By contrast, the size of female antennae and wings were influenced by an interaction of larval number and container size. This study demonstrates that male larvae are sensitive to cues that may reveal adult population density, and adjust investment in traits associated with fertilization success and mate detection accordingly. © 2017 The Author(s).

Decision Accuracy and the Role of Spatial Interaction in Opinion Dynamics

NASA Astrophysics Data System (ADS)

Torney, Colin J.; Levin, Simon A.; Couzin, Iain D.

2013-04-01

The opinions and actions of individuals within interacting groups are frequently determined by both social and personal information. When sociality (or the pressure to conform) is strong and individual preferences are weak, groups will remain cohesive until a consensus decision is reached. When group decisions are subject to a bias, representing for example private information known by some members of the population or imperfect information known by all, then the accuracy achieved for a fixed level of bias will increase with population size. In this work we determine how the scaling between accuracy and group size can be related to the microscopic properties of the decision-making process. By simulating a spatial model of opinion dynamics we show that the relationship between the instantaneous fraction of leaders in the population ( L), system size ( N), and accuracy depends on the frequency of individual opinion switches and the level of population viscosity. When social mixing is slow, and individual opinion changes are frequent, accuracy is determined by the absolute number of informed individuals. As mixing rates increase, or the rate of opinion updates decrease, a transition occurs to a regime where accuracy is determined by the value of L√{ N}. We investigate the transition between different scaling regimes analytically by examining a well-mixed limit.

OSSOS. II. A SHARP TRANSITION IN THE ABSOLUTE MAGNITUDE DISTRIBUTION OF THE KUIPER BELT’S SCATTERING POPULATION

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

Shankman, C.; Kavelaars, JJ.; Bannister, M. T.

We measure the absolute magnitude, H, distribution, dN(H) ∝ 10{sup αH}, of the scattering Trans-Neptunian Objects (TNOs) as a proxy for their size-frequency distribution. We show that the H-distribution of the scattering TNOs is not consistent with a single-slope distribution, but must transition around H{sub g} ∼ 9 to either a knee with a shallow slope or to a divot, which is a differential drop followed by second exponential distribution. Our analysis is based on a sample of 22 scattering TNOs drawn from three different TNO surveys—the Canada–France Ecliptic Plane Survey, Alexandersen et al., and the Outer Solar System Origins Survey, all of whichmore » provide well-characterized detection thresholds—combined with a cosmogonic model for the formation of the scattering TNO population. Our measured absolute magnitude distribution result is independent of the choice of cosmogonic model. Based on our analysis, we estimate that the number of scattering TNOs is (2.4–8.3) × 10{sup 5} for H{sub r} < 12. A divot H-distribution is seen in a variety of formation scenarios and may explain several puzzles in Kuiper Belt science. We find that a divot H-distribution simultaneously explains the observed scattering TNO, Neptune Trojan, Plutino, and Centaur H-distributions while simultaneously predicting a large enough scattering TNO population to act as the sole supply of the Jupiter-Family Comets.« less

Brain size and encephalization in early to Mid-Pleistocene Homo.

PubMed

Rightmire, G Philip

2004-06-01

Important changes in the brain have occurred during the course of human evolution. Both absolute and relative size increases can be documented for species of Homo, culminating in the appearance of modern humans. One species that is particularly well-represented by fossil crania is Homo erectus. The mean capacity for 30 individuals is 973 cm(3). Within this group there is substantial variation, but brain size increases slightly in specimens from later time periods. Other Middle Pleistocene crania differ from those of Homo erectus. Characters of the facial skeleton, vault, and cranial base suggest that fossils from sites such as Arago Cave in France, the Sima de los Huesos in Spain, Bodo in Ethiopia, Broken Hill in Zambia, and perhaps Dali in China belong to the taxon Homo heidelbergensis. Ten of these mid-Quaternary hominins have brains averaging 1,206 cm(3) in volume, and many fall beyond the limits of size predicted for Homo erectus of equivalent age. When orbit height is used to construct an index of relative brain size, it is apparent that the (significant) increase in volume documented for the Middle Pleistocene individuals is not simply a consequence of larger body mass. Encephalization quotient values confirm this finding. These changes in absolute and relative brain size can be taken as further corroborative evidence for a speciation event, in which Homo erectus produced a daughter lineage. It is probable that Homo heidelbergensis originated in Africa or western Eurasia and then ranged widely across the Old World. Archaeological traces indicate that these populations differed in their technology and behavior from earlier hominins. Copyright 2003 Wiley-Liss, Inc.

Derivation and Application of a Global Albedo yielding an Optical Brightness To Physical Size Transformation Free of Systematic Errors

NASA Technical Reports Server (NTRS)

Mulrooney, Dr. Mark K.; Matney, Dr. Mark J.

2007-01-01

Orbital object data acquired via optical telescopes can play a crucial role in accurately defining the space environment. Radar systems probe the characteristics of small debris by measuring the reflected electromagnetic energy from an object of the same order of size as the wavelength of the radiation. This signal is affected by electrical conductivity of the bulk of the debris object, as well as its shape and orientation. Optical measurements use reflected solar radiation with wavelengths much smaller than the size of the objects. Just as with radar, the shape and orientation of an object are important, but we only need to consider the surface electrical properties of the debris material (i.e., the surface albedo), not the bulk electromagnetic properties. As a result, these two methods are complementary in that they measure somewhat independent physical properties to estimate the same thing, debris size. Short arc optical observations such as are typical of NASA's Liquid Mirror Telescope (LMT) give enough information to estimate an Assumed Circular Orbit (ACO) and an associated range. This information, combined with the apparent magnitude, can be used to estimate an "absolute" brightness (scaled to a fixed range and phase angle). This absolute magnitude is what is used to estimate debris size. However, the shape and surface albedo effects make the size estimates subject to systematic and random errors, such that it is impossible to ascertain the size of an individual object with any certainty. However, as has been shown with radar debris measurements, that does not preclude the ability to estimate the size distribution of a number of objects statistically. After systematic errors have been eliminated (range errors, phase function assumptions, photometry) there remains a random geometric albedo distribution that relates object size to absolute magnitude. Measurements by the LMT of a subset of tracked debris objects with sizes estimated from their radar cross sections indicate that the random variations in the albedo follow a log-normal distribution quite well. In addition, this distribution appears to be independent of object size over a considerable range in size. Note that this relation appears to hold for debris only, where the shapes and other properties are not primarily the result of human manufacture, but of random processes. With this information in hand, it now becomes possible to estimate the actual size distribution we are sampling from. We have identified two characteristics of the space debris population that make this process tractable and by extension have developed a methodology for performing the transformation.

Redefinition of the crater-density and absolute-age boundaries for the chronostratigraphic system of Mars

USGS Publications Warehouse

Werner, S.C.; Tanaka, K.L.

2011-01-01

For the boundaries of each chronostratigraphic epoch on Mars, we present systematically derived crater-size frequencies based on crater counts of geologic referent surfaces and three proposed " standard" crater size-frequency production distributions as defined by (a) a simple -2 power law, (b) Neukum and Ivanov, (c) Hartmann. In turn, these crater count values are converted to model-absolute ages based on the inferred cratering rate histories. We present a new boundary definition for the Late Hesperian-Early Amazonian transition. Our fitting of crater size-frequency distributions to the chronostratigraphic record of Mars permits the assignment of cumulative counts of craters down to 100. m, 1. km, 2. km, 5. km, and 16. km diameters to martian epochs. Due to differences in the " standard" crater size-frequency production distributions, a generalized crater-density-based definition to the chronostratigraphic system cannot be provided. For the diameter range used for the boundary definitions, the resulting model absolute age fits vary within 1.5% for a given set of production function and chronology model ages. Crater distributions translated to absolute ages utilizing different curve descriptions can result in absolute age differences exceeding 10%. ?? 2011 Elsevier Inc.

Protection of obstetric dimensions in a small-bodied human sample.

PubMed

Kurki, Helen K

2007-08-01

In human females, the bony pelvis must find a balance between being small (narrow) for efficient bipedal locomotion, and being large to accommodate a relatively large newborn. It has been shown that within a given population, taller/larger-bodied women have larger pelvic canals. This study investigates whether in a population where small body size is the norm, pelvic geometry (size and shape), on average, shows accommodation to protect the obstetric canal. Osteometric data were collected from the pelves, femora, and clavicles (body size indicators) of adult skeletons representing a range of adult body size. Samples include Holocene Later Stone Age (LSA) foragers from southern Africa (n = 28 females, 31 males), Portuguese from the Coimbra-identified skeletal collection (CISC) (n = 40 females, 40 males) and European-Americans from the Hamann-Todd osteological collection (H-T) (n = 40 females, 40 males). Patterns of sexual dimorphism are similar in the samples. Univariate and multivariate analyses of raw and Mosimann shape-variables indicate that compared to the CISC and H-T females, the LSA females have relatively large midplane and outlet canal planes (particularly posterior and A-P lengths). The LSA males also follow this pattern, although with absolutely smaller pelves in multivariate space. The CISC females, who have equally small stature, but larger body mass, do not show the same type of pelvic canal size and shape accommodation. The results suggest that adaptive allometric modeling in at least some small-bodied populations protects the obstetric canal. These findings support the use of population-specific attributes in the clinical evaluation of obstetric risk. (c) 2007 Wiley-Liss, Inc.

Effect of distance-related heterogeneity on population size estimates from point counts

USGS Publications Warehouse

Efford, Murray G.; Dawson, Deanna K.

2009-01-01

Point counts are used widely to index bird populations. Variation in the proportion of birds counted is a known source of error, and for robust inference it has been advocated that counts be converted to estimates of absolute population size. We used simulation to assess nine methods for the conduct and analysis of point counts when the data included distance-related heterogeneity of individual detection probability. Distance from the observer is a ubiquitous source of heterogeneity, because nearby birds are more easily detected than distant ones. Several recent methods (dependent double-observer, time of first detection, time of detection, independent multiple-observer, and repeated counts) do not account for distance-related heterogeneity, at least in their simpler forms. We assessed bias in estimates of population size by simulating counts with fixed radius w over four time intervals (occasions). Detection probability per occasion was modeled as a half-normal function of distance with scale parameter sigma and intercept g(0) = 1.0. Bias varied with sigma/w; values of sigma inferred from published studies were often 50% for a 100-m fixed-radius count. More critically, the bias of adjusted counts sometimes varied more than that of unadjusted counts, and inference from adjusted counts would be less robust. The problem was not solved by using mixture models or including distance as a covariate. Conventional distance sampling performed well in simulations, but its assumptions are difficult to meet in the field. We conclude that no existing method allows effective estimation of population size from point counts.

Ancient Bombardment of the Inner Solar System: Reinvestigation of the "Fingerprints" of Different Impactor Populations on the Lunar Surface

NASA Astrophysics Data System (ADS)

Orgel, Csilla; Michael, Gregory; Fassett, Caleb I.; van der Bogert, Carolyn H.; Riedel, Christian; Kneissl, Thomas; Hiesinger, Harald

2018-03-01

The lunar cratering record provides valuable information about the late accretion history of the inner solar system. However, our understanding of the origin, rate, and timing of the impacting projectiles is far from complete. To learn more about these projectiles, we can examine crater size-frequency distributions (CSFDs) on the Moon. Here we reinvestigate the crater populations of 30 lunar basins (≥ 300 km) using the buffered nonsparseness correction technique, which takes crater obliteration into account, thus providing more accurate measurements for the frequencies of smaller crater sizes. Moreover, we revisit the stratigraphic relationships of basins based on N(20) crater frequencies, absolute model ages, and observation data. The buffered nonsparseness correction-corrected CSFDs of individual basins, particularly at smaller crater diameters are shifted upward. Contrary to previous studies, the shapes of the summed CSFDs of Pre-Nectarian (excluding South Pole-Aitken Basin), Nectarian (including Nectaris), and Imbrian (including Imbrium) basins show no statistically significant differences and thus provide no evidence for a change of impactor population.

THE CANADA-FRANCE ECLIPTIC PLANE SURVEY-L3 DATA RELEASE: THE ORBITAL STRUCTURE OF THE KUIPER BELT

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

Kavelaars, J. J.; Jones, R. L.; Murray, I.

2009-06-15

We report the orbital distribution of the trans-Neptunian comets discovered during the first discovery year of the Canada-France Ecliptic Plane Survey (CFEPS). CFEPS is a Kuiper Belt object survey based on observations acquired by the Very Wide component of the Canada-France-Hawaii Telescope Legacy Survey (LS-VW). The first year's detections consist of 73 Kuiper Belt objects, 55 of which have now been tracked for three years or more, providing precise orbits. Although this sample size is small compared to the world-wide inventory, because we have an absolutely calibrated and extremely well-characterized survey (with known pointing history) we are able to de-biasmore » our observed population and make unbiased statements about the intrinsic orbital distribution of the Kuiper Belt. By applying the (publically available) CFEPS Survey Simulator to models of the true orbital distribution and comparing the resulting simulated detections to the actual detections made by the survey, we are able to rule out several hypothesized Kuiper Belt object orbit distributions. We find that the main classical belt's so-called 'cold' component is confined in semimajor axis (a) and eccentricity (e) compared to the more extended 'hot' component; the cold component is confined to lower e and does not stretch all the way out to the 2:1 resonance but rather depletes quickly beyond a = 45 AU. For the cold main classical belt population we find a robust population estimate of N(H{sub g} < 10) = 50 {+-} 5 x 10{sup 3} and find that the hot component of the main classical belt represents {approx}60% of the total population. The inner classical belt (sunward of the 3:2 mean-motion resonance) has a population of roughly 2000 trans-Neptunian objects with absolute magnitudes H{sub g} < 10, and may not share the inclination distribution of the main classical belt. We also find that the plutino population lacks a cold low-inclination component, and so, the population is somewhat larger than recent estimates; our analysis shows a plutino population of N(H{sub g} < 10){approx} 25{sup +25} {sub -12} x 10{sup 3}compared to our estimate of the size of main classical Kuiper Belt population of N(H{sub g} < 10) {approx} (126{sup +50} {sub -46}) x 10{sup 3}.« less

An ecocultural model predicts Neanderthal extinction through competition with modern humans.

PubMed

Gilpin, William; Feldman, Marcus W; Aoki, Kenichi

2016-02-23

Archaeologists argue that the replacement of Neanderthals by modern humans was driven by interspecific competition due to a difference in culture level. To assess the cogency of this argument, we construct and analyze an interspecific cultural competition model based on the Lotka-Volterra model, which is widely used in ecology, but which incorporates the culture level of a species as a variable interacting with population size. We investigate the conditions under which a difference in culture level between cognitively equivalent species, or alternatively a difference in underlying learning ability, may produce competitive exclusion of a comparatively (although not absolutely) large local Neanderthal population by an initially smaller modern human population. We find, in particular, that this competitive exclusion is more likely to occur when population growth occurs on a shorter timescale than cultural change, or when the competition coefficients of the Lotka-Volterra model depend on the difference in the culture levels of the interacting species.

A Carefully Characterized and Tracked Trans-Neptunian Survey: The Size distribution of the Plutinos and the Number of Neptunian Trojans

NASA Astrophysics Data System (ADS)

Alexandersen, Mike; Gladman, Brett; Kavelaars, J. J.; Petit, Jean-Marc; Gwyn, Stephen D. J.; Shankman, Cory J.; Pike, Rosemary E.

2016-11-01

The trans-Neptunian objects (TNOs) preserve evidence of planet building processes in their orbital and size distributions. While all populations show steep size distributions for large objects, a relative deficit of Neptunian trojans and scattering objects with diameters of D < 100 km has been detected. We investigated this deficit with a 32 square degree survey, in which we detected 77 TNOs that are brighter than a limiting r-band magnitude of 24.6. Our plutino sample (18 objects in 3:2 mean-motion resonance with Neptune) shows a deficit of D < 100 km objects, rejecting a single power-law size distribution at >99% confidence. Combining our survey with the Canada-France Ecliptic Plane Survey, we perform a detailed analysis of the allowable parameters for the plutino size distribution, including knees and divots. We surmise the existence of 9000 ± 3000 plutinos with an absolute magnitude of H r ≤ 8.66 and {37000}-10000+12000 with H r ≤ 10.0 (95% confidence). Our survey also discovered one temporary Uranian trojan, one temporary Neptunian trojan, and one stable Neptunian trojan, for which we estimate populations of {110}-100+500, {210}-200+900, and {150}-140+600 with H r ≤ 10.0, respectively. All three populations are thus less numerous than the main belt asteroids (592 asteroids with H r ≤ 10.0). With such population sizes, the temporary Neptunian trojans cannot be previously stable trojans diffusing out of the resonance now; they must be recently captured Centaurs or scattering objects. As the bias against the detection of objects grows with larger semimajor axes, our discovery of three 3:1 resonators and one 4:1 resonator adds to the growing evidence that the high-order resonances are far more populated than is typically predicted.

Descriptive, cross-country analysis of the nurse practitioner workforce in six countries: size, growth, physician substitution potential

PubMed Central

Maier, Claudia B; Barnes, Hilary; Aiken, Linda H; Busse, Reinhard

2016-01-01

Objectives Many countries are facing provider shortages and imbalances in primary care or are projecting shortfalls for the future, triggered by the rise in chronic diseases and multimorbidity. In order to assess the potential of nurse practitioners (NPs) in expanding access, we analysed the size, annual growth (2005–2015) and the extent of advanced practice of NPs in 6 Organisation for Economic Cooperation and Development (OECD) countries. Design Cross-country data analysis of national nursing registries, regulatory bodies, statistical offices data as well as OECD health workforce and population data, plus literature scoping review. Setting/participants NP and physician workforces in 6 OECD countries (Australia, Canada, Ireland, the Netherlands, New Zealand and USA). Primary and secondary outcome measures The main outcomes were the absolute and relative number of NPs per 100 000 population compared with the nursing and physician workforces, the compound annual growth rates, annual and median percentage changes from 2005 to 2015 and a synthesis of the literature on the extent of advanced clinical practice measured by physician substitution effect. Results The USA showed the highest absolute number of NPs and rate per population (40.5 per 100 000 population), followed by the Netherlands (12.6), Canada (9.8), Australia (4.4), and Ireland and New Zealand (3.1, respectively). Annual growth rates were high in all countries, ranging from annual compound rates of 6.1% in the USA to 27.8% in the Netherlands. Growth rates were between three and nine times higher compared with physicians. Finally, the empirical studies emanating from the literature scoping review suggested that NPs are able to provide 67–93% of all primary care services, yet, based on limited evidence. Conclusions NPs are a rapidly growing workforce with high levels of advanced practice potential in primary care. Workforce monitoring based on accurate data is critical to inform educational capacity and workforce planning. PMID:27601498

The Cluster Population of UGC 2885

NASA Astrophysics Data System (ADS)

Holwerda, Benne

2017-08-01

UGC 2885 was discoverd to be the most extended disk galaxy [250 kpc diameter] by Vera Rubin in the 1980's. We ask for HST observations of UGC 2885 as it is close enough to resolve the GC population with HST but it is a substantially more extended disk than any studied before. LCDM galaxy assembly implies that the GC population comes from small accreted systems and the disk -and the clusters associated with it- predominantly from gas accretion (matching angular momentum to the disk). Several scaling relations between the GC population and parent galaxy have been observed but these differ for disk and spheroidal (massive) galaxies.We propose to observe this galaxy with HST in 4 point WFC3 mosaic with coordinated ACS parallels to probe both the disk and outer halo component of the GC population. GC populations have been studied extensively using HST color mosaics of local disk galaxies and these can serve as comparison samples. How UGC 2885 cluster populations relate to its stellar and halo mass, luminosity and with radius will reveal the formation history of extra-ordinary disk.Our goals are twofold: our science goal is to map the luminosity, (some) size, and color distributions of the stellar and globular clusters in and around this disk. In absolute terms, we expect to find many GC but the relative relation of the GC population to this galaxy's mass (stellar and halo) and size will shed light on its formation history; similar to a group or cluster central elliptical or to a field galaxy (albeit one with a disk 10x the Milky Way's size)? Our secondary motive is to make an HST tribute image to the late Vera Rubin.

Detection of a Divot in the Scattering Population's Size Distribution

NASA Astrophysics Data System (ADS)

Shankman, Cory; Gladman, B.; Kaib, N.; Kavelaars, J.; Petit, J.

2012-10-01

Via joint analysis of the calibrated Canada France Ecliptic Place Survey (CFEPS, Petit et al 2011, AJ 142, 131), which found scattering Kuiper Belt objects, and models of their orbital distribution, we show that there should be enough kilometer-scale scattering objects to supply the Jupiter Family Comets (JFCs). Surprisingly, our analysis favours a divot (an abrupt drop and then recovery) in the size distribution at a diameter of 100 km, which results in a temporary flattening of the cumulative size distribution until it returns to a collisional equilibrium slope. Using the absolutely calibrated CFEPS survey we estimate that there are 2 x 10**9 scattering objects with H_g < 18, which is sufficient to provide the currently estimated JFC resupply rate. We also find that the primordial disk from which the scattering objects came must have had a "hot" initial inclination distribution before the giant planets scattered it out. We find that a divot, in the absolute magnitude number distribution, with a bright-end logarithmic slope of 0.8, a drop at a g-band H magnitude of 9, and a faint side logarithmic slope of 0.5 satisfies our data and simultaneously explains several existing nagging puzzles about Kuiper Belt luminosity functions (see Gladman et al., this meeting). Multiple explanations of how such a feature could have arisen will be discussed. This research was supported by the Natural Sciences and Engineering Research Council of Canada.

The genetic architecture of UV floral patterning in sunflower.

PubMed

Moyers, Brook T; Owens, Gregory L; Baute, Gregory J; Rieseberg, Loren H

2017-07-01

The patterning of floral ultraviolet (UV) pigmentation varies both intra- and interspecifically in sunflowers and many other plant species, impacts pollinator attraction, and can be critical to reproductive success and crop yields. However, the genetic basis for variation in UV patterning is largely unknown. This study examines the genetic architecture for proportional and absolute size of the UV bullseye in Helianthus argophyllus , a close relative of the domesticated sunflower. A camera modified to capture UV light (320-380 nm) was used to phenotype floral UV patterning in an F 2 mapping population, then quantitative trait loci (QTL) were identified using genotyping-by-sequencing and linkage mapping. The ability of these QTL to predict the UV patterning of natural population individuals was also assessed. Proportional UV pigmentation is additively controlled by six moderate effect QTL that are predictive of this phenotype in natural populations. In contrast, UV bullseye size is controlled by a single large effect QTL that also controls flowerhead size and co-localizes with a major flowering time QTL in Helianthus . The co-localization of the UV bullseye size QTL, flowerhead size QTL and a previously known flowering time QTL may indicate a single highly pleiotropic locus or several closely linked loci, which could inhibit UV bullseye size from responding to selection without change in correlated characters. The genetic architecture of proportional UV pigmentation is relatively simple and different from that of UV bullseye size, and so should be able to respond to natural or artificial selection independently. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Quantitative endoscopy: initial accuracy measurements.

PubMed

Truitt, T O; Adelman, R A; Kelly, D H; Willging, J P

2000-02-01

The geometric optics of an endoscope can be used to determine the absolute size of an object in an endoscopic field without knowing the actual distance from the object. This study explores the accuracy of a technique that estimates absolute object size from endoscopic images. Quantitative endoscopy involves calibrating a rigid endoscope to produce size estimates from 2 images taken with a known traveled distance between the images. The heights of 12 samples, ranging in size from 0.78 to 11.80 mm, were estimated with this calibrated endoscope. Backup distances of 5 mm and 10 mm were used for comparison. The mean percent error for all estimated measurements when compared with the actual object sizes was 1.12%. The mean errors for 5-mm and 10-mm backup distances were 0.76% and 1.65%, respectively. The mean errors for objects <2 mm and > or =2 mm were 0.94% and 1.18%, respectively. Quantitative endoscopy estimates endoscopic image size to within 5% of the actual object size. This method remains promising for quantitatively evaluating object size from endoscopic images. It does not require knowledge of the absolute distance of the endoscope from the object, rather, only the distance traveled by the endoscope between images.

Population-based absolute risk estimation with survey data

PubMed Central

Kovalchik, Stephanie A.; Pfeiffer, Ruth M.

2013-01-01

Absolute risk is the probability that a cause-specific event occurs in a given time interval in the presence of competing events. We present methods to estimate population-based absolute risk from a complex survey cohort that can accommodate multiple exposure-specific competing risks. The hazard function for each event type consists of an individualized relative risk multiplied by a baseline hazard function, which is modeled nonparametrically or parametrically with a piecewise exponential model. An influence method is used to derive a Taylor-linearized variance estimate for the absolute risk estimates. We introduce novel measures of the cause-specific influences that can guide modeling choices for the competing event components of the model. To illustrate our methodology, we build and validate cause-specific absolute risk models for cardiovascular and cancer deaths using data from the National Health and Nutrition Examination Survey. Our applications demonstrate the usefulness of survey-based risk prediction models for predicting health outcomes and quantifying the potential impact of disease prevention programs at the population level. PMID:23686614

The size evolution of star-forming and quenched galaxies in the IllustrisTNG simulation

NASA Astrophysics Data System (ADS)

Genel, Shy; Nelson, Dylan; Pillepich, Annalisa; Springel, Volker; Pakmor, Rüdiger; Weinberger, Rainer; Hernquist, Lars; Naiman, Jill; Vogelsberger, Mark; Marinacci, Federico; Torrey, Paul

2018-03-01

We analyse scaling relations and evolution histories of galaxy sizes in TNG100, part of the IllustrisTNG simulation suite. Observational qualitative trends of size with stellar mass, star formation rate and redshift are reproduced, and a quantitative comparison of projected r band sizes at 0 ≲ z ≲ 2 shows agreement to much better than 0.25 dex. We follow populations of z = 0 galaxies with a range of masses backwards in time along their main progenitor branches, distinguishing between main-sequence and quenched galaxies. Our main findings are as follows. (i) At M*, z = 0 ≳ 109.5 M⊙, the evolution of the median main progenitor differs, with quenched galaxies hardly growing in median size before quenching, whereas main-sequence galaxies grow their median size continuously, thus opening a gap from the progenitors of quenched galaxies. This is partly because the main-sequence high-redshift progenitors of quenched z = 0 galaxies are drawn from the lower end of the size distribution of the overall population of main-sequence high-redshift galaxies. (ii) Quenched galaxies with M*, z = 0 ≳ 109.5 M⊙ experience a steep size growth on the size-mass plane after their quenching time, but with the exception of galaxies with M*, z = 0 ≳ 1011 M⊙, the size growth after quenching is small in absolute terms, such that most of the size (and mass) growth of quenched galaxies (and its variation among them) occurs while they are still on the main sequence. After they become quenched, the size growth rate of quenched galaxies as a function of time, as opposed to versus mass, is similar to that of main-sequence galaxies. Hence, the size gap is retained down to z = 0.

Mapping Near-Earth Hazards

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-06-01

How can we hunt down all the near-Earth asteroids that are capable of posing a threat to us? A new study looks at whether the upcoming Large Synoptic Survey Telescope (LSST) is up to the job.Charting Nearby ThreatsLSST is an 8.4-m wide-survey telescope currently being built in Chile. When it goes online in 2022, it will spend the next ten years surveying our sky, mapping tens of billions of stars and galaxies, searching for signatures of dark energy and dark matter, and hunting for transient optical events like novae and supernovae. But in its scanning, LSST will also be looking for asteroids that approach near Earth.Cumulative number of near-Earth asteroids discovered over time, as of June 16, 2016. [NASA/JPL/Chamberlin]Near-Earth objects (NEOs) have the potential to be hazardous if they cross Earths path and are large enough to do significant damage when they impact Earth. Earths history is riddled with dangerous asteroid encounters, including the recent Chelyabinsk airburst in 2013, the encounter that caused the kilometer-sized Meteor Crater in Arizona, and the impact thought to contribute to the extinction of the dinosaurs.Recognizing the potential danger that NEOs can pose to Earth, Congress has tasked NASA with tracking down 90% of NEOs larger than 140 meters in diameter. With our current survey capabilities, we believe weve discovered roughly 25% of these NEOs thus far. Now a new study led by Tommy Grav (Planetary Science Institute) examines whether LSST will be able to complete this task.Absolute magnitude, H, of asynthetic NEO population. Though these NEOs are all larger than 140 m, they have a large spread in albedos. [Grav et al. 2016]Can LSST Help?Based on previous observations of NEOs and resulting predictions for NEO properties and orbits, Grav and collaborators simulate a synthetic population of NEOs all above 140 m in size. With these improved population models, they demonstrate that the common tactic of using an asteroids absolute magnitude as a proxy for its size is a poor approximation, due to asteroids large spread in albedos. Roughly 23% of NEOs larger than 140 m have absolute magnitudes fainter than H = 22 mag, the authors show which is the value usually assumed as the default absolute magnitude of a 140 m NEO.Fraction of NEOs weve detected as a function of time based on the authors simulations of the current surveys (red), LSST plus the current surveys (black), NEOCam plus the current surveys (blue), and the combined result for all surveys (green). [Grav et al. 2016]Taking this into account, Grav and collaborators then use information about the planned LSST survey strategies and detection limits to test what fraction of this synthetic NEO population LSST will be able to detect in its proposed 10-year mission.The authors find that, within 10 years, LSST will likely be able to detect only 63% of NEOs larger than 140 m. Luckily, LSST may not have to work alone; in addition to the current surveys in operation, a proposed infrared space-based survey mission called NEOCam is planned for launch in 2021. If NEOCam is funded, it will complement LSSTs discovery capabilities, potentially allowing the two surveys to jointly achieve the 90% detection goal within a decade.CitationT. Grav et al 2016 AJ 151 172. doi:10.3847/0004-6256/151/6/172

Comparing population size estimators for plethodontid salamanders

USGS Publications Warehouse

Bailey, L.L.; Simons, T.R.; Pollock, K.H.

2004-01-01

Despite concern over amphibian declines, few studies estimate absolute abundances because of logistic and economic constraints and previously poor estimator performance. Two estimation approaches recommended for amphibian studies are mark-recapture and depletion (or removal) sampling. We compared abundance estimation via various mark-recapture and depletion methods, using data from a three-year study of terrestrial salamanders in Great Smoky Mountains National Park. Our results indicate that short-term closed-population, robust design, and depletion methods estimate surface population of salamanders (i.e., those near the surface and available for capture during a given sampling occasion). In longer duration studies, temporary emigration violates assumptions of both open- and closed-population mark-recapture estimation models. However, if the temporary emigration is completely random, these models should yield unbiased estimates of the total population (superpopulation) of salamanders in the sampled area. We recommend using Pollock's robust design in mark-recapture studies because of its flexibility to incorporate variation in capture probabilities and to estimate temporary emigration probabilities.

Demographic Changes in Germany up to 2060 - Consequences for Blood Donation.

PubMed

Ehling, Manfred; Pötzsch, Olga

2010-06-01

This paper outlines the results of a most recent model calculation regarding the structure and development of Germany's population by 2060 with the aim to provide basic demographic data for the future provision of blood components to the population. Firstly, the paper describes the assumptions on fertility, life expectancy and Germany's balance of immigration and emigration which formed the basis for the projection. The following part discusses the results, quantifies future changes in the size and age structure of Germany's population, and illustrates the effects of demographic trends which can be identified from today's point of view. The number of potential blood donors will decline in absolute and relative terms (related to the total population and the age group of 'non-donors') in the future. This holds true for both the age bracket of 18 to 68 years and the alternatively chosen age group of 17 to 70 years. Depending on the variant, the population of blood donation age will decrease by one quarter to one third until 2060.

Hydrodynamic fractionation of finite size gold nanoparticle clusters.

PubMed

Tsai, De-Hao; Cho, Tae Joon; DelRio, Frank W; Taurozzi, Julian; Zachariah, Michael R; Hackley, Vincent A

2011-06-15

We demonstrate a high-resolution in situ experimental method for performing simultaneous size classification and characterization of functional gold nanoparticle clusters (GNCs) based on asymmetric-flow field flow fractionation (AFFF). Field emission scanning electron microscopy, atomic force microscopy, multi-angle light scattering (MALS), and in situ ultraviolet-visible optical spectroscopy provide complementary data and imagery confirming the cluster state (e.g., dimer, trimer, tetramer), packing structure, and purity of fractionated populations. An orthogonal analysis of GNC size distributions is obtained using electrospray-differential mobility analysis (ES-DMA). We find a linear correlation between the normalized MALS intensity (measured during AFFF elution) and the corresponding number concentration (measured by ES-DMA), establishing the capacity for AFFF to quantify the absolute number concentration of GNCs. The results and corresponding methodology summarized here provide the proof of concept for general applications involving the formation, isolation, and in situ analysis of both functional and adventitious nanoparticle clusters of finite size. © 2011 American Chemical Society

Weirs: Counting and sampling adult salmonids in streams and rivers

USGS Publications Warehouse

Zimmerman, Christian E.; Zabkar, Laura M.; Johnson, David H.; Shrier, Brianna M.; O'Neal, Jennifer S.; Knutzen, John A.; Augerot, Xanthippe; O'Neal, Thomas A.; Pearsons, Todd N.

2007-01-01

Weirs—which function as porous barriers built across stream—have long been used to capture migrating fish in flowing waters. For example, the Netsilik peoples of northern Canada used V-shaped weirs constructed of river rocks gathered onsite to capture migrating Arctic char Salvelinus alpinus (Balikci 1970). Similarly, fences constructed of stakes and a latticework of willow branches or staves were used by Native Americans to capture migrating salmon in streams along the West Coast of North America (Stewart 1994). In modern times, weirs have also been used in terminal fisheries and to capture brood fish for use in fish culture. Weirs have been used to gather data on age structure, condition, sex ratio, spawning escapement, abundance, and migratory patterns of fish in streams. One of the critical elements of fisheries management and stock assessment of salmonids is a count of adult fish returning to spawn. Weirs are frequently used to capture or count fish to determine status and trends of populations or direct inseason management of fisheries; generally, weirs are the standard against which other techniques are measured. To evaluate fishery management actions, the number of fish escaping to spawn is often compared to river-specific target spawning requirements (O’Connell and Dempson 1995). A critical factor in these analyses is the determination of total run size (O’Connell 2003). O’Connell compared methods of run-size estimation against absolute counts from a rigid weir and concluded that, given the uncertainty of estimators, the absolute counts obtained at the weir wer significantly better than modeled estimates, which deviated as much as 50–60% from actual counts. The use of weirs is generally restricted to streams and small rivers because of construction expense, formation of navigation barriers, and the tendency of weirs to clog with debris, which can cause flooding and collapse of the structure (Hubert 1996). When feasible, however, weirs are generally regarded as the most accurate technique available to quantify escapement as the result is supposedly an absolute count (Cousens et al. 1982). Weirs also provide the opportunity to capture fish for observation and sampling of biological characteristics and tissues; they may also serve as recapture sites for basin-wide, mark–recapture population estimates. Temporary weirs are useful in monitoring wild populations of salmonids as well as for capturing broodstock for artificial propagation.

Cell wall microstructure, pore size distribution and absolute density of hemp shiv

PubMed Central

Lawrence, M.; Ansell, M. P.; Hussain, A.

2018-01-01

This paper, for the first time, fully characterizes the intrinsic physical parameters of hemp shiv including cell wall microstructure, pore size distribution and absolute density. Scanning electron microscopy revealed microstructural features similar to hardwoods. Confocal microscopy revealed three major layers in the cell wall: middle lamella, primary cell wall and secondary cell wall. Computed tomography improved the visualization of pore shape and pore connectivity in three dimensions. Mercury intrusion porosimetry (MIP) showed that the average accessible porosity was 76.67 ± 2.03% and pore size classes could be distinguished into micropores (3–10 nm) and macropores (0.1–1 µm and 20–80 µm). The absolute density was evaluated by helium pycnometry, MIP and Archimedes' methods. The results show that these methods can lead to misinterpretation of absolute density. The MIP method showed a realistic absolute density (1.45 g cm−3) consistent with the density of the known constituents, including lignin, cellulose and hemi-cellulose. However, helium pycnometry and Archimedes’ methods gave falsely low values owing to 10% of the volume being inaccessible pores, which require sample pretreatment in order to be filled by liquid or gas. This indicates that the determination of the cell wall density is strongly dependent on sample geometry and preparation. PMID:29765652

Cell wall microstructure, pore size distribution and absolute density of hemp shiv

NASA Astrophysics Data System (ADS)

Jiang, Y.; Lawrence, M.; Ansell, M. P.; Hussain, A.

2018-04-01

This paper, for the first time, fully characterizes the intrinsic physical parameters of hemp shiv including cell wall microstructure, pore size distribution and absolute density. Scanning electron microscopy revealed microstructural features similar to hardwoods. Confocal microscopy revealed three major layers in the cell wall: middle lamella, primary cell wall and secondary cell wall. Computed tomography improved the visualization of pore shape and pore connectivity in three dimensions. Mercury intrusion porosimetry (MIP) showed that the average accessible porosity was 76.67 ± 2.03% and pore size classes could be distinguished into micropores (3-10 nm) and macropores (0.1-1 µm and 20-80 µm). The absolute density was evaluated by helium pycnometry, MIP and Archimedes' methods. The results show that these methods can lead to misinterpretation of absolute density. The MIP method showed a realistic absolute density (1.45 g cm-3) consistent with the density of the known constituents, including lignin, cellulose and hemi-cellulose. However, helium pycnometry and Archimedes' methods gave falsely low values owing to 10% of the volume being inaccessible pores, which require sample pretreatment in order to be filled by liquid or gas. This indicates that the determination of the cell wall density is strongly dependent on sample geometry and preparation.

Response variance in functional maps: neural darwinism revisited.

PubMed

Takahashi, Hirokazu; Yokota, Ryo; Kanzaki, Ryohei

2013-01-01

The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population.

Response Variance in Functional Maps: Neural Darwinism Revisited

PubMed Central

Takahashi, Hirokazu; Yokota, Ryo; Kanzaki, Ryohei

2013-01-01

The mechanisms by which functional maps and map plasticity contribute to cortical computation remain controversial. Recent studies have revisited the theory of neural Darwinism to interpret the learning-induced map plasticity and neuronal heterogeneity observed in the cortex. Here, we hypothesize that the Darwinian principle provides a substrate to explain the relationship between neuron heterogeneity and cortical functional maps. We demonstrate in the rat auditory cortex that the degree of response variance is closely correlated with the size of its representational area. Further, we show that the response variance within a given population is altered through training. These results suggest that larger representational areas may help to accommodate heterogeneous populations of neurons. Thus, functional maps and map plasticity are likely to play essential roles in Darwinian computation, serving as effective, but not absolutely necessary, structures to generate diverse response properties within a neural population. PMID:23874733

Synergism between urinary prothrombin fragment 1 and urine: a comparison of inhibitory activities in stone-prone and stone-free population groups.

PubMed

Webber, Dawn; Rodgers, Allen L; Sturrock, Edward D

2002-09-01

South African blacks rarely form kidney stones compared with whites. This study investigated whether purified urinary prothrombin fragment 1 (UPTF1) derived from blacks is a more potent inhibitor of calcium oxalate crystallisation than that from whites. UPTF1 was purified from the urine of both population groups and their inhibitory activities were compared in a cross-over design in which each protein was tested in ultrafiltered urine from both population groups. Coulter Multisizer, [14C]-oxalate deposition and scanning electron microscopy experiments were used to monitor crystallisation. The study has demonstrated for the first time that UPTF1 promotes nucleation and that inhibitory activity is synergistically dependent upon urine composition. The activity of the whites' UPTF1 was greater than that of the blacks in the whites' urine (e.g. particle size decrease: 31.7% vs. 25.2%), while the blacks' UPTF1 was superior to that of the whites in the blacks' urine (e.g. particle size decrease: 46.5% vs. 32.4%). In addition, when tested in their respective endogenous urines, the blacks' UPTF1 demonstrated superior inhibitory activity on an absolute scale (e.g. particle size decrease: 46.5% vs. 31.7%). Thus, the urine composition of black South Africans may influence their UPTF1 conformation, conferring greater efficacy for inhibition of calcium oxalate crystallisation.

A generalized population dynamics model for reproductive interference with absolute density dependence.

PubMed

Kyogoku, Daisuke; Sota, Teiji

2017-05-17

Interspecific mating interactions, or reproductive interference, can affect population dynamics, species distribution and abundance. Previous population dynamics models have assumed that the impact of frequency-dependent reproductive interference depends on the relative abundances of species. However, this assumption could be an oversimplification inappropriate for making quantitative predictions. Therefore, a more general model to forecast population dynamics in the presence of reproductive interference is required. Here we developed a population dynamics model to describe the absolute density dependence of reproductive interference, which appears likely when encounter rate between individuals is important. Our model (i) can produce diverse shapes of isoclines depending on parameter values and (ii) predicts weaker reproductive interference when absolute density is low. These novel characteristics can create conditions where coexistence is stable and independent from the initial conditions. We assessed the utility of our model in an empirical study using an experimental pair of seed beetle species, Callosobruchus maculatus and Callosobruchus chinensis. Reproductive interference became stronger with increasing total beetle density even when the frequencies of the two species were kept constant. Our model described the effects of absolute density and showed a better fit to the empirical data than the existing model overall.

Acellular pertussis vaccines effectiveness over time: A systematic review, meta-analysis and modeling study

PubMed Central

Chit, Ayman; Zivaripiran, Hossein; Shin, Thomas; Lee, Jason K. H.; Tomovici, Antigona; Macina, Denis; Johnson, David R.; Decker, Michael D.; Wu, Jianhong

2018-01-01

Background Acellular pertussis vaccine studies postulate that waning protection, particularly after the adolescent booster, is a major contributor to the increasing US pertussis incidence. However, these studies reported relative (ie, vs a population given prior doses of pertussis vaccine), not absolute (ie, vs a pertussis vaccine naïve population) efficacy following the adolescent booster. We aim to estimate the absolute protection offered by acellular pertussis vaccines. Methods We conducted a systematic review of acellular pertussis vaccine effectiveness (VE) publications. Studies had to comply with the US schedule, evaluate clinical outcomes, and report VE over discrete time points. VE after the 5-dose childhood series and after the adolescent sixth-dose booster were extracted separately and pooled. All relative VE estimates were transformed to absolute estimates. VE waning was estimated using meta-regression modeling. Findings Three studies reported VE after the childhood series and four after the adolescent booster. All booster studies reported relative VE (vs acellular pertussis vaccine-primed population). We estimate initial childhood series absolute VE is 91% (95% CI: 87% to 95%) and declines at 9.6% annually. Initial relative VE after adolescent boosting is 70% (95% CI: 54% to 86%) and declines at 45.3% annually. Initial absolute VE after adolescent boosting is 85% (95% CI: 84% to 86%) and declines at 11.7% (95% CI: 11.1% to 12.3%) annually. Interpretation Acellular pertussis vaccine efficacy is initially high and wanes over time. Observational VE studies of boosting failed to recognize that they were measuring relative, not absolute, VE and the absolute VE in the boosted population is better than appreciated. PMID:29912887

Nanocarbon condensation in detonation

DOE PAGES

Bastea, Sorin

2017-02-08

We analyze the definition of the Gibbs free energy of a nanoparticle in a reactive fluid environment, and propose an approach for predicting the size of carbon nanoparticles produced by the detonation of carbon-rich explosives that regards their condensation as a nucleation process and takes into account absolute entropy effects of the cluster population. The results are consistent with experimental observations and indicate that such entropy considerations are important for determining chemical equilibrium states in energetic materials that contain an excess of carbon. The analysis may be useful for other applications that deal with the nucleation of nanoparticles under reactivemore » conditions.« less

Nanocarbon condensation in detonation

PubMed Central

Bastea, Sorin

2017-01-01

We analyze the definition of the Gibbs free energy of a nanoparticle in a reactive fluid environment, and propose an approach for predicting the size of carbon nanoparticles produced by the detonation of carbon-rich explosives that regards their condensation as a nucleation process and takes into account absolute entropy effects of the cluster population. The results are consistent with experimental observations and indicate that such entropy considerations are important for determining chemical equilibrium states in energetic materials that contain an excess of carbon. The analysis may be useful for other applications that deal with the nucleation of nanoparticles under reactive conditions. PMID:28176827

The influence of maturation, body size and physical self-perceptions on longitudinal changes in physical activity in adolescent girls.

PubMed

Fawkner, Samantha; Henretty, Joan; Knowles, Ann-Marie; Nevill, Alan; Niven, Ailsa

2014-01-01

The aim of this study was to adopt a longitudinal design to explore the direct effects of both absolute and relative maturation and changes in body size on physical activity, and explore if, and how, physical self-perceptions might mediate this effect. We recruited 208 girls (11.8 ± 0.4 years) at baseline. Data were collected at three subsequent time points, each 6 months apart. At 18 months, 119 girls remained in the study. At each time point, girls completed the Physical Activity Questionnaire for Children, the Pubertal Development Scale (from which, both a measure of relative and absolute maturation were defined) and the Physical Self-Perception Profile, and had physical size characteristics assessed. Multilevel modelling for physical activity indicated a significant negative effect of age, positive effect for physical condition and sport competence and positive association for relatively early maturers. Absolute maturation, body mass, waist circumference and sum of skinfolds did not significantly contribute to the model. Contrary to common hypotheses, relatively more mature girls may, in fact, be more active than their less mature peers. However, neither changes in absolute maturation nor physical size appear to directly influence changes in physical activity in adolescent girls.

Variance computations for functional of absolute risk estimates.

PubMed

Pfeiffer, R M; Petracci, E

2011-07-01

We present a simple influence function based approach to compute the variances of estimates of absolute risk and functions of absolute risk. We apply this approach to criteria that assess the impact of changes in the risk factor distribution on absolute risk for an individual and at the population level. As an illustration we use an absolute risk prediction model for breast cancer that includes modifiable risk factors in addition to standard breast cancer risk factors. Influence function based variance estimates for absolute risk and the criteria are compared to bootstrap variance estimates.

Variance computations for functional of absolute risk estimates

PubMed Central

Pfeiffer, R.M.; Petracci, E.

2011-01-01

We present a simple influence function based approach to compute the variances of estimates of absolute risk and functions of absolute risk. We apply this approach to criteria that assess the impact of changes in the risk factor distribution on absolute risk for an individual and at the population level. As an illustration we use an absolute risk prediction model for breast cancer that includes modifiable risk factors in addition to standard breast cancer risk factors. Influence function based variance estimates for absolute risk and the criteria are compared to bootstrap variance estimates. PMID:21643476

Statistical distribution of foveal transverse chromatic aberration, pupil centration, and angle psi in a population of young adult eyes

NASA Astrophysics Data System (ADS)

Rynders, Maurice; Lidkea, Bruce; Chisholm, William; Thibos, Larry N.

1995-10-01

Subjective transverse chromatic aberration (sTCA) manifest at the fovea was determined for a population of 85 young adults (19-38 years old) by means of a two-dimensional, two-color, vernier alignment technique. The statistical distribution of sTCA was well fitted by a bivariate Gaussian function with mean values that were not significantly different from zero in either the horizontal or the vertical direction. We conclude from this result that a hypothetical, average eye representing the population mean of human eyes with medium-sized pupils is free of foveal sTCA. However, the absolute magnitude of sTCA for any given individual was often significantly greater than zero and ranged from 0.05 to 2.67 arcmin for the red and the blue lights of a computer monitor (mean wavelengths, 605 and 497 nm, respectively). The statistical distribution of the absolute magnitude of sTCA was well described by a Rayleigh probability distribution with a mean of 0.8 arcmin. A simple device useful for population screening in a clinical setting was also tested and gave concordant results. Assuming that sTCA at the fovea is due to decentering of the pupil with respect to the visual axis, we infer from these results that the pupil is, on average, well centered in human eyes. The average magnitude of pupil decentration in individual eyes is less than 0.5 mm, which corresponds to psi =3 deg for the angle between the achromatic and the visual axes of the eye.

Race and colorectal cancer screening compliance among persons with a family history of cancer

PubMed Central

Laiyemo, Adeyinka O; Thompson, Nicole; Williams, Carla D; Idowu, Kolapo A; Bull-Henry, Kathy; Sherif, Zaki A; Lee, Edward L; Brim, Hassan; Ashktorab, Hassan; Platz, Elizabeth A; Smoot, Duane T

2015-01-01

AIM: To determine compliance to colorectal cancer (CRC) screening guidelines among persons with a family history of any type of cancer and investigate racial differences in screening compliance. METHODS: We used the 2007 Health Information National Trends Survey and identified 1094 (27.4%) respondents (weighted population size = 21959672) without a family history of cancer and 3138 (72.6%) respondents (weighted population size = 58201479) with a family history of cancer who were 50 years and older. We defined compliance with CRC screening as the use of fecal occult blood testing within 1 year, sigmoidoscopy within 5 years, or colonoscopy within 10 years. We compared compliance with CRC screening among those with and without a family member with a history of cancer. RESULTS: Overall, those with a family member with cancer were more likely to be compliant with CRC screening (64.9% vs 55.1%; OR = 1.45; 95%CI: 1.20-1.74). The absolute increase in screening rates associated with family history of cancer was 8.2% among whites. Hispanics had lowest screening rates among those without family history of cancer 41.9% but had highest absolute increase (14.7%) in CRC screening rate when they have a family member with cancer. Blacks had the lowest absolute increase in CRC screening (5.3%) when a family member has a known history of cancer. However, the noted increase in screening rates among blacks and Hispanics when they have a family member with cancer were not higher than whites without a family history of cancer: (54.5% vs 58.7%; OR = 1.16; 95%CI: 0.72-1.88) for blacks and (56.7% vs 58.7%; OR = 1.25; 95%CI: 0.72-2.18) for Hispanics. CONCLUSION: While adults with a family history of any cancer were more likely to be compliant with CRC screening guidelines irrespective of race/ethnicity, blacks and Hispanics with a family history of cancer were less likely to be compliant than whites without a family history. Increased burden from CRC among blacks may be related to poor uptake of screening among high-risk groups. PMID:26672497

Relationships between income inequality and health: a study on rural and urban regions of Canada.

PubMed

Vafaei, Afshin; Rosenberg, Mark W; Pickett, William

2010-01-01

Many studies have demonstrated that health is a function of relative and not absolute income within populations. Canadian studies are not conclusive; most indicate that there is no relationship between income inequality and health within Canada. There is a need for further investigation into the validity of the 'relative income' hypothesis in the Canadian population. The primary objective of this research was to test the 'relative income' hypothesis across Canadian health regions. The second objective was to extend the hypothesis to consider rural versus urban populations. This research involved ecological analyses. The source of the data was the Canadian Community Health Survey, Cycle 3.1. The units of analysis were Canadian health regions. Health of a region was estimated as the percentage of people who rated their health as good or excellent. The primary exposure variable was the ratio of people whose personal income was less than $15,000 relative to those reporting more than $80,000 in the year preceding the survey. This ratio provided a measure of the distribution of income. The main covariates were ecological measures of socio-demographic variables, social capital, substance use behaviours (smoking and alcohol consumption), rural/urban status of the region, and absolute income in the region. Correlation analyses and multiple linear regressions were performed to ascertain the relationship between income inequality and population health, adjusting for important covariates. The measure of income inequality alone appeared to explain 18% of the variability in the measure of population health. However, after adding the measure of absolute income to the model, although 29% of the variability was explained, the independent contribution of the inequality measure became non-significant. Linear regression models suggested that the absolute income variable alone could explain 30% of the variance in the health status of populations. Other variables with a statistically significant contribution to the final model were education and alcohol consumption. The effect of rural/urban geographic status on the relationship of interest was similar to other covariates. This variable did not change the individual relationship between income inequality or absolute income and the measure of population health status. In both rural and urban regions, absolute income and education had positive effects on population health. In urban regions alcohol consumption was a significant negative contributor to population health status; whereas, in rural regions, smoking status had a significant negative effect on population health status. Across Canadian health regions, health status in populations was a function of absolute income but not relative income. Regions with higher levels of education had better levels of self-rated health. A larger percentage of heavy drinkers was also correlated with lower population health status. Findings were consistently observed in rural and urban populations. The study findings have implications for public health, economic, and social policies.

Domestication and human demographic history in South America.

PubMed

Perez, S Ivan; Postillone, María Bárbara; Rindel, Diego

2017-05-01

The early groups of hunter-gatherers who peopled South America faced significant ecological changes in their trophic niche for a relatively short period after the initial peopling. In particular, the incorporation of cultigens during the Holocene led to a wider trophic niche and probably to an increased carrying capacity of the environment. Here, we study the relationship between the incorporation of domestic resources during the Holocene and the demographic dynamics of human populations at a regional scale in South America. We employ mitochondrial DNA (mtDNA), radiocarbon data and Bayesian methods to estimate differences in population size, human occupation and explore the demographic changes of human populations in three regions (i.e., South-Central Andes, Northwest, and South Patagonia). We also use archaeological evidence to infer the main diet changes in these regions. The absolute population size during the later Late Holocene was fifteen times larger in the South-Central Andes than in Northwest Patagonia, and two times larger in the latter region than in South Patagonia. The South-Central Andes display the earlier and more abrupt population growth, beginning about 9000 years BP, whereas Northwest Patagonia exhibits a more slow growth, beginning about 7000-7500 years BP. South Patagonia represents a later and slower population increase. In this work we uncovered a well-supported pattern of the demographic change in the populations from South-Central Andes and Patagonia, obtained on the basis of different data and quantitative approaches, which suggests that the incorporation of domestic resources was paramount for the demographic expansion of these populations during the Holocene. © 2017 Wiley Periodicals, Inc.

Post-Chelyabinsk Risk Assessment for Near Earth Objects (NEOs)

NASA Astrophysics Data System (ADS)

Boslough, M.; Harris, A. W.

2014-12-01

The widely-accepted NEO risk assessments published in the 1990s concluded that the largest asteroids (> 1 km) dominated the hazard. Even though large NEOs represent only a tiny fraction of the population because of a power-law size distribution, the potential for global catastrophe means that the contribution from these low-probability, high-consequence events is large. This conclusion led to the Spaceguard survey, which has now catalogued about 90% of these objects, none of which is on a collision course. The survey has reduced the assessed risk from this size range by more than an order of magnitude because completion is highest for the largest and most dangerous. The relative risk from objects tens of meters in diameter is therefore increasing.The absolute assessed risk from airbursts caused by objects of this size is also higher for two reasons. First, they may be more frequent than previously thought because of an underestimated population. Second, they are significantly more damaging than assumed in the original assessment because (in most cases) they more efficiently couple energy to the surface than nuclear explosions. Last year's half-megaton airburst over Chelyabinsk, Russia, appears to challenge the notion that such events are extremely rare—especially when also considering the 1908 Tunguska event along with decades of infrasound bolide data showing higher-than-expected numbers of large airbursts.We will present a new analysis of the risk based on updated estimates for the population of undiscovered NEOs, taking into account the enhanced damage potential of collisional airbursts. Merging the survey population estimates with the bolide frequency estimates suggests a population of tens-of-meters sized bodies that may be a factor of three or so greater than estimated from surveys alone. Uncertainty in the population of airburst-class NEOs remains quite large, and can only be unambiguously reduced by expanded surveys focused on objects in the tens-of-meters size range. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.

The Case for Absolute Ligand Discrimination: Modeling Information Processing and Decision by Immune T Cells

NASA Astrophysics Data System (ADS)

François, Paul; Altan-Bonnet, Grégoire

2016-03-01

Some cells have to take decision based on the quality of surroundings ligands, almost irrespective of their quantity, a problem we name "absolute discrimination". An example of absolute discrimination is recognition of not-self by immune T Cells. We show how the problem of absolute discrimination can be solved by a process called "adaptive sorting". We review several implementations of adaptive sorting, as well as its generic properties such as antagonism. We show how kinetic proofreading with negative feedback implement an approximate version of adaptive sorting in the immune context. Finally, we revisit the decision problem at the cell population level, showing how phenotypic variability and feedbacks between population and single cells are crucial for proper decision.

Relative and absolute level populations in beam-foil-excited neutral helium

NASA Technical Reports Server (NTRS)

Davidson, J.

1975-01-01

Relative and absolute populations of 19 levels in beam-foil-excited neutral helium at 0.275 MeV have been measured. The singlet angular-momentum sequences show dependences on principal quantum number consistent with n to the -3rd power, but the triplet sequences do not. Singlet and triplet angular-momentum sequences show similar dependences on level excitation energy. Excitation functions for six representative levels were measured in the range from 0.160 to 0.500 MeV. The absolute level populations increase with energy, whereas the neutral fraction of the beam decreases with energy. Further, the P angular-momentum levels are found to be overpopulated with respect to the S and D levels. The overpopulation decreases with increasing principal quantum number.

The size distribution of the earth-approaching asteroids

NASA Technical Reports Server (NTRS)

Rabinowitz, D. L.

1993-01-01

The discovery circumstances of the first asteroids ever observed outside the earth's atmosphere but within the neighborhood of the earth-moon system are described. Four natural objects with diameters in the range 5-50 m were detected during a search for earth-approaching asteroids conducted each month at the 0.91-m Spacewatch Telescope at Kitt Peak. An additional 19 earth approachers with sizes in the range 50 m to 5 km were discovered. These obervations determine the cumulative flux of asteroids near earth as a function of absolute magnitude. For asteroids larger than about 100 m, a power-law dependence with exponent of about 0.9 is observed, consistent with their evolution from the main-belt population. At about 10 m, the flux is more than two orders of magnitude greater than this power-law extrapolation.

Demographic Changes in Germany up to 2060 – Consequences for Blood Donation

PubMed Central

Ehling, Manfred; Pötzsch, Olga

2010-01-01

Summary This paper outlines the results of a most recent model calculation regarding the structure and development of Germany's population by 2060 with the aim to provide basic demographic data for the future provision of blood components to the population. Firstly, the paper describes the assumptions on fertility, life expectancy and Germany's balance of immigration and emigration which formed the basis for the projection. The following part discusses the results, quantifies future changes in the size and age structure of Germany's population, and illustrates the effects of demographic trends which can be identified from today's point of view. The number of potential blood donors will decline in absolute and relative terms (related to the total population and the age group of ‘non-donors’) in the future. This holds true for both the age bracket of 18 to 68 years and the alternatively chosen age group of 17 to 70 years. Depending on the variant, the population of blood donation age will decrease by one quarter to one third until 2060. PMID:20737016

Absolute molecular sieve separation of ethylene/ethane mixtures with silver zeolite A.

PubMed

Aguado, Sonia; Bergeret, Gérard; Daniel, Cecile; Farrusseng, David

2012-09-12

Absolute ethylene/ethane separation is achieved by ethane exclusion on silver-exchanged zeolite A adsorbent. This molecular sieving type separation is attributed to the pore size of the adsorbent, which falls between ethylene and ethane kinetic diameters.

Absolute and relative kinetic changes of high-sensitivity cardiac troponin T in acute coronary syndrome and in patients with increased troponin in the absence of acute coronary syndrome.

PubMed

Mueller, Matthias; Biener, Moritz; Vafaie, Mehrshad; Doerr, Susanne; Keller, Till; Blankenberg, Stefan; Katus, Hugo A; Giannitsis, Evangelos

2012-01-01

We evaluated kinetic changes of high-sensitivity cardiac troponin T (hs-cTnT) in patients with acute coronary syndrome (ACS) and patients with hs-cTnT increases not due to ACS to rule in or rule out non-ST-segment elevation myocardial infarction (STEMI). hs-cTnT was measured serially in consecutive patients presenting to the emergency department. Patients with ACS who had at least 2 hs-cTnT measurements within 6 h and non-ACS patients with hs-cTnT concentrations above the 99th percentile value (14 ng/L) were enrolled to compare absolute and relative kinetic changes of hs-cTnT. For discrimination of non-STEMI (n=165) in the entire study population (n=784), the absolute δ change with the ROC-optimized value of 9.2 ng/L yielded an area under the curve of 0.898 and was superior to all relative δ changes (P<0.0001). The positive predictive value for the absolute δ change was 48.7%, whereas the negative predictive value was 96.5%. In a specific ACS population with exclusion of STEMI (n=342), the absolute δ change with the ROC-optimized value of 6.9 ng/L yielded a positive predictive value of 82.8% and a negative predictive value of 93.0%. In comparison to the ≥20% relative δ change, the ROC-optimized absolute δ change demonstrated a significantly added value for the entire study population and for the ACS cohort (net reclassification index 0.331 and 0.499, P<0.0001). Absolute δ changes appear superior to relative δ changes in discriminating non-STEMI. A rise or fall of at least 9.2 ng/L in the entire study population and 6.9 ng/L in selected ACS patients seems adequate to rule-out non-STEMI. However, δ-values are useful to rule-in non-STEMI only in a specific ACS population.

The genealogy and genetic viability of reintroduced Yellowstone grey wolves.

PubMed

Vonholdt, Bridgett M; Stahler, Daniel R; Smith, Douglas W; Earl, Dent A; Pollinger, John P; Wayne, Robert K

2008-01-01

The recovery of the grey wolf in Yellowstone National Park is an outstanding example of a successful reintroduction. A general question concerning reintroduction is the degree to which genetic variation has been preserved and the specific behavioural mechanisms that enhance the preservation of genetic diversity and reduce inbreeding. We have analysed 200 Yellowstone wolves, including all 31 founders, for variation in 26 microsatellite loci over the 10-year reintroduction period (1995-2004). The population maintained high levels of variation (1995 H(0) = 0.69; 2004 H(0) = 0.73) with low levels of inbreeding (1995 F(IS) = -0.063; 2004 F(IS) = -0.051) and throughout, the population expanded rapidly (N(1995) = 21; N(2004) = 169). Pedigree-based effective population size ratios did not vary appreciably over the duration of population expansion (1995 N(e)/N(g) = 0.29; 2000 N(e)/N(g) = 0.26; 2004 N(e)/N(g) = 0.33). We estimated kinship and found only two of 30 natural breeding pairs showed evidence of being related (average r = -0.026, SE = 0.03). We reconstructed the genealogy of 200 wolves based on genetic and field data and discovered that they avoid inbreeding through a wide variety of behavioural mechanisms including absolute avoidance of breeding with related pack members, male-biased dispersal to packs where they breed with nonrelatives, and female-biased subordinate breeding. We documented a greater diversity of such population assembly patterns in Yellowstone than previously observed in any other natural wolf population. Inbreeding avoidance is nearly absolute despite the high probability of within-pack inbreeding opportunities and extensive interpack kinship ties between adjacent packs. Simulations showed that the Yellowstone population has levels of genetic variation similar to that of a population managed for high variation and low inbreeding, and greater than that expected for random breeding within packs or across the entire breeding pool. Although short-term losses in variation seem minimal, future projections of the population at carrying capacity suggest significant inbreeding depression will occur without connectivity and migratory exchange with other populations.

Comparison of absolute intensity between EAS with gamma-families and general EAS at Mount Norikura

NASA Technical Reports Server (NTRS)

Mitsumune, T.; Nakatsuka, T.; Nishikawa, K.; Saito, T.; Sakata, M.; Shima, M.; Yamamoto, Y.; Dake, S.; Kawamoto, M.; Kusumose, M.

1985-01-01

Gamma-families with total energy greater than 10 TeV, found in the EX chamber which was cooperated with the EAS array were combined with EAS triggered by big bursts. The absolute intensity of the size spectrum of these combined EAS was compared with that of general EAS obtained by AS trigger. The EAS with sizes greater than 2x1 million were always accompanied by gamma-families with sigma E sub gamma H 10 TeV, n sub gamma, H 2 and Emin=3 TeV, although the rate of EAS accompaning such gamma-families decreases rapidly as their sizes decrease.

[Inequalities in mortality in the Italian longitudinal studies].

PubMed

Cardano, M; Costa, G; Demaria, M; Merler, E; Biggeri, A

1999-01-01

The article presents some of the most relevant results on inequalities in mortality, obtained by the two Italian longitudinal studies carried out in Turin, and Tuscany (in Leghorn and Florence). The two studies share the same methodology. Each database contains census data, information from population register and from death certificates. The authors approach this issue not in an analytical way (as they did in the works cited in the reference list), but answering some questions, relevant both from a scientific and a political point of view. How big are the health inequalities in Italy? Are the health inequalities in Italy increasing or decreasing? Are the health inequalities due to absolute or to relative deprivation? Does the mortality profile of the Italian population express the presence of old or new health inequalities? Can the health inequalities be reduced? The study's results prove that the health inequalities in Italy are deep and strictly related to individuals' position in the social fabric. Facing the other questions the authors focus only in the Turin data. From the 1970's to the 1990's the health inequalities in Turin have increased, despite of general improvement of population's health condition and the progressive reduction of the size of deprived groups. Turin data support both the hypotheses on the source of health inequalities, using long term unemployment as absolute deprivation's indicator, and status' inconsistency as (a row) indicator of relative deprivation. The growth of drug-related causes of death (AIDS and overdose) shows that in the Turin and--quite reasonably--Italian population old and new health inequalities live together. The essay closes offering evidence on the possibility to reduce health inequalities. For this purpose the authors analyses the Turin trend of avoidable deaths and infant and adolescent mortality.

Male Choice in the Stream-Anadromous Stickleback Complex

PubMed Central

McKinnon, Jeffrey S.; Hamele, Nick; Frey, Nicole; Chou, Jennifer; McAleavey, Leia; Greene, Jess; Paulson, Windi

2012-01-01

Studies of mating preferences and pre-mating reproductive isolation have often focused on females, but the potential importance of male preferences is increasingly appreciated. We investigated male behavior in the context of reproductive isolation between divergent anadromous and stream-resident populations of threespine stickleback, Gasterosteus aculeatus, using size-manipulated females of both ecotypes. Specifically, we asked if male courtship preferences are present, and if they are based on relative body size, non-size aspects of ecotype, or other traits. Because male behaviors were correlated with each other, we conducted a principal components analysis on the correlations and ran subsequent analyses on the principal components. The two male ecotypes differed in overall behavioral frequencies, with stream-resident males exhibiting consistently more vigorous and positive courtship than anadromous males, and an otherwise aggressive behavior playing a more positive role in anadromous than stream-resident courtship. We observed more vigorous courtship toward smaller females by (relatively small) stream-resident males and the reverse pattern for (relatively large) anadromous males. Thus size-assortative male courtship preferences may contribute to reproductive isolation in this system, although preferences are far from absolute. We found little indication of males responding preferentially to females of their own ecotype independent of body size. PMID:22701589

Application of assisted reproduction for population management in felids: the potential and reality for conservation of small cats.

PubMed

Swanson, William F

2006-07-01

Assisted reproductive technology (ART), using the primary applied tools of AI, ET, and sperm and embryo cryopreservation, has been promoted over the past decades for its potential to conserve endangered wildlife, including felids. However, if the goal is efficient, consistent production of viable offspring for population management, then the 'potential' of ART has yet to become 'reality' for any non-domestic cat species. For the five small-sized felids (i.e., Brazilian ocelot, fishing cat, Pallas' cat, Arabian sand cat, black-footed cat) managed by Species Survival Plans (SSPs) in North American zoos, achieving this potential may be an absolute necessity if genetically viable captive populations are to be maintained into the next century. Modeling programs suggest that current SSP populations are not sustainable without periodic introduction of new founders and improved demographic parameters, including longer generation intervals and larger population sizes. ART provides the means to address each of these management challenges. In each small cat SSP species, fecal hormone metabolite assays and seminal analysis have proven useful for characterizing basal reproductive parameters, a necessary prerequisite to developing ART. Of the five SSP species, ART has been used to produce living offspring only in the ocelot, including after AI with frozen-thawed spermatozoa and following transfer of frozen-thawed IVF embryos. The true efficacy of these techniques, however, is still unknown. To improve the applicability of ART for population management, priorities for immediate research include further investigation of ovarian stimulation protocols, sperm and embryo cryopreservation methods, embryo culture systems, and fetal and neonatal viability following ART.

De-biased populations of Kuiper belt objects from the deep ecliptic survey

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

Adams, E. R.; Benecchi, S. D.; Gulbis, A. A. S.

2014-09-01

The Deep Ecliptic Survey (DES) was a survey project that discovered hundreds of Kuiper Belt objects from 1998 to 2005. Extensive follow-up observations of these bodies has yielded 304 objects with well-determined orbits and dynamical classifications into one of several categories: Classical, Scattered, Centaur, or 16 mean-motion resonances with Neptune. The DES search fields are well documented, enabling us to calculate the probability on each frame of detecting an object with its particular orbital parameters and absolute magnitude at a randomized point in its orbit. The detection probabilities range from a maximum of 0.32 for the 3:2 resonant object 2002more » GF {sub 32} to a minimum of 1.5 × 10{sup –7} for the faint Scattered object 2001 FU {sub 185}. By grouping individual objects together by dynamical classes, we can estimate the distributions of four parameters that define each class: semimajor axis, eccentricity, inclination, and object size. The orbital element distributions (a, e, and i) were fit to the largest three classes (Classical, 3:2, and Scattered) using a maximum likelihood fit. Using the absolute magnitude (H magnitude) as a proxy for the object size, we fit a power law to the number of objects versus H magnitude for eight classes with at least five detected members (246 objects). The Classical objects are best fit with a power-law slope of α = 1.02 ± 0.01 (observed from 5 ≤ H ≤ 7.2). Six other dynamical classes (Scattered plus five resonances) have consistent magnitude distribution slopes with the Classicals, provided that the absolute number of objects is scaled. Scattered objects are somewhat more numerous than Classical objects, while there are only a quarter as many 3:2 objects as Classicals. The exception to the power law relation is the Centaurs, which are non-resonant objects with perihelia closer than Neptune and therefore brighter and detectable at smaller sizes. Centaurs were observed from 7.5 < H < 11, and that population is best fit by a power law with α = 0.42 ± 0.02. This is consistent with a knee in the H-distribution around H = 7.2 as reported elsewhere. Based on the Classical-derived magnitude distribution, the total number of objects (H ≤ 7) in each class is: Classical (2100 ± 300 objects), Scattered (2800 ± 400), 3:2 (570 ± 80), 2:1 (400 ± 50), 5:2 (270 ± 40), 7:4 (69 ± 9), 5:3 (60 ± 8). The independent estimate for the number of Centaurs in the same H range is 13 ± 5. If instead all objects are divided by inclination into 'Hot' and 'Cold' populations, following Fraser et al., we find that α{sub Hot} = 0.90 ± 0.02, while α{sub Cold} = 1.32 ± 0.02, in good agreement with that work.« less

Spatial capture-recapture: a promising method for analyzing data collected using artificial cover objects

USGS Publications Warehouse

Sutherland, Chris; Munoz, David; Miller, David A.W.; Grant, Evan H. Campbell

2016-01-01

Spatial capture–recapture (SCR) is a relatively recent development in ecological statistics that provides a spatial context for estimating abundance and space use patterns, and improves inference about absolute population density. SCR has been applied to individual encounter data collected noninvasively using methods such as camera traps, hair snares, and scat surveys. Despite the widespread use of capture-based surveys to monitor amphibians and reptiles, there are few applications of SCR in the herpetological literature. We demonstrate the utility of the application of SCR for studies of reptiles and amphibians by analyzing capture–recapture data from Red-Backed Salamanders, Plethodon cinereus, collected using artificial cover boards. Using SCR to analyze spatial encounter histories of marked individuals, we found evidence that density differed little among four sites within the same forest (on average, 1.59 salamanders/m2) and that salamander detection probability peaked in early October (Julian day 278) reflecting expected surface activity patterns of the species. The spatial scale of detectability, a measure of space use, indicates that the home range size for this population of Red-Backed Salamanders in autumn was 16.89 m2. Surveying reptiles and amphibians using artificial cover boards regularly generates spatial encounter history data of known individuals, which can readily be analyzed using SCR methods, providing estimates of absolute density and inference about the spatial scale of habitat use.

The visual perception of size and distance.

DOT National Transportation Integrated Search

1962-07-01

The perception of absolute distance has been assumed to be important in the perception of the size of objects and the depth between them. A different hypothesis is proposed. It is asserted that perceived relative size and distance are the primary psy...

An Overview of Methods for Monitoring Social Disparities in Cancer with an Example Using Trends in Lung Cancer Incidence by Area-Socioeconomic Position and Race-Ethnicity, 1992–2004

PubMed Central

Harper, Sam; Lynch, John; Meersman, Stephen C.; Breen, Nancy; Davis, William W.; Reichman, Marsha E.

2008-01-01

The authors provide an overview of methods for summarizing social disparities in health using the example of lung cancer. They apply four measures of relative disparity and three measures of absolute disparity to trends in US lung cancer incidence by area-socioeconomic position and race-ethnicity from 1992 to 2004. Among females, measures of absolute and relative disparity suggested that area-socioeconomic and race-ethnic disparities increased over these 12 years but differed widely with respect to the magnitude of the change. Among males, the authors found substantial disagreement among summary measures of relative disparity with respect to the magnitude and the direction of change in disparities. Among area-socioeconomic groups, the index of disparity increased by 47% and the relative concentration index decreased by 116%, while for race-ethnicity the index of disparity increased by 36% and the Theil index increased by 13%. The choice of a summary measure of disparity may affect the interpretation of changes in health disparities. Important issues to consider are the reference point from which differences are measured, whether to measure disparity on the absolute or relative scale, and whether to weight disparity measures by population size. A suite of indicators is needed to provide a clear picture of health disparity change. PMID:18344513

Population and reproductive biology of the fiddler crab Uca thayeri Rathbun, 1900 (Crustacea: Ocypodidae) in a tropical mangrove from Northeast Brazil

NASA Astrophysics Data System (ADS)

Arruda Bezerra, Luis Ernesto; Matthews-Cascon, Helena

2007-05-01

Population and reproductive biology of Uca thayeri Rathbun, 1900 were studied for the first time in a tropical mangrove. Absolute density, sex ratio, population structure, handedness, breeding season and fecundity were investigated. Seven transects were delimited in a mangrove area of the Pacoti River, Northeast of Brazil (3° 43' 02″ S/38° 32' 35″ W). On each transect, ten 0.25 m 2 squares were sampled on a monthly basis during low tide periods from September 2003 to August 2004. A total of 483 crabs were obtained, of which 250 were males, 219 non-ovigerous females, and 14 ovigerous females. The U. thayeri population presented bi-modal size frequency distribution, with males and non-ovigerous females not differing significantly size-wise. Ovigerous females were larger than males and non-ovigerous females. The overall sex ratio (1:1.07) did not differ significantly from the expected 1:1 proportion. The major cheliped was the right one in 50% of the males. The observed density was of 8.5 individuals/m 2, with the specimens being found mostly in shaded areas. Ovigerous females were found in 5 months of the year, coinciding with the rainy season, suggesting that the population of U. thayeri presents seasonal reproductive events. Juvenile crabs were more abundant during the dry period, while larger crabs were found mainly during the rainy period. The fecundity of the studied population was much smaller than that of subtropical populations of this species. The regression analysis shows that the number of eggs increases linearly with the increase of carapace width.

SU-G-BRB-15: Verifications of Absolute and Relative Dosimetry of a Novel Stereotactic Breast Device: GammaPodTM

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

Becker, S; Mossahebi, S; Yi, B

Purpose: A dedicated stereotactic breast radiotherapy device, GammaPod, was developed to treat early stage breast cancer. The first clinical unit was installed and commissioned at University of Maryland. We report our methodology of absolute dosimetry in multiple calibration conditions and dosimetric verifications of treatment plans produced by the system. Methods: GammaPod unit is comprised of a rotating hemi-spherical source carrier containing 36 Co-60 sources and a concentric tungsten collimator providing beams of 15 and 25 mm. Absolute dose calibration formalism was developed with modifications to AAPM protocols for unique geometry and different calibration medium (acrylic, polyethylene or liquid water). Breastmore » cup-size specific and collimator output factors were measured and verified with respect to Monte-Carlo simulations for single isocenter plans. Multiple isocenter plans were generated for various target size, location and cup-sizes in phantoms and 20 breast cancer patients images. Stereotactic mini-farmer chamber, OSL and TLD detectors as well as radio-chromic films were used for dosimetric measurements. Results: At the time of calibration (1/14/2016), absolute dose rate of the GammaPod was established to be 2.10 Gy/min in acrylic for 25 mm for sources installed in March 2011. Output factor for 15 mm collimator was measured to be 0.950. Absolute dose calibration was independently verified by IROC-Houston with a TLD/Institution ratio of 0.99. Cup size specific output measurements in liquid water for single isocenter were found to be within 3.0% of MC simulations. Point-dose measurements of multiple isocenter treatment plans were found to be within −1.0 ± 1.2 % of treatment planning system while 2-dimensional gamma analysis yielded a pass rate of 97.9 ± 2.2 % using gamma criteria of 3% and 2mm. Conclusion: The first GammaPod treatment unit for breast stereotactic radiotherapy was successfully installed, calibrated and commissioned for patient treatments. An absolute dosimetry and dosimetric verification protocols were successfully created.« less

Spatiotemporal Fluctuations and Triggers of Ebola Virus Spillover.

PubMed

Schmidt, John Paul; Park, Andrew W; Kramer, Andrew M; Han, Barbara A; Alexander, Laura W; Drake, John M

2017-03-01

Because the natural reservoir of Ebola virus remains unclear and disease outbreaks in humans have occurred only sporadically over a large region, forecasting when and where Ebola spillovers are most likely to occur constitutes a continuing and urgent public health challenge. We developed a statistical modeling approach that associates 37 human or great ape Ebola spillovers since 1982 with spatiotemporally dynamic covariates including vegetative cover, human population size, and absolute and relative rainfall over 3 decades across sub-Saharan Africa. Our model (area under the curve 0.80 on test data) shows that spillover intensity is highest during transitions between wet and dry seasons; overall, high seasonal intensity occurs over much of tropical Africa; and spillover intensity is greatest at high (>1,000/km 2 ) and very low (<100/km 2 ) human population densities compared with intermediate levels. These results suggest strong seasonality in Ebola spillover from wild reservoirs and indicate particular times and regions for targeted surveillance.

Evaluating small-body landing hazards due to blocks

NASA Astrophysics Data System (ADS)

Ernst, C.; Rodgers, D.; Barnouin, O.; Murchie, S.; Chabot, N.

2014-07-01

Introduction: Landed missions represent a vital stage of spacecraft exploration of planetary bodies. Landed science allows for a wide variety of measurements essential to unraveling the origin and evolution of a body that are not possible remotely, including but not limited to compositional measurements, microscopic grain characterization, and the physical properties of the regolith. To date, two spacecraft have performed soft landings on the surface of a small body. In 2001, the Near Earth Asteroid Rendezvous (NEAR) mission performed a controlled descent and landing on (433) Eros following the completion of its mission [1]; in 2005, the Hayabusa spacecraft performed two touch-and-go maneuvers at (25143) Itokawa [2]. Both landings were preceded by rendezvous spacecraft reconnaissance, which enabled selection of a safe landing site. Three current missions have plans to land on small bodies (Rosetta, Hayabusa 2, and OSIRIS-REx); several other mission concepts also include small-body landings. Small-body landers need to land at sites having slopes and block abundances within spacecraft design limits. Due to the small scale of the potential hazards, it can be difficult or impossible to fully characterize a landing surface before the arrival of the spacecraft at the body. Although a rendezvous mission phase can provide global reconnaissance from which a landing site can be chosen, reasonable a priori assurance that a safe landing site exists is needed to validate the design approach for the spacecraft. Method: Many robotic spacecraft have landed safely on the Moon and Mars. Images of these landing sites, as well as more recent, extremely high-resolution orbital datasets, have enabled the comparison of orbital block observations to the smaller blocks that pose hazards to landers. Analyses of the Surveyor [3], Viking 1 and 2, Mars Pathfinder, Phoenix, Spirit, Opportunity, and Curiosity landing sites [4--8] have indicated that for a reasonable difference in size (a factor of several to ten), the size-frequency distribution of blocks can be modeled, allowing extrapolation from large block distributions to estimate small block densities. From that estimate, the probability of a lander encountering hazardous blocks can be calculated for a given lander design. Such calculations are used routinely to vet candidate sites for Mars landers [5--8]. Application to Small Bodies: To determine whether a similar approach will work for small bodies, we must determine if the large and small block populations can be linked. To do so, we analyze the comprehensive block datasets for the intermediate-sized Eros [9,10] and the small Itokawa [11,12]. Global and local block size-frequency distributions for Eros and Itokawa have power-law slopes on the order of -3 and match reasonably well between larger block sizes (from lower-resolution images) and smaller block sizes (from higher-resolution images). Although absolute block densities differ regionally on each asteroid, the slopes match reasonably well between Itokawa and Eros, with the geologic implications of this result discussed in [10]. For Eros and Itokawa, the approach of extending the size-frequency distribution from large, tens-of-meter-sized blocks down to small, tens-of-centimeter-sized blocks using a power-law fit to the large population yields reasonable estimates of small block populations. It is important to note that geologic context matters for the absolute block density --- if the global counts include multiple geologic settings, they will not directly extend to local areas containing only one setting [10]. A small number of high-resolution images of Phobos are sufficient for measuring blocks. These images are concentrated in the area outside of Stickney crater, which is thought to be the source of most of the observed blocks [13]. Block counts by Thomas et al. [13] suggest a power-law slope similar to those of Eros [9] and Itokawa global counts, with the absolute density of blocks similar to that of global Eros. Because blocks tend to be more numerous proximal to large, young craters (e.g., Stickney on Phobos, Shoemaker on Eros), the block density across most of Phobos is likely to be lower than that observed in the available high-resolution images. We suggest that a power-law extrapolation of Eros or Phobos large-block distributions provides upper limits for assessing the block landing hazards faced by a Phobos lander.

Properties and evolution of NEO families created by tidal disruption at Earth

NASA Astrophysics Data System (ADS)

Schunová, Eva; Jedicke, Robert; Walsh, Kevin J.; Granvik, Mikael; Wainscoat, Richard J.; Haghighipour, Nader

2014-08-01

We have calculated the coherence and detectable lifetimes of synthetic near-Earth object (NEO) families created by catastrophic disruption of a progenitor as it suffers a very close Earth approach. The closest or slowest approaches yield the most violent ‘s-class’ disruption events where the largest remaining fragment after disruption and reaccumulation retains less than 50% of the parent’s mass. The resulting fragments have a ‘string of pearls’ configuration after their reaccummulation into gravitationally bound components (Richardson, D.C., Bottke, W.F., Love, S.G. [1998]. Icarus 134, 47-76). We found that the average absolute magnitude (H) difference between the parent body and the largest fragment is ΔH∼1.0. The average slope of the absolute magnitude (H) distribution, N(H)∝10, for the fragments in the s-class families is steeper than the slope of the NEO population (Mainzer, A., et al. [2011]. Astrophys. J. 743, 156) in the same size range. The es remain coherent as statistically significant clusters of orbits within the NEO population for an average of τbarc=(14.7±0.6)×103 yr after disruption. The detectable lifetimes of tidally disrupted families are extremely short compared to the multi-Myr and -Gyr lifetimes of main belt families due to the chaotic dynamical environment in NEO space-they are detectable with the techniques developed by Fu et al. and Schunová et al. (Fu, H., Jedicke, R., Durda, D.D., Fevig, R., Binzel, R.P. [2005]. Icarus 178(2), 434-449 and Schunová, E., Granvik, M., Jedicke, R., Gronchi, G., Wainscoat, R., Abe, S. [2012]. Icarus 220, 1050-1063) for an average duration (τbardet) ranging from about 2000 to about 12,000 years for progenitors in the absolute magnitude (Hp) range from 20 to 13 corresponding to diameters in the range from about 0.5 to 10 km respectively. The maximum absolute magnitude of a progenitor capable of producing an observable NEO family (i.e. detectable by our family finding technique) is Hp,max=20 (about 350 m diameter). The short detectability lifetime explains why zero NEO families have been discovered to-date. Nonetheless, every tidal disruption event of a progenitor with diameter greater than 0.5 km is capable of producing several million fragments in the 1-10 m diameter range that can contribute to temporary local density enhancements of small NEOs in Earth’s vicinity. We expect that there are about 1200 objects in the steady state NEO population in this size range due to tidal disruption assuming that one 1 km diameter NEO tidally disrupts at Earth every 2500 years. These objects may be suitable targets for asteroid retrieval missions due to their Earth-like orbits with corresponding low v∞ which permits low-cost missions. The fragments from the tidal disruptions evolve into orbits that bring them into collision with terrestrial planets or the Sun or they may be ejected from the Solar System on hyperbolic orbits due to deep planetary encounters. The end-state for the fragments from a tidal disruption at Earth have ∼5× the collision probability with Earth compared to the background NEO population.

Lesion Size Does Not Predict Outcomes in Fresh Osteochondral Allograft Transplantation.

PubMed

Tírico, Luis E P; McCauley, Julie C; Pulido, Pamela A; Bugbee, William D

2018-03-01

Cartilage repair algorithms use lesion size to choose surgical techniques when selecting a cartilage repair procedure. The association of fresh osteochondral allograft (OCA) size with graft survivorship and subjective patient outcomes is still unknown. To determine if lesion size (absolute or relative) affects outcomes after OCA transplantation. Cohort study; Level of evidence, 3. The study included 156 knees in 143 patients who underwent OCA transplantation from 1998 to 2014 for isolated femoral condyle lesions. The mean age was 29.6 ± 11.4 years, and 62.9% were male. The majority of patients (62.2%) presented for cartilage repair because of osteochondritis dissecans. The mean graft area, used as a surrogate for absolute size of the lesion, was 6.4 cm 2 (range, 2.3-11.5 cm 2 ). The relative size of the lesion was calculated as the tibial width ratio (TWR; ratio of graft area to tibial width) and affected femoral condyle ratio (AFCR; ratio of graft area to affected femoral condyle width) using preoperative radiographs. All patients had a minimum follow-up of 2 years. Further surgical procedures were documented, and graft failure was defined as revision OCA transplantation or conversion to arthroplasty. International Knee Documentation Committee (IKDC) pain, function, and total scores were obtained. Satisfaction with OCA transplantation was assessed. The mean follow-up among patients with grafts remaining in situ was 6.0 years (range, 1.9-16.5 years). The OCA failure rate was 5.8%. Overall survivorship of the graft was 97.2% at 5 years and 93.5% at 10 years. No difference in postoperative outcomes between groups was found in absolute or relative size. Change in IKDC scores (from preoperative to latest follow-up) was greater for knees with large lesions compared to knees with small lesions, among all measurement methods. Overall satisfaction with the results of OCA transplantation was 89.8%. The size of the lesion, either absolute or relative, does not influence outcomes after OCA transplantation for isolated femoral condyle lesions of the knee.

Absolute pitch among American and Chinese conservatory students: prevalence differences, and evidence for a speech-related critical period.

PubMed

Deutsch, Diana; Henthorn, Trevor; Marvin, Elizabeth; Xu, HongShuai

2006-02-01

Absolute pitch is extremely rare in the U.S. and Europe; this rarity has so far been unexplained. This paper reports a substantial difference in the prevalence of absolute pitch in two normal populations, in a large-scale study employing an on-site test, without self-selection from within the target populations. Music conservatory students in the U.S. and China were tested. The Chinese subjects spoke the tone language Mandarin, in which pitch is involved in conveying the meaning of words. The American subjects were nontone language speakers. The earlier the age of onset of musical training, the greater the prevalence of absolute pitch; however, its prevalence was far greater among the Chinese than the U.S. students for each level of age of onset of musical training. The findings suggest that the potential for acquiring absolute pitch may be universal, and may be realized by enabling infants to associate pitches with verbal labels during the critical period for acquisition of features of their native language.

Discrete bivariate population balance modelling of heteroaggregation processes.

PubMed

Rollié, Sascha; Briesen, Heiko; Sundmacher, Kai

2009-08-15

Heteroaggregation in binary particle mixtures was simulated with a discrete population balance model in terms of two internal coordinates describing the particle properties. The considered particle species are of different size and zeta-potential. Property space is reduced with a semi-heuristic approach to enable an efficient solution. Aggregation rates are based on deterministic models for Brownian motion and stability, under consideration of DLVO interaction potentials. A charge-balance kernel is presented, relating the electrostatic surface potential to the property space by a simple charge balance. Parameter sensitivity with respect to the fractal dimension, aggregate size, hydrodynamic correction, ionic strength and absolute particle concentration was assessed. Results were compared to simulations with the literature kernel based on geometric coverage effects for clusters with heterogeneous surface properties. In both cases electrostatic phenomena, which dominate the aggregation process, show identical trends: impeded cluster-cluster aggregation at low particle mixing ratio (1:1), restabilisation at high mixing ratios (100:1) and formation of complex clusters for intermediate ratios (10:1). The particle mixing ratio controls the surface coverage extent of the larger particle species. Simulation results are compared to experimental flow cytometric data and show very satisfactory agreement.

The population of faint Jupiter family comets near the Earth

NASA Astrophysics Data System (ADS)

Fernández, Julio A.; Morbidelli, Alessandro

2006-11-01

We study the population of faint Jupiter family comets (JFCs) that approach the Earth (perihelion distances q<1.3 AU) by applying a debiasing technique to the observed sample. We found for the debiased cumulative luminosity function (CLF) of absolute total magnitudes H a bimodal distribution in which brighter comets ( H≲9) follow a linear relation with a steep slope α=0.65±0.14, while fainter comets follow a much shallower slope α=0.25±0.06 down to H˜18. The slope can be pushed up to α=0.35±0.09 if a second break in the H distribution to a much shallower slope is introduced at H˜16. We estimate a population of about 10 3 faint JFCs with q<1.3 AU and 10

Debiased orbit and absolute-magnitude distributions for near-Earth objects

NASA Astrophysics Data System (ADS)

Granvik, Mikael; Morbidelli, Alessandro; Jedicke, Robert; Bolin, Bryce; Bottke, William F.; Beshore, Edward; Vokrouhlický, David; Nesvorný, David; Michel, Patrick

2018-09-01

The debiased absolute-magnitude and orbit distributions as well as source regions for near-Earth objects (NEOs) provide a fundamental frame of reference for studies of individual NEOs and more complex population-level questions. We present a new four-dimensional model of the NEO population that describes debiased steady-state distributions of semimajor axis, eccentricity, inclination, and absolute magnitude H in the range 17 < H < 25. The modeling approach improves upon the methodology originally developed by Bottke et al. (2000, Science 288, 2190-2194) in that it is, for example, based on more realistic orbit distributions and uses source-specific absolute-magnitude distributions that allow for a power-law slope that varies with H. We divide the main asteroid belt into six different entrance routes or regions (ER) to the NEO region: the ν6, 3:1J, 5:2J and 2:1J resonance complexes as well as Hungarias and Phocaeas. In addition we include the Jupiter-family comets as the primary cometary source of NEOs. We calibrate the model against NEO detections by Catalina Sky Surveys' stations 703 and G96 during 2005-2012, and utilize the complementary nature of these two systems to quantify the systematic uncertainties associated to the resulting model. We find that the (fitted) H distributions have significant differences, although most of them show a minimum power-law slope at H ∼ 20. As a consequence of the differences between the ER-specific H distributions we find significant variations in, for example, the NEO orbit distribution, average lifetime, and the relative contribution of different ERs as a function of H. The most important ERs are the ν6 and 3:1J resonance complexes with JFCs contributing a few percent of NEOs on average. A significant contribution from the Hungaria group leads to notable changes compared to the predictions by Bottke et al. in, for example, the orbit distribution and average lifetime of NEOs. We predict that there are 962-56+52 (802-42+48 ×103) NEOs with H < 17.75 (H < 25) and these numbers are in agreement with the most recent estimates found in the literature (the uncertainty estimates only account for the random component). Based on our model we find that relative shares between different NEO groups (Amor, Apollo, Aten, Atira, Vatira) are (39.4,54.4,3.5,1.2,0.3)%, respectively, for the considered H range and that these ratios have a negligible dependence on H. Finally, we find an agreement between our estimate for the rate of Earth impacts by NEOs and recent estimates in the literature, but there remains a potentially significant discrepancy in the frequency of Tunguska-sized and Chelyabinsk-sized impacts.

The absolute magnitude distribution of cold classical Kuiper belt objects

NASA Astrophysics Data System (ADS)

Petit, Jean-Marc; Bannister, Michele T.; Alexandersen, Mike; Chen, Ying-Tung; Gladman, Brett; Gwyn, Stephen; Kavelaars, JJ; Volk, Kathryn

2016-10-01

We report measurements of the low inclination component of the main Kuiper Belt showing a size freqency distribution very steep for sizes larger than H_r ~ 6.5-7.0 and then a flattening to shallower slope that is still steeper than the collisional equilibrium slope.The Outer Solar System Origins Survey (OSSOS) is ongoing and is expected to detect over 500 TNOs in a precisely calibrated and characterized survey. Combining our current sample with CFEPS and the Alexandersen et al. (2015) survey, we analyse a sample of ~180 low inclination main classical (cold) TNOs, with absolute magnitude H_r (SDSS r' like flter) in the range 5 to 8.8. We confirm that the H_r distribution can be approximated by an exponential with a very steep slope (>1) at the bright end of the distribution, as has been recognized long ago. A transition to a shallower slope occurs around H_r ~ 6.5 - 7.0, an H_r mag identified by Fraster et al (2014). Faintward of this transition, we find a second exponential to be a good approximation at least until H_r ~ 8.5, but with a slope significantly steeper than the one proposed by Fraser et al. (2014) or even the collisional equilibrium value of 0.5.The transition in the cold TNO H_r distribution thus appears to occur at larger sizes than is observed in the high inclination main classical (hot) belt, an important indicator of a different cosmogony for these two sub-components of the main classical Kuiper belt. Given the largish slope faintward of the transition, the cold population with ~100 km diameter may dominate the mass of the Kuiper belt in the 40 AU < a < 47 au region.

Impact and Cratering History of the Pluto System

NASA Astrophysics Data System (ADS)

Greenstreet, Sarah; Gladman, Brett; McKinnon, William B.

2014-11-01

The observational opportunity of the New Horizons spacecraft fly-through of the Pluto system in July 2015 requires a current understanding of the Kuiper belt dynamical sub-populations to accurately interpret the cratering history of the surfaces of Pluto and its satellites. We use an Opik-style collision probability code to compute impact rates and impact velocity distributions onto Pluto and its binary companion Charon from the Canada-France Ecliptic Plane Survey (CFEPS) model of classical and resonant Kuiper belt populations (Petit et al., 2011; Gladman et al., 2012) and the scattering model of Kaib et al. (2011) calibrated to Shankman et al. (2013). Due to the uncertainty in how the well-characterized size distribution for Kuiper belt objects (with diameter d>100 km) connects to smaller objects, we compute cratering rates using three simple impactor size distribution extrapolations (a single power-law, a power-law with a knee, and a power-law with a divot) as well as the "curvy" impactor size distributions from Minton et al. (2012) and Schlichting et al. (2013). Current size distribution uncertainties cause absolute ages computed for Pluto surfaces to be entirely dependent on the extrapolation to small sizes and thus uncertain to a factor of approximately 6. We illustrate the relative importance of each Kuiper belt sub-population to Pluto's cratering rate, both now and integrated into the past, and provide crater retention ages for several cases. We find there is only a small chance a crater with diameter D>200 km has been created on Pluto in the past 4 Gyr. The 2015 New Horizons fly-through coupled with telescope surveys that cover objects with diameters d=10-100 km should eventually drop current crater retention age uncertainties on Pluto to <30%. In addition, we compute the "disruption timescale" (to a factor of three accuracy) for Pluto's smaller satellites: Styx, Nix, Kerberos, and Hydra.

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Science.gov Websites

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A statistical approach to estimate the 3D size distribution of spheres from 2D size distributions

USGS Publications Warehouse

Kong, M.; Bhattacharya, R.N.; James, C.; Basu, A.

2005-01-01

Size distribution of rigidly embedded spheres in a groundmass is usually determined from measurements of the radii of the two-dimensional (2D) circular cross sections of the spheres in random flat planes of a sample, such as in thin sections or polished slabs. Several methods have been devised to find a simple factor to convert the mean of such 2D size distributions to the actual 3D mean size of the spheres without a consensus. We derive an entirely theoretical solution based on well-established probability laws and not constrained by limitations of absolute size, which indicates that the ratio of the means of measured 2D and estimated 3D grain size distribution should be r/4 (=.785). Actual 2D size distribution of the radii of submicron sized, pure Fe0 globules in lunar agglutinitic glass, determined from backscattered electron images, is tested to fit the gamma size distribution model better than the log-normal model. Numerical analysis of 2D size distributions of Fe0 globules in 9 lunar soils shows that the average mean of 2D/3D ratio is 0.84, which is very close to the theoretical value. These results converge with the ratio 0.8 that Hughes (1978) determined for millimeter-sized chondrules from empirical measurements. We recommend that a factor of 1.273 (reciprocal of 0.785) be used to convert the determined 2D mean size (radius or diameter) of a population of spheres to estimate their actual 3D size. ?? 2005 Geological Society of America.

Ravens, New Caledonian crows and jackdaws parallel great apes in motor self-regulation despite smaller brains.

PubMed

Kabadayi, Can; Taylor, Lucy A; von Bayern, Auguste M P; Osvath, Mathias

2016-04-01

Overriding motor impulses instigated by salient perceptual stimuli represent a fundamental inhibitory skill. Such motor self-regulation facilitates more rational behaviour, as it brings economy into the bodily interaction with the physical and social world. It also underlies certain complex cognitive processes including decision making. Recently, MacLean et al. (MacLean et al. 2014 Proc. Natl Acad. Sci. USA 111, 2140-2148. (doi:10.1073/pnas.1323533111)) conducted a large-scale study involving 36 species, comparing motor self-regulation across taxa. They concluded that absolute brain size predicts level of performance. The great apes were most successful. Only a few of the species tested were birds. Given birds' small brain size-in absolute terms-yet flexible behaviour, their motor self-regulation calls for closer study. Corvids exhibit some of the largest relative avian brain sizes-although small in absolute measure-as well as the most flexible cognition in the animal kingdom. We therefore tested ravens, New Caledonian crows and jackdaws in the so-called cylinder task. We found performance indistinguishable from that of great apes despite the much smaller brains. We found both absolute and relative brain volume to be a reliable predictor of performance within Aves. The complex cognition of corvids is often likened to that of great apes; our results show further that they share similar fundamental cognitive mechanisms.

The relationship between poverty and fertility in some less developed countries.

PubMed

Chin Ptc

1985-12-01

The author investigates the extent to which both absolute and relative poverty affect population growth in developing countries. Aggregate data from U.N. sources for 26 countries at various stages of the fertility transition are used. The results indicate that the most significant steps in reducing fertility would be more effective provision of basic human needs and reforms in land tenure. The need to distinguish between absolute and relative poverty in formulating population policies is noted.

Accuracy of genomic selection models in a large population of open-pollinated families in white spruce

PubMed Central

Beaulieu, J; Doerksen, T; Clément, S; MacKay, J; Bousquet, J

2014-01-01

Genomic selection (GS) is of interest in breeding because of its potential for predicting the genetic value of individuals and increasing genetic gains per unit of time. To date, very few studies have reported empirical results of GS potential in the context of large population sizes and long breeding cycles such as for boreal trees. In this study, we assessed the effectiveness of marker-aided selection in an undomesticated white spruce (Picea glauca (Moench) Voss) population of large effective size using a GS approach. A discovery population of 1694 trees representative of 214 open-pollinated families from 43 natural populations was phenotyped for 12 wood and growth traits and genotyped for 6385 single-nucleotide polymorphisms (SNPs) mined in 2660 gene sequences. GS models were built to predict estimated breeding values using all the available SNPs or SNP subsets of the largest absolute effects, and they were validated using various cross-validation schemes. The accuracy of genomic estimated breeding values (GEBVs) varied from 0.327 to 0.435 when the training and the validation data sets shared half-sibs that were on average 90% of the accuracies achieved through traditionally estimated breeding values. The trend was also the same for validation across sites. As expected, the accuracy of GEBVs obtained after cross-validation with individuals of unknown relatedness was lower with about half of the accuracy achieved when half-sibs were present. We showed that with the marker densities used in the current study, predictions with low to moderate accuracy could be obtained within a large undomesticated population of related individuals, potentially resulting in larger gains per unit of time with GS than with the traditional approach. PMID:24781808

Population Coding of Visual Space: Modeling

PubMed Central

Lehky, Sidney R.; Sereno, Anne B.

2011-01-01

We examine how the representation of space is affected by receptive field (RF) characteristics of the encoding population. Spatial responses were defined by overlapping Gaussian RFs. These responses were analyzed using multidimensional scaling to extract the representation of global space implicit in population activity. Spatial representations were based purely on firing rates, which were not labeled with RF characteristics (tuning curve peak location, for example), differentiating this approach from many other population coding models. Because responses were unlabeled, this model represents space using intrinsic coding, extracting relative positions amongst stimuli, rather than extrinsic coding where known RF characteristics provide a reference frame for extracting absolute positions. Two parameters were particularly important: RF diameter and RF dispersion, where dispersion indicates how broadly RF centers are spread out from the fovea. For large RFs, the model was able to form metrically accurate representations of physical space on low-dimensional manifolds embedded within the high-dimensional neural population response space, suggesting that in some cases the neural representation of space may be dimensionally isomorphic with 3D physical space. Smaller RF sizes degraded and distorted the spatial representation, with the smallest RF sizes (present in early visual areas) being unable to recover even a topologically consistent rendition of space on low-dimensional manifolds. Finally, although positional invariance of stimulus responses has long been associated with large RFs in object recognition models, we found RF dispersion rather than RF diameter to be the critical parameter. In fact, at a population level, the modeling suggests that higher ventral stream areas with highly restricted RF dispersion would be unable to achieve positionally-invariant representations beyond this narrow region around fixation. PMID:21344012

Eight new Milky Way companions discovered in first-year Dark Energy Survey data

DOE PAGES

Bechtol, K.

2015-06-30

We report the discovery of eight new Milky Way companions inmore » $$\\sim 1800\\;{\\mathrm{deg}}^{2}$$ of optical imaging data collected during the first year of the Dark Energy Survey (DES). Each system is identified as a statistically significant over-density of individual stars consistent with the expected isochrone and luminosity function of an old and metal-poor stellar population. The objects span a wide range of absolute magnitudes (MV from $-2.2$ to $$-7.4\\;\\mathrm{mag}$$), physical sizes ($$10-170\\;\\mathrm{pc}$$), and heliocentric distances ($$30-330\\;\\mathrm{kpc}$$). Based on the low surface brightnesses, large physical sizes, and/or large Galactocentric distances of these objects, several are likely to be new ultra-faint satellite galaxies of the Milky Way and/or Magellanic Clouds. We introduce a likelihood-based algorithm to search for and characterize stellar over-densities, as well as identify stars with high satellite membership probabilities. As a result, we also present completeness estimates for detecting ultra-faint galaxies of varying luminosities, sizes, and heliocentric distances in the first-year DES data.« less

Water fluoridation in Brazilian cities at the first decade of the 21st century.

PubMed

Frazão, Paulo; Narvai, Paulo Capel

2017-05-15

To assess the coverage of the fluoridation of the public water supply in Brazilian municipalities at the first decade of the 21st century, according to population size and municipal human development index (MHDI). We have used data produced by national information agencies and the United Nations Development Programme. Population size was separated into < 10,000, 10,000-50,000, and > 50,000 inhabitants. The MHDI was classified into < 0.600, 0.600-0.699, 0.700-0.799, and > 0.799. Absolute and relative inequalities between categories were evaluated using indicators of effect and total impact. We have obtained information for 5,558 municipalities. The coverage rate of water fluoridation increased from 67.7% to 76.3%. Approximately 884 (15.9%) municipalities and 29,600,000 inhabitants started being benefited by the measure. We have observed a significant expansion in municipalities with < 10,000 inhabitants (increase of 21.0 percentage points) and low or very low MHDI (17.7 percentage points). Population coverage of the public policy has increased 8.6%, and we can also see significant reductions in absolute and relative inequality according to population size and MHDI. Regarding municipal coverage rate, there was also a reduction in inequality in all comparisons except for absolute inequality between the categories of MHDI. The public policy has operated as a factor of health protection in the context of the ongoing social protection policies in the country. Avaliar a cobertura da fluoretação da água de abastecimento público em municípios brasileiros na primeira década do século XXI, segundo porte demográfico e nível de desenvolvimento humano municipal (IDH-M). Foram utilizados dados produzidos por agências nacionais de informação e pelo Programa das Nações Unidas para o Desenvolvimento. O porte demográfico foi separado em < 10 mil; 10-50 mil; > 50 mil habitantes. O IDH-M foi classificado em < 0,600; 0,600-0,699; 0,700-0,799; > 0,799. As desigualdades absoluta e relativa entre as categorias foram avaliadas por meio de indicadores de efeito e de impacto total. Foram obtidas informações para 5.558 municípios. A taxa de cobertura da fluoretação da água aumentou de 67,7% para 76,3%. Passaram a ser beneficiados pela medida 884 (15,9%) municípios, e 29,6 milhões de habitantes. Observou-se ampliação expressiva em municípios com < 10 mil habitantes (aumento de 21,0 pontos percentuais) e com IDH-M baixo ou muito baixo (17,7 pontos percentuais). A cobertura populacional da política pública aumentou 8,6%, sendo expressivas as reduções das desigualdades absoluta e relativa segundo o porte demográfico e o IDH-M. Quanto à taxa de cobertura municipal, houve também redução da desigualdade em todas as comparações com exceção da desigualdade absoluta entre as categorias de IDH-M. A política pública operou como fator de proteção sanitária no contexto das políticas de proteção social em curso no país.

A new multidimensional population health indicator for policy makers: absolute level, inequality and spatial clustering - an empirical application using global sub-national infant mortality data.

PubMed

Sartorius, Benn K D; Sartorius, Kurt

2014-11-01

The need for a multidimensional measure of population health that accounts for its distribution remains a central problem to guide the allocation of limited resources. Absolute proxy measures, like the infant mortality rate (IMR), are limited because they ignore inequality and spatial clustering. We propose a novel, three-part, multidimensional mortality indicator that can be used as the first step to differentiate interventions in a region or country. The three-part indicator (MortalityABC index) combines absolute mortality rate, the Theil Index to calculate mortality inequality and the Getis-Ord G statistic to determine the degree of spatial clustering. The analysis utilises global sub-national IMR data to empirically illustrate the proposed indicator. The three-part indicator is mapped globally to display regional/country variation and further highlight its potential application. Developing countries (e.g. in sub-Saharan Africa) display high levels of absolute mortality as well as variable mortality inequality with evidence of spatial clustering within certain sub-national units ("hotspots"). Although greater inequality is observed outside developed regions, high mortality inequality and spatial clustering are common in both developed and developing countries. Significant positive correlation was observed between the degree of spatial clustering and absolute mortality. The proposed multidimensional indicator should prove useful for spatial allocation of healthcare resources within a country, because it can prompt a wide range of policy options and prioritise high-risk areas. The new indicator demonstrates the inadequacy of IMR as a single measure of population health, and it can also be adapted to lower administrative levels within a country and other population health measures.

Greater absolute risk for all subtypes of breast cancer in the US than Malaysia.

PubMed

Horne, Hisani N; Beena Devi, C R; Sung, Hyuna; Tang, Tieng Swee; Rosenberg, Philip S; Hewitt, Stephen M; Sherman, Mark E; Anderson, William F; Yang, Xiaohong R

2015-01-01

Hormone receptor (HR) negative breast cancers are relatively more common in low-risk than high-risk countries and/or populations. However, the absolute variations between these different populations are not well established given the limited number of cancer registries with incidence rate data by breast cancer subtype. We, therefore, used two unique population-based resources with molecular data to compare incidence rates for the 'intrinsic' breast cancer subtypes between a low-risk Asian population in Malaysia and high-risk non-Hispanic white population in the National Cancer Institute's surveillance, epidemiology, and end results 18 registries database (SEER 18). The intrinsic breast cancer subtypes were recapitulated with the joint expression of the HRs (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor-2 (HER2). Invasive breast cancer incidence rates overall were fivefold greater in SEER 18 than in Malaysia. The majority of breast cancers were HR-positive in SEER 18 and HR-negative in Malaysia. Notwithstanding the greater relative distribution for HR-negative cancers in Malaysia, there was a greater absolute risk for all subtypes in SEER 18; incidence rates were nearly 7-fold higher for HR-positive and 2-fold higher for HR-negative cancers in SEER 18. Despite the well-established relative breast cancer differences between low-risk and high-risk countries and/or populations, there was a greater absolute risk for HR-positive and HR-negative subtypes in the US than Malaysia. Additional analytical studies are sorely needed to determine the factors responsible for the elevated risk of all subtypes of breast cancer in high-risk countries like the United States.

Risk aversion affects economic values of blue fox breeding scheme.

PubMed

Peura, J; Kempe, R; Strandén, I; Rydhmer, L

2016-12-01

The profit and production of an average Finnish blue fox farm was simulated using a deterministic bio-economic farm model. Risk was included using Arrow-Prat absolute risk aversion coefficient and profit variance. Risk-rated economic values were calculated for pregnancy rate, litter loss, litter size, pelt size, pelt quality, pelt colour clarity, feed efficiency and eye infection. With high absolute risk aversion, economic values were lower than with low absolute risk aversion. Economic values were highest for litter loss (18.16 and 26.42 EUR), litter size (13.27 and 19.40 EUR), pregnancy (11.99 and 18.39 EUR) and eye infection (12.39 and 13.81 EUR). Sensitivity analysis showed that selection pressure for improved eye health depended strongly on proportion of culled animals among infected animals and much less on the proportion of infected animals. The economic value of feed efficiency was lower than expected (6.06 and 8.03 EUR). However, it was almost the same magnitude as pelt quality (7.30 and 7.30 EUR) and higher than the economic value of pelt size (3.37 and 5.26 EUR). Risk factors should be considered in blue fox breeding scheme because they change the relative importance of traits. © 2016 Blackwell Verlag GmbH.

Determination of collagen fibril size via absolute measurements of second-harmonic generation signals

NASA Astrophysics Data System (ADS)

Bancelin, Stéphane; Aimé, Carole; Gusachenko, Ivan; Kowalczuk, Laura; Latour, Gaël; Coradin, Thibaud; Schanne-Klein, Marie-Claire

2014-09-01

The quantification of collagen fibril size is a major issue for the investigation of pathological disorders associated with structural defects of the extracellular matrix. Second-harmonic generation microscopy is a powerful technique to characterize the macromolecular organization of collagen in unstained biological tissues. Nevertheless, due to the complex coherent building of this nonlinear optical signal, it has never been used to measure fibril diameter so far. Here we report absolute measurements of second-harmonic signals from isolated fibrils down to 30 nm diameter, via implementation of correlative second-harmonic-electron microscopy. Moreover, using analytical and numerical calculations, we demonstrate that the high sensitivity of this technique originates from the parallel alignment of collagen triple helices within fibrils and the subsequent constructive interferences of second-harmonic radiations. Finally, we use these absolute measurements as a calibration for ex vivo quantification of fibril diameter in the Descemet’s membrane of a diabetic rat cornea.

Towards resolving the Knautia arvensis agg. (Dipsacaceae) puzzle: primary and secondary contact zones and ploidy segregation at landscape and microgeographic scales

PubMed Central

Kolář, Filip; Štech, Milan; Trávníček, Pavel; Rauchová, Jana; Urfus, Tomáš; Vít, Petr; Kubešová, Magdalena; Suda, Jan

2009-01-01

Background and Aims Detailed knowledge of variations in ploidy levels and their geographic distributions is one of the key tasks faced in polyploid research in natural systems. Flow cytometry has greatly facilitated the field of cytogeography by allowing characterization of ploidy levels at both the regional and population scale, and at multiple stages of the life cycle. In the present study, flow cytometry was employed to investigate the patterns and dynamics of ploidy variation in the taxonomically challenging complex Knautia arvensis (Dipsacaceae) and some of its allies (K. dipsacifolia, K. slovaca) in Central Europe. Methods DNA ploidy levels were estimated by DAPI flow cytometry in 5205 adult plants, 228 seedlings and 400 seeds collected from 292 Knautia populations in seven European countries. The flow cytometric data were supplemented with conventional chromosome counts. A subset of 79 accessions was subjected to estimation of the absolute genome size using propidium iodide flow cytometry. Key Results and Conclusions Five different ploidy levels (from 2x to 6x) were found, with triploids of K. arvensis being recorded for the first time. The species also exhibited variation in the monoploid genome size, corresponding to the types of habitats occupied (grassland diploid populations had larger genome sizes than relict and subalpine diploid populations). Disregarding relict populations, the distribution of 2x and 4x cytotypes was largely parapatric, with a diffuse secondary contact zone running along the north-west margin of the Pannonian basin. Spatial segregation of the cytotypes was also observed on regional and microgeographic scales. The newly detected sympatric growth of diploids and tetraploids in isolated relict habitats most likely represents the primary zone of cytotype contact. Ploidy level was found to be a major determinant of the strength of inter-cytotype reproductive barriers. While mixed 2x + 4x populations virtually lacked the intermediate ploidy level at any ontogenetic stage, pentaploid hybrids were common in 4x +6x populations, despite the cytotypes representing different taxonomic entities. PMID:19196717

Size relationships of different body parts in the three dipteran species Drosophila melanogaster, Ceratitis capitata and Musca domestica.

PubMed

Siomava, Natalia; Wimmer, Ernst A; Posnien, Nico

2016-06-01

Body size is an integral feature of an organism that influences many aspects of life such as fecundity, life span and mating success. Size of individual organs and the entire body size represent quantitative traits with a large reaction norm, which are influenced by various environmental factors. In the model system Drosophila melanogaster, pupal size and adult traits, such as tibia and thorax length or wing size, accurately estimate the overall body size. However, it is unclear whether these traits can be used in other flies. Therefore, we studied changes in size of pupae and adult organs in response to different rearing temperatures and densities for D. melanogaster, Ceratitis capitata and Musca domestica. We confirm a clear sexual size dimorphism (SSD) for Drosophila and show that the SSD is less uniform in the other species. Moreover, the size response to changing growth conditions is sex dependent. Comparison of static and evolutionary allometries of the studied traits revealed that response to the same environmental variable is genotype specific but has similarities between species of the same order. We conclude that the value of adult traits as estimators of the absolute body size may differ among species and the use of a single trait may result in wrong assumptions. Therefore, we suggest using a body size coefficient computed from several individual measurements. Our data is of special importance for monitoring activities of natural populations of the three dipteran flies, since they are harmful species causing economical damage (Drosophila, Ceratitis) or transferring diseases (Musca).

Sertoli cell androgen receptor expression regulates temporal fetal and adult Leydig cell differentiation, function, and population size.

PubMed

Hazra, Rasmani; Jimenez, Mark; Desai, Reena; Handelsman, David J; Allan, Charles M

2013-09-01

We recently created a mouse model displaying precocious Sertoli cell (SC) and spermatogenic development induced by SC-specific transgenic androgen receptor expression (TgSCAR). Here we reveal that TgSCAR regulates the development, function, and absolute number of Leydig cells (LCs). Total fetal and adult type LC numbers were reduced in postnatal and adult TgSCAR vs control testes, despite normal circulating LH levels. Normal LC to SC ratios found in TgSCAR testes indicate that SC androgen receptor (SCAR)-mediated activity confers a quorum-dependent relationship between total SC and LC numbers. TgSCAR enhanced LC differentiation, shown by elevated ratios of advanced to immature LC types, and reduced LC proliferation in postnatal TgSCAR vs control testes. Postnatal TgSCAR testes displayed up-regulated expression of coupled ligand-receptor transcripts (Amh-Amhr2, Dhh-Ptch1, Pdgfa-Pdgfra) for potential SCAR-stimulated paracrine pathways, which may coordinate LC differentiation. Neonatal TgSCAR testes displayed normal T and dihydrotestosterone levels despite differential changes to steroidogenic gene expression, with down-regulated Star, Cyp11a1, and Cyp17a1 expression contrasting with up-regulated Hsd3b1, Hsd17b3, and Srd5a1 expression. TgSCAR males also displayed elevated postnatal and normal adult serum testosterone levels, despite reduced LC numbers. Enhanced adult-type LC steroidogenic output was revealed by increased pubertal testicular T, dihydrotestosterone, 3α-diol and 3β-diol levels per LC and up-regulated steroidogenic gene (Nr5a1, Lhr, Cyp11a1, Cyp17a1, Hsd3b6, Srd5a1) expression in pubertal or adult TgSCAR vs control males, suggesting regulatory mechanisms maintain androgen levels independently of absolute LC numbers. Our unique gain-of-function TgSCAR model has revealed that SCAR activity controls temporal LC differentiation, steroidogenic function, and population size.

Prevalence Incidence Mixture Models

Cancer.gov

The R package and webtool fits Prevalence Incidence Mixture models to left-censored and irregularly interval-censored time to event data that is commonly found in screening cohorts assembled from electronic health records. Absolute and relative risk can be estimated for simple random sampling, and stratified sampling (the two approaches of superpopulation and a finite population are supported for target populations). Non-parametric (absolute risks only), semi-parametric, weakly-parametric (using B-splines), and some fully parametric (such as the logistic-Weibull) models are supported.

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

Moore, Bria M.; Brady, Samuel L., E-mail: samuel.brady@stjude.org; Kaufman, Robert A.

Purpose: To investigate the correlation of size-specific dose estimate (SSDE) with absorbed organ dose, and to develop a simple methodology for estimating patient organ dose in a pediatric population (5–55 kg). Methods: Four physical anthropomorphic phantoms representing a range of pediatric body habitus were scanned with metal oxide semiconductor field effect transistor (MOSFET) dosimeters placed at 23 organ locations to determine absolute organ dose. Phantom absolute organ dose was divided by phantom SSDE to determine correlation between organ dose and SSDE. Organ dose correlation factors (CF{sub SSDE}{sup organ}) were then multiplied by patient-specific SSDE to estimate patient organ dose. Themore » CF{sub SSDE}{sup organ} were used to retrospectively estimate individual organ doses from 352 chest and 241 abdominopelvic pediatric CT examinations, where mean patient weight was 22 kg ± 15 (range 5–55 kg), and mean patient age was 6 yrs ± 5 (range 4 months to 23 yrs). Patient organ dose estimates were compared to published pediatric Monte Carlo study results. Results: Phantom effective diameters were matched with patient population effective diameters to within 4 cm; thus, showing appropriate scalability of the phantoms across the entire pediatric population in this study. IndividualCF{sub SSDE}{sup organ} were determined for a total of 23 organs in the chest and abdominopelvic region across nine weight subcategories. For organs fully covered by the scan volume, correlation in the chest (average 1.1; range 0.7–1.4) and abdominopelvic region (average 0.9; range 0.7–1.3) was near unity. For organ/tissue that extended beyond the scan volume (i.e., skin, bone marrow, and bone surface), correlation was determined to be poor (average 0.3; range: 0.1–0.4) for both the chest and abdominopelvic regions, respectively. A means to estimate patient organ dose was demonstrated. Calculated patient organ dose, using patient SSDE and CF{sub SSDE}{sup organ}, was compared to previously published pediatric patient doses that accounted for patient size in their dose calculation, and was found to agree in the chest to better than an average of 5% (27.6/26.2) and in the abdominopelvic region to better than 2% (73.4/75.0). Conclusions: For organs fully covered within the scan volume, the average correlation of SSDE and organ absolute dose was found to be better than ±10%. In addition, this study provides a complete list of organ dose correlation factors (CF{sub SSDE}{sup organ}) for the chest and abdominopelvic regions, and describes a simple methodology to estimate individual pediatric patient organ dose based on patient SSDE.« less

Exploring the population-level impact of antiretroviral treatment: the influence of baseline intervention context.

PubMed

Mishra, Sharmistha; Mountain, Elisa; Pickles, Michael; Vickerman, Peter; Shastri, Suresh; Gilks, Charles; Dhingra, Nandini K; Washington, Reynold; Becker, Marissa L; Blanchard, James F; Alary, Michel; Boily, Marie-Claude

2014-01-01

To compare the potential population-level impact of expanding antiretroviral treatment (ART) in HIV epidemics concentrated among female sex workers (FSWs) and clients, with and without existing condom-based FSW interventions. Mathematical model of heterosexual HIV transmission in south India. We simulated HIV epidemics in three districts to assess the 10-year impact of existing ART programs (ART eligibility at CD4 cell count ≤350) beyond that achieved with high condom use, and the incremental benefit of expanding ART by either increasing ART eligibility, improving access to care, or prioritizing ART expansion to FSWs/clients. Impact was estimated in the total population (including FSWs and clients). In the presence of existing condom-based interventions, existing ART programs (medium-to-good coverage) were predicted to avert 11-28% of remaining HIV infections between 2014 and 2024. Increasing eligibility to all risk groups prevented an incremental 1-15% over existing ART programs, compared with 29-53% when maximizing access to all risk groups. If there was no condom-based intervention, and only poor ART coverage, then expanding ART prevented a larger absolute number but a smaller relative fraction of HIV infections for every additional person-year of ART. Across districts and baseline interventions, for every additional person-year of treatment, prioritizing access to FSWs was most efficient (and resource saving), followed by prioritizing access to FSWs and clients. The relative and absolute benefit of ART expansion depends on baseline condom use, ART coverage, and epidemic size. In south India, maximizing FSWs' access to care, followed by maximizing clients' access are the most efficient ways to expand ART for HIV prevention, across baseline intervention context.

Spatial distribution of limited resources and local density regulation in juvenile Atlantic salmon.

PubMed

Finstad, Anders G; Einum, Sigurd; Ugedal, Ola; Forseth, Torbjørn

2009-01-01

1. Spatial heterogeneity of resources may influence competition among individuals and thus have a fundamental role in shaping population dynamics and carrying capacity. In the present study, we identify shelter opportunities as a limiting resource for juvenile Atlantic salmon (Salmo salar L.). Experimental and field studies are combined in order to demonstrate how the spatial distribution of shelters may influence population dynamics on both within and among population scales. 2. In closed experimental streams, fish performance scaled negatively with decreasing shelter availability and increasing densities. In contrast, the fish in open stream channels dispersed according to shelter availability and performance of fish remaining in the streams did not depend on initial density or shelters. 3. The field study confirmed that spatial variation in densities of 1-year-old juveniles was governed both by initial recruit density and shelter availability. Strength of density-dependent population regulation, measured as carrying capacity, increased with decreasing number of shelters. 4. Nine rivers were surveyed for spatial variation in shelter availability and increased shelter heterogeneity tended to decrease maximum observed population size (measured using catch statistics of adult salmon as a proxy). 5. Our studies highlight the importance of small-scale within-population spatial structure in population dynamics and demonstrate that not only the absolute amount of limiting resources but also their spatial arrangement can be an important factor influencing population carrying capacity.

[Motor transport emission, ambient air quality, and the Moscow population's health].

PubMed

Ivanenko, A V; Volkova, I F; Kornienko, A P

2007-01-01

As of 2006, the city's motor transport fleet amounted to as many as 3 million units that annually consume about 5 million tons of petrol. The use rate of all kinds of vehicles has increased, resulting in the growth of the proportion of ambient air pollutants discharged by motor transport, which surpasses the increase of the absolute size of the fleet. The contribution of traveling sources to ambient air pollution is growing steadily and it has been recently about 90% (1 million tons). Implementation of measures and developed managerial decisions, and ecological programs, improvement of Moscow town-planning measures, and environment-improving measures against motor vehicles have contributed to a reduction in chemical and physical burdens on the population. The characteristics of the capital's ambient air pollution have been recently observed to become stable and improve. There is stabilization in morbidity due to respiratory diseases in all population groups. The prevalence of chronic respiratory diseases in children is on the decrease, the increase rate was 1.4% versus 33.5% in the preceding period. Assessment of carcinogenic risk showed that ambient air pollution and drinking water contamination had a negative impact on the Moscow population.

Low absolute neutrophil counts in African infants.

PubMed

Kourtis, Athena P; Bramson, Brian; van der Horst, Charles; Kazembe, Peter; Ahmed, Yusuf; Chasela, Charles; Hosseinipour, Mina; Knight, Rodney; Lugalia, Lebah; Tegha, Gerald; Joaki, George; Jafali, Robert; Jamieson, Denise J

2005-07-01

Infants of African origin have a lower normal range of absolute neutrophil counts than white infants; this fact, however, remains under appreciated by clinical researchers in the United States. During the initial stages of a clinical trial in Malawi, the authors noted an unexpectedly high number of infants with absolute neutrophil counts that would be classifiable as neutropenic using the National Institutes of Health's Division of AIDS toxicity tables. The authors argue that the relevant Division of AIDS table does not take into account the available evidence of low absolute neutrophil counts in African infants and that a systematic collection of data from many African settings might help establish the absolute neutrophil count cutpoints to be used for defining neutropenia in African populations.

Evolution of brain-body allometry in Lake Tanganyika cichlids.

PubMed

Tsuboi, Masahito; Kotrschal, Alexander; Hayward, Alexander; Buechel, Severine Denise; Zidar, Josefina; Løvlie, Hanne; Kolm, Niclas

2016-07-01

Brain size is strongly associated with body size in all vertebrates. This relationship has been hypothesized to be an important constraint on adaptive brain size evolution. The essential assumption behind this idea is that static (i.e., within species) brain-body allometry has low ability to evolve. However, recent studies have reported mixed support for this view. Here, we examine brain-body static allometry in Lake Tanganyika cichlids using a phylogenetic comparative framework. We found considerable variation in the static allometric intercept, which explained the majority of variation in absolute and relative brain size. In contrast, the slope of the brain-body static allometry had relatively low variation, which explained less variation in absolute and relative brain size compared to the intercept and body size. Further examination of the tempo and mode of evolution of static allometric parameters confirmed these observations. Moreover, the estimated evolutionary parameters indicate that the limited observed variation in the static allometric slope could be a result of strong stabilizing selection. Overall, our findings suggest that the brain-body static allometric slope may represent an evolutionary constraint in Lake Tanganyika cichlids. © 2016 The Author(s).

Population growth is a variable open to change

NASA Astrophysics Data System (ADS)

Potts, M.

2016-12-01

The absolute number of people and the rate of population growth have an impact on climate mitigation, adaptation and possible conflict. Half the pregnancies in the US are unintended. Robust quantitative evidence from California demonstrates that improving access to family planning is the single most cost-effective way of mitigating our carbon footprint. Globally, there are 80 million unintended pregnancies annually. Many non-evidence barriers deprive women of the information and means required to separate sex from childbearing. Between 1960 and 1990, meeting the need for family planning led to a rapid fall in family size in much of Asia. Since 1990, funding for family planning has collapsed and fertility decline has stalled. The UN projects that by 2100 global population will increase by 3.8 billion (equal to world population in 1975). 80% of this growth will be in Africa. Studies project that climate change will undermine crop yields in parts of Africa, especially the Sahel. A high ratio of young males to the rest of the population is a risk factor in conflict. Today, only 1% of overseas assistance is allocated to family planning. Based on analysis of the past, doubling that investment would accelerate fertility decline, facilitating climate mitigation and adaptation, and possibly reducing conflict. Population and family planning were pushed off the international agenda by unacceptably and tragic episodes of coercion in China and India. However, there is compelling data that when voluntary family planning is widely available then family size can fall rapidly, as occurred in the Islamic Republic of Iran, where fertility fell more rapidly than in any other country in history. Family planning is listening to what women want not telling people want to do. Population growth is a variable open to change in a human rights framework. Population and family planning are variables relevant to the scientific agenda of the AGU.

Speed and Accuracy of Absolute Pitch Judgments: Some Latter-Day Results.

ERIC Educational Resources Information Center

Carroll, John B.

Nine subjects, 5 of whom claimed absolute pitch (AP) ability were instructed to rapidly strike notes on the piano to match randomized tape-recorded piano notes. Stimulus set sizes were 64, 16, or 4 consecutive semitones, or 7 diatonic notes of a designated octave. A control task involved motor movements to notes announced in advance. Accuracy,…

Towards a Solution to the Goose-Agriculture Conflict in North Norway, 1988–2012: The Interplay between Policy, Stakeholder Influence and Goose Population Dynamics

PubMed Central

Tombre, Ingunn M.; Eythórsson, Einar; Madsen, Jesper

2013-01-01

This paper presents results from a multidisciplinary study of a negotiation process between farmers and wildlife authorities which led to an agricultural subsidy scheme to alleviate conflicts between agriculture and geese in Norway. The Svalbard-breeding population of pink-footed geese Anser brachyrhynchus has increased considerably over the last decades and conflicts with farmers have escalated, especially at stopover sites in spring when geese feed on newly sprouted pasture grass. In Vesterålen, an important stopover site for geese in North Norway, farmers deployed scaring of geese at varying intensity dependent on the level of conflict during 1988–2012. We assessed the efficiency of a subsidy scheme established in 2006, in terms of its conflict mitigation, reflected in a near discontinuation of scaring activities. The presence of pink-footed geese was analysed in relation to scaring intensity, the total goose population size and the increasing occurrence of another goose species, the barnacle goose Branta leucopsis. Scaring significantly affected the number of geese staging in Vesterålen, both in absolute and relative terms (controlling for total population size). The geese responded immediately to an increased, and reduced, level of scaring. Despite the establishment of the subsidy scheme, the number of pink-footed geese has recently declined which is probably caused by the increasing number of barnacle geese. For the farmers, the subsidy scheme provides funding that reduces the economic costs caused by the geese. Sustaining a low level of conflict will require close monitoring, dialogue and adaptation of the subsidy scheme to cater for changes in goose population dynamics. PMID:23977175

OSSOS. VIII. The Transition between Two Size Distribution Slopes in the Scattering Disk

NASA Astrophysics Data System (ADS)

Lawler, S. M.; Shankman, C.; Kavelaars, J. J.; Alexandersen, M.; Bannister, M. T.; Chen, Ying-Tung; Gladman, B.; Fraser, W. C.; Gwyn, S.; Kaib, N.; Petit, J.-M.; Volk, K.

2018-05-01

The scattering trans-Neptunian Objects (TNOs) can be measured to smaller sizes than any other distant small-body population. We use the largest sample yet obtained, 68 discoveries, primarily by the Outer Solar System Origins Survey (OSSOS), to constrain the slope of its luminosity distribution, with sensitivity to much fainter absolute H-magnitudes than previous work. Using the analysis technique in Shankman et al., we confirm that a single slope for the H-distribution is not an accurate representation of the scattering TNOs and Centaurs, and that a break in the distribution is required, in support of previous conclusions. A bright-end slope of α b = 0.9 transitioning to a faint-end slope α f of 0.4–0.5 with a differential number contrast c from 1 (a knee) to 10 (a divot) provides an acceptable match to our data. We find that break magnitudes H b of 7.7 and 8.3, values both previously suggested for dynamically hot Kuiper Belt populations, are equally non-rejectable for a range of α f and c in our statistical analysis. Our preferred divot H-distribution transitions to α f = 0.5 with a divot of contrast c = 3 at H b = 8.3, while our preferred knee H-distribution transitions to α f = 0.4 at H b = 7.7. The intrinsic population of scattering TNOs required to match the OSSOS detections is 3 × 106 for H r < 12, and 9 × 104 for H r < 8.66 (D ≳ 100 km), with Centaurs having an intrinsic population two orders of magnitude smaller.

Is there sufficient evidence regarding signage-based stair use interventions? A sequential meta-analysis

PubMed Central

Bauman, Adrian; Milton, Karen; Kariuki, Maina; Fedel, Karla; Lewicka, Mary

2017-01-01

Objective The proliferation of studies using motivational signs to promote stair use continues unabated, with their oft-cited potential for increasing population-level physical activity participation. This study examined all stair use promotional signage studies since 1980, calculating pre-estimates and post-estimates of stair use. The aim of this project was to conduct a sequential meta-analysis to pool intervention effects, in order to determine when the evidence base was sufficient for population-wide dissemination. Design Using comparable data from 50 stair-promoting studies (57 unique estimates) we pooled data to assess the effect sizes of such interventions. Results At baseline, median stair usage across interventions was 8.1%, with an absolute median increase of 2.2% in stair use following signage-based interventions. The overall pooled OR indicated that participants were 52% more likely to use stairs after exposure to promotional signs (adjusted OR 1.52, 95% CI 1.37 to 1.70). Incremental (sequential) meta-analyses using z-score methods identified that sufficient evidence for stair use interventions has existed since 2006, with recent studies providing no further evidence on the effect sizes of such interventions. Conclusions This analysis has important policy and practice implications. Researchers continue to publish stair use interventions without connection to policymakers' needs, and few stair use interventions are implemented at a population level. Researchers should move away from repeating short-term, small-scale, stair sign interventions, to investigating their scalability, adoption and fidelity. Only such research translation efforts will provide sufficient evidence of external validity to inform their scaling up to influence population physical activity. PMID:29183924

On the structure-bounded growth processes in plant populations.

PubMed

Kilian, H G; Kazda, M; Király, F; Kaufmann, D; Kemkemer, R; Bartkowiak, D

2010-07-01

If growing cells in plants are considered to be composed of increments (ICs) an extended version of the law of mass action can be formulated. It evidences that growth of plants runs optimal if the reaction-entropy term (entropy times the absolute temperature) matches the contact energy of ICs. Since these energies are small, thermal molecular movements facilitate via relaxation the removal of structure disturbances. Stem diameter distributions exhibit extra fluctuations likely to be caused by permanent constraints. Since the signal-response system enables in principle perfect optimization only within finite-sized cell ensembles, plants comprising relatively large cell numbers form a network of size-limited subsystems. The maximal number of these constituents depends both on genetic and environmental factors. Accounting for logistical structure-dynamics interrelations, equations can be formulated to describe the bimodal growth curves of very different plants. The reproduction of the S-bended growth curves verifies that the relaxation modes with a broad structure-controlled distribution freeze successively until finally growth is fully blocked thus bringing about "continuous solidification".

More reliable estimates of divergence times in Pan using complete mtDNA sequences and accounting for population structure.

PubMed

Stone, Anne C; Battistuzzi, Fabia U; Kubatko, Laura S; Perry, George H; Trudeau, Evan; Lin, Hsiuman; Kumar, Sudhir

2010-10-27

Here, we report the sequencing and analysis of eight complete mitochondrial genomes of chimpanzees (Pan troglodytes) from each of the three established subspecies (P. t. troglodytes, P. t. schweinfurthii and P. t. verus) and the proposed fourth subspecies (P. t. ellioti). Our population genetic analyses are consistent with neutral patterns of evolution that have been shaped by demography. The high levels of mtDNA diversity in western chimpanzees are unlike those seen at nuclear loci, which may reflect a demographic history of greater female to male effective population sizes possibly owing to the characteristics of the founding population. By using relaxed-clock methods, we have inferred a timetree of chimpanzee species and subspecies. The absolute divergence times vary based on the methods and calibration used, but relative divergence times show extensive uniformity. Overall, mtDNA produces consistently older times than those known from nuclear markers, a discrepancy that is reduced significantly by explicitly accounting for chimpanzee population structures in time estimation. Assuming the human-chimpanzee split to be between 7 and 5 Ma, chimpanzee time estimates are 2.1-1.5, 1.1-0.76 and 0.25-0.18 Ma for the chimpanzee/bonobo, western/(eastern + central) and eastern/central chimpanzee divergences, respectively.

Density of mushroom body synaptic complexes limits intraspecies brain miniaturization in highly polymorphic leaf-cutting ant workers

PubMed Central

Groh, Claudia; Kelber, Christina; Grübel, Kornelia; Rössler, Wolfgang

2014-01-01

Hymenoptera possess voluminous mushroom bodies (MBs), brain centres associated with sensory integration, learning and memory. The mushroom body input region (calyx) is organized in distinct synaptic complexes (microglomeruli, MG) that can be quantified to analyse body size-related phenotypic plasticity of synaptic microcircuits in these small brains. Leaf-cutting ant workers (Atta vollenweideri) exhibit an enormous size polymorphism, which makes them outstanding to investigate neuronal adaptations underlying division of labour and brain miniaturization. We particularly asked how size-related division of labour in polymorphic workers is reflected in volume and total numbers of MG in olfactory calyx subregions. Whole brains of mini, media and large workers were immunolabelled with anti-synapsin antibodies, and mushroom body volumes as well as densities and absolute numbers of MG were determined by confocal imaging and three-dimensional analyses. The total brain volume and absolute volumes of olfactory mushroom body subdivisions were positively correlated with head widths, but mini workers had significantly larger MB to total brain ratios. Interestingly, the density of olfactory MG was remarkably independent from worker size. Consequently, absolute numbers of olfactory MG still were approximately three times higher in large compared with mini workers. The results show that the maximum packing density of synaptic microcircuits may represent a species-specific limit to brain miniaturization. PMID:24807257

Reconstructing the ups and downs of primate brain evolution: implications for adaptive hypotheses and Homo floresiensis

PubMed Central

2010-01-01

Background Brain size is a key adaptive trait. It is often assumed that increasing brain size was a general evolutionary trend in primates, yet recent fossil discoveries have documented brain size decreases in some lineages, raising the question of how general a trend there was for brains to increase in mass over evolutionary time. We present the first systematic phylogenetic analysis designed to answer this question. Results We performed ancestral state reconstructions of three traits (absolute brain mass, absolute body mass, relative brain mass) using 37 extant and 23 extinct primate species and three approaches to ancestral state reconstruction: parsimony, maximum likelihood and Bayesian Markov-chain Monte Carlo. Both absolute and relative brain mass generally increased over evolutionary time, but body mass did not. Nevertheless both absolute and relative brain mass decreased along several branches. Applying these results to the contentious case of Homo floresiensis, we find a number of scenarios under which the proposed evolution of Homo floresiensis' small brain appears to be consistent with patterns observed along other lineages, dependent on body mass and phylogenetic position. Conclusions Our results confirm that brain expansion began early in primate evolution and show that increases occurred in all major clades. Only in terms of an increase in absolute mass does the human lineage appear particularly striking, with both the rate of proportional change in mass and relative brain size having episodes of greater expansion elsewhere on the primate phylogeny. However, decreases in brain mass also occurred along branches in all major clades, and we conclude that, while selection has acted to enlarge primate brains, in some lineages this trend has been reversed. Further analyses of the phylogenetic position of Homo floresiensis and better body mass estimates are required to confirm the plausibility of the evolution of its small brain mass. We find that for our dataset the Bayesian analysis for ancestral state reconstruction is least affected by inclusion of fossil data suggesting that this approach might be preferable for future studies on other taxa with a poor fossil record. PMID:20105283

Spatiotemporal Fluctuations and Triggers of Ebola Virus Spillover

PubMed Central

Park, Andrew W.; Kramer, Andrew M.; Han, Barbara A.; Alexander, Laura W.; Drake, John M.

2017-01-01

Because the natural reservoir of Ebola virus remains unclear and disease outbreaks in humans have occurred only sporadically over a large region, forecasting when and where Ebola spillovers are most likely to occur constitutes a continuing and urgent public health challenge. We developed a statistical modeling approach that associates 37 human or great ape Ebola spillovers since 1982 with spatiotemporally dynamic covariates including vegetative cover, human population size, and absolute and relative rainfall over 3 decades across sub-Saharan Africa. Our model (area under the curve 0.80 on test data) shows that spillover intensity is highest during transitions between wet and dry seasons; overall, high seasonal intensity occurs over much of tropical Africa; and spillover intensity is greatest at high (>1,000/km2) and very low (<100/km2) human population densities compared with intermediate levels. These results suggest strong seasonality in Ebola spillover from wild reservoirs and indicate particular times and regions for targeted surveillance. PMID:28221131

Blood pressure and the global burden of cardiovascular disease.

PubMed

Rodgers, A; MacMahon, S

1999-01-01

Cardiovascular disease is responsible for a large and increasing proportion of death and disability worldwide. Half of this burden occurs in Asia. This study assessed the possible effects of population-wide (2% lower DBP for all) and targeted (7% lower DBP for those with usual DBP > or = 95 mmHg) BP interventions in Asia, using data from surveys of blood pressure levels, the Global Burden of Disease Project, Eastern Asian cohort studies and randomised trials of blood pressure lowering. Overall each of the two interventions would be expected to avert about one million deaths per year throughout Asia in 2020. These benefits would be approximately additive. About half a million deaths might be averted annually by each intervention in China alone, with about four-fifths of this benefit due to averted stroke. The relative benefits of these two strategies are similar to estimates made for US and UK populations. However, the absolute benefits are many times greater due to the size of the predicted CVD burden in Asia.

Hypoglossal canal size and hominid speech

PubMed Central

DeGusta, David; Gilbert, W. Henry; Turner, Scott P.

1999-01-01

The mammalian hypoglossal canal transmits the nerve that supplies the motor innervation to the tongue. Hypoglossal canal size has previously been used to date the origin of human-like speech capabilities to at least 400,000 years ago and to assign modern human vocal abilities to Neandertals. These conclusions are based on the hypothesis that the size of the hypoglossal canal is indicative of speech capabilities. This hypothesis is falsified here by the finding of numerous nonhuman primate taxa that have hypoglossal canals in the modern human size range, both absolutely and relative to oral cavity volume. Specimens of Australopithecus afarensis, Australopithecus africanus, and Australopithecus boisei also have hypoglossal canals that, both absolutely and relative to oral cavity volume, are equal in size to those of modern humans. The basis for the hypothesis that hypoglossal canal size is indicative of speech was the assumption that hypoglossal canal size is correlated with hypoglossal nerve size, which in turn is related to tongue function. This assumption is probably incorrect, as we found no apparent correlation between the size of the hypoglossal nerve, or the number of axons it contains, and the size of the hypoglossal canal in a sample of cadavers. Our data demonstrate that the size of the hypoglossal canal does not reflect vocal capabilities or language usage. Thus the date of origin for human language and the speech capabilities of Neandertals remain open questions. PMID:9990105

Income inequality and periodontal diseases in rich countries: an ecological cross-sectional study.

PubMed

Sabbah, Wael; Sheiham, Aubrey; Bernabé, Eduardo

2010-10-01

There are adverse effects of income inequality on morbidity and mortality. This relationship has not been adequately examined in relation to oral health. To examine the relationship between income inequality and periodontal disease in rich countries. Adults aged 35-44 years in 17 rich countries with populations of more than 2 million. National level data on periodontal disease, income inequality and absolute national income were collected from 17 rich countries with populations of more than 2m. Pearson and partial correlations were used to examine the relationship between income inequality and percentage of 35-44-year-old adults with periodontal pockets > or = 4 mm and > or = 6 mm deep, adjusting for absolute national income. Higher levels of income inequality were significantly associated with higher levels of periodontal disease, independently of absolute national income. Absolute income was not associated with levels of periodontal disease in these 17 rich countries. Income inequality appears to be an important contextual determinant of periodontal disease. The results emphasise the importance of relative income rather than absoluteincome in relation to periodontal disease in rich countries.

Development of an adaptive harvest management program for Taiga bean geese

USGS Publications Warehouse

Johnson, Fred A.; Alhainen, Mikko; Fox, Anthony D.; Madsen, Jesper

2016-01-01

This report describes recent progress in specifying the elements of an adaptive harvest program for taiga bean goose. It describes harvest levels appropriate for first rebuilding the population of the Central Management Unit and then maintaining it near the goal specified in the AEWA International Single Species Action Plan (ISSAP). This report also provides estimates of the length of time it would take under ideal conditions (no density dependence and no harvest) to rebuild depleted populations in the Western and Eastern Management Units. We emphasize that our estimates are a first approximation because detailed demographic information is lacking for taiga bean geese. Using allometric relationships, we estimated parameters of a thetalogistic matrix population model. The mean intrinsic rate of growth was estimated as r = 0.150 (90% credible interval: 0.120 – 0.182). We estimated the mean form of density dependence as   2.361 (90% credible interval: 0.473 – 11.778), suggesting the strongest density dependence occurs when the population is near its carrying capacity. Based on expert opinion, carrying capacity (i.e., population size expected in the absence of hunting) for the Central Management Unit was estimated as K  87,900 (90% credible interval: 82,000 – 94,100). The ISSAP specifies a population goal for the Central Management Unit of 60,000 – 80,000 individuals in winter; thus, we specified a preliminary objective function as one which would minimize the difference between this goal and population size. Using the concept of stochastic dominance to explicitly account for uncertainty in demography, we determined that optimal harvest rates for 5, 10, 15, and 20-year time horizons were h = 0.00, 0.02, 0.05, and 0.06, respectively. These optima represent a tradeoff between the harvest rate and the time required to achieve and maintain a population size within desired bounds. We recognize, however, that regulation of absolute harvest rather than harvest rate is more practical, but our matrix model does not permit one to calculate an exact harvest associated with a specific harvest rate. Approximate harvests for current population size in the Central Management Unit are 0, 1,200, 2,300, and 3,500 for the 5, 10, 15, and 20-year time horizons, respectively. Populations of taiga bean geese in the Western and Eastern Units would require at least 10 and 13 years, respectively, to reach their minimum goals under the most optimistic of scenarios. The presence of harvest, density dependence, or environmental variation could extend these time frames considerably. Finally, we stress that development and implementation of internationally coordinated monitoring programs will be essential to further development and implementation of an adaptive harvest management program.

Optical and Nanoparticle Analysis of Normal and Cancer Cells by Light Transmission Spectroscopy

NASA Astrophysics Data System (ADS)

Deatsch, Alison; Sun, Nan; Johnson, Jeffery; Stack, Sharon; Szajko, John; Sander, Christopher; Rebuyon, Roland; Easton, Judah; Tanner, Carol; Ruggiero, Steven

2015-03-01

We have investigated the optical properties of human oral and ovarian cancer and normal cells. Specifically, we have measured the absolute optical extinction for intra-cellular material (lysates) in aqueous suspension. Measurements were conducted over a wavelength range of 250 to 1000 nm with 1 nm resolution using Light Transmission Spectroscopy (LTS). This provides both the absolute extinction of materials under study and, with Mie inversion, the absolute number of particles of a given diameter as a function of diameter in the range of 1 to 3000 nm. Our preliminary studies show significant differences in both the extinction and particle size distributions associated with cancer versus normal cells, which appear to be correlated with differences in the particle size distribution in the range of approximately 50 to 250 nm. Especially significant is a clearly higher density of particles at about 100 nm and smaller for normal cells. Department of Physics, Harper Cancer Research Institute, and the Office of Research at the University of Notre Dame.

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Science.gov Websites

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Gravitational acceleration as a cue for absolute size and distance?

NASA Technical Reports Server (NTRS)

Hecht, H.; Kaiser, M. K.; Banks, M. S.

1996-01-01

When an object's motion is influenced by gravity, as in the rise and fall of a thrown ball, the vertical component of acceleration is roughly constant at 9.8 m/sec2. In principle, an observer could use this information to estimate the absolute size and distance of the object (Saxberg, 1987a; Watson, Banks, von Hofsten, & Royden, 1992). In five experiments, we examined people's ability to utilize the size and distance information provided by gravitational acceleration. Observers viewed computer simulations of an object rising and falling on a trajectory aligned with the gravitational vector. The simulated objects were balls of different diameters presented across a wide range of simulated distances. Observers were asked to identify the ball that was presented and to estimate its distance. The results showed that observers were much more sensitive to average velocity than to the gravitational acceleration pattern. Likewise, verticality of the motion and visibility of the trajectory's apex had negligible effects on the accuracy of size and distance judgments.

Study on improving the turbidity measurement of the absolute coagulation rate constant.

PubMed

Sun, Zhiwei; Liu, Jie; Xu, Shenghua

2006-05-23

The existing theories dealing with the evaluation of the absolute coagulation rate constant by turbidity measurement were experimentally tested for different particle-sized (radius = a) suspensions at incident wavelengths (lambda) ranging from near-infrared to ultraviolet light. When the size parameter alpha = 2pi a/lambda > 3, the rate constant data from previous theories for fixed-sized particles show significant inconsistencies at different light wavelengths. We attribute this problem to the imperfection of these theories in describing the light scattering from doublets through their evaluation of the extinction cross section. The evaluations of the rate constants by all previous theories become untenable as the size parameter increases and therefore hampers the applicable range of the turbidity measurement. By using the T-matrix method, we present a robust solution for evaluating the extinction cross section of doublets formed in the aggregation. Our experiments show that this new approach is effective in extending the applicability range of the turbidity methodology and increasing measurement accuracy.

Ranking metrics in gene set enrichment analysis: do they matter?

PubMed

Zyla, Joanna; Marczyk, Michal; Weiner, January; Polanska, Joanna

2017-05-12

There exist many methods for describing the complex relation between changes of gene expression in molecular pathways or gene ontologies under different experimental conditions. Among them, Gene Set Enrichment Analysis seems to be one of the most commonly used (over 10,000 citations). An important parameter, which could affect the final result, is the choice of a metric for the ranking of genes. Applying a default ranking metric may lead to poor results. In this work 28 benchmark data sets were used to evaluate the sensitivity and false positive rate of gene set analysis for 16 different ranking metrics including new proposals. Furthermore, the robustness of the chosen methods to sample size was tested. Using k-means clustering algorithm a group of four metrics with the highest performance in terms of overall sensitivity, overall false positive rate and computational load was established i.e. absolute value of Moderated Welch Test statistic, Minimum Significant Difference, absolute value of Signal-To-Noise ratio and Baumgartner-Weiss-Schindler test statistic. In case of false positive rate estimation, all selected ranking metrics were robust with respect to sample size. In case of sensitivity, the absolute value of Moderated Welch Test statistic and absolute value of Signal-To-Noise ratio gave stable results, while Baumgartner-Weiss-Schindler and Minimum Significant Difference showed better results for larger sample size. Finally, the Gene Set Enrichment Analysis method with all tested ranking metrics was parallelised and implemented in MATLAB, and is available at https://github.com/ZAEDPolSl/MrGSEA . Choosing a ranking metric in Gene Set Enrichment Analysis has critical impact on results of pathway enrichment analysis. The absolute value of Moderated Welch Test has the best overall sensitivity and Minimum Significant Difference has the best overall specificity of gene set analysis. When the number of non-normally distributed genes is high, using Baumgartner-Weiss-Schindler test statistic gives better outcomes. Also, it finds more enriched pathways than other tested metrics, which may induce new biological discoveries.

Invasibility of a nutrient-poor pasture through resident and non-resident herbs is controlled by litter, gap size and propagule pressure.

PubMed

Eckstein, R Lutz; Ruch, Diana; Otte, Annette; Donath, Tobias W

2012-01-01

Since inference concerning the relative effects of propagule pressure, biotic interactions, site conditions and species traits on the invasibility of plant communities is limited, we carried out a field experiment to study the role of these factors for absolute and relative seedling emergence in three resident and three non-resident confamilial herb species on a nutrient-poor temperate pasture. We set up a factorial field experiment with two levels each of the factors litter cover (0 and 400 g m(-2)), gap size (0.01 and 0.1 m(2)) and propagule pressure (5 and 50 seeds) and documented soil temperature, soil water content and relative light availability. Recruitment was recorded in spring and autumn 2010 and in spring 2011 to cover initial seedling emergence, establishment after summer drought and final establishment after the first winter. Litter alleviated temperature and moisture conditions and had positive effects on proportional and absolute seedling emergence during all phases of recruitment. Large gaps presented competition-free space with high light availability but showed higher temperature amplitudes and lower soil moisture. Proportional and absolute seedling recruitment was significantly higher in large than in small gaps. In contrast, propagule pressure facilitated absolute seedling emergence but had no effects on proportional emergence or the chance for successful colonisation. Despite significantly higher initial seedling emergence of resident than non-resident species, seed mass and other species-specific traits may be better predictors for idiosyncratic variation in seedling establishment than status. Our data support the fluctuating resource hypothesis and demonstrate that the reserve effect of seeds may facilitate seedling emergence. The direct comparison of propagule pressure with other environmental factors showed that propagule pressure affects absolute seedling abundance, which may be crucial for species that depend on other individuals for sexual reproduction. However, propagule batch size did not significantly affect the chance for successful colonisation of disturbed plots.

Properties and evolution of near-Earth-object families created by tidal disruption at the Earth

NASA Astrophysics Data System (ADS)

Schunova, E.; Walsh, K.; Granvik, M.; Jedicke, R.; Wainscoat, R.; Haghighipour, N.

2014-07-01

We have calculated the coherence and detectable lifetimes of synthetic near-Earth object (NEO) families created by catastrophic disruption of a progenitor as it suffers a very close Earth approach. The closest or slowest approaches yield the most violent 'S-class' disruption events and create a 'string of pearls' configuration of the resulting fragments after their reaccummulation into gravitationally bound components [3]. We found that the average absolute magnitude (H) difference between the parent body and the largest fragment is Δ H ˜ 1.0. The average slope of the absolute magnitude (H) distribution, N(H)∝10^{(0.55±0.04) H}, for the fragments in the S-class families is steeper than the slope of the NEO population [2] in the same size range. The families remain coherent as statistically significant clusters of orbits within the NEO population for an average of barτ_c = (14.7±0.6)×10^3 years after disruption. The detectable lifetimes of tidally disrupted families are extremely short compared to the multi-Myr and -Gyr lifetimes of main belt families due to the chaotic dynamical environment in NEO space -- they are detectable with the techniques developed by [1] and [4] for an average duration (barτ_{det}) ranging from about 2,000 to about 12,000 years for progenitors in the absolute magnitude (H_p) range from 20 to 13 corresponding to diameters in the range from about 0.5 to 10 km respectively. The maximum absolute magnitude of a progenitor capable of producing an observable NEO family (i.e. detectable by our family finding technique) is H_{p,max} = 20 (about 350 m diameter). The short detectability lifetime explains why zero NEO families have been discovered to-date. Nonetheless, every tidal disruption event of a progenitor with diameter greater than 0.5 km is capable of producing several million fragments in the 1 m to 10 m diameter range that can contribute to temporary local density enhancements of small NEOs in Earth's vicinity. These objects may be suitable targets for asteroid retrieval missions due to their Earth-like orbits with corresponding low v_∞ which permits low-cost missions. The fragments from the tidal disruptions evolve into orbits that bring them into collision with terrestrial planets or the Sun or they may be ejected from the solar system on hyperbolic orbits due to deep planetary encounters. The end-state for the fragments from a tidal disruption at Earth have ˜5× the collision probability with Earth compared to the background NEO population.

Using specific volume increment (SVI) for quantifying growth responses in trees - theoretical and practical considerations

Treesearch

Eddie Bevilacqua

2002-01-01

Comparative analysis of growth responses among trees following natural or anthropogenic disturbances is often confounded when comparing trees of different size because of the high correlation between growth and initial tree size: large trees tend to have higher absolute grow rates. Relative growth rate (RGR) may not be the most suitable size-dependent measure of growth...

Identification of racial disparities in breast cancer mortality: does scale matter?

PubMed

Tian, Nancy; Goovaerts, Pierre; Zhan, F Benjamin; Wilson, Jeff G

2010-07-05

This paper investigates the impact of geographic scale (census tract, zip code, and county) on the detection of disparities in breast cancer mortality among three ethnic groups in Texas (period 1995-2005). Racial disparities were quantified using both relative (RR) and absolute (RD) statistics that account for the population size and correct for unreliable rates typically observed for minority groups and smaller geographic units. Results were then correlated with socio-economic status measured by the percentage of habitants living below the poverty level. African-American and Hispanic women generally experience higher mortality than White non-Hispanics, and these differences are especially significant in the southeast metropolitan areas and southwest border of Texas. The proportion and location of significant racial disparities however changed depending on the type of statistic (RR versus RD) and the geographic level. The largest proportion of significant results was observed for the RD statistic and census tract data. Geographic regions with significant racial disparities for African-Americans and Hispanics frequently had a poverty rate above 10.00%. This study investigates both relative and absolute racial disparities in breast cancer mortality between White non-Hispanic and African-American/Hispanic women at the census tract, zip code and county levels. Analysis at the census tract level generally led to a larger proportion of geographical units experiencing significantly higher mortality rates for minority groups, although results varied depending on the use of the relative versus absolute statistics. Additional research is needed before general conclusions can be formulated regarding the choice of optimal geographic regions for the detection of racial disparities.

Identification of racial disparities in breast cancer mortality: does scale matter?

PubMed Central

2010-01-01

Background This paper investigates the impact of geographic scale (census tract, zip code, and county) on the detection of disparities in breast cancer mortality among three ethnic groups in Texas (period 1995-2005). Racial disparities were quantified using both relative (RR) and absolute (RD) statistics that account for the population size and correct for unreliable rates typically observed for minority groups and smaller geographic units. Results were then correlated with socio-economic status measured by the percentage of habitants living below the poverty level. Results African-American and Hispanic women generally experience higher mortality than White non-Hispanics, and these differences are especially significant in the southeast metropolitan areas and southwest border of Texas. The proportion and location of significant racial disparities however changed depending on the type of statistic (RR versus RD) and the geographic level. The largest proportion of significant results was observed for the RD statistic and census tract data. Geographic regions with significant racial disparities for African-Americans and Hispanics frequently had a poverty rate above 10.00%. Conclusions This study investigates both relative and absolute racial disparities in breast cancer mortality between White non-Hispanic and African-American/Hispanic women at the census tract, zip code and county levels. Analysis at the census tract level generally led to a larger proportion of geographical units experiencing significantly higher mortality rates for minority groups, although results varied depending on the use of the relative versus absolute statistics. Additional research is needed before general conclusions can be formulated regarding the choice of optimal geographic regions for the detection of racial disparities. PMID:20602784

Combining real-time PCR and next-generation DNA sequencing to provide quantitative comparisons of fungal aerosol populations

NASA Astrophysics Data System (ADS)

Dannemiller, Karen C.; Lang-Yona, Naama; Yamamoto, Naomichi; Rudich, Yinon; Peccia, Jordan

2014-02-01

We examined fungal communities associated with the PM10 mass of Rehovot, Israel outdoor air samples collected in the spring and fall seasons. Fungal communities were described by 454 pyrosequencing of the internal transcribed spacer (ITS) region of the fungal ribosomal RNA encoding gene. To allow for a more quantitative comparison of fungal exposure in humans, the relative abundance values of specific taxa were transformed to absolute concentrations through multiplying these values by the sample's total fungal spore concentration (derived from universal fungal qPCR). Next, the sequencing-based absolute concentrations for Alternaria alternata, Cladosporium cladosporioides, Epicoccum nigrum, and Penicillium/Aspergillus spp. were compared to taxon-specific qPCR concentrations for A. alternata, C. cladosporioides, E. nigrum, and Penicillium/Aspergillus spp. derived from the same spring and fall aerosol samples. Results of these comparisons showed that the absolute concentration values generated from pyrosequencing were strongly associated with the concentration values derived from taxon-specific qPCR (for all four species, p < 0.005, all R > 0.70). The correlation coefficients were greater for species present in higher concentrations. Our microbial aerosol population analyses demonstrated that fungal diversity (number of fungal operational taxonomic units) was higher in the spring compared to the fall (p = 0.02), and principal coordinate analysis showed distinct seasonal differences in taxa distribution (ANOSIM p = 0.004). Among genera containing allergenic and/or pathogenic species, the absolute concentrations of Alternaria, Aspergillus, Fusarium, and Cladosporium were greater in the fall, while Cryptococcus, Penicillium, and Ulocladium concentrations were greater in the spring. The transformation of pyrosequencing fungal population relative abundance data to absolute concentrations can improve next-generation DNA sequencing-based quantitative aerosol exposure assessment.

The gender- and age-specific 10-year and lifetime absolute fracture risk in Tromsø, Norway.

PubMed

Ahmed, Luai A; Schirmer, Henrik; Bjørnerem, Ashild; Emaus, Nina; Jørgensen, Lone; Størmer, Jan; Joakimsen, Ragnar M

2009-01-01

Aim of this study is to estimate the gender- and age-specific 10-year and lifetime absolute risks of non-vertebral and osteoporotic (included hip, distal forearm and proximal humerus) fractures in a large cohort of men and women. This is a population-based 10 years follow-up study of 26,891 subjects aged 25 years and older in Tromsø, Norway. All non-vertebral fractures were registered from 1995 throughout 2004 by computerized search in radiographic archives. Absolute risks were estimated by life-table method taking into account the competing risk of death. The absolute fracture risk at each year of age was estimated for the next 10 years (10-year risk) or up to the age of 90 years (lifetime risk). The estimated 10-year absolute risk of all non-vertebral fracture was higher in men than women before but not after the age of 45 years. The 10-year absolute risk for non-vertebral and osteoporotic fractures was over 10%, respectively, in men over 65 and 70 years and in women over 45 and 50 years of age. The 10-year absolute risks of hip fractures at the age of 65 and 80 years were 4.2 and 18.6% in men, and 9.0 and 24.0% in women, respectively. The risk estimates for distal forearm and proximal humerus fractures were under 5% in men and 13% in women. The estimated lifetime risks for all fracture locations were higher in women than men at all ages. At the age of 50 years, the risks were 38.1 and 24.8% in men and 67.4 and 55.0% in women for all non-vertebral and osteoporotic fractures, respectively. The estimated gender- and age-specific 10-year and lifetime absolute fracture risk were higher in Tromsø than in other populations. The high lifetime fracture risk reflects the increased burden of fractures in this cohort.

Auditory working memory predicts individual differences in absolute pitch learning.

PubMed

Van Hedger, Stephen C; Heald, Shannon L M; Koch, Rachelle; Nusbaum, Howard C

2015-07-01

Absolute pitch (AP) is typically defined as the ability to label an isolated tone as a musical note in the absence of a reference tone. At first glance the acquisition of AP note categories seems like a perceptual learning task, since individuals must assign a category label to a stimulus based on a single perceptual dimension (pitch) while ignoring other perceptual dimensions (e.g., loudness, octave, instrument). AP, however, is rarely discussed in terms of domain-general perceptual learning mechanisms. This is because AP is typically assumed to depend on a critical period of development, in which early exposure to pitches and musical labels is thought to be necessary for the development of AP precluding the possibility of adult acquisition of AP. Despite this view of AP, several previous studies have found evidence that absolute pitch category learning is, to an extent, trainable in a post-critical period adult population, even if the performance typically achieved by this population is below the performance of a "true" AP possessor. The current studies attempt to understand the individual differences in learning to categorize notes using absolute pitch cues by testing a specific prediction regarding cognitive capacity related to categorization - to what extent does an individual's general auditory working memory capacity (WMC) predict the success of absolute pitch category acquisition. Since WMC has been shown to predict performance on a wide variety of other perceptual and category learning tasks, we predict that individuals with higher WMC should be better at learning absolute pitch note categories than individuals with lower WMC. Across two studies, we demonstrate that auditory WMC predicts the efficacy of learning absolute pitch note categories. These results suggest that a higher general auditory WMC might underlie the formation of absolute pitch categories for post-critical period adults. Implications for understanding the mechanisms that underlie the phenomenon of AP are also discussed. Copyright © 2015. Published by Elsevier B.V.

Michigan Orbital DEbris Survey Telescope Observations of the Geosynchronous Orbital Debris Environment. Observing Years: 2007-2009

NASA Technical Reports Server (NTRS)

Abercromby, K. J.; Seitzer, P.; Cowardin, H. M.; Barker, E. S.; Matney, M. J.

2011-01-01

NASA uses the Michigan Orbital DEbris Survey Telescope (MODEST), the University of Michigan's 0.61-m aperture Curtis-Schmidt telescope at the Cerro Tololo Inter-American Observatory in Chile, to help characterize the debris environment in geosynchronous orbit; this began in February 2001 and continues to the present day. Detected objects that are found to be on the U.S. Space Surveillance Network cataloged objects list are termed correlated targets (CTs), while those not found on the list are called uncorrelated targets (UCTs). This Johnson Space Center report provides details of observational and data-reduction processes for the entire MODEST dataset acquired in calendar years (CYs) 2007, 2008, and 2009. Specifically, this report describes the collection and analysis of 36 nights of data collected in CY 2007, 43 nights of data collected in CY 2008, and 43 nights of data collected in CY 2009. MODEST is equipped with a 2048 x 2048-pixel charged coupled device camera with a 1.3 by 1.3 deg field of view. This system is capable of detecting objects fainter than 18th magnitude (R filter) using a 5-s integration. This corresponds to a 20-cm diameter, 0.175-albedo object at 36,000 km altitude assuming a diffuse Lambertian phase function. The average number of detections each night over all 3 years was 26. The percentage of this number that represented the UCT population ranged from 34% to 18%, depending on the observing strategy and the field center location. Due to the short orbital arc over which observations are made, the eccentricity of the object s orbit is extremely difficult to measure accurately. Therefore, a circular orbit was assumed when calculating the orbital elements. A comparison of the measured inclination (INC), right ascension of ascending node (RAAN), and mean motion to the quantities for CTs from the U.S. Space Surveillance Network shows acceptable errors. This analysis lends credibility to the determination of the UCT orbital distributions. Figure 1 shows the size distribution of 3,143 objects detected in the data processed for CYs 2007, 2008, and 2009. The actual peak of the absolute magnitude distribution for the functional correlated targets is 10th magnitude, whereas the peak was 11th magnitude in 2002 2003 and 10th magnitude for 2004-2006. An absolute magnitude of 10.5 corresponds to objects with average diameters of 6.3 m, assuming an albedo of 0.175 and a diffuse Lambertian phase function. This result generally agrees with the known sizes of intact satellites. The absolute magnitude distribution for the UCTs is broad, but starts to roll off near 25 cm diameter or 17.5 magnitude. This roll off in the distribution reflects the detection capability of MODEST, not the true nature of the population. The true population is believed to continue at the same slope through fainter magnitudes based on comparisons with the LEO break-up law.

Absolute colors and phase coefficients of Trans-Neptunian objects: HV - HR colors.

NASA Astrophysics Data System (ADS)

Ayala-Loera, Carmen; Alvarez-Candal, Alvaro; Ortiz, Jose Luis; Duffard, Rene; Fernández-Valenzuela, Estela; Santos-Sanz, Pablo; Morales, Nicolas

2017-10-01

We present results of our photometric follow up of Trans-Neptunian objects (TNOs). New data for 35 objects, together with previously data presented in Alvarez-Candal et al. 2016, as well as data from literature allow us to obtain absolute magnitudes and absolute coefficients HV (βV) for 113 TNOs and HR (βR) for 117 TNOs from which we obtained absolute colors HV - HR, and relative phase coefficients Δβ, for 106 objects.We explored associations between HV - HR and Δβ vs. orbital and physical parameters of TNOs, such associations were tested by Spearman’s coefficient rs . The correlations we found between HV - HR and orbital parameters semimayor axis a, eccentricity e, and inclination i, reflect observational biases: first, against farther fainter objects; second, against eccentric and high-inclination orbits.We followed Brown criteria (Brown 2012), and separated into two groups: large and small using HV = 4.5 instead of D=500 km. We detected a gap at HV = 4.5 which not reported before to the best of our knowledge.We found a strong anticorrelation between HV - HR and Δβ, with rs = -0.8273, which indicates that redder objects have steeper phase curves in the R filter than in the V filter, while the opposite is true for bluer objects. The anticorrelation holds if we consider different bins in semi-major axis and separate between large HV < 4.5 mag (D > 500 km) and small objects HV > 4.5 mag (D < 500 km). Therefore, we conclude it is intrinsic to the TNO (and associated) populations. As many different surfaces types, sizes, and dynamical evolutions of TNOs we considered in our sample, we cannot assure that we are seeing an evolutionary effect, but probably something related to the porosity and compation of the surfaces. Further studies are granted.

Physiological condition of bank voles (Myodes glareolus) during the increase and decline phases of the population cycle.

PubMed

Nieminen, Petteri; Huitu, Otso; Henttonen, Heikki; Finnilä, Mikko A J; Voutilainen, Liina; Itämies, Juhani; Kärjä, Vesa; Saarela, Seppo; Halonen, Toivo; Aho, Jari; Mustonen, Anne-Mari

2015-09-01

The dynamics of animal populations are greatly influenced by interactions with their natural enemies and food resources. However, quantifying the relative effects of these factors on demographic rates remains a perpetual challenge for animal population ecology. Food scarcity is assumed to limit the growth and to initiate the decline of cyclic herbivore populations, but this has not been verified with physiological health indices. We hypothesized that individuals in declining populations would exhibit signs of malnutrition-induced deterioration of physiological condition. We evaluated the association of body condition with population cycle phase in bank voles (Myodes glareolus) during the increase and decline phases of a population cycle. The bank voles had lower body masses, condition indices and absolute masses of particular organs during the decline. Simultaneously, they had lower femoral masses, mineral contents and densities. Hemoglobin and hematocrit values and several parameters known to respond to food deprivation were unaffected by the population phase. There were no signs of lymphopenia, eosinophilia, granulocytosis or monocytosis. Erythrocyte counts were higher and plasma total protein levels and tissue proportions of essential polyunsaturated fatty acids lower in the population decline. Ectoparasite load was lower and adrenal gland masses or catecholamine concentrations did not suggest higher stress levels. Food availability seems to limit the size of voles during the decline but they can adapt to the prevailing conditions without clear deleterious health effects. This highlights the importance of quantifying individual health state when evaluating the effects of complex trophic interactions on the dynamics of wild animal populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Estimating the absolute wealth of households.

PubMed

Hruschka, Daniel J; Gerkey, Drew; Hadley, Craig

2015-07-01

To estimate the absolute wealth of households using data from demographic and health surveys. We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. The median absolute wealth estimates of 1,403,186 households were 2056 international dollars per capita (interquartile range: 723-6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R(2)  = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality.

Estimating the absolute wealth of households

PubMed Central

Gerkey, Drew; Hadley, Craig

2015-01-01

Abstract Objective To estimate the absolute wealth of households using data from demographic and health surveys. Methods We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. Findings The median absolute wealth estimates of 1 403 186 households were 2056 international dollars per capita (interquartile range: 723–6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R2 = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Conclusion Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality. PMID:26170506

Is there sufficient evidence regarding signage-based stair use interventions? A sequential meta-analysis.

PubMed

Bauman, Adrian; Milton, Karen; Kariuki, Maina; Fedel, Karla; Lewicka, Mary

2017-11-28

The proliferation of studies using motivational signs to promote stair use continues unabated, with their oft-cited potential for increasing population-level physical activity participation. This study examined all stair use promotional signage studies since 1980, calculating pre-estimates and post-estimates of stair use. The aim of this project was to conduct a sequential meta-analysis to pool intervention effects, in order to determine when the evidence base was sufficient for population-wide dissemination. Using comparable data from 50 stair-promoting studies (57 unique estimates) we pooled data to assess the effect sizes of such interventions. At baseline, median stair usage across interventions was 8.1%, with an absolute median increase of 2.2% in stair use following signage-based interventions. The overall pooled OR indicated that participants were 52% more likely to use stairs after exposure to promotional signs (adjusted OR 1.52, 95% CI 1.37 to 1.70). Incremental (sequential) meta-analyses using z-score methods identified that sufficient evidence for stair use interventions has existed since 2006, with recent studies providing no further evidence on the effect sizes of such interventions. This analysis has important policy and practice implications. Researchers continue to publish stair use interventions without connection to policymakers' needs, and few stair use interventions are implemented at a population level. Researchers should move away from repeating short-term, small-scale, stair sign interventions, to investigating their scalability, adoption and fidelity. Only such research translation efforts will provide sufficient evidence of external validity to inform their scaling up to influence population physical activity. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

A hierarchical model for spatial capture-recapture data

USGS Publications Warehouse

Royle, J. Andrew; Young, K.V.

2008-01-01

Estimating density is a fundamental objective of many animal population studies. Application of methods for estimating population size from ostensibly closed populations is widespread, but ineffective for estimating absolute density because most populations are subject to short-term movements or so-called temporary emigration. This phenomenon invalidates the resulting estimates because the effective sample area is unknown. A number of methods involving the adjustment of estimates based on heuristic considerations are in widespread use. In this paper, a hierarchical model of spatially indexed capture recapture data is proposed for sampling based on area searches of spatial sample units subject to uniform sampling intensity. The hierarchical model contains explicit models for the distribution of individuals and their movements, in addition to an observation model that is conditional on the location of individuals during sampling. Bayesian analysis of the hierarchical model is achieved by the use of data augmentation, which allows for a straightforward implementation in the freely available software WinBUGS. We present results of a simulation study that was carried out to evaluate the operating characteristics of the Bayesian estimator under variable densities and movement patterns of individuals. An application of the model is presented for survey data on the flat-tailed horned lizard (Phrynosoma mcallii) in Arizona, USA.

Extensive analysis of native and non-native Centaurea solstitialis L. populations across the world shows no traces of polyploidization

PubMed Central

Montesinos, Daniel; Eren, Özkan; Lortie, Christopher J.; French, Kristine; Cavieres, Lohengrin A.; Sotes, Gastón J.; Hierro, José L.; Jorge, Andreia; Loureiro, João

2017-01-01

Centaurea solstitialis L. (yellow starthistle, Asteraceae) is a Eurasian native plant introduced as an exotic into North and South America, and Australia, where it is regarded as a noxious invasive. Changes in ploidy level have been found to be responsible for numerous plant biological invasions, as they are involved in trait shifts critical to invasive success, like increased growth rate and biomass, longer life-span, or polycarpy. C. solstitialis had been reported to be diploid (2n = 2x = 16 chromosomes), however, actual data are scarce and sometimes contradictory. We determined for the first time the absolute nuclear DNA content by flow cytometry and estimated ploidy level in 52 natural populations of C. solstitialis across its native and non-native ranges, around the world. All the C. solstitialis populations screened were found to be homogeneously diploid (average 2C value of 1.72 pg, SD = ±0.06 pg), with no significant variation in DNA content between invasive and non-invasive genotypes. We did not find any meaningful difference among the extensive number of native and non-native C. solstitialis populations sampled around the globe, indicating that the species invasive success is not due to changes in genome size or ploidy level. PMID:28828232

Extensive analysis of native and non-native Centaurea solstitialis L. populations across the world shows no traces of polyploidization.

PubMed

Irimia, Ramona-Elena; Montesinos, Daniel; Eren, Özkan; Lortie, Christopher J; French, Kristine; Cavieres, Lohengrin A; Sotes, Gastón J; Hierro, José L; Jorge, Andreia; Loureiro, João

2017-01-01

Centaurea solstitialis L. (yellow starthistle, Asteraceae) is a Eurasian native plant introduced as an exotic into North and South America, and Australia, where it is regarded as a noxious invasive. Changes in ploidy level have been found to be responsible for numerous plant biological invasions, as they are involved in trait shifts critical to invasive success, like increased growth rate and biomass, longer life-span, or polycarpy. C . solstitialis had been reported to be diploid (2 n  = 2 x  = 16 chromosomes), however, actual data are scarce and sometimes contradictory. We determined for the first time the absolute nuclear DNA content by flow cytometry and estimated ploidy level in 52 natural populations of C . solstitialis across its native and non-native ranges, around the world. All the C. solstitialis populations screened were found to be homogeneously diploid (average 2C value of 1.72 pg, SD = ±0.06 pg), with no significant variation in DNA content between invasive and non-invasive genotypes. We did not find any meaningful difference among the extensive number of native and non-native C . solstitialis populations sampled around the globe, indicating that the species invasive success is not due to changes in genome size or ploidy level.

Shoulder strength value differences between genders and age groups.

PubMed

Balcells-Diaz, Eudald; Daunis-I-Estadella, Pepus

2018-03-01

The strength of a normal shoulder differs according to gender and decreases with age. Therefore, the Constant score, which is a shoulder function measurement tool that allocates 25% of the final score to strength, differs from the absolute values but likely reflects a normal shoulder. To compare group results, a normalized Constant score is needed, and the first step to achieving normalization involves statistically establishing the gender differences and age-related decline. In this investigation, we sought to verify the gender difference and age-related decline in strength. We obtained a randomized representative sample of the general population in a small to medium-sized Spanish city. We then invited this population to participate in our study, and we measured their shoulder strength. We performed a statistical analysis with a power of 80% and a P value < .05. We observed a statistically significant difference between the genders and a statistically significant decline with age. To the best of our knowledge, this is the first investigation to study a representative sample of the general population from which conclusions can be drawn regarding Constant score normalization. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

The disappearance of Guam's wildlife: new insights for herpetology, evolutionary ecology, and conservation

USGS Publications Warehouse

Rodda, G.H.; Fritts, T.H.; Chiszar, D.

1997-01-01

The wealth of data generated from intensive study of the brown tree snake as a result of the need to control introduced populations of this pest species allow several important conclusions. First, that the snakes on Guam are extraordinary in terms of their absolute abundance and in terms of their ability to exploit a broad prey base. Our data suggest an exceptionally high reproductive success on Guam for a snake with an otherwise unnoteworthy reproductive capability and life history (i.e. small clutch size, typical ontogenetic shift from small heterothermic prey to larger homeotherms). Especially important was the snakes versatility in taking advantage of extremely common prey on islands; population expansion was slow but survival was maximal, ultimately leading to high population levels. The brown tree snake shares many attributes with other snakes that could cause similar biodiversity crises in a wide variety of contexts in which they lack coevolutionary histories (especially formerly snake-free island environments). As opposed to their relatively poor history as over-water dispersers, snakes may be especially problematic as travelers in increasing ship and air traffic between widely separated geographic regions of the world.

The fading American dream: Trends in absolute income mobility since 1940.

PubMed

Chetty, Raj; Grusky, David; Hell, Maximilian; Hendren, Nathaniel; Manduca, Robert; Narang, Jimmy

2017-04-28

We estimated rates of "absolute income mobility"-the fraction of children who earn more than their parents-by combining data from U.S. Census and Current Population Survey cross sections with panel data from de-identified tax records. We found that rates of absolute mobility have fallen from approximately 90% for children born in 1940 to 50% for children born in the 1980s. Increasing Gross Domestic Product (GDP) growth rates alone cannot restore absolute mobility to the rates experienced by children born in the 1940s. However, distributing current GDP growth more equally across income groups as in the 1940 birth cohort would reverse more than 70% of the decline in mobility. These results imply that reviving the "American dream" of high rates of absolute mobility would require economic growth that is shared more broadly across the income distribution. Copyright © 2017, American Association for the Advancement of Science.

Formation and maintenance of the territorial balance in the conditions of high-rise construction in the city

NASA Astrophysics Data System (ADS)

Kisel, Tatiana

2018-03-01

High-rise construction results in the need of planning of infrastructure facilities, taking into account the increase in loading, as high-rise construction allows to place considerably bigger number of residents in the limited territory. For this purpose it is necessary to estimate the required and actual level of providing the population with each particular type of the facilities of social infrastructure. The compliance of required and actual level of providing can be characterized as the territorial balance, while the discrepancy acts as the territorial imbalance. The article is devoted to the development of such instruments of planning of urban development, which will allow to create the qualitative urban environment, founded on the territorial balances. Namely, it is devoted to the calculation of level of providing the population with the facilities of social infrastructure, to the determination of level of the imbalance in absolute and relative units and also to the ranging of imbalances on urgency of their elimination. The size of the imbalance is of great importance for planning and realization of managerial influences from the executive authorities, operating the city development. In order to determine the urgency of realization of actions for the construction of facilities of social infrastructure it is offered to range the imbalances according to their size, having determined the deviation size from balance, which is so insignificant that it does not demand any managerial influences (it can be characterized as balance) and also the groups of the imbalances, differing in urgency of managerial influences, directed to the decrease and elimination of the revealed imbalance.

Inequality of Size and Size Increment in Pinus banksiana in Relation to Stand Dynamics and Annual Growth Rate

PubMed Central

Metsaranta, Juha M.; Lieffers, Victor J.

2008-01-01

Background and Aims Changes in size inequality in tree populations are often attributed to changes in the mode of competition over time. The mode of competition may also fluctuate annually in response to variation in growing conditions. Factors causing growth rate to vary can also influence competition processes, and thus influence how size hierarchies develop. Methods Detailed data obtained by tree-ring reconstruction were used to study annual changes in size and size increment inequality in several even-aged, fire-origin jack pine (Pinus banksiana) stands in the boreal shield and boreal plains ecozones in Saskatchewan and Manitoba, Canada, by using the Gini and Lorenz asymmetry coefficients. Key Results The inequality of size was related to variables reflecting long-term stand dynamics (e.g. stand density, mean tree size and average competition, as quantified using a distance-weighted absolute size index). The inequality of size increment was greater and more variable than the inequality of size. Inequality of size increment was significantly related to annual growth rate at the stand level, and was higher when growth rate was low. Inequality of size increment was usually due primarily to large numbers of trees with low growth rates, except during years with low growth rate when it was often due to small numbers of trees with high growth rates. The amount of competition to which individual trees were subject was not strongly related to the inequality of size increment. Conclusions Differences in growth rate among trees during years of poor growth may form the basis for development of size hierarchies on which asymmetric competition can act. A complete understanding of the dynamics of these forests requires further evaluation of the way in which factors that influence variation in annual growth rate also affect the mode of competition and the development of size hierarchies. PMID:18089583

Inequality of size and size increment in Pinus banksiana in relation to stand dynamics and annual growth rate.

PubMed

Metsaranta, Juha M; Lieffers, Victor J

2008-03-01

Changes in size inequality in tree populations are often attributed to changes in the mode of competition over time. The mode of competition may also fluctuate annually in response to variation in growing conditions. Factors causing growth rate to vary can also influence competition processes, and thus influence how size hierarchies develop. Detailed data obtained by tree-ring reconstruction were used to study annual changes in size and size increment inequality in several even-aged, fire-origin jack pine (Pinus banksiana) stands in the boreal shield and boreal plains ecozones in Saskatchewan and Manitoba, Canada, by using the Gini and Lorenz asymmetry coefficients. The inequality of size was related to variables reflecting long-term stand dynamics (e.g. stand density, mean tree size and average competition, as quantified using a distance-weighted absolute size index). The inequality of size increment was greater and more variable than the inequality of size. Inequality of size increment was significantly related to annual growth rate at the stand level, and was higher when growth rate was low. Inequality of size increment was usually due primarily to large numbers of trees with low growth rates, except during years with low growth rate when it was often due to small numbers of trees with high growth rates. The amount of competition to which individual trees were subject was not strongly related to the inequality of size increment. Differences in growth rate among trees during years of poor growth may form the basis for development of size hierarchies on which asymmetric competition can act. A complete understanding of the dynamics of these forests requires further evaluation of the way in which factors that influence variation in annual growth rate also affect the mode of competition and the development of size hierarchies.

Monitoring Butterfly Abundance: Beyond Pollard Walks

PubMed Central

Pellet, Jérôme; Bried, Jason T.; Parietti, David; Gander, Antoine; Heer, Patrick O.; Cherix, Daniel; Arlettaz, Raphaël

2012-01-01

Most butterfly monitoring protocols rely on counts along transects (Pollard walks) to generate species abundance indices and track population trends. It is still too often ignored that a population count results from two processes: the biological process (true abundance) and the statistical process (our ability to properly quantify abundance). Because individual detectability tends to vary in space (e.g., among sites) and time (e.g., among years), it remains unclear whether index counts truly reflect population sizes and trends. This study compares capture-mark-recapture (absolute abundance) and count-index (relative abundance) monitoring methods in three species (Maculinea nausithous and Iolana iolas: Lycaenidae; Minois dryas: Satyridae) in contrasted habitat types. We demonstrate that intraspecific variability in individual detectability under standard monitoring conditions is probably the rule rather than the exception, which questions the reliability of count-based indices to estimate and compare specific population abundance. Our results suggest that the accuracy of count-based methods depends heavily on the ecology and behavior of the target species, as well as on the type of habitat in which surveys take place. Monitoring programs designed to assess the abundance and trends in butterfly populations should incorporate a measure of detectability. We discuss the relative advantages and inconveniences of current monitoring methods and analytical approaches with respect to the characteristics of the species under scrutiny and resources availability. PMID:22859980

ON A POSSIBLE SIZE/COLOR RELATIONSHIP IN THE KUIPER BELT

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

Pike, R. E.; Kavelaars, J. J., E-mail: repike@uvic.ca

2013-10-01

Color measurements and albedo distributions introduce non-intuitive observational biases in size-color relationships among Kuiper Belt Objects (KBOs) that cannot be disentangled without a well characterized sample population with systematic photometry. Peixinho et al. report that the form of the KBO color distribution varies with absolute magnitude, H. However, Tegler et al. find that KBO color distributions are a property of object classification. We construct synthetic models of observed KBO colors based on two B-R color distribution scenarios: color distribution dependent on H magnitude (H-Model) and color distribution based on object classification (Class-Model). These synthetic B-R color distributions were modified tomore » account for observational flux biases. We compare our synthetic B-R distributions to the observed ''Hot'' and ''Cold'' detected objects from the Canada-France Ecliptic Plane Survey and the Meudon Multicolor Survey. For both surveys, the Hot population color distribution rejects the H-Model, but is well described by the Class-Model. The Cold objects reject the H-Model, but the Class-Model (while not statistically rejected) also does not provide a compelling match for data. Although we formally reject models where the structure of the color distribution is a strong function of H magnitude, we also do not find that a simple dependence of color distribution on orbit classification is sufficient to describe the color distribution of classical KBOs.« less

The effects of deprivation and relative deprivation on self-reported morbidity in England: an area-level ecological study

PubMed Central

2013-01-01

Background Socioeconomic status gradients in health outcomes are well recognised and may operate in part through the psychological effect of observing disparities in affluence. At an area-level, we explored whether the deprivation differential between neighbouring areas influenced self-reported morbidity over and above the known effect of the deprivation of the area itself. Methods Deprivation differentials between small areas (population size approximately 1,500) and their immediate neighbours were derived (from the Index of Multiple Deprivation (IMD)) for Lower Super Output Area (LSOA) in the whole of England (n=32482). Outcome variables were self-reported from the 2001 UK Census: the proportion of the population suffering Limiting Long-Term Illness (LLTI) and ‘not good health’. Linear regression was used to identify the effect of the deprivation differential on morbidity in different segments of the population, controlling for the absolute deprivation. The population was segmented using IMD tertiles and P2 People and Places geodemographic classification. P2 is a commercial market segmentation tool, which classifies small areas according to the characteristics of the population. The classifications range in deprivation, with the most affluent type being ‘Mature Oaks’ and the least being ‘Urban Challenge’. Results Areas that were deprived compared to their immediate neighbours suffered higher rates of ‘not good health’ (β=0.312, p<0.001) and LLTI (β=0.278, p<0.001), after controlling for the deprivation of the area itself (‘not good health’—ß=0.655, p<0.001; LLTI—ß=0.548, p<0.001). The effect of the deprivation differential relative to the effect of deprivation was strongest in least deprived segments (e.g., for ‘not good health’, P2 segments ‘Mature Oaks’—β=0.638; ‘Rooted Households’—β=0.555). Conclusions Living in an area that is surrounded by areas of greater affluence has a negative impact on health in England. A possible explanation for this phenomenon is that negative social comparisons between areas cause ill-health. This ‘psychosocial effect’ is greater still in least deprived segments of the population, supporting the notion that psychosocial effects become more important when material (absolute) deprivation is less relevant. PMID:23360584

Basics of meta-analysis: I2 is not an absolute measure of heterogeneity.

PubMed

Borenstein, Michael; Higgins, Julian P T; Hedges, Larry V; Rothstein, Hannah R

2017-03-01

When we speak about heterogeneity in a meta-analysis, our intent is usually to understand the substantive implications of the heterogeneity. If an intervention yields a mean effect size of 50 points, we want to know if the effect size in different populations varies from 40 to 60, or from 10 to 90, because this speaks to the potential utility of the intervention. While there is a common belief that the I 2 statistic provides this information, it actually does not. In this example, if we are told that I 2 is 50%, we have no way of knowing if the effects range from 40 to 60, or from 10 to 90, or across some other range. Rather, if we want to communicate the predicted range of effects, then we should simply report this range. This gives readers the information they think is being captured by I 2 and does so in a way that is concise and unambiguous. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Exploratory Factor Analysis with Small Sample Sizes

ERIC Educational Resources Information Center

de Winter, J. C. F.; Dodou, D.; Wieringa, P. A.

2009-01-01

Exploratory factor analysis (EFA) is generally regarded as a technique for large sample sizes ("N"), with N = 50 as a reasonable absolute minimum. This study offers a comprehensive overview of the conditions in which EFA can yield good quality results for "N" below 50. Simulations were carried out to estimate the minimum required "N" for different…

Absolute Humidity and the Seasonality of Influenza (Invited)

NASA Astrophysics Data System (ADS)

Shaman, J. L.; Pitzer, V.; Viboud, C.; Grenfell, B.; Goldstein, E.; Lipsitch, M.

2010-12-01

Much of the observed wintertime increase of mortality in temperate regions is attributed to seasonal influenza. A recent re-analysis of laboratory experiments indicates that absolute humidity strongly modulates the airborne survival and transmission of the influenza virus. Here we show that the onset of increased wintertime influenza-related mortality in the United States is associated with anomalously low absolute humidity levels during the prior weeks. We then use an epidemiological model, in which observed absolute humidity conditions temper influenza transmission rates, to successfully simulate the seasonal cycle of observed influenza-related mortality. The model results indicate that direct modulation of influenza transmissibility by absolute humidity alone is sufficient to produce this observed seasonality. These findings provide epidemiological support for the hypothesis that absolute humidity drives seasonal variations of influenza transmission in temperate regions. In addition, we show that variations of the basic and effective reproductive numbers for influenza, caused by seasonal changes in absolute humidity, are consistent with the general timing of pandemic influenza outbreaks observed for 2009 A/H1N1 in temperate regions. Indeed, absolute humidity conditions correctly identify the region of the United States vulnerable to a third, wintertime wave of pandemic influenza. These findings suggest that the timing of pandemic influenza outbreaks is controlled by a combination of absolute humidity conditions, levels of susceptibility and changes in population mixing and contact rates.

Validation of two-dimensional and three-dimensional measurements of subpleural alveolar size parameters by optical coherence tomography

PubMed Central

Warger, William C.; Hostens, Jeroen; Namati, Eman; Birngruber, Reginald; Bouma, Brett E.; Tearney, Guillermo J.

2012-01-01

Abstract. Optical coherence tomography (OCT) has been increasingly used for imaging pulmonary alveoli. Only a few studies, however, have quantified individual alveolar areas, and the validity of alveolar volumes represented within OCT images has not been shown. To validate quantitative measurements of alveoli from OCT images, we compared the cross-sectional area, perimeter, volume, and surface area of matched subpleural alveoli from microcomputed tomography (micro-CT) and OCT images of fixed air-filled swine samples. The relative change in size between different alveoli was extremely well correlated (r>0.9, P<0.0001), but OCT images underestimated absolute sizes compared to micro-CT by 27% (area), 7% (perimeter), 46% (volume), and 25% (surface area) on average. We hypothesized that the differences resulted from refraction at the tissue–air interfaces and developed a ray-tracing model that approximates the reconstructed alveolar size within OCT images. Using this model and OCT measurements of the refractive index for lung tissue (1.41 for fresh, 1.53 for fixed), we derived equations to obtain absolute size measurements of superellipse and circular alveoli with the use of predictive correction factors. These methods and results should enable the quantification of alveolar sizes from OCT images in vivo. PMID:23235834

Validation of two-dimensional and three-dimensional measurements of subpleural alveolar size parameters by optical coherence tomography

NASA Astrophysics Data System (ADS)

Unglert, Carolin I.; Warger, William C.; Hostens, Jeroen; Namati, Eman; Birngruber, Reginald; Bouma, Brett E.; Tearney, Guillermo J.

2012-12-01

Optical coherence tomography (OCT) has been increasingly used for imaging pulmonary alveoli. Only a few studies, however, have quantified individual alveolar areas, and the validity of alveolar volumes represented within OCT images has not been shown. To validate quantitative measurements of alveoli from OCT images, we compared the cross-sectional area, perimeter, volume, and surface area of matched subpleural alveoli from microcomputed tomography (micro-CT) and OCT images of fixed air-filled swine samples. The relative change in size between different alveoli was extremely well correlated (r>0.9, P<0.0001), but OCT images underestimated absolute sizes compared to micro-CT by 27% (area), 7% (perimeter), 46% (volume), and 25% (surface area) on average. We hypothesized that the differences resulted from refraction at the tissue-air interfaces and developed a ray-tracing model that approximates the reconstructed alveolar size within OCT images. Using this model and OCT measurements of the refractive index for lung tissue (1.41 for fresh, 1.53 for fixed), we derived equations to obtain absolute size measurements of superellipse and circular alveoli with the use of predictive correction factors. These methods and results should enable the quantification of alveolar sizes from OCT images in vivo.

Sampling methods to detect and estimate populations of Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) infesting dry-cured hams

USDA-ARS?s Scientific Manuscript database

Spatial and temporal dynamics of pest populations is an important aspect of effective pest management. However, absolute sampling of some pest populations such as the ham mite, Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae), a serious pest of dry-cured ham, can be difficult. Sampling ...

Population Growth and Poverty in the Developing World.

ERIC Educational Resources Information Center

Birdsall, Nancy

1980-01-01

The link between rapid population growth and the absolute poverty which currently afflicts 780 million people in developing countries (excluding China and other centrally planned economies) is examined. As a result of rapid population growth, many countries suffer slow per capita income growth, a lack of progress in reducing income inequality, and…

Patient characteristics and factors associated with inter-arm difference of blood pressure measurements in a general population in Ohasama, Japan.

PubMed

Kimura, Atsushi; Hashimoto, Junichiro; Watabe, Daisuke; Takahashi, Hisaki; Ohkubo, Takayoshi; Kikuya, Masahiro; Imai, Yutaka

2004-12-01

To assess whether there is a natural difference in blood pressure (BP) measurements between the right and left arms, and to identify what factors are associated with this difference in a general population. The study subjects were 1090 individuals who participated in a medical check-up in Ohasama, Japan. The BP was measured simultaneously in both arms, using an automated device. The inter-arm BP difference was expressed as the relative difference [right-arm BP (R) minus left-arm BP (L): R - L] and the absolute difference (|R - L|). The relationship between inter-arm difference and various factors was analyzed using univariate analysis. The characteristics of subjects in whom the absolute systolic BP (SBP) difference was greater than 10 mmHg were analyzed using multivariate logistic analysis. The relative differences in SBP and diastolic BP (DBP) were -0.6 +/- 6.6 (mean +/- SD) and 1.1 +/- 4.7 mmHg, while the absolute differences were 4.9 +/- 4.4 and 3.7 +/- 3.0 mmHg. The absolute SBP difference was found to correlate significantly with age, body mass index, ankle-brachial index (ABI), and hypertension. Subjects with hypertension, hypercholesterolemia, obesity, elevated hemoglobin A1c (HbA1c) and low ABI had a significant and independent increase in the risk of an absolute SBP difference greater than 10 mmHg. The results suggest that there is considerable difference in the measured BP in the right and left arms and that large differences in the absolute SBP are associated with risk factors for arteriosclerosis such as hypertension, hypercholesterolemia, obesity, metabolic abnormalities and low ABI.

Breast Cancer Risk From Modifiable and Nonmodifiable Risk Factors Among White Women in the United States

PubMed Central

Maas, Paige; Barrdahl, Myrto; Joshi, Amit D.; Auer, Paul L.; Gaudet, Mia M.; Milne, Roger L.; Schumacher, Fredrick R.; Anderson, William F.; Check, David; Chattopadhyay, Subham; Baglietto, Laura; Berg, Christine D.; Chanock, Stephen J.; Cox, David G.; Figueroa, Jonine D.; Gail, Mitchell H.; Graubard, Barry I.; Haiman, Christopher A.; Hankinson, Susan E.; Hoover, Robert N.; Isaacs, Claudine; Kolonel, Laurence N.; Le Marchand, Loic; Lee, I-Min; Lindström, Sara; Overvad, Kim; Romieu, Isabelle; Sanchez, Maria-Jose; Southey, Melissa C.; Stram, Daniel O.; Tumino, Rosario; VanderWeele, Tyler J.; Willett, Walter C.; Zhang, Shumin; Buring, Julie E.; Canzian, Federico; Gapstur, Susan M.; Henderson, Brian E.; Hunter, David J.; Giles, Graham G; Prentice, Ross L.; Ziegler, Regina G.; Kraft, Peter; Garcia-Closas, Montse; Chatterjee, Nilanjan

2017-01-01

IMPORTANCE An improved model for risk stratification can be useful for guiding public health strategies of breast cancer prevention. OBJECTIVE To evaluate combined risk stratification utility of common low penetrant single nucleotide polymorphisms (SNPs) and epidemiologic risk factors. DESIGN, SETTING, AND PARTICIPANTS Using a total of 17 171 cases and 19 862 controls sampled from the Breast and Prostate Cancer Cohort Consortium (BPC3) and 5879 women participating in the 2010 National Health Interview Survey, a model for predicting absolute risk of breast cancer was developed combining information on individual level data on epidemiologic risk factors and 24 genotyped SNPs from prospective cohort studies, published estimate of odds ratios for 68 additional SNPs, population incidence rate from the National Cancer Institute-Surveillance, Epidemiology, and End Results Program cancer registry and data on risk factor distribution from nationally representative health survey. The model is used to project the distribution of absolute risk for the population of white women in the United States after adjustment for competing cause of mortality. EXPOSURES Single nucleotide polymorphisms, family history, anthropometric factors, menstrual and/or reproductive factors, and lifestyle factors. MAIN OUTCOMES AND MEASURES Degree of stratification of absolute risk owing to nonmodifiable (SNPs, family history, height, and some components of menstrual and/or reproductive history) and modifiable factors (body mass index [BMI; calculated as weight in kilograms divided by height in meters squared], menopausal hormone therapy [MHT], alcohol, and smoking). RESULTS The average absolute risk for a 30-year-old white woman in the United States developing invasive breast cancer by age 80 years is 11.3%. A model that includes all risk factors provided a range of average absolute risk from 4.4% to 23.5% for women in the bottom and top deciles of the risk distribution, respectively. For women who were at the lowest and highest deciles of nonmodifiable risks, the 5th and 95th percentile range of the risk distribution associated with 4 modifiable factors was 2.9% to 5.0% and 15.5% to 25.0%, respectively. For women in the highest decile of risk owing to nonmodifiable factors, those who had low BMI, did not drink or smoke, and did not use MHT had risks comparable to an average woman in the general population. CONCLUSIONS AND RELEVANCE This model for absolute risk of breast cancer including SNPs can provide stratification for the population of white women in the United States. The model can also identify subsets of the population at an elevated risk that would benefit most from risk-reduction strategies based on altering modifiable factors. The effectiveness of this model for individual risk communication needs further investigation. PMID:27228256

Gout and subsequent erectile dysfunction: a population-based cohort study from England.

PubMed

Abdul Sultan, Alyshah; Mallen, Christian; Hayward, Richard; Muller, Sara; Whittle, Rebecca; Hotston, Matthew; Roddy, Edward

2017-06-06

An association has been suggested between gout and erectile dysfunction (ED), however studies quantifying the risk of ED amongst gout patients are lacking. We aimed to precisely determine the population-level absolute and relative rate of ED reporting among men with gout over a decade in England. We utilised the UK-based Clinical Practice Research Datalink to identify 9653 men with incident gout age- and practice-matched to 38,218 controls. Absolute and relative rates of incident ED were calculated using Cox regression models. Absolute rates within specific time periods before and after gout diagnosis were compared to control using a Poisson regression model. Overall, the absolute rate of ED post-gout diagnosis was 193 (95% confidence interval (CI): 184-202) per 10,000 person-years. This corresponded to a 31% (hazard ratio (HR): 1.31 95%CI: 1.24-1.40) increased relative risk and 0.6% excess absolute risk compared to those without gout. We did not observe statistically significant differences in the risk of ED among those prescribed ULT within 1 and 3 years after gout diagnosis. Compared to those unexposed, the risk of ED was also high in the year before gout diagnosis (relative rate = 1.63 95%CI 1.27-2.08). Similar findings were also observed for severe ED warranting pharmacological intervention. We have shown a statistically significant increased risk of ED among men with gout. Our findings will have important implications in planning a multidisciplinary approach to managing patients with gout.

Interpretation of the COBE FIRAS CMBR spectrum

NASA Technical Reports Server (NTRS)

Wright, E. L.; Mather, J. C.; Fixsen, D. J.; Kogut, A.; Shafer, R. A.; Bennett, C. L.; Boggess, N. W.; Cheng, E. S.; Silverberg, R. F.; Smoot, G. F.

1994-01-01

The cosmic microwave background radiation (CMBR) spectrum measured by the Far-Infrared Absolute Spectrophotometer (FIRAS) instrument on NASA's Cosmic Background Explorer (COBE) is indistinguishable from a blackbody, implying stringent limits on energy release in the early universe later than the time t = 1 yr after the big bang. We compare the FIRAS data to previous precise measurements of the cosmic microwave background spectrum and find a reasonable agreement. We discuss the implications of the absolute value of y is less than 2.5 x 10(exp -5) and the absolute value of mu is less than 3.3 x 10(exp -4) 95% confidence limits found by Mather et al. (1994) on many processes occurring after t = 1 yr, such as explosive structure formation, reionization, and dissipation of small-scale density perturbations. We place limits on models with dust plus Population III stars, or evolving populations of IR galaxies, by directly comparing the Mather et al. spectrum to the model predictions.

Simulated building energy demand biases resulting from the use of representative weather stations

DOE PAGES

Burleyson, Casey D.; Voisin, Nathalie; Taylor, Z. Todd; ...

2017-11-06

Numerical building models are typically forced with weather data from a limited number of “representative cities” or weather stations representing different climate regions. The use of representative weather stations reduces computational costs, but often fails to capture spatial heterogeneity in weather that may be important for simulations aimed at understanding how building stocks respond to a changing climate. Here, we quantify the potential reduction in temperature and load biases from using an increasing number of weather stations over the western U.S. Our novel approach is based on deriving temperature and load time series using incrementally more weather stations, ranging frommore » 8 to roughly 150, to evaluate the ability to capture weather patterns across different seasons. Using 8 stations across the western U.S., one from each IECC climate zone, results in an average absolute summertime temperature bias of ~4.0 °C with respect to a high-resolution gridded dataset. The mean absolute bias drops to ~1.5 °C using all available weather stations. Temperature biases of this magnitude could translate to absolute summertime mean simulated load biases as high as 13.5%. Increasing the size of the domain over which biases are calculated reduces their magnitude as positive and negative biases may cancel out. Using 8 representative weather stations can lead to a 20–40% bias of peak building loads during both summer and winter, a significant error for capacity expansion planners who may use these types of simulations. Using weather stations close to population centers reduces both mean and peak load biases. Our approach could be used by others designing aggregate building simulations to understand the sensitivity to their choice of weather stations used to drive the models.« less

Simulated building energy demand biases resulting from the use of representative weather stations

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

Burleyson, Casey D.; Voisin, Nathalie; Taylor, Z. Todd

Numerical building models are typically forced with weather data from a limited number of “representative cities” or weather stations representing different climate regions. The use of representative weather stations reduces computational costs, but often fails to capture spatial heterogeneity in weather that may be important for simulations aimed at understanding how building stocks respond to a changing climate. Here, we quantify the potential reduction in temperature and load biases from using an increasing number of weather stations over the western U.S. Our novel approach is based on deriving temperature and load time series using incrementally more weather stations, ranging frommore » 8 to roughly 150, to evaluate the ability to capture weather patterns across different seasons. Using 8 stations across the western U.S., one from each IECC climate zone, results in an average absolute summertime temperature bias of ~4.0 °C with respect to a high-resolution gridded dataset. The mean absolute bias drops to ~1.5 °C using all available weather stations. Temperature biases of this magnitude could translate to absolute summertime mean simulated load biases as high as 13.5%. Increasing the size of the domain over which biases are calculated reduces their magnitude as positive and negative biases may cancel out. Using 8 representative weather stations can lead to a 20–40% bias of peak building loads during both summer and winter, a significant error for capacity expansion planners who may use these types of simulations. Using weather stations close to population centers reduces both mean and peak load biases. Our approach could be used by others designing aggregate building simulations to understand the sensitivity to their choice of weather stations used to drive the models.« less

Simulated building energy demand biases resulting from the use of representative weather stations

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

Burleyson, Casey D.; Voisin, Nathalie; Taylor, Z. Todd

Numerical building models are typically forced with weather data from a limited number of “representative cities” or weather stations representing different climate regions. The use of representative weather stations reduces computational costs, but often fails to capture spatial heterogeneity in weather that may be important for simulations aimed at understanding how building stocks respond to a changing climate. We quantify the potential reduction in bias from using an increasing number of weather stations over the western U.S. The approach is based on deriving temperature and load time series using incrementally more weather stations, ranging from 8 to roughly 150, tomore » capture weather across different seasons. Using 8 stations, one from each climate zone, across the western U.S. results in an average absolute summertime temperature bias of 7.2°F with respect to a spatially-resolved gridded dataset. The mean absolute bias drops to 2.8°F using all available weather stations. Temperature biases of this magnitude could translate to absolute summertime mean simulated load biases as high as 13.8%, a significant error for capacity expansion planners who may use these types of simulations. Increasing the size of the domain over which biases are calculated reduces their magnitude as positive and negative biases may cancel out. Using 8 representative weather stations can lead to a 20-40% overestimation of peak building loads during both summer and winter. Using weather stations close to population centers reduces both mean and peak load biases. This approach could be used by others designing aggregate building simulations to understand the sensitivity to their choice of weather stations used to drive the models.« less

Genomic selection of agronomic traits in hybrid rice using an NCII population.

PubMed

Xu, Yang; Wang, Xin; Ding, Xiaowen; Zheng, Xingfei; Yang, Zefeng; Xu, Chenwu; Hu, Zhongli

2018-05-10

Hybrid breeding is an effective tool to improve yield in rice, while parental selection remains the key and difficult issue. Genomic selection (GS) provides opportunities to predict the performance of hybrids before phenotypes are measured. However, the application of GS is influenced by several genetic and statistical factors. Here, we used a rice North Carolina II (NC II) population constructed by crossing 115 rice varieties with five male sterile lines as a model to evaluate effects of statistical methods, heritability, marker density and training population size on prediction for hybrid performance. From the comparison of six GS methods, we found that predictabilities for different methods are significantly different, with genomic best linear unbiased prediction (GBLUP) and least absolute shrinkage and selection operation (LASSO) being the best, support vector machine (SVM) and partial least square (PLS) being the worst. The marker density has lower influence on predicting rice hybrid performance compared with the size of training population. Additionally, we used the 575 (115 × 5) hybrid rice as a training population to predict eight agronomic traits of all hybrids derived from 120 (115 + 5) rice varieties each mating with 3023 rice accessions from the 3000 rice genomes project (3 K RGP). Of the 362,760 potential hybrids, selection of the top 100 predicted hybrids would lead to 35.5%, 23.25%, 30.21%, 42.87%, 61.80%, 75.83%, 19.24% and 36.12% increase in grain yield per plant, thousand-grain weight, panicle number per plant, plant height, secondary branch number, grain number per panicle, panicle length and primary branch number, respectively. This study evaluated the factors affecting predictabilities for hybrid prediction and demonstrated the implementation of GS to predict hybrid performance of rice. Our results suggest that GS could enable the rapid selection of superior hybrids, thus increasing the efficiency of rice hybrid breeding.

Prediction of renal crystalline size distributions in space using a PBE analytic model. 1. Effect of microgravity-induced biochemical alterations.

PubMed

Kassemi, Mohammad; Thompson, David

2016-09-01

An analytical Population Balance Equation model is developed and used to assess the risk of critical renal stone formation for astronauts during future space missions. The model uses the renal biochemical profile of the subject as input and predicts the steady-state size distribution of the nucleating, growing, and agglomerating calcium oxalate crystals during their transit through the kidney. The model is verified through comparison with published results of several crystallization experiments. Numerical results indicate that the model is successful in clearly distinguishing between 1-G normal and 1-G recurrent stone-former subjects based solely on their published 24-h urine biochemical profiles. Numerical case studies further show that the predicted renal calculi size distribution for a microgravity astronaut is closer to that of a recurrent stone former on Earth rather than to a normal subject in 1 G. This interestingly implies that the increase in renal stone risk level in microgravity is relatively more significant for a normal person than a stone former. However, numerical predictions still underscore that the stone-former subject carries by far the highest absolute risk of critical stone formation during space travel. Copyright © 2016 the American Physiological Society.

Population education in the nineties: a quest for a regional programme strategy in Asia and the Pacific.

PubMed

1991-01-01

In 1990, Asia and the Pacific constituted 59% of the world's population and this percentage has been estimated to climb to 61.76% by 1995. In addition to rapid population growth, some of the other problems plaguing the region in the early 1990s included illiteracy, absolute poverty, environmental pollution, and low status of women. Population education can play a key role in an intervention strategy for fertility decline. Schools should include population education because, if girls attend school, it can improve girls' chances for employment and affect future family sizes, and both male and female students are most apt to occupy important private sector and government positions and be leaders. UNESCO has proposed a 1992-1995 regional population education and communication program and hoped to gain UNFPA support for the program. UNESCO has heeded UNFPA's plea for more formidable and intensive backstopping to country programs. It proposed to create regional advisory teams that will provide technical assistance, organize study tours and workshops, facilitate intercountry sharing, and identify new areas of development. This team would also be population education advocates. It has also proposed a workshop in population communication for staff of rural oriented nongovernmental organizations and religious groups to close the UNFPA identified gap in information, education, and communication (IEC). Other similar proposed activities to close the IEC gap included workshops on audiovisual (AV) aids development and use and maintenance of AV equipment and on communication strategies to reach male family planning acceptors and intercountry research studies. UNESCO has also planned to place more emphasis on management, development of prototype population education materials, and other needed population education activities.

A comparison of entropy balance and probability weighting methods to generalize observational cohorts to a population: a simulation and empirical example.

PubMed

Harvey, Raymond A; Hayden, Jennifer D; Kamble, Pravin S; Bouchard, Jonathan R; Huang, Joanna C

2017-04-01

We compared methods to control bias and confounding in observational studies including inverse probability weighting (IPW) and stabilized IPW (sIPW). These methods often require iteration and post-calibration to achieve covariate balance. In comparison, entropy balance (EB) optimizes covariate balance a priori by calibrating weights using the target's moments as constraints. We measured covariate balance empirically and by simulation by using absolute standardized mean difference (ASMD), absolute bias (AB), and root mean square error (RMSE), investigating two scenarios: the size of the observed (exposed) cohort exceeds the target (unexposed) cohort and vice versa. The empirical application weighted a commercial health plan cohort to a nationally representative National Health and Nutrition Examination Survey target on the same covariates and compared average total health care cost estimates across methods. Entropy balance alone achieved balance (ASMD ≤ 0.10) on all covariates in simulation and empirically. In simulation scenario I, EB achieved the lowest AB and RMSE (13.64, 31.19) compared with IPW (263.05, 263.99) and sIPW (319.91, 320.71). In scenario II, EB outperformed IPW and sIPW with smaller AB and RMSE. In scenarios I and II, EB achieved the lowest mean estimate difference from the simulated population outcome ($490.05, $487.62) compared with IPW and sIPW, respectively. Empirically, only EB differed from the unweighted mean cost indicating IPW, and sIPW weighting was ineffective. Entropy balance demonstrated the bias-variance tradeoff achieving higher estimate accuracy, yet lower estimate precision, compared with IPW methods. EB weighting required no post-processing and effectively mitigated observed bias and confounding. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Exposure to microbial components and allergens in population studies: a comparison of two house dust collection methods applied by participants and fieldworkers.

PubMed

Schram-Bijkerk, D; Doekes, G; Boeve, M; Douwes, J; Riedler, J; Ublagger, E; von Mutius, E; Benz, M; Pershagen, G; Wickman, M; Alfvén, T; Braun-Fahrländer, C; Waser, M; Brunekreef, B

2006-12-01

Dust collection by study participants instead of fieldworkers would be a practical and cost-effective alternative in large-scale population studies estimating exposure to indoor allergens and microbial agents. We aimed to compare dust weights and biological agent levels in house dust samples taken by study participants with nylon socks, with those in samples taken by fieldworkers using the sampling nozzle of the Allergology Laboratory Copenhagen (ALK). In homes of 216 children, parents and fieldworkers collected house dust within the same year. Dust samples were analyzed for levels of allergens, endotoxin, (1-->3)-beta-D-glucans and fungal extracellular polysaccharides (EPS). Socks appeared to yield less dust from mattresses at relatively low dust amounts and more dust at high dust amounts than ALK samples. Correlations between the methods ranged from 0.47-0.64 for microbial agents and 0.64-0.87 for mite and pet allergens. Cat allergen levels were two-fold lower and endotoxin levels three-fold higher in socks than in ALK samples. Levels of allergens and microbial agents in sock samples taken by study participants are moderately to highly correlated to levels in ALK samples taken by fieldworkers. Absolute levels may differ, probably because of differences in the method rather than in the person who performed the sampling. Practical Implications Dust collection by participants is a reliable and practical option for allergen and microbial agent exposure assessment. Absolute levels of biological agents are not (always) comparable between studies using different dust collection methods, even when expressed per gram dust, because of potential differences in particle-size constitution of the collected dust.

[Prediction of schistosomiasis infection rates of population based on ARIMA-NARNN model].

PubMed

Ke-Wei, Wang; Yu, Wu; Jin-Ping, Li; Yu-Yu, Jiang

2016-07-12

To explore the effect of the autoregressive integrated moving average model-nonlinear auto-regressive neural network (ARIMA-NARNN) model on predicting schistosomiasis infection rates of population. The ARIMA model, NARNN model and ARIMA-NARNN model were established based on monthly schistosomiasis infection rates from January 2005 to February 2015 in Jiangsu Province, China. The fitting and prediction performances of the three models were compared. Compared to the ARIMA model and NARNN model, the mean square error (MSE), mean absolute error (MAE) and mean absolute percentage error (MAPE) of the ARIMA-NARNN model were the least with the values of 0.011 1, 0.090 0 and 0.282 4, respectively. The ARIMA-NARNN model could effectively fit and predict schistosomiasis infection rates of population, which might have a great application value for the prevention and control of schistosomiasis.

Decomposing health inequality with population-based surveys: a case study in Rwanda.

PubMed

Liu, Kai; Lu, Chunling

2018-05-10

Ensuring equal access to care and providing financial risk protection are at the center of the global health agenda. While Rwanda has made impressive progress in improving health outcomes, inequalities in medical care utilization and household catastrophic health spending (HCHS) between the impoverished and non-impoverished populations persist. Decomposing inequalities will help us understand the factors contributing to inequalities and design effective policy instruments in reducing inequalities. This study aims to decompose the inequalities in medical care utilization among those reporting illnesses and HCHS between the poverty and non-poverty groups in Rwanda. Using the 2005 and 2010 nationally representative Integrated Living Conditions Surveys, our analysis focuses on measuring contributions to inequalities from poverty status and other sources. We conducted multivariate logistic regression analysis to obtain poverty's contribution to inequalities by controlling for all observed covariates. We used multivariate nonlinear decomposition method with logistic regression models to partition the relative and absolute contributions from other sources to inequalities due to compositional or response effects. Poverty status accounted for the majority of inequalities in medical care utilization (absolute contribution 0.093 in 2005 and 0.093 in 2010) and HCHS (absolute contribution 0.070 in 2005 and 0.032 in 2010). Health insurance status (absolute contribution 0.0076 in 2005 and 0.0246 in 2010) and travel time to health centers (absolute contribution 0.0025 in 2005 and 0.0014 in 2010) were significant contributors to inequality in medical care utilization. Health insurance status (absolute contribution 0.0021 in 2005 and 0.0011 in 2010), having under-five children (absolute contribution 0.0012 in 2005 and 0.0011 in 2010), and having disabled family members (absolute contribution 0.0002 in 2005 and 0.0001 in 2010) were significant contributors to inequality in HCHS. Between 2005 and 2010, the main sources of the inequalities remained unchanged. Expanding insurance coverage and reducing travel time to health facilities for those living in poverty could be used as policy instruments to mitigate inequalities in medical care utilization and HCHS between the poverty and non-poverty groups.

[Comparison study on sampling methods of Oncomelania hupensis snail survey in marshland schistosomiasis epidemic areas in China].

PubMed

An, Zhao; Wen-Xin, Zhang; Zhong, Yao; Yu-Kuan, Ma; Qing, Liu; Hou-Lang, Duan; Yi-di, Shang

2016-06-29

To optimize and simplify the survey method of Oncomelania hupensis snail in marshland endemic region of schistosomiasis and increase the precision, efficiency and economy of the snail survey. A quadrate experimental field was selected as the subject of 50 m×50 m size in Chayegang marshland near Henghu farm in the Poyang Lake region and a whole-covered method was adopted to survey the snails. The simple random sampling, systematic sampling and stratified random sampling methods were applied to calculate the minimum sample size, relative sampling error and absolute sampling error. The minimum sample sizes of the simple random sampling, systematic sampling and stratified random sampling methods were 300, 300 and 225, respectively. The relative sampling errors of three methods were all less than 15%. The absolute sampling errors were 0.221 7, 0.302 4 and 0.047 8, respectively. The spatial stratified sampling with altitude as the stratum variable is an efficient approach of lower cost and higher precision for the snail survey.

Assessing epistemic sophistication by considering domain-specific absolute and multiplicistic beliefs separately.

PubMed

Peter, Johannes; Rosman, Tom; Mayer, Anne-Kathrin; Leichner, Nikolas; Krampen, Günter

2016-06-01

Particularly in higher education, not only a view of science as a means of finding absolute truths (absolutism), but also a view of science as generally tentative (multiplicism) can be unsophisticated and obstructive for learning. Most quantitative epistemic belief inventories neglect this and understand epistemic sophistication as disagreement with absolute statements. This article suggests considering absolutism and multiplicism as separate dimensions. Following our understanding of epistemic sophistication as a cautious and reluctant endorsement of both positions, we assume evaluativism (a contextually adaptive view of knowledge as personally constructed and evidence-based) to be reflected by low agreement with both generalized absolute and generalized multiplicistic statements. Three studies with a total sample size of N = 416 psychology students were conducted. A domain-specific inventory containing both absolute and multiplicistic statements was developed. Expectations were tested by exploratory factor analysis, confirmatory factor analysis, and correlational analyses. Results revealed a two-factor solution with an absolute and a multiplicistic factor. Criterion validity of both factors was confirmed. Cross-sectional analyses revealed that agreement to generalized multiplicistic statements decreases with study progress. Moreover, consistent with our understanding of epistemic sophistication as a reluctant attitude towards generalized epistemic statements, evidence for a negative relationship between epistemic sophistication and need for cognitive closure was found. We recommend including multiplicistic statements into epistemic belief questionnaires and considering them as a separate dimension, especially when investigating individuals in later stages of epistemic development (i.e., in higher education). © 2015 The British Psychological Society.

Evaluating the performance of the Lee-Carter method and its variants in modelling and forecasting Malaysian mortality

NASA Astrophysics Data System (ADS)

Zakiyatussariroh, W. H. Wan; Said, Z. Mohammad; Norazan, M. R.

2014-12-01

This study investigated the performance of the Lee-Carter (LC) method and it variants in modeling and forecasting Malaysia mortality. These include the original LC, the Lee-Miller (LM) variant and the Booth-Maindonald-Smith (BMS) variant. These methods were evaluated using Malaysia's mortality data which was measured based on age specific death rates (ASDR) for 1971 to 2009 for overall population while those for 1980-2009 were used in separate models for male and female population. The performance of the variants has been examined in term of the goodness of fit of the models and forecasting accuracy. Comparison was made based on several criteria namely, mean square error (MSE), root mean square error (RMSE), mean absolute deviation (MAD) and mean absolute percentage error (MAPE). The results indicate that BMS method was outperformed in in-sample fitting for overall population and when the models were fitted separately for male and female population. However, in the case of out-sample forecast accuracy, BMS method only best when the data were fitted to overall population. When the data were fitted separately for male and female, LCnone performed better for male population and LM method is good for female population.

Optoelectronic fuzzy associative memory with controllable attraction basin sizes

NASA Astrophysics Data System (ADS)

Wen, Zhiqing; Campbell, Scott; Wu, Weishu; Yeh, Pochi

1995-10-01

We propose and demonstrate a new fuzzy associative memory model that provides an option to control the sizes of the attraction basins in neural networks. In our optoelectronic implementation we use spatial/polarization encoding to represent the fuzzy variables. Shadow casting of the encoded patterns is employed to yield the fuzzy-absolute difference between fuzzy variables.

How Infants Encode Spatial Extent

ERIC Educational Resources Information Center

Duffy, Sean; Huttenlocher, Janellen; Levine, Susan; Duffy, Renee

2005-01-01

This study explores how infants encode an object's spatial extent. We habituated 6.5-month-old infants to a dowel inside a container and then tested whether they dishabituate to a change in absolute size when the relation between dowel and container is held constant (by altering the size of both container and dowel) and when the relation changes…

Characterizing spatial structure of sediment E. coli populations to inform sampling design.

PubMed

Piorkowski, Gregory S; Jamieson, Rob C; Hansen, Lisbeth Truelstrup; Bezanson, Greg S; Yost, Chris K

2014-01-01

Escherichia coli can persist in streambed sediments and influence water quality monitoring programs through their resuspension into overlying waters. This study examined the spatial patterns in E. coli concentration and population structure within streambed morphological features during baseflow and following stormflow to inform sampling strategies for representative characterization of E. coli populations within a stream reach. E. coli concentrations in bed sediments were significantly different (p = 0.002) among monitoring sites during baseflow, and significant interactive effects (p = 0.002) occurred among monitoring sites and morphological features following stormflow. Least absolute shrinkage and selection operator (LASSO) regression revealed that water velocity and effective particle size (D 10) explained E. coli concentration during baseflow, whereas sediment organic carbon, water velocity and median particle diameter (D 50) were important explanatory variables following stormflow. Principle Coordinate Analysis illustrated the site-scale differences in sediment E. coli populations between disconnected stream segments. Also, E. coli populations were similar among depositional features within a reach, but differed in relation to high velocity features (e.g., riffles). Canonical correspondence analysis resolved that E. coli population structure was primarily explained by spatial (26.9–31.7 %) over environmental variables (9.2–13.1 %). Spatial autocorrelation existed among monitoring sites and morphological features for both sampling events, and gradients in mean particle diameter and water velocity influenced E. coli population structure for the baseflow and stormflow sampling events, respectively. Representative characterization of streambed E. coli requires sampling of depositional and high velocity environments to accommodate strain selectivity among these features owing to sediment and water velocity heterogeneity.

Pixel-based absolute surface metrology by three flat test with shifted and rotated maps

NASA Astrophysics Data System (ADS)

Zhai, Dede; Chen, Shanyong; Xue, Shuai; Yin, Ziqiang

2018-03-01

In traditional three flat test, it only provides the absolute profile along one surface diameter. In this paper, an absolute testing algorithm based on shift-rotation with three flat test has been proposed to reconstruct two-dimensional surface exactly. Pitch and yaw error during shift procedure is analyzed and compensated in our method. Compared with multi-rotation method proposed before, it only needs a 90° rotation and a shift, which is easy to carry out especially in condition of large size surface. It allows pixel level spatial resolution to be achieved without interpolation or assumption to the test surface. In addition, numerical simulations and optical tests are implemented and show the high accuracy recovery capability of the proposed method.

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

Davidson, J.

Relative and absolute populations of 19 levels in beam-foil--excited neutral helium at 0.275 MeV have been measured. The singlet angular-momentum sequences show dependences on principal quantum number consistent with n$sup -3$, but the triplet sequences do not. Singlet and triplet angular-momentum sequences show similar dependences on level excitation energy. Excitation functions for six representative levels were measured in the range 0.160 to 0.500 MeV. The absolute level populations increase with energy, whereas the neutral fraction of the beam decreases with energy. Further, the P angular-momentum levels are found to be overpopulated with respect to the S and D levels. Themore » overpopulation decreases with increasing principal quantum number.« less

Accuracy, precision, and economic efficiency for three methods of thrips (Thysanoptera: Thripidae) population density assessment.

PubMed

Sutherland, Andrew M; Parrella, Michael P

2011-08-01

Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is a major horticultural pest and an important vector of plant viruses in many parts of the world. Methods for assessing thrips population density for pest management decision support are often inaccurate or imprecise due to thrips' positive thigmotaxis, small size, and naturally aggregated populations. Two established methods, flower tapping and an alcohol wash, were compared with a novel method, plant desiccation coupled with passive trapping, using accuracy, precision and economic efficiency as comparative variables. Observed accuracy was statistically similar and low (37.8-53.6%) for all three methods. Flower tapping was the least expensive method, in terms of person-hours, whereas the alcohol wash method was the most expensive. Precision, expressed by relative variation, depended on location within the greenhouse, location on greenhouse benches, and the sampling week, but it was generally highest for the flower tapping and desiccation methods. Economic efficiency, expressed by relative net precision, was highest for the flower tapping method and lowest for the alcohol wash method. Advantages and disadvantages are discussed for all three methods used. If relative density assessment methods such as these can all be assumed to accurately estimate a constant proportion of absolute density, then high precision becomes the methodological goal in terms of measuring insect population density, decision making for pest management, and pesticide efficacy assessments.

Do rewardless orchids show a positive relationship between phenotypic diversity and reproductive success?

PubMed

Smithson, Ann; Juillet, Nicolas; Macnair, Mark R; Gigord, Luc D B

2007-02-01

Among rewardless orchids, pollinator sampling behavior has been suggested to drive a positive relationship between population phenotypic variability and absolute reproductive success, and hence population fitness. We tested this hypothesis by constructing experimental arrays using the rewardless orchid Dactylorhiza sambucina, which is dimorphic for corolla color. We found no evidence that polymorphic arrays had higher mean reproductive success than monomorphic arrays for pollinia removal, pollen deposition, or fruit set. For pollinia removal, monomorphic yellow arrays had significantly greater reproductive success, and monomorphic red the least. A tendency for yellow arrays to have higher pollen deposition was also found. We argue that differential population fitness was most likely to reflect differential numbers of pollinators attracted to arrays, through preferential long-distance attraction to arrays with yellow inflorescences. Correlative studies of absolute reproductive success in 52 populations of D. sambucina supported our experimental results. To our knowledge this is the first study to suggest that attraction of a greater number of pollinators to rewardless orchids may be of greater functional importance to population fitness, and thus ecology and conservation, than are the behavioral sequences of individual pollinators.

Cryptosporidium: A Guide to Water Filters

MedlinePlus

... label> Parasites Home A Guide to Water Filters Recommend on Facebook Tweet Share Compartir Filtering Tap ... absolute pore size of 1 micron or smaller. Filters designed to remove Crypto (any of the four ...

Body size, swimming speed, or thermal sensitivity? Predator-imposed selection on amphibian larvae.

PubMed

Gvoždík, Lumír; Smolinský, Radovan

2015-11-02

Many animals rely on their escape performance during predator encounters. Because of its dependence on body size and temperature, escape velocity is fully characterized by three measures, absolute value, size-corrected value, and its response to temperature (thermal sensitivity). The primary target of the selection imposed by predators is poorly understood. We examined predator (dragonfly larva)-imposed selection on prey (newt larvae) body size and characteristics of escape velocity using replicated and controlled predation experiments under seminatural conditions. Specifically, because these species experience a wide range of temperatures throughout their larval phases, we predict that larvae achieving high swimming velocities across temperatures will have a selective advantage over more thermally sensitive individuals. Nonzero selection differentials indicated that predators selected for prey body size and both absolute and size-corrected maximum swimming velocity. Comparison of selection differentials with control confirmed selection only on body size, i.e., dragonfly larvae preferably preyed on small newt larvae. Maximum swimming velocity and its thermal sensitivity showed low group repeatability, which contributed to non-detectable selection on both characteristics of escape performance. In the newt-dragonfly larvae interaction, body size plays a more important role than maximum values and thermal sensitivity of swimming velocity during predator escape. This corroborates the general importance of body size in predator-prey interactions. The absence of an appropriate control in predation experiments may lead to potentially misleading conclusions about the primary target of predator-imposed selection. Insights from predation experiments contribute to our understanding of the link between performance and fitness, and further improve mechanistic models of predator-prey interactions and food web dynamics.

Comparison of NTF Experimental Data with CFD Predictions from the Third AIAA CFD Drag Prediction Workshop

NASA Technical Reports Server (NTRS)

Vassberg, John C.; Tinoco, Edward N.; Mani, Mori; Levy, David; Zickuhr, Tom; Mavriplis, Dimitri J.; Wahls, Richard A.; Morrison, Joseph H.; Brodersen, Olaf P.; Eisfeld, Bernhard;

The evolution of self-control

PubMed Central

MacLean, Evan L.; Hare, Brian; Nunn, Charles L.; Addessi, Elsa; Amici, Federica; Anderson, Rindy C.; Aureli, Filippo; Baker, Joseph M.; Bania, Amanda E.; Barnard, Allison M.; Boogert, Neeltje J.; Brannon, Elizabeth M.; Bray, Emily E.; Bray, Joel; Brent, Lauren J. N.; Burkart, Judith M.; Call, Josep; Cantlon, Jessica F.; Cheke, Lucy G.; Clayton, Nicola S.; Delgado, Mikel M.; DiVincenti, Louis J.; Fujita, Kazuo; Herrmann, Esther; Hiramatsu, Chihiro; Jacobs, Lucia F.; Jordan, Kerry E.; Laude, Jennifer R.; Leimgruber, Kristin L.; Messer, Emily J. E.; de A. Moura, Antonio C.; Ostojić, Ljerka; Picard, Alejandra; Platt, Michael L.; Plotnik, Joshua M.; Range, Friederike; Reader, Simon M.; Reddy, Rachna B.; Sandel, Aaron A.; Santos, Laurie R.; Schumann, Katrin; Seed, Amanda M.; Sewall, Kendra B.; Shaw, Rachael C.; Slocombe, Katie E.; Su, Yanjie; Takimoto, Ayaka; Tan, Jingzhi; Tao, Ruoting; van Schaik, Carel P.; Virányi, Zsófia; Visalberghi, Elisabetta; Wade, Jordan C.; Watanabe, Arii; Widness, Jane; Young, Julie K.; Zentall, Thomas R.; Zhao, Yini

2014-01-01

Cognition presents evolutionary research with one of its greatest challenges. Cognitive evolution has been explained at the proximate level by shifts in absolute and relative brain volume and at the ultimate level by differences in social and dietary complexity. However, no study has integrated the experimental and phylogenetic approach at the scale required to rigorously test these explanations. Instead, previous research has largely relied on various measures of brain size as proxies for cognitive abilities. We experimentally evaluated these major evolutionary explanations by quantitatively comparing the cognitive performance of 567 individuals representing 36 species on two problem-solving tasks measuring self-control. Phylogenetic analysis revealed that absolute brain volume best predicted performance across species and accounted for considerably more variance than brain volume controlling for body mass. This result corroborates recent advances in evolutionary neurobiology and illustrates the cognitive consequences of cortical reorganization through increases in brain volume. Within primates, dietary breadth but not social group size was a strong predictor of species differences in self-control. Our results implicate robust evolutionary relationships between dietary breadth, absolute brain volume, and self-control. These findings provide a significant first step toward quantifying the primate cognitive phenome and explaining the process of cognitive evolution. PMID:24753565

Conception and realization of a parallel-plate free-air ionization chamber for the absolute dosimetry of an ultrasoft X-ray beam

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

Groetz, J.-E., E-mail: jegroetz@univ-fcomte.fr; Mavon, C.; Fromm, M.

2014-08-15

We report the design of a millimeter-sized parallel plate free-air ionization chamber (IC) aimed at determining the absolute air kerma rate of an ultra-soft X-ray beam (E = 1.5 keV). The size of the IC was determined so that the measurement volume satisfies the condition of charged-particle equilibrium. The correction factors necessary to properly measure the absolute kerma using the IC have been established. Particular attention was given to the determination of the effective mean energy for the 1.5 keV photons using the PENELOPE code. Other correction factors were determined by means of computer simulation (COMSOL™and FLUKA). Measurements of airmore » kerma rates under specific operating parameters of the lab-bench X-ray source have been performed at various distances from that source and compared to Monte Carlo calculations. We show that the developed ionization chamber makes it possible to determine accurate photon fluence rates in routine work and will constitute substantial time-savings for future radiobiological experiments based on the use of ultra-soft X-rays.« less

Simultaneous measurement of monocomponent droplet temperature/refractive index, size and evaporation rate with phase rainbow refractometry

NASA Astrophysics Data System (ADS)

Wu, Yingchun; Crua, Cyril; Li, Haipeng; Saengkaew, Sawitree; Mädler, Lutz; Wu, Xuecheng; Gréhan, Gérard

2018-07-01

The accurate measurements of droplet temperature, size and evaporation rate are of great importance to characterize the heat and mass transfer during evaporation/condensation processes. The nanoscale size change of a micron-sized droplet exactly describes its transient mass transfer, but is difficult to measure because it is smaller than the resolutions of current size measurement techniques. The Phase Rainbow Refractometry (PRR) technique is developed and applied to measure droplet temperature, size and transient size changes and thereafter evaporation rate simultaneously. The measurement principle of PRR is theoretically derived, and it reveals that the phase shift of the time-resolved ripple structures linearly depends on, and can directly yield, nano-scale size changes of droplets. The PRR technique is first verified through the simulation of rainbows of droplets with changing size, and results show that PRR can precisely measure droplet refractive index, absolute size, as well as size change with absolute and relative errors within several nanometers and 0.6%, respectively, and thus PRR permits accurate measurements of transient droplet evaporation rates. The evaporations of flowing single n-nonane droplet and mono-dispersed n-heptane droplet stream are investigated by two PRR systems with a high speed linear CCD and a low speed array CCD, respectively. Their transient evaporation rates are experimentally determined and quantitatively agree well with the theoretical values predicted by classical Maxwell and Stefan-Fuchs models. With the demonstration of evaporation rate measurement of monocomponent droplet in this work, PRR is an ideal tool for measurements of transient droplet evaporation/condensation processes, and can be extended to multicomponent droplets in a wide range of industrially-relevant applications.

Trends and patterns in the use of computed tomography in children and young adults in Catalonia - results from the EPI-CT study.

PubMed

Bosch de Basea, Magda; Salotti, Jane A; Pearce, Mark S; Muchart, Jordi; Riera, Luis; Barber, Ignasi; Pedraza, Salvador; Pardina, Marina; Capdevila, Antoni; Espinosa, Ana; Cardis, Elisabeth

2016-01-01

Although there are undeniable diagnostic benefits of CT scanning, its increasing use in paediatric radiology has become a topic of concern regarding patient radioprotection. To assess the rate of CT scanning in Catalonia, Spain, among patients younger than 21 years old at the scan time. This is a sub-study of a larger international cohort study (EPI-CT, the International pediatric CT scan study). Data were retrieved from the radiological information systems (RIS) of eight hospitals in Catalonia since the implementation of digital registration (between 1991 and 2010) until 2013. The absolute number of CT scans annually increased 4.5% between 1991 and 2013, which was less accentuated when RIS was implemented in most hospitals. Because the population attending the hospitals also increased, however, the rate of scanned patients changed little (8.3 to 9.4 per 1,000 population). The proportions of patients with more than one CT and more than three CTs showed a 1.51- and 2.7-fold increase, respectively, over the 23 years. Gradual increases in numbers of examinations and scanned patients were observed in Catalonia, potentially explained by new CT scanning indications and increases in the availability of scanners, the number of scans per patient and the size of the attended population.

Experimental reduction in interaction intensity strongly affects biotic selection.

PubMed

Sletvold, Nina; Ågren, Jon

2016-11-01

The link between biotic interaction intensity and strength of selection is of fundamental interest for understanding biotically driven diversification and predicting the consequences of environmental change. The strength of selection resulting from biotic interactions is determined by the strength of the interaction and by the covariance between fitness and the trait under selection. When the relationship between trait and absolute fitness is constant, selection strength should be a direct function of mean population interaction intensity. To test this prediction, we excluded pollinators for intervals of different length to induce five levels of pollination intensity within a single plant population. Pollen limitation (PL) increased from 0 to 0.77 across treatments, accompanied by a fivefold increase in the opportunity for selection. Trait-fitness covariance declined with PL for number of flowers, but varied little for other traits. Pollinator-mediated selection on plant height, corolla size, and spur length increased by 91%, 34%, and 330%, respectively, in the most severely pollen-limited treatment compared to open-pollinated plants. The results indicate that realized biotic selection can be predicted from mean population interaction intensity when variation in trait-fitness covariance is limited, and that declines in pollination intensity will strongly increase selection on traits involved in the interaction. © 2016 by the Ecological Society of America.

Estimating the effect of native Indian population on county alcohol consumption: the example of Ontario.

PubMed

Adrian, M; Layne, N; Williams, R T

Multiple regression analysis of cross-sectional 1985-1986 Ontario county data indicated that the presence of Native Indians on reserves is a significant factor in explaining differences in county alcohol consumption levels. Consumption in counties with reserves was higher than in those without reserves by roughly 1.48 liters of absolute alcohol per adult; consumption increased as the Native reserve population increased (p less than 0.05). When income, employment, household crowding, type of industrial activity, northern isolation, and tourism were included, we could account for over 60% of the variation in alcohol consumption between Ontario counties (p less than 0.01). Every extra $1,000 in income per tax return was associated with a 0.297-liter reduction in absolute alcohol consumption. Efforts to reduce alcohol consumption in the Native population would have their greatest impact when associated with improved economic conditions.

--No Title--

Science.gov Websites

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Camera traps and activity signs to estimate wild boar density and derive abundance indices.

PubMed

Massei, Giovanna; Coats, Julia; Lambert, Mark Simon; Pietravalle, Stephane; Gill, Robin; Cowan, Dave

2018-04-01

Populations of wild boar and feral pigs are increasing worldwide, in parallel with their significant environmental and economic impact. Reliable methods of monitoring trends and estimating abundance are needed to measure the effects of interventions on population size. The main aims of this study, carried out in five English woodlands were: (i) to compare wild boar abundance indices obtained from camera trap surveys and from activity signs; and (ii) to assess the precision of density estimates in relation to different densities of camera traps. For each woodland, we calculated a passive activity index (PAI) based on camera trap surveys, rooting activity and wild boar trails on transects, and estimated absolute densities based on camera trap surveys. PAIs obtained using different methods showed similar patterns. We found significant between-year differences in abundance of wild boar using PAIs based on camera trap surveys and on trails on transects, but not on signs of rooting on transects. The density of wild boar from camera trap surveys varied between 0.7 and 7 animals/km 2 . Increasing the density of camera traps above nine per km 2 did not increase the precision of the estimate of wild boar density. PAIs based on number of wild boar trails and on camera trap data appear to be more sensitive to changes in population size than PAIs based on signs of rooting. For wild boar densities similar to those recorded in this study, nine camera traps per km 2 are sufficient to estimate the mean density of wild boar. © 2017 Crown copyright. Pest Management Science © 2017 Society of Chemical Industry. © 2017 Crown copyright. Pest Management Science © 2017 Society of Chemical Industry.

Crater-based dating of geological units on Mars: methods and application for the new global geological map

USGS Publications Warehouse

Platz, Thomas; Michael, Gregory; Tanaka, Kenneth L.; Skinner, James A.; Fortezzo, Corey M.

2013-01-01

The new, post-Viking generation of Mars orbital imaging and topographical data provide significant higher-resolution details of surface morphologies, which induced a new effort to photo-geologically map the surface of Mars at 1:20,000,000 scale. Although from unit superposition relations a relative stratigraphical framework can be compiled, it was the ambition of this mapping project to provide absolute unit age constraints through crater statistics. In this study, the crater counting method is described in detail, starting with the selection of image data, type locations (both from the mapper’s and crater counter’s perspectives) and the identification of impact craters. We describe the criteria used to validate and analyse measured crater populations, and to derive and interpret crater model ages. We provide examples of how geological information about the unit’s resurfacing history can be retrieved from crater size–frequency distributions. Three cases illustrate short-, intermediate, and long-term resurfacing histories. In addition, we introduce an interpretation-independent visualisation of the crater resurfacing history that uses the reduction of the crater population in a given size range relative to the expected population given the observed crater density at larger sizes. From a set of potential type locations, 48 areas from 22 globally mapped units were deemed suitable for crater counting. Because resurfacing ages were derived from crater statistics, these secondary ages were used to define the unit age rather than the base age. Using the methods described herein, we modelled ages that are consistent with the interpreted stratigraphy. Our derived model ages allow age assignments to be included in unit names. We discuss the limitations of using the crater dating technique for global-scale geological mapping. Finally, we present recommendations for the documentation and presentation of crater statistics in publications.

Reproduction and early-life accommodations of landlocked alewives to a southern range extension

USGS Publications Warehouse

Nigro, A.A.; Ney, John J.

1982-01-01

Reproduction and first-year growth and food habits of landlocked alewives Alosa pseudoharengus in Claytor Lake, Virginia were examined and compared to descriptions for populations in the species' established New England-Great Lakes range. Alewives in mesothermal (2–27 C) Claytor Lake are shorter-lived (3 years) but grow faster, mature earlier (age 1), and have higher relative and absolute fecundities than have been reported for populations in colder northern waters. The 1979 spawning period extended from early May to early August, beginning at least 1 month earlier and lasting 4–9 weeks longer than in northern lakes. Changes in ovary condition during the spawning period suggest that alewives may be fractional spawners. Evidence of spawning was found in littoral areas throughout the lower 15 km of the reservoir. Growth in length of age-0 Claytor Lake alewives was linear through September and terminated in late autumn. Total first-year growth was reduced in 1979 (maximum of 130 mm total length, TL) from previous years (average of 160 mm TL), although it was substantially greater than recorded in the Great Lakes and the northeastern United States. The longer growing season, rather than accelerated in-season growth, appears to account for larger size achieved in Claytor Lake. High annual growth limits predation by Claytor Lake game fish on early spawned age-0 alewives by late summer. As elsewhere, larval and juvenile alewives (6–70 mm TL) fed primarily on copepods and cladocerans. Age-0 alewives longer than 35 mm TL demonstrated positive size-selection for cyclopoid copepods comparable to that shown by adults. Our findings suggest that self-sustaining alewife populations can be established in many inland waters but raise concerns regarding their forage value and community impacts.

Arbuscular mycorrhizal mediation of biomass-density relationship of Medicago sativa L. under two water conditions in a field experiment.

PubMed

Zhang, Qian; Xu, Liming; Tang, Jianjun; Bai, Minge; Chen, Xin

2011-05-01

The biomass-density relationship (whereby the biomass of individual plants decreases as plant density increases) has generally been explained by competition for resources. Arbuscular mycorrhizal fungi (AMF) are able to affect plant interactions by mediating resource utilization, but whether this AMF-mediated interaction will change the biomass-density relationship is unclear. We conducted an experiment to test the hypothesis that AMF will shift the biomass-density relationship by affecting intraspecific competition. Four population densities (10, 100, 1,000, or 10,000 seedlings per square meter) of Medicago sativa L. were planted in field plots. Water application (1,435 or 327.7 mm/year) simulated precipitation in wet areas (sufficient water) and arid areas (insufficient water). The fungicide benomyl was applied to suppress AMF in some plots ("low-AMF" treatment) and not in others ("high-AMF" treatment). The effect of the AMF treatment on the biomass-density relationship depended on water conditions. High AMF enhanced the decrease of individual biomass with increasing density (the biomass-density line had a steeper slope) when water was sufficient but not when water was insufficient. AMF treatment did not affect plant survival rate or population size but did affect absolute competition intensity (ACI). When water was sufficient, ACI was significantly higher in the high-AMF treatment than in the low-AMF treatment, but ACI was unaffected by AMF treatment when water was insufficient. Our results suggest that AMF status did not impact survival rate and population size but did shift the biomass-density relationship via effects on intraspecific competition. This effect of AMF on the biomass-density relationship depended on the availability of water.

Comparisons of body sizes at sexual maturity and at sex change in the parrotfishes of Hawaii: input needed for management regulations and stock assessments.

PubMed

DeMartini, E E; Howard, K G

2016-02-01

First estimates of sex allocation patterns and body size-at-sexual maturity and at protogynous sex change are presented for the five major (including one endemic) species of parrotfishes of Hawaii. Median body size at initial maturation as a female (LM50) and at protogynous sex change from adult female to adult male (LΔ50) varied greatly among the five species. Estimates of LM50 were about 14, 17, 24, 34 and 35 cm fork length (LF) in palenose Scarus psittacus, Pacific bullethead Chlorurus spilurus, stareye Calotomus carolinus, spectacled Chlorurus perspicillatus and redlip parrotfish Scarus rubroviolaceus. Values of LΔ50 were c. 23, 27, 37, 46 and 47 cm LF in the respective species. Length at female maturation was proportional to maximum body size (Lmax) of the respective species, ranging from 50 to 72% and averaging 62% of Lmax across species. LΔ50 was also proportional to Lmax, ranging from 82 to 97% and averaging 92%. Males of both pairs of Scarus and Chlorurus spp. reported here are diandric. Only one of the five major species (C. carolinus) is functionally monandric, with either all or nearly all males secondarily derived from adult females. The broadly differing absolute body sizes at sexual maturation and at sex change among the five species have important implications for improving regulatory size limits for parrotfishes in the State of Hawaii, where parrotfish species have historically been managed based on a single minimum size limit of 30·5 cm LF. This study provides a model demonstration of why catch data for parrotfishes, and other size-structured reef-fish populations, should be recorded either by species or by functional size-groups of species that allow setting more meaningful minimum size limits. © 2016 The Fisheries Society of the British Isles.

Bio-Inspired Stretchable Absolute Pressure Sensor Network

PubMed Central

Guo, Yue; Li, Yu-Hung; Guo, Zhiqiang; Kim, Kyunglok; Chang, Fu-Kuo; Wang, Shan X.

2016-01-01

A bio-inspired absolute pressure sensor network has been developed. Absolute pressure sensors, distributed on multiple silicon islands, are connected as a network by stretchable polyimide wires. This sensor network, made on a 4’’ wafer, has 77 nodes and can be mounted on various curved surfaces to cover an area up to 0.64 m × 0.64 m, which is 100 times larger than its original size. Due to Micro Electro-Mechanical system (MEMS) surface micromachining technology, ultrathin sensing nodes can be realized with thicknesses of less than 100 µm. Additionally, good linearity and high sensitivity (~14 mV/V/bar) have been achieved. Since the MEMS sensor process has also been well integrated with a flexible polymer substrate process, the entire sensor network can be fabricated in a time-efficient and cost-effective manner. Moreover, an accurate pressure contour can be obtained from the sensor network. Therefore, this absolute pressure sensor network holds significant promise for smart vehicle applications, especially for unmanned aerial vehicles. PMID:26729134

Note: An absolute X-Y-Θ position sensor using a two-dimensional phase-encoded binary scale

NASA Astrophysics Data System (ADS)

Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan

2018-04-01

This Note presents a new absolute X-Y-Θ position sensor for measuring planar motion of a precision multi-axis stage system. By analyzing the rotated image of a two-dimensional phase-encoded binary scale (2D), the absolute 2D position values at two separated points were obtained and the absolute X-Y-Θ position could be calculated combining these values. The sensor head was constructed using a board-level camera, a light-emitting diode light source, an imaging lens, and a cube beam-splitter. To obtain the uniform intensity profiles from the vignette scale image, we selected the averaging directions deliberately, and higher resolution in the angle measurement could be achieved by increasing the allowable offset size. The performance of a prototype sensor was evaluated in respect of resolution, nonlinearity, and repeatability. The sensor could resolve 25 nm linear and 0.001° angular displacements clearly, and the standard deviations were less than 18 nm when 2D grid positions were measured repeatedly.

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

Masiero, Joseph R.; Mainzer, A. K.; Bauer, J. M.

We present initial results from the Wide-field Infrared Survey Explorer (WISE), a four-band all-sky thermal infrared survey that produces data well suited for measuring the physical properties of asteroids, and the NEOWISE enhancement to the WISE mission allowing for detailed study of solar system objects. Using a NEATM thermal model fitting routine, we compute diameters for over 100,000 Main Belt asteroids from their IR thermal flux, with errors better than 10%. We then incorporate literature values of visible measurements (in the form of the H absolute magnitude) to determine albedos. Using these data we investigate the albedo and diameter distributionsmore » of the Main Belt. As observed previously, we find a change in the average albedo when comparing the inner, middle, and outer portions of the Main Belt. We also confirm that the albedo distribution of each region is strongly bimodal. We observe groupings of objects with similar albedos in regions of the Main Belt associated with dynamical breakup families. Asteroid families typically show a characteristic albedo for all members, but there are notable exceptions to this. This paper is the first look at the Main Belt asteroids in the WISE data, and only represents the preliminary, observed raw size, and albedo distributions for the populations considered. These distributions are subject to survey biases inherent to the NEOWISE data set and cannot yet be interpreted as describing the true populations; the debiased size and albedo distributions will be the subject of the next paper in this series.« less

The influence of music-elicited emotions and relative pitch on absolute pitch memory for familiar melodies.

PubMed

Jakubowski, Kelly; Müllensiefen, Daniel

2013-01-01

Levitin's findings that nonmusicians could produce from memory the absolute pitches of self-selected pop songs have been widely cited in the music psychology literature. These findings suggest that latent absolute pitch (AP) memory may be a more widespread trait within the population than traditional AP labelling ability. However, it has been left unclear what factors may facilitate absolute pitch retention for familiar pieces of music. The aim of the present paper was to investigate factors that may contribute to latent AP memory using Levitin's sung production paradigm for AP memory and comparing results to the outcomes of a pitch labelling task, a relative pitch memory test, measures of music-induced emotions, and various measures of participants' musical backgrounds. Our results suggest that relative pitch memory and the quality and degree of music-elicited emotions impact on latent AP memory.

Trends in income-related inequality in untreated caries among children in the United States: findings from NHANES I, NHANES III, and NHANES 1999-2004.

PubMed

Capurro, Diego Alberto; Iafolla, Timothy; Kingman, Albert; Chattopadhyay, Amit; Garcia, Isabel

2015-12-01

The goal of this analysis was to describe income-related inequality in untreated caries among children in the United States over time. The analysis focuses on children ages 2-12 years in three nationally representative U.S. surveys: the National Health and Nutrition Examination Survey (NHANES) 1971-1974, NHANES 1988-1994, and NHANES 1999-2004. The outcome of interest is untreated dental caries. Various methods are employed to measure absolute and relative inequality within each survey such as pair-wise comparisons, measures of association (odds ratios), and three summary measures of overall inequality: the slope index of inequality, the relative index of inequality, and the concentration index. Inequality trends are then assessed by comparing these estimates across the three surveys. Inequality was present in each of the three surveys analyzed. Whether measured on an absolute or relative scale, untreated caries disproportionately affected those with lower income. Trend analysis shows that, despite population-wide reductions in untreated caries between NHANES I and NHANES III, overall absolute inequality slightly increased, while overall relative inequality significantly increased. Between NHANES III and NHANES 1999-2004, both absolute and relative inequality tended to decrease; however, these changes were not statistically significant. Socioeconomic inequality in oral health is an important measure of progress in overall population health and a key input to inform health policies. This analysis shows the presence of socioeconomic inequality in oral health in the American child population, as well as changes in its magnitude over time. Further research is needed to determine the factors related to these changes and their relative contribution to inequality trends. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Social Contact and Loneliness in a University Population.

ERIC Educational Resources Information Center

Corty, Eric; Young, Richard David

To explore the relation between social contact and loneliness in a college student population, 40 male and 41 female undergraduates kept daily calendars of social contacts, recorded their activities for one week, and completed inventories on feelings and social interactions. A replication study involved 64 male undergraduates. The absolute level…

Absolute quantification by droplet digital PCR versus analog real-time PCR

PubMed Central

Hindson, Christopher M; Chevillet, John R; Briggs, Hilary A; Gallichotte, Emily N; Ruf, Ingrid K; Hindson, Benjamin J; Vessella, Robert L; Tewari, Muneesh

2014-01-01

Nanoliter-sized droplet technology paired with digital PCR (ddPCR) holds promise for highly precise, absolute nucleic acid quantification. Our comparison of microRNA quantification by ddPCR and real-time PCR revealed greater precision (coefficients of variation decreased by 37–86%) and improved day-to-day reproducibility (by a factor of seven) of ddPCR but with comparable sensitivity. When we applied ddPCR to serum microRNA biomarker analysis, this translated to superior diagnostic performance for identifying individuals with cancer. PMID:23995387

The coevolution of innovation and technical intelligence in primates

PubMed Central

Street, Sally E.; Whalen, Andrew; Laland, Kevin N.

2016-01-01

In birds and primates, the frequency of behavioural innovation has been shown to covary with absolute and relative brain size, leading to the suggestion that large brains allow animals to innovate, and/or that selection for innovativeness, together with social learning, may have driven brain enlargement. We examined the relationship between primate brain size and both technical (i.e. tool using) and non-technical innovation, deploying a combination of phylogenetically informed regression and exploratory causal graph analyses. Regression analyses revealed that absolute and relative brain size correlated positively with technical innovation, and exhibited consistently weaker, but still positive, relationships with non-technical innovation. These findings mirror similar results in birds. Our exploratory causal graph analyses suggested that technical innovation shares strong direct relationships with brain size, body size, social learning rate and social group size, whereas non-technical innovation did not exhibit a direct relationship with brain size. Nonetheless, non-technical innovation was linked to brain size indirectly via diet and life-history variables. Our findings support ‘technical intelligence’ hypotheses in linking technical innovation to encephalization in the restricted set of primate lineages where technical innovation has been reported. Our findings also provide support for a broad co-evolving complex of brain, behaviour, life-history, social and dietary variables, providing secondary support for social and ecological intelligence hypotheses. The ability to gain access to difficult-to-extract, but potentially nutrient-rich, resources through tool use may have conferred on some primates adaptive advantages, leading to selection for brain circuitry that underlies technical proficiency. PMID:26926276

The coevolution of innovation and technical intelligence in primates.

PubMed

Navarrete, Ana F; Reader, Simon M; Street, Sally E; Whalen, Andrew; Laland, Kevin N

2016-03-19

In birds and primates, the frequency of behavioural innovation has been shown to covary with absolute and relative brain size, leading to the suggestion that large brains allow animals to innovate, and/or that selection for innovativeness, together with social learning, may have driven brain enlargement. We examined the relationship between primate brain size and both technical (i.e. tool using) and non-technical innovation, deploying a combination of phylogenetically informed regression and exploratory causal graph analyses. Regression analyses revealed that absolute and relative brain size correlated positively with technical innovation, and exhibited consistently weaker, but still positive, relationships with non-technical innovation. These findings mirror similar results in birds. Our exploratory causal graph analyses suggested that technical innovation shares strong direct relationships with brain size, body size, social learning rate and social group size, whereas non-technical innovation did not exhibit a direct relationship with brain size. Nonetheless, non-technical innovation was linked to brain size indirectly via diet and life-history variables. Our findings support 'technical intelligence' hypotheses in linking technical innovation to encephalization in the restricted set of primate lineages where technical innovation has been reported. Our findings also provide support for a broad co-evolving complex of brain, behaviour, life-history, social and dietary variables, providing secondary support for social and ecological intelligence hypotheses. The ability to gain access to difficult-to-extract, but potentially nutrient-rich, resources through tool use may have conferred on some primates adaptive advantages, leading to selection for brain circuitry that underlies technical proficiency. © 2016 The Author(s).

Has the National Cancer Screening Program reduced income inequalities in screening attendance in South Korea?

PubMed

Kim, Sujin; Kwon, Soonman; Subramanian, S V

2015-11-01

In 1999, the Korean government introduced the National Cancer Screening Program (NCSP) to increase the cancer-screening rate, particularly among the low-income population. This study investigates how the NCSP has decreased both relative and absolute income inequalities in the uptake of cancer screening in South Korea. A nationally representative cross-sectional repeated data from the Korea National Health and Nutrition Examination Survey 1998-2012, managed by the Ministry of Health and Welfare, was used to assess changes over time and the extent of discontinuity at the NCSP-recommended initiation age in the uptake of screening for breast, colorectal, and gastric cancers across income quartiles. Relative inequalities in the uptake of screening for all cancers decreased significantly over the policy period. Absolute inequalities did not change for most cancers, but marginally increased from 9 to 14% points in the uptake of screening for colorectal cancer among men. At the recommended initiation age, absolute inequalities did not change for breast and colorectal cancers but increased from 5 to 16% points for gastric cancer, for which relative inequality significantly decreased. The NCSP, which reduced out-of-pocket payment, may not decrease absolute gap although it leads to overall increases in the uptake of cancer screening and decreases in relative inequalities. Further investigations are needed to understand barriers that prevent the low-income population from attending cancer screening.

Educational Inequalities in Post-Hip Fracture Mortality: A NOREPOS Study.

PubMed

Omsland, Tone K; Eisman, John A; Naess, Øyvind; Center, Jacqueline R; Gjesdal, Clara G; Tell, Grethe S; Emaus, Nina; Meyer, Haakon E; Søgaard, Anne Johanne; Holvik, Kristin; Schei, Berit; Forsmo, Siri; Magnus, Jeanette H

2015-12-01

Hip fractures are associated with high excess mortality. Education is an important determinant of health, but little is known about educational inequalities in post-hip fracture mortality. Our objective was to investigate educational inequalities in post-hip fracture mortality and to examine whether comorbidity or family composition could explain any association. We conducted a register-based population study of Norwegians aged 50 years and older from 2002 to 2010. We measured total mortality according to educational attainment in 56,269 hip fracture patients (NORHip) and in the general Norwegian population. Both absolute and relative educational inequalities in mortality in people with and without hip fracture were compared. There was an educational gradient in post-hip fracture mortality in both sexes. Compared with those with primary education only, the age-adjusted relative risk (RR) of mortality in hip fracture patients with tertiary education was 0.82 (95% confidence interval [CI] 0.77-0.87) in men and 0.79 (95% CI 0.75-0.84) in women. Additional adjustments for Charlson comorbidity index, marital status, and number of children did not materially change the estimates. Regardless of educational attainment, the 1-year age-adjusted mortality was three- to fivefold higher in hip fracture patients compared with peers in the general population without fracture. The absolute differences in 1-year mortality according to educational attainment were considerably larger in hip fracture patients than in the population without hip fracture. Absolute educational inequalities in mortality were higher after hip fracture compared with the general population without hip fracture and were not mediated by comorbidity or family composition. Investigation of other possible mediating factors might help to identify new targets for interventions, based on lower educational attainment, to reduce post-hip fracture mortality. © 2015 American Society for Bone and Mineral Research.

Craters and ejecta on Pluto and Charon: Anticipated results from the New Horizons flyby

NASA Astrophysics Data System (ADS)

Bierhaus, Edward B.; Dones, Luke

2015-01-01

We examine the flux of bodies striking Pluto and Charon, and the nature of the crater populations that will form as a result of these impacts. Assuming impact speeds of 2 km/s and an impact angle of 45 ° , a 1 km impactor will form a 4.2 km diameter transient crater on Pluto, and a ∼5.0 km crater on Charon, as compared with 8-13 km for several mid-sized saturnian satellites and 8-10 km for the icy Galilean satellites. We predict that secondary craters will be present in the crater size-frequency distribution (SFD) for Pluto and Charon at sizes less than a few km, at spatial densities comparable to the range seen on the mid-sized saturnian satellites and distinctly less than seen on the icy Galilean satellites. Pluto should have more secondary craters formed per primary impact than Charon, so if neither crater population on these bodies is in saturation, Charon's crater SFD should be the "cleanest" reflection of the primary, impacting SFD. Ejecta from Pluto and Charon escape more efficiently from the combined system, relative to ejecta from a satellite in orbit around a giant planet, due to the absence of a large central body. We estimate that Kuiper Belt Objects (KBOs) with diameters larger than 1 km should strike Pluto and Charon on (nominal) timescales of 2.2 and 10 million years, respectively. These estimates are uncertain because the numbers of small KBOs are poorly constrained. Our estimated rates are smaller than earlier predictions of impact rates, primarily because we assume a KBO size distribution that is shallower overall than previous studies did. The impact rate, combined with the observed crater SFD, will enable estimates of relative and absolute age of different geologic units, should different geologic units exist. We explore two scenarios in regards to the crater population: (1) a shallow (differential power-law index of p ∼ 2 , i.e. for dN / dD ∝D-p), based on the crater SFD observed on young terrains of Galilean and saturnian satellites; and (2) a slightly steeper SFD (p ∼ 3), based on extrapolations of larger (∼100 km) KBOs from ground-based surveys. If the observed primary crater SFD, at diameters less than a few tens of km, is consistent with a differential power-law index p ∼ 2 , that will confirm that KBOs are deficient in small bodies relative to extrapolations from known ∼100 km KBOs, consistent with expectations derived from examination of crater populations in young terrains on the Galilean and saturnian satellites. If the crater SFD has p ⩾ 3 over all observed sizes, then that power-law index applies across the KBO population over at least two orders of magnitude (1 km to100 km objects), and there must be some process that erodes the small KBOs when they migrate to the Jupiter-Saturn region of the Solar System. Whatever SFD is observed, the primary crater population on Pluto and Charon will provide the strongest constraint on the SFD of small KBOs, which will be beyond the observational reach of ground- and space-based telescopes for years to come. This, in turn, will provide a fundamental constraint for further understanding of the evolution of this distant and compelling population of bodies beyond Neptune.

Trends in absolute and relative educational inequalities in four modifiable ischaemic heart disease risk factors: repeated cross-sectional surveys from the Nord-Trøndelag Health Study (HUNT) 1984–2008

PubMed Central

2012-01-01

Background There has been an overall decrease in incident ischaemic heart disease (IHD), but the reduction in IHD risk factors has been greater among those with higher social position. Increased social inequalities in IHD mortality in Scandinavian countries is often referred to as the Scandinavian “public health puzzle”. The objective of this study was to examine trends in absolute and relative educational inequalities in four modifiable ischaemic heart disease risk factors (smoking, diabetes, hypertension and high total cholesterol) over the last three decades among Norwegian middle-aged women and men. Methods Population-based, cross-sectional data from The Nord-Trøndelag Health Study (HUNT): HUNT 1 (1984–1986), HUNT 2 (1995–1997) and HUNT 3 (2006–2008), women and men 40–59 years old. Educational inequalities were assessed using the Slope Index of Inequality (SII) and The Relative Index of Inequality (RII). Results Smoking prevalence increased for all education groups among women and decreased in men. Relative and absolute educational inequalities in smoking widened in both genders, with significantly higher absolute inequalities among women than men in the two last surveys. Diabetes prevalence increased in all groups. Relative inequalities in diabetes were stable, while absolute inequalities increased both among women (p = 0.05) and among men (p = 0.01). Hypertension prevalence decreased in all groups. Relative inequalities in hypertension widened over time in both genders. However, absolute inequalities in hypertension decreased among women (p = 0.05) and were stable among men (p = 0.33). For high total cholesterol relative and absolute inequalities remained stable in both genders. Conclusion Widening absolute educational inequalities in smoking and diabetes over the last three decades gives rise to concern. The mechanisms behind these results are less clear, and future studies are needed to assess if educational inequalities in secondary prevention of IHD are larger compared to educational inequalities in primary prevention of IHD. Continued monitoring of IHD risk factors at the population level is therefore warranted. The results emphasise the need for public health efforts to prevent future burdens of life-style-related diseases and to avoid further widening in socioeconomic inequalities in IHD mortality in Norway, especially among women. PMID:22471945

Simulation of a central scotoma using contact lenses with an opaque centre.

PubMed

Almutleb, Essam S; Bradley, Arthur; Jedlicka, Jason; Hassan, Shirin E

2018-01-01

This study evaluated the feasibility of using soft contact lenses (CLs) with an opaque centre to induce absolute central scotomas that move with the eye. We examined the geometrical optics prediction that scotoma size will vary with the size of the CL's opaque centre and with ocular pupil size. We also tested the hypothesis that high environmental light levels will ensure that the ocular pupil will remain small enough, even with opaque centre CLs, to generate absolute scotomas representative of those experienced by patients with age-related macular disease. Using an Octopus 900 Perimeter ( www.Haag-Streit.com), kinetic visual fields (VFs) were measured in five normally-sighted subjects using a V4e Goldmann target with CLs that had central opaque areas with diameters of 2.8, 3.0, and 3.2 mm. To control pupil size, VFs were measured with background perimeter bowl luminances of 10, 585, and 1155 cd m -2 . Subjects attempted to (i) fixate the bowl centre; and (ii) place the scotoma edge at the bowl fixation target (eccentric viewing). As predicted, there was a direct relationship between scotoma size and both luminance level and diameter of the opacity. Mean scotoma diameters were 0°, 17.6° and 22°, for the low, medium and high bowl luminances, respectively. Scotoma size was determined primarily by the difference between the diameters of CL opacity and the entrance pupil of the eye and the axial separation between them, and between-subject differences in pupil diameters contributed most to the between-subject variability in scotoma diameter at each light level (SD: 6.01°). Scotoma displacement during eccentric fixation confirmed the gaze-contingent characteristics of this experimental model. It is possible to induce a gaze-contingent absolute scotoma and hence mimic central vision loss using centrally-opaque CLs provided that the CL opacity is larger than the entrance pupil of the eye. This simulation tool will, therefore, be ineffective at low environmental light levels (as shown previously) if the entrance pupil of the eye is larger than the CL opacity. © 2017 The Authors Ophthalmic & Physiological Optics © 2017 The College of Optometrists.

Accounting for rate instability and spatial patterns in the boundary analysis of cancer mortality maps

PubMed Central

Goovaerts, Pierre

2006-01-01

Boundary analysis of cancer maps may highlight areas where causative exposures change through geographic space, the presence of local populations with distinct cancer incidences, or the impact of different cancer control methods. Too often, such analysis ignores the spatial pattern of incidence or mortality rates and overlooks the fact that rates computed from sparsely populated geographic entities can be very unreliable. This paper proposes a new methodology that accounts for the uncertainty and spatial correlation of rate data in the detection of significant edges between adjacent entities or polygons. Poisson kriging is first used to estimate the risk value and the associated standard error within each polygon, accounting for the population size and the risk semivariogram computed from raw rates. The boundary statistic is then defined as half the absolute difference between kriged risks. Its reference distribution, under the null hypothesis of no boundary, is derived through the generation of multiple realizations of the spatial distribution of cancer risk values. This paper presents three types of neutral models generated using methods of increasing complexity: the common random shuffle of estimated risk values, a spatial re-ordering of these risks, or p-field simulation that accounts for the population size within each polygon. The approach is illustrated using age-adjusted pancreatic cancer mortality rates for white females in 295 US counties of the Northeast (1970–1994). Simulation studies demonstrate that Poisson kriging yields more accurate estimates of the cancer risk and how its value changes between polygons (i.e. boundary statistic), relatively to the use of raw rates or local empirical Bayes smoother. When used in conjunction with spatial neutral models generated by p-field simulation, the boundary analysis based on Poisson kriging estimates minimizes the proportion of type I errors (i.e. edges wrongly declared significant) while the frequency of these errors is predicted well by the p-value of the statistical test. PMID:19023455

Atrial natriuretic peptide synthesis in atrial tumors of transgenic mice.

PubMed

Gardner, D G; Camargo, M J; Behringer, R R; Brinster, R L; Baxter, J D; Atlas, S A; Laragh, J H; Deschepper, C F

1992-04-01

Transgenic mice harboring a chimeric gene linking mouse protamine 1 5'-flanking sequence to the coding sequence of the simian virus 40 T-antigen develop spontaneous rhabdomyosarcomas of the right atria. The presence of the tumors is accompanied by dramatic elevations in plasma atrial natriuretic peptide (ANP) immunoreactivity (1,698 +/- 993 vs. 60 +/- 18 fmol/ml for controls) and hematocrit (56 +/- 8 vs. 51 +/- 2 for controls). The immunoreactive ANP (irANP) present in the tumors is similar in size to irANP found in normal mouse atria. ANP mRNA transcripts present in the tumors also appear to be very similar in overall size and 5'-termini to those produced in normal cardiac tissue. Microscopically, the tumors are composed of a disorganized array of densely packed abnormal-appearing cells. Immunocytochemistry and in situ hybridization analysis reveal considerable heterogeneity in ANP gene expression. ANP peptide and mRNA are detectable throughout the parenchyma of the tumors, but absolute levels of expression vary widely among different cells in the population. These tumors represent a potentially valuable model for the study of inappropriate ANP secretion and may provide a tissue source for the development of an ANP-producing atrial cell line.

Accuracy of Monte Carlo photon transport simulation in characterizing brachytherapy dosimeter energy-response artefacts.

PubMed

Das, R K; Li, Z; Perera, H; Williamson, J F

1996-06-01

Practical dosimeters in brachytherapy, such as thermoluminescent dosimeters (TLD) and diodes, are usually calibrated against low-energy megavoltage beams. To measure absolute dose rate near a brachytherapy source, it is necessary to establish the energy response of the detector relative to that of the calibration energy. The purpose of this paper is to assess the accuracy of Monte Carlo photon transport (MCPT) simulation in modelling the absolute detector response as a function of detector geometry and photon energy. We have exposed two different sizes of TLD-100 (LiF chips) and p-type silicon diode detectors to calibrated 60Co, HDR source (192Ir) and superficial x-ray beams. For the Scanditronix electron-field diode, the relative detector response, defined as the measured detector readings per measured unit of air kerma, varied from 38.46 V cGy-1 (40 kVp beam) to 6.22 V cGy-1 (60Co beam). Similarly for the large and small chips the same quantity varied from 2.08-3.02 nC cGy-1 and 0.171-0.244 nC cGy-1, respectively. Monte Carlo simulation was used to calculate the absorbed dose to the active volume of the detector per unit air kerma. If the Monte Carlo simulation is accurate, then the absolute detector response, which is defined as the measured detector reading per unit dose absorbed by the active detector volume, and is calculated by Monte Carlo simulation, should be a constant. For the diode, the absolute response is 5.86 +/- 0.15 (V cGy-1). For TLDs of size 3 x 3 x 1 mm3 the absolute response is 2.47 +/- 0.07 (nC cGy-1) and for TLDs of 1 x 1 x 1 mm3 it is 0.201 +/- 0.008 (nC cGy-1). From the above results we can conclude that the absolute response function of detectors (TLDs and diodes) is directly proportional to absorbed dose by the active volume of the detector and is independent of beam quality.

Special electronic distance meter calibration for precise engineering surveying industrial applications

NASA Astrophysics Data System (ADS)

Braun, Jaroslav; Štroner, Martin; Urban, Rudolf

2015-05-01

All surveying instruments and their measurements suffer from some errors. To refine the measurement results, it is necessary to use procedures restricting influence of the instrument errors on the measured values or to implement numerical corrections. In precise engineering surveying industrial applications the accuracy of the distances usually realized on relatively short distance is a key parameter limiting the resulting accuracy of the determined values (coordinates, etc.). To determine the size of systematic and random errors of the measured distances were made test with the idea of the suppression of the random error by the averaging of the repeating measurement, and reducing systematic errors influence of by identifying their absolute size on the absolute baseline realized in geodetic laboratory at the Faculty of Civil Engineering CTU in Prague. The 16 concrete pillars with forced centerings were set up and the absolute distances between the points were determined with a standard deviation of 0.02 millimetre using a Leica Absolute Tracker AT401. For any distance measured by the calibrated instruments (up to the length of the testing baseline, i.e. 38.6 m) can now be determined the size of error correction of the distance meter in two ways: Firstly by the interpolation on the raw data, or secondly using correction function derived by previous FFT transformation usage. The quality of this calibration and correction procedure was tested on three instruments (Trimble S6 HP, Topcon GPT-7501, Trimble M3) experimentally using Leica Absolute Tracker AT401. By the correction procedure was the standard deviation of the measured distances reduced significantly to less than 0.6 mm. In case of Topcon GPT-7501 is the nominal standard deviation 2 mm, achieved (without corrections) 2.8 mm and after corrections 0.55 mm; in case of Trimble M3 is nominal standard deviation 3 mm, achieved (without corrections) 1.1 mm and after corrections 0.58 mm; and finally in case of Trimble S6 is nominal standard deviation 1 mm, achieved (without corrections) 1.2 mm and after corrections 0.51 mm. Proposed procedure of the calibration and correction is in our opinion very suitable for increasing of the accuracy of the electronic distance measurement and allows the use of the common surveying instrument to achieve uncommonly high precision.

Eye height scaling of absolute size in immersive and nonimmersive displays

NASA Technical Reports Server (NTRS)

Dixon, M. W.; Wraga, M.; Proffitt, D. R.; Williams, G. C.; Kaiser, M. K. (Principal Investigator)

2000-01-01

Eye-height (EH) scaling of absolute height was investigated in three experiments. In Experiment 1, standing observers viewed cubes in an immersive virtual environment. Observers' center of projection was placed at actual EH and at 0.7 times actual EH. Observers' size judgments revealed that the EH manipulation was 76.8% effective. In Experiment 2, seated observers viewed the same cubes on an interactive desktop display; however, no effect of EH was found in response to the simulated EH manipulation. Experiment 3 tested standing observers in the immersive environment with the field of view reduced to match that of the desktop. Comparable to Experiment 1, the effect of EH was 77%. These results suggest that EH scaling is not generally used when people view an interactive desktop display because the altitude of the center of projection is indeterminate. EH scaling is spontaneously evoked, however, in immersive environments.

Absolute versus relative intensity of physical activity in a dose-response context.

PubMed

Shephard, R J

2001-06-01

To examine the importance of relative versus absolute intensities of physical activity in the context of population health. A standard computer-search of the literature was supplemented by review of extensive personal files. Consensus reports (Category D Evidence) have commonly recommended moderate rather than hard physical activity in the context of population health. Much of the available literature provides Category C Evidence. It has often confounded issues of relative intensity with absolute intensity or total weekly dose of exercise. In terms of cardiovascular health, there is some evidence for a threshold intensity of effort, perhaps as high as 6 METs, in addition to a minimum volume of physical activity. Decreases in blood pressure and prevention of stroke seem best achieved by moderate rather than high relative intensities of physical activity. Many aspects of metabolic health depend on the total volume of activity; moderate relative intensities of effort are more effective in mobilizing body fat, but harder relative intensities may help to increase energy expenditures postexercise. Hard relative intensities seem needed to augment bone density, but this may reflect an associated increase in volume of activity. Hard relative intensities of exercise induce a transient immunosuppression. The optimal intensity of effort, relative or absolute, for protection against various types of cancer remains unresolved. Acute effects of exercise on mood state also require further study; long-term benefits seem associated with a moderate rather than a hard relative intensity of effort. The importance of relative versus absolute intensity of effort depends on the desired health outcome, and many issues remain to be resolved. Progress will depend on more precise epidemiological methods of assessing energy expenditures and studies that equate total energy expenditures between differing relative intensities. There is a need to focus on gains in quality-adjusted life expectancy.

Absolute and Functional Iron Deficiency Is a Common Finding in Patients With Heart Failure and After Heart Transplantation.

PubMed

Przybylowski, P; Wasilewski, G; Golabek, K; Bachorzewska-Gajewska, H; Dobrzycki, S; Koc-Zorawska, E; Malyszko, J

2016-01-01

Anemia is relatively common in patients with heart failure and heart transplant recipients. Both absolute and functional iron deficiency may contribute to the anemia in these populations. Functional iron deficiency (defined as ferritin greater than 200 ng/mL with TSAT (Transferrin saturation) less than 20%) is characterized by the presence of adequate iron stores as defined by conventional criteria, but with insufficient iron mobilization to adequately support. The aim of this study was to determine prevalence of absolute and functional iron deficiency in patients with heart failure (n = 269) and after heart transplantation (n = 130) and their relation to parameters of iron status and inflammation. Iron status, complete blood count, and creatinine levels were assessed using standard laboratory methods. C-reactive protein, hepcidin and hemojuvelin were measured using commercially available kits. Absolute iron deficiency was present in 15% of patients with heart failure and 30% in heart transplant recipients, whereas functional iron deficiency was present in 18% of patients with heart failure and 17% in heart transplant recipients. Functional iron deficiency was associated with significantly higher C-reactive protein and hepcidin levels in heart failure patients, and higher hepcidin and lower estimate glomerular filtration rates in heart transplant recipients. Prevalence of anemia (according to the World Health Organization) was significantly higher in heart transplant recipients (40% vs 22%, P < .001), they were also younger, but with worse kidney function than patients with heart failure. Both absolute and functional iron deficiency were present in a considerable group of patients. This population should be carefully screened for possible reversible causes of inflammation. Copyright © 2016 Elsevier Inc. All rights reserved.

Gender differences in socioeconomic inequality in mortality.

PubMed

Mustard, C A; Etches, J

2003-12-01

There is uncertainty about whether position in a socioeconomic hierarchy confers different mortality risks on men and women. The objective of this study was to conduct a systematic review of gender differences in socioeconomic inequality in risk of death. This research systematically reviewed observational cohort studies describing all cause or cause specific mortality for populations aged 25-64 in developed countries. For inclusion in the review, mortality had to be reported stratified by gender and by one or more measures of socioeconomic status. For all eligible studies, five absolute and six relative measures of the socioeconomic inequality in mortality were computed for male and female populations separately. A total of 136 published papers were reviewed for eligibility, with 58 studies deemed eligible for inclusion. Of these eligible studies, 20 papers published data that permitted the computation of both absolute and relative measures of inequality. Absolute measures of socioeconomic mortality inequality for men and women generally agreed, with about 90% of studies indicating that male mortality was more unequal than female mortality across socioeconomic groups. In contrast, the pattern of relative inequality results across the 20 studies suggested that male and female socioeconomic inequality in mortality was equivalent. Inferences about gender differences in socioeconomic inequality in mortality are sensitive to the choice of inequality measure. Wider understanding of this methodological issue would improve the clarity of the reporting and synthesis of evidence on the magnitude of health inequalities in populations.

Efficient Merge and Insert Operations for Binary Heaps and Trees

NASA Technical Reports Server (NTRS)

Kuszmaul, Christopher Lee; Woo, Alex C. (Technical Monitor)

2000-01-01

Binary heaps and binary search trees merge efficiently. We introduce a new amortized analysis that allows us to prove the cost of merging either binary heaps or balanced binary trees is O(l), in the amortized sense. The standard set of other operations (create, insert, delete, extract minimum, in the case of binary heaps, and balanced binary trees, as well as a search operation for balanced binary trees) remain with a cost of O(log n). For binary heaps implemented as arrays, we show a new merge algorithm that has a single operation cost for merging two heaps, a and b, of O(absolute value of a + min(log absolute value of b log log absolute value of b. log absolute value of a log absolute value of b). This is an improvement over O(absolute value of a + log absolute value of a log absolute value of b). The cost of the new merge is so low that it can be used in a new structure which we call shadow heaps. to implement the insert operation to a tunable efficiency. Shadow heaps support the insert operation for simple priority queues in an amortized time of O(f(n)) and other operations in time O((log n log log n)/f (n)), where 1 less than or equal to f (n) less than or equal to log log n. More generally, the results here show that any data structure with operations that change its size by at most one, with the exception of a merge (aka meld) operation, can efficiently amortize the cost of the merge under conditions that are true for most implementations of binary heaps and search trees.

[Disease numbers in pneumology - a projection to 2060].

PubMed

Pritzkuleit, R; Beske, F; Katalinic, A

2010-09-01

The demographic change leads to a change in the age-composition of the population. We have calculated a status quo projection of the absolute numbers for five diagnoses of the lung (COPD, CAP, lung cancer, bronchial asthma and tuberculosis) for Germany up to 2060. Based on the 12 (th) coordinated population prediction of the Federal Statistics Office, we transferred age- and sex-specific incidence and prevalence rates, respectively, to the expected population. All described developments are based solely on demographic changes. The absolute numbers of bronchial asthma and tuberculosis will experience a minor decrease. We expect at first increasing and later decreasing case numbers for COPD and lung cancer. A major increase of the case numbers for CAP will be probable. By reason of a decreasing population, the rates (burden of disease for the population) will increase considerably. The demographic change is mainly caused by increasing life expectancy, constantly low birth rates, and the entry of the baby-boom generation into the age of higher disease risks. A discussion about prioritisation of health care is needed because of the rising burdens for the health system, including diseases of the lung. Copyright Georg Thieme Verlag KG Stuttgart . New York.

Particle visualization in high-power impulse magnetron sputtering. II. Absolute density dynamics

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

Britun, Nikolay, E-mail: nikolay.britun@umons.ac.be; Palmucci, Maria; Konstantinidis, Stephanos

2015-04-28

Time-resolved characterization of an Ar-Ti high-power impulse magnetron sputtering discharge has been performed. The present, second, paper of the study is related to the discharge characterization in terms of the absolute density of species using resonant absorption spectroscopy. The results on the time-resolved density evolution of the neutral and singly-ionized Ti ground state atoms as well as the metastable Ti and Ar atoms during the discharge on- and off-time are presented. Among the others, the questions related to the inversion of population of the Ti energy sublevels, as well as to re-normalization of the two-dimensional density maps in terms ofmore » the absolute density of species, are stressed.« less

Optoelectronic device for the measurement of the absolute linear position in the micrometric displacement range

NASA Astrophysics Data System (ADS)

Morlanes, Tomas; de la Pena, Jose L.; Sanchez-Brea, Luis M.; Alonso, Jose; Crespo, Daniel; Saez-Landete, Jose B.; Bernabeu, Eusebio

2005-07-01

In this work, an optoelectronic device that provides the absolute position of a measurement element with respect to a pattern scale upon switch-on is presented. That means that there is not a need to perform any kind of transversal displacement after the startup of the system. The optoelectronic device is based on the process of light propagation passing through a slit. A light source with a definite size guarantees the relation of distances between the different elements that constitute our system and allows getting a particular optical intensity profile that can be measured by an electronic post-processing device providing the absolute location of the system with a resolution of 1 micron. The accuracy of this measuring device is restricted to the same limitations of any incremental position optical encoder.

Self-Referenced Method for Estimating Refractive Index and Absolute Absorption of Loose Semiconductor Powders

DOE PAGES

Huang, Huafeng; Colabello, Diane M.; Sklute, Elizabeth C.; ...

2017-04-23

The absolute absorption coefficient, α(E), is a critical design parameter for devices using semiconductors for light harvesting associated with renewable energy production, both for classic technologies such as photovoltaics and for emerging technologies such as direct solar fuel production. While α(E) is well-known for many classic simple semiconductors used in photovoltaic applications, the absolute values of α(E) are typically unknown for the complex semiconductors being explored for solar fuel production due to the absence of single crystals or crystalline epitaxial films that are needed for conventional methods of determining α(E). In this work, a simple self-referenced method for estimating bothmore » the refractive indices, n(E), and absolute absorption coefficients, α(E), for loose powder samples using diffuse reflectance data is demonstrated. In this method, the sample refractive index can be deduced by refining n to maximize the agreement between the relative absorption spectrum calculated from bidirectional reflectance data (calculated through a Hapke transform which depends on n) and integrating sphere diffuse reflectance data (calculated through a Kubleka–Munk transform which does not depend on n). This new method can be quickly used to screen the suitability of emerging semiconductor systems for light-harvesting applications. The effectiveness of this approach is tested using the simple classic semiconductors Ge and Fe 2O 3 as well as the complex semiconductors La 2MoO 5 and La 4Mo 2O 11. The method is shown to work well for powders with a narrow size distribution (exemplified by Fe 2O 3) and to be ineffective for semiconductors with a broad size distribution (exemplified by Ge). As such, it provides a means for rapidly estimating the absolute optical properties of complex solids which are only available as loose powders.« less

Absolute Depth Sensitivity in Cat Primary Visual Cortex under Natural Viewing Conditions.

PubMed

Pigarev, Ivan N; Levichkina, Ekaterina V

2016-01-01

Mechanisms of 3D perception, investigated in many laboratories, have defined depth either relative to the fixation plane or to other objects in the visual scene. It is obvious that for efficient perception of the 3D world, additional mechanisms of depth constancy could operate in the visual system to provide information about absolute distance. Neurons with properties reflecting some features of depth constancy have been described in the parietal and extrastriate occipital cortical areas. It has also been shown that, for some neurons in the visual area V1, responses to stimuli of constant angular size differ at close and remote distances. The present study was designed to investigate whether, in natural free gaze viewing conditions, neurons tuned to absolute depths can be found in the primary visual cortex (area V1). Single-unit extracellular activity was recorded from the visual cortex of waking cats sitting on a trolley in front of a large screen. The trolley was slowly approaching the visual scene, which consisted of stationary sinusoidal gratings of optimal orientation rear-projected over the whole surface of the screen. Each neuron was tested with two gratings, with spatial frequency of one grating being twice as high as that of the other. Assuming that a cell is tuned to a spatial frequency, its maximum response to the grating with a spatial frequency twice as high should be shifted to a distance half way closer to the screen in order to attain the same size of retinal projection. For hypothetical neurons selective to absolute depth, location of the maximum response should remain at the same distance irrespective of the type of stimulus. It was found that about 20% of neurons in our experimental paradigm demonstrated sensitivity to particular distances independently of the spatial frequencies of the gratings. We interpret these findings as an indication of the use of absolute depth information in the primary visual cortex.

Should Tricuspid Annuloplasty be Performed With Pulmonary Valve Replacement for Pulmonary Regurgitation in Repaired Tetralogy of Fallot?

PubMed

Kurkluoglu, Mustafa; John, Anitha S; Cross, Russell; Chung, David; Yerebakan, Can; Zurakowski, David; Jonas, Richard A; Sinha, Pranava

2015-01-01

Indications for prophylactic tricuspid annuloplasty in patients with pulmonary regurgitation (PR) after tetralogy of Fallot (TOF) repair are unclear and often extrapolated from acquired functional tricuspid regurgitation (TR) data in adults, where despite correction of primary left heart pathology, progressive tricuspid annular dilation is noted beyond a threshold diameter >4 cm (21 mm/m(2)). We hypothesized that unlike in adult functional TR, in pure volume-overload conditions such as patients with PR after TOF, the tricuspid valve size is likely to regress after pulmonary valve replacement (PVR). A total of 43 consecutive patients who underwent PVR from 2005 until 2012 at a single institution were retrospectively reviewed. Absolute and indexed tricuspid annulus diameters (TADs), tricuspid annulus Z-scores, grade of TR along with right ventricular size, and function indices were recorded before and after PVR. Preoperative and postoperative echocardiographic data were available in all patients. A higher tricuspid valve Z-score correlated with greater TR both preoperatively (P = 0.005) and postoperatively (P = 0.02). Overall reductions in the absolute and indexed TAD and tricuspid valve Z-scores were seen postoperatively, with greater absolute as well as percentage reduction seen with larger preoperative TAD index (P = 0.007) and higher tricuspid annulus Z-scores (P = 0.06). In pure volume-overload conditions such as patients with PR after TOF, reduction in the tricuspid valve size is seen after PVR. Concomitant tricuspid annuloplasty should not be considered based on tricuspid annular dilation alone. Copyright © 2015 Elsevier Inc. All rights reserved.

Socioeconomic differences in emotional symptoms among adolescents in the Nordic countries: recommendations on how to present inequality.

PubMed

Nielsen, Line; Damsgaard, Mogens Trab; Meilstrup, Charlotte; Due, Pernille; Madsen, Katrine Rich; Koushede, Vibeke; Holstein, Bjørn Evald

2015-02-01

This comparative study examines absolute and relative socioeconomic differences in emotional symptoms among adolescents using standardised data from five Nordic countries and gives recommendations on how to present socioeconomic inequality. The Health Behaviour in School-aged Children (HBSC) international cross-sectional study from 2005/2006 provided data on 29,642 11-15-year-old adolescents from nationally random samples in Denmark, Finland, Iceland, Norway and Sweden. The outcome was daily emotional symptoms. Family Affluence Scale (FAS) was used as indicator of socioeconomic position. We applied four summary measures of inequality: Prevalence Difference, Odds Ratio, Slope Index of Inequality and Relative Index of Inequality, and presented the socioeconomic inequality by a graphical illustration of the prevalence of emotional symptoms, the size of the FAS groups and the summary indices of inequality in each country. The prevalence of emotional symptoms ranged from 8.1% in Denmark to 13.2% in Iceland. There were large country variations in the size of the low FAS-group ranging from 2% in Iceland to 12% in Finland. The largest absolute and relative socioeconomic inequalities were found in Iceland and the smallest in Finland for girls and in Denmark for boys. Emotional symptoms were more common among nordic adolescents from low affluence families this association appeared in the study of both absolute and relative inequality. A comprehensive presentation of socioeconomic inequality should include the prevalence of the health outcome, the size of the socioeconomic groups, and the regression line representing the summary indices of inequality. © 2014 the Nordic Societies of Public Health.

Volume reduction of benign thyroid nodules 3 months after a single treatment with high-intensity focused ultrasound (HIFU).

PubMed

Korkusuz, Huedayi; Fehre, Niklas; Sennert, Michael; Happel, Christian; Grünwald, Frank

2015-01-01

High-intensity focused ultrasound (HIFU) is a promising, non-invasive technique in treating benign thyroid nodules (TNs). The aim of this study was to evaluate the efficacy of HIFU to induce clinically meaningful shrinkage in benign predominantly solid TNs and to identify variables that influence or predict the magnitude of TN volume reduction. For each of ten subjects, HIFU treatment was conducted on a single nodule. Nodular volume was measured sonographically at baseline and at 3 months post-procedure. Nodular function and early treatment assessment was done scintigraphically. Median nodular volume reduction was 0.7 ml absolute and 48.8% relative to pre-interventional size (p < 0.05). Absolute shrinkage was negatively correlated with the average treatment depth (τ = -0.61, p < 0.05). Absolute nodular volume was positively correlated with the scintigraphic nodular uptake reduction (τ = 0.66, p < 0.05). HIFU treatment of benign predominantly solid TNs appears to be safe and effective for inducing nodular shrinkage. Despite potential for improvement, a single treatment session with HIFU is already a viable alternative to more standard methods. The feasibility of multiple HIFU treatments requires further investigation. Due to the small sample size, the findings of this analysis need conformation by larger studies.

Size-specific dose estimate (SSDE) provides a simple method to calculate organ dose for pediatric CT examinations

PubMed Central

Moore, Bria M.; Brady, Samuel L.; Mirro, Amy E.; Kaufman, Robert A.

2014-01-01

Purpose: To investigate the correlation of size-specific dose estimate (SSDE) with absorbed organ dose, and to develop a simple methodology for estimating patient organ dose in a pediatric population (5–55 kg). Methods: Four physical anthropomorphic phantoms representing a range of pediatric body habitus were scanned with metal oxide semiconductor field effect transistor (MOSFET) dosimeters placed at 23 organ locations to determine absolute organ dose. Phantom absolute organ dose was divided by phantom SSDE to determine correlation between organ dose and SSDE. Organ dose correlation factors (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${\\rm CF}_{{\\rm SSDE}}^{{\\rm organ}}$\\end{document} CF SSDE organ ) were then multiplied by patient-specific SSDE to estimate patient organ dose. The \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${\\rm CF}_{{\\rm SSDE}}^{{\\rm organ}}$\\end{document} CF SSDE organ were used to retrospectively estimate individual organ doses from 352 chest and 241 abdominopelvic pediatric CT examinations, where mean patient weight was 22 kg ± 15 (range 5–55 kg), and mean patient age was 6 yrs ± 5 (range 4 months to 23 yrs). Patient organ dose estimates were compared to published pediatric Monte Carlo study results. Results: Phantom effective diameters were matched with patient population effective diameters to within 4 cm; thus, showing appropriate scalability of the phantoms across the entire pediatric population in this study. Individual\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${\\rm CF}_{{\\rm SSDE}}^{{\\rm organ}}$\\end{document} CF SSDE organ were determined for a total of 23 organs in the chest and abdominopelvic region across nine weight subcategories. For organs fully covered by the scan volume, correlation in the chest (average 1.1; range 0.7–1.4) and abdominopelvic region (average 0.9; range 0.7–1.3) was near unity. For organ/tissue that extended beyond the scan volume (i.e., skin, bone marrow, and bone surface), correlation was determined to be poor (average 0.3; range: 0.1–0.4) for both the chest and abdominopelvic regions, respectively. A means to estimate patient organ dose was demonstrated. Calculated patient organ dose, using patient SSDE and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${\\rm CF}_{{\\rm SSDE}}^{{\\rm organ}}$\\end{document} CF SSDE organ , was compared to previously published pediatric patient doses that accounted for patient size in their dose calculation, and was found to agree in the chest to better than an average of 5% (27.6/26.2) and in the abdominopelvic region to better than 2% (73.4/75.0). Conclusions: For organs fully covered within the scan volume, the average correlation of SSDE and organ absolute dose was found to be better than ±10%. In addition, this study provides a complete list of organ dose correlation factors (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${\\rm CF}_{{\\rm SSDE}}^{{\\rm organ}}$\\end{document} CF SSDE organ ) for the chest and abdominopelvic regions, and describes a simple methodology to estimate individual pediatric patient organ dose based on patient SSDE. PMID:24989395

Determinants of Market Structure and the Airline Industry

NASA Technical Reports Server (NTRS)

Raduchel, W.

1972-01-01

The general economic determinants of market structure are outlined with special reference to the airline industry. Included are the following facets: absolute size of firms; distributions of firms by size; concentration; entry barriers; product and service differentiation; diversification; degrees of competition; vertical integration; market boundaries; and economies of scale. Also examined are the static and dynamic properties of market structure in terms of mergers, government policies, and economic growth conditions.

Lunar impact basins: Stratigraphy, sequence and ages from superposed impact crater populations measured from Lunar Orbiter Laser Altimeter (LOLA) data

NASA Astrophysics Data System (ADS)

Fassett, C. I.; Head, J. W.; Kadish, S. J.; Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

2012-02-01

Impact basin formation is a fundamental process in the evolution of the Moon and records the history of impactors in the early solar system. In order to assess the stratigraphy, sequence, and ages of impact basins and the impactor population as a function of time, we have used topography from the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO) to measure the superposed impact crater size-frequency distributions for 30 lunar basins (D ≥ 300 km). These data generally support the widely used Wilhelms sequence of lunar basins, although we find significantly higher densities of superposed craters on many lunar basins than derived by Wilhelms (50% higher densities). Our data also provide new insight into the timing of the transition between distinct crater populations characteristic of ancient and young lunar terrains. The transition from a lunar impact flux dominated by Population 1 to Population 2 occurred before the mid-Nectarian. This is before the end of the period of rapid cratering, and potentially before the end of the hypothesized Late Heavy Bombardment. LOLA-derived crater densities also suggest that many Pre-Nectarian basins, such as South Pole-Aitken, have been cratered to saturation equilibrium. Finally, both crater counts and stratigraphic observations based on LOLA data are applicable to specific basin stratigraphic problems of interest; for example, using these data, we suggest that Serenitatis is older than Nectaris, and Humboldtianum is younger than Crisium. Sample return missions to specific basins can anchor these measurements to a Pre-Imbrian absolute chronology.

Lunar Impact Basins: Stratigraphy, Sequence and Ages from Superposed Impact Crater Populations Measured from Lunar Orbiter Laser Altimeter (LOLA) Data

NASA Technical Reports Server (NTRS)

Fassett, C. I.; Head, J. W.; Kadish, S. J.; Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

2012-01-01

Impact basin formation is a fundamental process in the evolution of the Moon and records the history of impactors in the early solar system. In order to assess the stratigraphy, sequence, and ages of impact basins and the impactor population as a function of time, we have used topography from the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO) to measure the superposed impact crater size-frequency distributions for 30 lunar basins (D = 300 km). These data generally support the widely used Wilhelms sequence of lunar basins, although we find significantly higher densities of superposed craters on many lunar basins than derived by Wilhelms (50% higher densities). Our data also provide new insight into the timing of the transition between distinct crater populations characteristic of ancient and young lunar terrains. The transition from a lunar impact flux dominated by Population 1 to Population 2 occurred before the mid-Nectarian. This is before the end of the period of rapid cratering, and potentially before the end of the hypothesized Late Heavy Bombardment. LOLA-derived crater densities also suggest that many Pre-Nectarian basins, such as South Pole-Aitken, have been cratered to saturation equilibrium. Finally, both crater counts and stratigraphic observations based on LOLA data are applicable to specific basin stratigraphic problems of interest; for example, using these data, we suggest that Serenitatis is older than Nectaris, and Humboldtianum is younger than Crisium. Sample return missions to specific basins can anchor these measurements to a Pre-Imbrian absolute chronology.

Socioeconomic inequalities in suicide in Europe: the widening gap.

PubMed

Lorant, Vincent; de Gelder, Rianne; Kapadia, Dharmi; Borrell, Carme; Kalediene, Ramune; Kovács, Katalin; Leinsalu, Mall; Martikainen, Pekka; Menvielle, Gwenn; Regidor, Enrique; Rodríguez-Sanz, Maica; Wojtyniak, Bogdan; Strand, Bjørn Heine; Bopp, Matthias; Mackenbach, Johan P

2018-06-01

Suicide has been decreasing over the past decade. However, we do not know whether socioeconomic inequality in suicide has been decreasing as well.AimsWe assessed recent trends in socioeconomic inequalities in suicide in 15 European populations. The DEMETRIQ study collected and harmonised register-based data on suicide mortality follow-up of population censuses, from 1991 and 2001, in European populations aged 35-79. Absolute and relative inequalities of suicide according to education were computed on more than 300 million person-years. In the 1990s, people in the lowest educational group had 1.82 times more suicides than those in the highest group. In the 2000s, this ratio increased to 2.12. Among men, absolute and relative inequalities were substantial in both periods and generally did not decrease over time, whereas among women inequalities were absent in the first period and emerged in the second. The World Health Organization (WHO) plan for 'Fair opportunity of mental wellbeing' is not likely to be met.Declaration of interestNone.

Split-step eigenvector-following technique for exploring enthalpy landscapes at absolute zero.

PubMed

Mauro, John C; Loucks, Roger J; Balakrishnan, Jitendra

2006-03-16

The mapping of enthalpy landscapes is complicated by the coupling of particle position and volume coordinates. To address this issue, we have developed a new split-step eigenvector-following technique for locating minima and transition points in an enthalpy landscape at absolute zero. Each iteration is split into two steps in order to independently vary system volume and relative atomic coordinates. A separate Lagrange multiplier is used for each eigendirection in order to provide maximum flexibility in determining step sizes. This technique will be useful for mapping the enthalpy landscapes of bulk systems such as supercooled liquids and glasses.

Design considerations and validation of the MSTAR absolute metrology system

NASA Astrophysics Data System (ADS)

Peters, Robert D.; Lay, Oliver P.; Dubovitsky, Serge; Burger, Johan; Jeganathan, Muthu

2004-08-01

Absolute metrology measures the actual distance between two optical fiducials. A number of methods have been employed, including pulsed time-of-flight, intensity-modulated optical beam, and two-color interferometry. The rms accuracy is currently limited to ~5 microns. Resolving the integer number of wavelengths requires a 1-sigma range accuracy of ~0.1 microns. Closing this gap has a large pay-off: the range (length measurement) accuracy can be increased substantially using the unambiguous optical phase. The MSTAR sensor (Modulation Sideband Technology for Absolute Ranging) is a new system for measuring absolute distance, capable of resolving the integer cycle ambiguity of standard interferometers, and making it possible to measure distance with sub-nanometer accuracy. In this paper, we present recent experiments that use dispersed white light interferometry to independently validate the zero-point of the system. We also describe progress towards reducing the size of optics, and stabilizing the laser wavelength for operation over larger target ranges. MSTAR is a general-purpose tool for conveniently measuring length with much greater accuracy than was previously possible, and has a wide range of possible applications.

Seamount statistics in the Pacific Ocean

NASA Astrophysics Data System (ADS)

Smith, Deborah K.; Jordan, Thomas H.

1988-04-01

We apply the wide-beam sampling technique of Jordan et al. (1983) to approximately 157,000 km of wide-beam profiles to obtain seamount population statistics for eight regions in the eastern and southern Pacific Ocean. Population statistics derived from wide-beam echograms are compared with seamount counts from Sea Beam swaths and with counts from bathymetric maps. We find that the average number of seamounts with summit heights h ≥ H is well-approximated by the exponential frequency-size distribution: ν(H)=νoe-βH. The exponential model for seamount sizes, characterized by the single scale parameter β-1, is found to be superior to a power-law (self-similar) model, which has no intrinsic scale, in describing the average distribution of Pacific seamounts, and it appears to be valid over a size spectrum spanning 5 orders of magnitude in abundance. Large-scale regional variations in seamount populations are documented. We observe significant differences in seamount densities across the Murray fracture zone in the North Pacific and the Eltanin fracture zone system in the South Pacific. The Eltanin discontinuity is equally evident on both sides of the Pacific-Antarctic ridge. In the South Pacific, regions symmetrically disposed about the ridge axis have very similar seamount densities, despite the large difference between Pacific plate and Antarctic plate absolute velocities; evidently, any differences in the shear flows at the base of the Pacific and Antarctic plates do not affect seamount emplacement. Systematic variations in νo and β are observed as a function of lithospheric age, with the number of large seamounts increasing more rapidly than small seamounts. These observations have been used to develop a simple model for seamount production under the assumptions that (1) an exponential size-frequency distribution is maintained, (2) production is steady state, and (3) most small seamounts are formed on or near the ridge axis. The limited data available from this study appear to be consistent with the model, but they are insufficient to provide a rigorous test of the assumptions or determine accurately the model parameters. However, the data from the South Pacific indicate that the off-axis production of large seamounts probably accounts for the majority of seamounts with summit heights greater than 1000 m.

Biological characteristics of crucian by quantitative inspection method

NASA Astrophysics Data System (ADS)

Chu, Mengqi

2015-04-01

Biological characteristics of crucian by quantitative inspection method Through quantitative inspection method , the biological characteristics of crucian was preliminary researched. Crucian , Belongs to Cypriniformes, Cyprinidae, Carassius auratus, is a kind of main plant-eating omnivorous fish,like Gregarious, selection and ranking. Crucian are widely distributed, perennial water all over the country all have production. Determine the indicators of crucian in the experiment, to understand the growth, reproduction situation of crucian in this area . Using the measured data (such as the scale length ,scale size and wheel diameter and so on) and related functional to calculate growth of crucian in any one year.According to the egg shape, color, weight ,etc to determine its maturity, with the mean egg diameter per 20 eggs and the number of eggs per 0.5 grams, to calculate the relative and absolute fecundity of the fish .Measured crucian were female puberty. Based on the relation between the scale diameter and length and the information, linear relationship between crucian scale diameter and length: y=1.530+3.0649. From the data, the fertility and is closely relative to the increase of age. The older, the more mature gonad development. The more amount of eggs. In addition, absolute fecundity increases with the pituitary gland.Through quantitative check crucian bait food intake by the object, reveals the main food, secondary foods, and chance food of crucian ,and understand that crucian degree of be fond of of all kinds of bait organisms.Fish fertility with weight gain, it has the characteristics of species and populations, and at the same tmes influenced by the age of the individual, body length, body weight, environmental conditions (especially the nutrition conditions), and breeding habits, spawning times factors and the size of the egg. After a series of studies of crucian biological character, provide the ecological basis for local crucian's feeding, breeding, proliferation, fishing, resources protection and management of specific plans.

Determination of the Absolute Number of Cytokine mRNA Molecules within Individual Activated Human T Cells

NASA Technical Reports Server (NTRS)

Karr, Laurel J.; Marshall, Gwen; Hockett, Richard D.; Bucy, R. Pat; Curreri, Peter A. (Technical Monitor)

2002-01-01

A primary function of activated T cells is the expression and subsequent secretion of cytokines, which orchestrate the differentiation of other lymphocytes, modulate antigen presenting cell activity, and alter vascular endothelium to mediate an immune response. Since many features of immune regulation probably result from modest alterations of endogenous rates of multiple interacting processes, quantitative analysis of the frequency and specific activity of individual T cells is critically important. Using a coordinated set of quantitative methods, the absolute number of molecules of several key cytokine mRNA species in individual T cells has been determined. The frequency of human blood T cells activated in vitro by mitogens and recall protein antigens was determined by intracellular cytokine protein staining, in situ hybridization for cytokine mRNA, and by limiting dilution analysis for cytokine mRNA+ cells. The absolute number of mRNA molecules was simultaneously determined in both homogenates of the entire population of cells and in individual cells obtained by limiting dilution, using a quantitative, competitive RT-PCR assay. The absolute numbers of mRNA molecules in a population of cells divided by the frequency of individual positive cells, yielded essentially the same number of mRNA molecules per cell as direct analysis of individual cells by limiting dilution analysis. Mean numbers of mRNA per positive cell from both mitogen and antigen activated T cells, using these stimulation conditions, were 6000 for IL-2, 6300 for IFN-gamma, and 1600 for IL-4.

Strong fluctuations in aboveground population size do not limit genetic diversity in populations of an endangered biennial species.

PubMed

Münzbergová, Zuzana; Šurinová, Maria; Husáková, Iveta; Brabec, Jiří

2018-04-26

Assessing genetic diversity within populations of rare species and understanding its determinants are crucial for effective species protection. While a lot is known about the relationships between genetic diversity, fitness, and current population size, very few studies explored the effects of past population size. Knowledge of past population size may, however, improve our ability to predict future population fates. We studied Gentianella praecox subsp. bohemica, a biennial species with extensive seed bank. We tested the effect of current, past minimal and maximal population size, and harmonic mean of population sizes within the last 15 years on genetic diversity and fitness. Maximum population size over the last 15 years was the best predictor of expected heterozygosity of the populations and was significantly related to current population size and management. Plant fitness was significantly related to current as well as maximum population size and expected heterozygosity. The results suggested that information on past population size may improve our understanding of contemporary genetic diversity across populations. They demonstrated that despite the strong fluctuations in population size, large reductions in population size do not result in immediate loss of genetic diversity and reduction of fitness within the populations. This is likely due to the seed bank of the species serving as reservoir of the genetic diversity of the populations. From a conservation point of view, this suggests that the restoration of small populations of short-lived species with permanent seed bank is possible as these populations may still be genetically diverse.

Rate of tree carbon accumulation increases continuously with tree size

USGS Publications Warehouse

Stephenson, N.L.; Das, A.J.; Condit, R.; Russo, S.E.; Baker, P.J.; Beckman, N.G.; Coomes, D.A.; Lines, E.R.; Morris, W.K.; Rüger, N.; Álvarez, E.; Blundo, C.; Bunyavejchewin, S.; Chuyong, G.; Davies, S.J.; Duque, Á.; Ewango, C.N.; Flores, O.; Franklin, J.F.; Grau, H.R.; Hao, Z.; Harmon, M.E.; Hubbell, S.P.; Kenfack, D.; Lin, Y.; Makana, J.-R.; Malizia, A.; Malizia, L.R.; Pabst, R.J.; Pongpattananurak, N.; Su, S.-H.; Sun, I-F.; Tan, S.; Thomas, D.; van Mantgem, P.J.; Wang, X.; Wiser, S.K.; Zavala, M.A.

2014-01-01

Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle—particularly net primary productivity and carbon storage - increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree’s total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to understand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

Rate of tree carbon accumulation increases continuously with tree size.

PubMed

Stephenson, N L; Das, A J; Condit, R; Russo, S E; Baker, P J; Beckman, N G; Coomes, D A; Lines, E R; Morris, W K; Rüger, N; Alvarez, E; Blundo, C; Bunyavejchewin, S; Chuyong, G; Davies, S J; Duque, A; Ewango, C N; Flores, O; Franklin, J F; Grau, H R; Hao, Z; Harmon, M E; Hubbell, S P; Kenfack, D; Lin, Y; Makana, J-R; Malizia, A; Malizia, L R; Pabst, R J; Pongpattananurak, N; Su, S-H; Sun, I-F; Tan, S; Thomas, D; van Mantgem, P J; Wang, X; Wiser, S K; Zavala, M A

2014-03-06

Forests are major components of the global carbon cycle, providing substantial feedback to atmospheric greenhouse gas concentrations. Our ability to understand and predict changes in the forest carbon cycle--particularly net primary productivity and carbon storage--increasingly relies on models that represent biological processes across several scales of biological organization, from tree leaves to forest stands. Yet, despite advances in our understanding of productivity at the scales of leaves and stands, no consensus exists about the nature of productivity at the scale of the individual tree, in part because we lack a broad empirical assessment of whether rates of absolute tree mass growth (and thus carbon accumulation) decrease, remain constant, or increase as trees increase in size and age. Here we present a global analysis of 403 tropical and temperate tree species, showing that for most species mass growth rate increases continuously with tree size. Thus, large, old trees do not act simply as senescent carbon reservoirs but actively fix large amounts of carbon compared to smaller trees; at the extreme, a single big tree can add the same amount of carbon to the forest within a year as is contained in an entire mid-sized tree. The apparent paradoxes of individual tree growth increasing with tree size despite declining leaf-level and stand-level productivity can be explained, respectively, by increases in a tree's total leaf area that outpace declines in productivity per unit of leaf area and, among other factors, age-related reductions in population density. Our results resolve conflicting assumptions about the nature of tree growth, inform efforts to undertand and model forest carbon dynamics, and have additional implications for theories of resource allocation and plant senescence.

The influence of solid rocket motor retro-burns on the space debris environment

NASA Astrophysics Data System (ADS)

Stabroth, Sebastian; Homeister, Maren; Oswald, Michael; Wiedemann, Carsten; Klinkrad, Heiner; Vörsmann, Peter

The ESA space debris population model MASTER (Meteoroid and Space Debris Terrestrial Environment Reference) considers firings of solid rocket motors (SRM) as a debris source with the associated generation of slag and dust particles. The resulting slag and dust population is a major contribution to the sub-millimetre size debris environment in Earth orbit. The current model version, MASTER-2005, is based on the simulation of 1076 orbital SRM firings which contributed to the long-term debris environment. A comparison of the modelled flux with impact data from returned surfaces shows that the shape and quantity of the modelled SRM dust distribution matches that of recent Hubble Space Telescope (HST) solar array measurements very well. However, the absolute flux level for dust is under-predicted for some of the analysed Long Duration Exposure Facility (LDEF) surfaces. This points into the direction of some past SRM firings not included in the current event database. The most suitable candidates for these firings are the large number of SRM retro-burns of return capsules. Objects released by those firings have highly eccentric orbits with perigees in the lower regions of the atmosphere. Thus, they produce no long-term effect on the debris environment. However, a large number of those firings during the on-orbit time frame of LDEF might lead to an increase of the dust population for some of the LDEF surfaces. In this paper, the influence of SRM retro-burns on the short- and long-term debris environment is analysed. The existing firing database is updated with gathered information of some 800 Russian retro-firings. Each firing is simulated with the MASTER population generation module. The resulting population is compared against the existing background population of SRM slag and dust particles in terms of spatial density and flux predictions.

Patterns of Z chromosome divergence among Heliconius species highlight the importance of historical demography.

PubMed

Van Belleghem, Steven M; Baquero, Margarita; Papa, Riccardo; Salazar, Camilo; McMillan, W Owen; Counterman, Brian A; Jiggins, Chris D; Martin, Simon H

2018-03-22

Sex chromosomes are disproportionately involved in reproductive isolation and adaptation. In support of such a "large-X" effect, genome scans between recently diverged populations and species pairs often identify distinct patterns of divergence on the sex chromosome compared to autosomes. When measures of divergence between populations are higher on the sex chromosome compared to autosomes, such patterns could be interpreted as evidence for faster divergence on the sex chromosome, that is "faster-X", barriers to gene flow on the sex chromosome. However, demographic changes can strongly skew divergence estimates and are not always taken into consideration. We used 224 whole-genome sequences representing 36 populations from two Heliconius butterfly clades (H. erato and H. melpomene) to explore patterns of Z chromosome divergence. We show that increased divergence compared to equilibrium expectations can in many cases be explained by demographic change. Among Heliconius erato populations, for instance, population size increase in the ancestral population can explain increased absolute divergence measures on the Z chromosome compared to the autosomes, as a result of increased ancestral Z chromosome genetic diversity. Nonetheless, we do identify increased divergence on the Z chromosome relative to the autosomes in parapatric or sympatric species comparisons that imply postzygotic reproductive barriers. Using simulations, we show that this is consistent with reduced gene flow on the Z chromosome, perhaps due to greater accumulation of incompatibilities. Our work demonstrates the importance of taking demography into account to interpret patterns of divergence on the Z chromosome, but nonetheless provides evidence to support the Z chromosome as a strong barrier to gene flow in incipient Heliconius butterfly species. © 2018 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Diversity in ATP concentrations in a single bacterial cell population revealed by quantitative single-cell imaging

PubMed Central

Yaginuma, Hideyuki; Kawai, Shinnosuke; Tabata, Kazuhito V.; Tomiyama, Keisuke; Kakizuka, Akira; Komatsuzaki, Tamiki; Noji, Hiroyuki; Imamura, Hiromi

2014-01-01

Recent advances in quantitative single-cell analysis revealed large diversity in gene expression levels between individual cells, which could affect the physiology and/or fate of each cell. In contrast, for most metabolites, the concentrations were only measureable as ensemble averages of many cells. In living cells, adenosine triphosphate (ATP) is a critically important metabolite that powers many intracellular reactions. Quantitative measurement of the absolute ATP concentration in individual cells has not been achieved because of the lack of reliable methods. In this study, we developed a new genetically-encoded ratiometric fluorescent ATP indicator “QUEEN”, which is composed of a single circularly-permuted fluorescent protein and a bacterial ATP binding protein. Unlike previous FRET-based indicators, QUEEN was apparently insensitive to bacteria growth rate changes. Importantly, intracellular ATP concentrations of numbers of bacterial cells calculated from QUEEN fluorescence were almost equal to those from firefly luciferase assay. Thus, QUEEN is suitable for quantifying the absolute ATP concentration inside bacteria cells. Finally, we found that, even for a genetically-identical Escherichia coli cell population, absolute concentrations of intracellular ATP were significantly diverse between individual cells from the same culture, by imaging QUEEN signals from single cells. PMID:25283467

The orbit and size distribution of small Solar System objects orbiting the Sun interior to the Earth's orbit

NASA Astrophysics Data System (ADS)

Zavodny, Maximilian; Jedicke, Robert; Beshore, Edward C.; Bernardi, Fabrizio; Larson, Stephen

2008-12-01

We present the first observational measurement of the orbit and size distribution of small Solar System objects whose orbits are wholly interior to the Earth's (Inner Earth Objects, IEOs, with aphelion <0.983 AU). We show that we are able to model the detections of near-Earth objects (NEO) by the Catalina Sky Survey (CSS) using a detailed parameterization of the CSS survey cadence and detection efficiencies as implemented within the Jedicke et al. [Jedicke, R., Morbidelli, A., Spahr, T., Petit, J.M., Bottke, W.F., 2003. Icarus 161, 17-33] survey simulator and utilizing the Bottke et al. [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] model of the NEO population's size and orbit distribution. We then show that the CSS detections of 4 IEOs are consistent with the Bottke et al. [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] IEO model. Observational selection effects for the IEOs discovered by the CSS were then determined using the survey simulator in order to calculate the corrected number and H distribution of the IEOs. The actual number of IEOs with H<18 (21) is 36±26 ( 530±240) and the slope of the H magnitude distribution ( ∝10) for the IEOs is α=0.44-0.22+0.23. The slope is consistent with previous measurements for the NEO population of α=0.35±0.02 [Bottke, W.F., Morbidelli, A., Jedicke, R., Petit, J.-M., Levison, H.F., Michel, P., Metcalfe, T.S., 2002. Icarus 156, 399-433] and α=0.39±0.013 [Stuart, J.S., Binzel, R.P., 2004. Icarus 170, 295-311]. Based on the agreement between the predicted and observed IEO orbit and absolute magnitude distributions there is no indication of any non-gravitational effects (e.g. Yarkovsky, tidal disruption) affecting the known IEO population.

The effects of maximising the UK's tobacco control score on inequalities in smoking prevalence and premature coronary heart disease mortality: a modelling study.

PubMed

Allen, Kirk; Kypridemos, Chris; Hyseni, Lirije; Gilmore, Anna B; Diggle, Peter; Whitehead, Margaret; Capewell, Simon; O'Flaherty, Martin

2016-04-01

Smoking is more than twice as common among the most disadvantaged socioeconomic groups in England compared to the most affluent and is a major contributor to health-related inequalities. The United Kingdom (UK) has comprehensive smoking policies in place: regular tax increases; public information campaigns; on-pack pictorial health warnings; advertising bans; cessation; and smoke-free areas. This is confirmed from its high Tobacco Control Scale (TCS) score, an expert-developed instrument for assessing the strength of tobacco control policies. However, room remains for improvement in tobacco control policies. Our aim was to evaluate the cumulative effect on smoking prevalence of improving all TCS components in England, stratified by socioeconomic circumstance. Effect sizes and socioeconomic gradients for all six types of smoking policy in the UK setting were adapted from systematic reviews, or if not available, from primary studies. We used the IMPACT Policy Model to link predicted changes in smoking prevalence to changes in premature coronary heart disease (CHD) mortality for ages 35-74. Health outcomes with a time horizon of 2025 were stratified by quintiles of socioeconomic circumstance. The model estimated that improving all smoking policies to achieve a maximum score on the TCS might reduce smoking prevalence in England by 3% (95% Confidence Interval (CI): 1-4%), from 20 to 17% in absolute terms, or by 15% in relative terms (95% CI: 7-21%). The most deprived quintile would benefit more, with absolute reductions from 31 to 25%, or a 6% reduction (95% CI: 2-7%). There would be some 3300 (95% CI: 2200-4700) fewer premature CHD deaths between 2015-2025, a 2% (95% CI: 1.4-2.9%) reduction. The most disadvantaged quintile would benefit more, reducing absolute inequality of CHD mortality by about 4 % (95% CI: 3-9%). Further, feasible improvements in tobacco control policy could substantially improve population health, and reduce health-related inequalities in England.

Socioeconomic inequality in neonatal mortality in countries of low and middle income: a multicountry analysis.

PubMed

McKinnon, Britt; Harper, Sam; Kaufman, Jay S; Bergevin, Yves

2014-03-01

Neonatal mortality rates (NMRs) in countries of low and middle income have been only slowly decreasing; coverage of essential maternal and newborn health services needs to increase, particularly for disadvantaged populations. Our aim was to produce comparable estimates of changes in socioeconomic inequalities in NMR in the past two decades across these countries. We used data from Demographic and Health Surveys (DHS) for countries in which a survey was done in 2008 or later and one about 10 years previously. We measured absolute inequalities with the slope index of inequality and relative inequalities with the relative index of inequality. We used an asset-based wealth index and maternal education as measures of socioeconomic position and summarised inequality estimates for all included countries with random-effects meta-analysis. 24 low-income and middle-income countries were eligible for inclusion. In most countries, absolute and relative wealth-related and educational inequalities in NMR decreased between survey 1 and survey 2. In five countries (Cameroon, Nigeria, Malawi, Mozambique, and Uganda), the difference in NMR between the top and bottom of the wealth distribution was reduced by more than two neonatal deaths per 1000 livebirths per year. By contrast, wealth-related inequality increased by more than 1·5 neonatal deaths per 1000 livebirths per year in Ethiopia and Cambodia. Patterns of change in absolute and relative educational inequalities in NMR were similar to those of wealth-related NMR inequalities, although the size of educational inequalities tended to be slightly larger. Socioeconomic inequality in NMR seems to have decreased in the past two decades in most countries of low and middle income. However, a substantial survival advantage remains for babies born into wealthier households with a high educational level, which should be considered in global efforts to further reduce NMR. Canadian Institutes of Health Research. Copyright © 2014 McKinnon et al. Open Access article distributed under the terms of CC BY. Published by .. All rights reserved.

Rotational Diffusion Depends on Box Size in Molecular Dynamics Simulations.

PubMed

Linke, Max; Köfinger, Jürgen; Hummer, Gerhard

2018-06-07

We show that the rotational dynamics of proteins and nucleic acids determined from molecular dynamics simulations under periodic boundary conditions suffer from significant finite-size effects. We remove the box-size dependence of the rotational diffusion coefficients by adding a hydrodynamic correction k B T/6 ηV with k B Boltzmann's constant, T the absolute temperature, η the solvent shear viscosity, and V the box volume. We show that this correction accounts for the finite-size dependence of the rotational diffusion coefficients of horse-heart myoglobin and a B-DNA dodecamer in aqueous solution. The resulting hydrodynamic radii are in excellent agreement with experiment.

Factors influencing the specific interaction of Neisseria gonorrhoeae with transforming DNA.

PubMed Central

Goodman, S D; Scocca, J J

1991-01-01

The specific interaction of transformable Neisseria gonorrhoeae with DNA depends on the recognition of specific 10-residue target sequences. The relative affinity for DNA between 3 and 17 kb in size appears to be linearly related to the frequency of targets on the segment and is unaffected by absolute size. The average frequency of targets in chromosomal DNA of N. gonorrhoeae appears to be approximately one per 1,000 bp. PMID:1909325

Tight-binding chains with off-diagonal disorder: Bands of extended electronic states induced by minimal quasi-one-dimensionality

NASA Astrophysics Data System (ADS)

Nandy, Atanu; Pal, Biplab; Chakrabarti, Arunava

2016-08-01

It is shown that an entire class of off-diagonally disordered linear lattices composed of two basic building blocks and described within a tight-binding model can be tailored to generate absolutely continuous energy bands. It can be achieved if linear atomic clusters of an appropriate size are side-coupled to a suitable subset of sites in the backbone, and if the nearest-neighbor hopping integrals, in the backbone and in the side-coupled cluster, bear a certain ratio. We work out the precise relationship between the number of atoms in one of the building blocks in the backbone and that in the side attachment. In addition, we also evaluate the definite correlation between the numerical values of the hopping integrals at different subsections of the chain, that can convert an otherwise point spectrum (or a singular continuous one for deterministically disordered lattices) with exponentially (or power law) localized eigenfunctions to an absolutely continuous spectrum comprising one or more bands (subbands) populated by extended, totally transparent eigenstates. The results, which are analytically exact, put forward a non-trivial variation of the Anderson localization (Anderson P. W., Phys. Rev., 109 (1958) 1492), pointing towards its unusual sensitivity to the numerical values of the system parameters and, go well beyond the other related models such as the Random Dimer Model (RDM) (Dunlap D. H. et al., Phys. Rev. Lett., 65 (1990) 88).

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

Huang, Huafeng; Colabello, Diane M.; Sklute, Elizabeth C.

The absolute absorption coefficient, α(E), is a critical design parameter for devices using semiconductors for light harvesting associated with renewable energy production, both for classic technologies such as photovoltaics and for emerging technologies such as direct solar fuel production. While α(E) is well-known for many classic simple semiconductors used in photovoltaic applications, the absolute values of α(E) are typically unknown for the complex semiconductors being explored for solar fuel production due to the absence of single crystals or crystalline epitaxial films that are needed for conventional methods of determining α(E). In this work, a simple self-referenced method for estimating bothmore » the refractive indices, n(E), and absolute absorption coefficients, α(E), for loose powder samples using diffuse reflectance data is demonstrated. In this method, the sample refractive index can be deduced by refining n to maximize the agreement between the relative absorption spectrum calculated from bidirectional reflectance data (calculated through a Hapke transform which depends on n) and integrating sphere diffuse reflectance data (calculated through a Kubleka–Munk transform which does not depend on n). This new method can be quickly used to screen the suitability of emerging semiconductor systems for light-harvesting applications. The effectiveness of this approach is tested using the simple classic semiconductors Ge and Fe 2O 3 as well as the complex semiconductors La 2MoO 5 and La 4Mo 2O 11. The method is shown to work well for powders with a narrow size distribution (exemplified by Fe 2O 3) and to be ineffective for semiconductors with a broad size distribution (exemplified by Ge). As such, it provides a means for rapidly estimating the absolute optical properties of complex solids which are only available as loose powders.« less

Shape of Thyroid Cartilage Influences Outcome of Montgomery Medialization Thyroplasty: A Gender Issue.

PubMed

Desuter, Gauthier; Henrard, Sylvie; Van Lith-Bijl, Julie T; Amory, Avigaëlle; Duprez, Thierry; van Benthem, Peter Paul; Sjögren, Elisabeth

2017-03-01

This study aimed to determine whether the shape of the thyroid cartilage and gender influence voice outcomes after a Montgomery thyroplasty implant system (MTIS). A retrospective cohort study was performed on 20 consecutive patients who underwent MTIS. Voice outcome variables were the relative decrease in Voice Handicap Index (%) and the absolute increase in maximum phonation time (MPT) (in seconds). Material variables were the angle between the thyroid cartilage laminae (α-angle), the size of the prosthesis, and a combination of both (the α-ratio). Continuous variables were analyzed using medians and were compared between groups using the Mann-Whitney U test. Factors associated with the outcome variables were assessed by multivariable linear regression. A Pearson coefficient was calculated between material variables. The absolute increase in MPT between the pre- and postoperative period was significantly different between men and women, with a median absolute increase of 11.0 seconds for men and of 1.3 seconds for women (P < 0.001). A strong inverse correlation between the α-ratio and the absolute increase in MPT is observed in all patients, with a Pearson correlation coefficient R = -0.769 (P < 0.001). No factors were significantly associated with the relative Voice Handicap Index decrease in univariable or multivariable analyses. A better Pearson coefficient between the α-angle and the prosthesis size was found for females (0.8 vs 0.71). The MTIS is a good thyroplasty modality for male patients, but inadequate design of MTIS female implants leads to poor MPT outcomes. This represents a gender issue that needs to be further studied and eventually tackled. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

The Contributions of Selected Diseases to Disparities in Death Rates and Years of Life Lost for Racial/Ethnic Minorities in the United States, 1999–2010

PubMed Central

Peace, Frederick; Howard, Virginia J.

2014-01-01

Introduction Differences in risk for death from diseases and other causes among racial/ethnic groups likely contributed to the limited improvement in the state of health in the United States in the last few decades. The objective of this study was to identify causes of death that are the largest contributors to health disparities among racial/ethnic groups. Methods Using data from WONDER system, we measured the relative (age-adjusted mortality ratio [AAMR]) and absolute (difference in years of life lost [dYLL]) differences in mortality risk between the non-Hispanic white population and the black, Hispanic, American Indian/Alaska Native, and Asian/Pacific Islander populations for the 25 leading causes of death. Results Many causes contributed to disparities between non-Hispanic whites and blacks, led by assault (AAMR, 7.56; dYLL, 4.5 million). Malignant neoplasms were the second largest absolute contributor (dYLL, 3.8 million) to black–white disparities; we also found substantial relative and absolute differences for several cardiovascular diseases. Only assault, diabetes, and diseases of the liver contributed substantially to disparities between non-Hispanic whites and Hispanics (AAMR ≥ 1.65; dYLL ≥ 325,000). Many causes of death, led by assault (AAMR, 3.25; dYLL, 98,000), contributed to disparities between non-Hispanic whites and American Indians/Alaska Natives; Asian/Pacific Islanders did not have a higher risk than non-Hispanic whites for death from any disease. Conclusion Assault was a substantial contributor to disparities in mortality among non-Asian racial/ethnic minority populations. Research and intervention resources need to target diseases (such as diabetes and diseases of the liver) that affect certain racial/ethnic populations. PMID:25078566

Weight-watching at the university: the consequences of growth.

PubMed

Gallant, J A; Prothero, J W

1972-01-28

We began by pointing out that tools (for example) have size optima that are dictated by function. If we assume that the university has a function, it would seem reasonable to think about the size which will serve that function best. The principle of size optimization is fundamental, but its application to the university at once encounters a difficulty: What is the function of a university? It might take forever to secure general agreement on the answer to this question. The problem is that universities have a number of different functions, to which different individuals will attach different weights, and each function may well have a unique size optimum. Just as it is, in general, mathematically impossible to maximize simultaneously for two different functions of the same variable (29), so it is unsound to conceive of a single optimum for the multiversity. Nonetheless, a range of workable sizes may be defined by analyzing the effect of variation in size on all essential functions. The examples from biological systems illustrate this approach. Cells exist in a variety of sizes, each size presumably representing an optimization to one or another set of constraints, yet there are upper bounds. There are no cells the size of basketballs because essential metabolic functions are limited by the surface-to-volume ratio. We must emphasize that one does not need a grand theory of life in order to identify this limiting condition. If cells could talk, they would no doubt differ on the general philosophy of being a cell, yet all conceptions would be subject to certain physically inevitable limitations on size. In the case of the university, no grand theory of education is needed in order to identify dysfunctions of growth that affect essential activities (for example, the diffusion of individuals through, in, and out of the university) or that affect all activities (for example, overall morale). Balanced against these dysfunctions are such advantages of growth as economy, the achievement of a critical mass, and flexibility in staffing. Our analyis of data from the California system indicates that unit costs of education decline very little above a size of 10,000 or 15,000 students. Moreover, the critical mass for departmental excellence, at least in terms of the ACE ratings of graduate departments, is achieved by a university of about this size. Growth beyond this size range conitinues to provide flexibility in staffing and spares administrators the trouble of having to make difficult decisions. At the same time, the dysfunctions attendant on growth become steadily more severe. Our impression is that the dysfunctions have not been seriously considered, while the advantages have been greatly oversold. The idea of dysfunctional growth, although fundamental in biology, contradicts one of America's most cherished illusions. Particular dysfunctions of growth are rarely formulated, set down, and explicitly weighed against the potential advantages. Rather, the American prejudice has been to assume that growth is always good, or at least inevitable, and to treat the dysfunctions (which are inevitable) as managerial problems to be ironed out later or glossed over. There has also been a remarkable failure to think in terms of optima and to distinguish in this way between what we have termed functional and dysfunctional growth. Rather, the tendency has been to extrapolate functional growth into the dysfunctional range: If a university population of 10,000 confers certain advantages as compared with a population of 1,000, then it is assumed that a population of 100,000 must confer even more advantages. We suggest that it is time, in fact past time, to subject university growth to a more searching scrutiny. Functional and dysfunctional consequences need to be spelled out. Scale effects ought to be considered in connection with every plan for expansion. Ideally, one might expect a farsighted and tough-minded administration to carry out this function. This has rarely been the case. Too often administrators regard their function as simply that of broker among competing expansionist tendencies. Such a conception replaces philosophy by politics and often encourages mindless growth. Perhaps it is time for faculties to involve themselves in long-range planning and to pay the price of a more satisfactory environment by giving up some individual dreams of empire. The first step for every large university ought to be a careful analysis of scale effects (30). If analysis indicates that continued growth of a university will be, on balance, dysfunctional, we suggest that plans be formulated to establish an absolute limit on further enrollment increase, and an absolute limit on further building expansion. If further analysis indicates that a university is already well into the dysfunctional size range, then the obvious solution is to cut back. If this turns out to be the case, then we suggest that a program for the gradual reduction of the campus population be undertaken. There are two distinct ways to accomplish this: (i) the establishment of a new university and (ii) the decentralization of the existing university into two or more campuses. Decentralization strikes us as an attractive idea, worthy of careful study. One of the recommendations of the Scranton commission was, "Large universities should take steps to decentralize or reorganize to make possible a more human scale" (18, p. 14). Returning to the natural world, we note again that cells do not grow indefinitely. Instead, they divide.

Reliability, minimal detectable change and responsiveness to change: Indicators to select the best method to measure sedentary behaviour in older adults in different study designs.

PubMed

Dontje, Manon L; Dall, Philippa M; Skelton, Dawn A; Gill, Jason M R; Chastin, Sebastien F M

2018-01-01

Prolonged sedentary behaviour (SB) is associated with poor health. It is unclear which SB measure is most appropriate for interventions and population surveillance to measure and interpret change in behaviour in older adults. The aims of this study: to examine the relative and absolute reliability, Minimal Detectable Change (MDC) and responsiveness to change of subjective and objective methods of measuring SB in older adults and give recommendations of use for different study designs. SB of 18 older adults (aged 71 (IQR 7) years) was assessed using a systematic set of six subjective tools, derived from the TAxonomy of Self report Sedentary behaviour Tools (TASST), and one objective tool (activPAL3c), over 14 days. Relative reliability (Intra Class Correlation coefficients-ICC), absolute reliability (SEM), MDC, and the relative responsiveness (Cohen's d effect size (ES) and Guyatt's Responsiveness coefficient (GR)) were calculated for each of the different tools and ranked for different study designs. ICC ranged from 0.414 to 0.946, SEM from 36.03 to 137.01 min, MDC from 1.66 to 8.42 hours, ES from 0.017 to 0.259 and GR from 0.024 to 0.485. Objective average day per week measurement ranked as most responsive in a clinical practice setting, whereas a one day measurement ranked highest in quasi-experimental, longitudinal and controlled trial study designs. TV viewing-Previous Week Recall (PWR) ranked as most responsive subjective measure in all study designs. The reliability, Minimal Detectable Change and responsiveness to change of subjective and objective methods of measuring SB is context dependent. Although TV viewing-PWR is the more reliable and responsive subjective method in most situations, it may have limitations as a reliable measure of total SB. Results of this study can be used to guide choice of tools for detecting change in sedentary behaviour in older adults in the contexts of population surveillance, intervention evaluation and individual care.

SU-E-T-538: Does Abdominal Compression Through Prone Patient Position Reduce Respiratory Motion in Lung Cancer Radiotherapy?

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

Catron, T; Rosu, M; Weiss, E

2014-06-01

Purpose: This study assesses the effect of physiological abdominal compression from prone positioning by comparing respiratory-induced tumor movements in supine and prone positions. Methods: 19 lung cancer patients underwent repeated supine and prone free-breathing 4DCT scans. The effect of patient position on motion magnitude was investigated for tumors, lymph nodes (9 cases), and subgroups of central (11 cases), peripheral (8 cases) and small peripheral tumors (5 cases), by evaluating the population average excursions, absolute and relative to a carina-point. Results: Absolute motion analysis: In prone, motion increased by ~20% for tumors and ~25% for lymph nodes. Central tumors moved moremore » compared to peripheral tumors in both supine and prone (~22%, and ~4% respectively). Central tumors movement increased by ~12% in prone. For peripheral tumors the increase in prone position was ~25% (~40% and 29% changes on along RL and AP directions). Motion relative to carina-point analysis: Overall, tumor excursions relative to carina-point increased by ~17% in prone. Lymph node relative magnitudes were lower by ~4%. Likewise, the central tumors moved ~7% less in prone. The subgroup of peripheral tumors exhibited increased amplitudes by ~44%; the small peripheral tumors had even larger relative displacements in prone (~46%). Conclusion: Tumor and lymph node movement in the patient population from this study averaged to be higher in prone than in supine position. Results from carina analysis also suggest that peripheral tissues have more physiologic freedom of motility when placed in the prone position, regardless of size. From these observations we should continue to avoid prone positioning for all types of primary lung tumor, suggesting that patients should receive radiotherapy for primary lung cancer in supine position to minimize target tissue mobility during normal respiratory effort. Further investigation will include more patients with peripheral tumors to validate our observations.« less

Patterns and determinants of functional and absolute iron deficiency in patients undergoing cardiac rehabilitation following heart surgery.

PubMed

Tramarin, Roberto; Pistuddi, Valeria; Maresca, Luigi; Pavesi, Marco; Castelvecchio, Serenella; Menicanti, Lorenzo; de Vincentiis, Carlo; Ranucci, Marco

2017-05-01

Background Anaemia and iron deficiency are frequent following major surgery. The present study aims to identify the iron deficiency patterns in cardiac surgery patients at their admission to a cardiac rehabilitation programme, and to determine which perioperative risk factor(s) may be associated with functional and absolute iron deficiency. Design This was a retrospective study on prospectively collected data. Methods The patient population included 339 patients. Functional iron deficiency was defined in the presence of transferrin saturation <20% and serum ferritin ≥100 µg/l. Absolute iron deficiency was defined in the presence of serum ferritin values <100 µg/l. Results Functional iron deficiency was found in 62.9% of patients and absolute iron deficiency in 10% of the patients. At a multivariable analysis, absolute iron deficiency was significantly ( p = 0.001) associated with mechanical prosthesis mitral valve replacement (odds ratio 5.4, 95% confidence interval 1.9-15) and tissue valve aortic valve replacement (odds ratio 4.5, 95% confidence interval 1.9-11). In mitral valve surgery, mitral repair carried a significant ( p = 0.013) lower risk of absolute iron deficiency (4.4%) than mitral valve replacement with tissue valves (8.3%) or mechanical prostheses (22.5%). Postoperative outcome did not differ between patients with functional iron deficiency and patients without iron deficiency; patients with absolute iron deficiency had a significantly ( p = 0.017) longer postoperative hospital stay (median 11 days) than patients without iron deficiency (median nine days) or with functional iron deficiency (median eight days). Conclusions Absolute iron deficiency following cardiac surgery is more frequent in heart valve surgery and is associated with a prolonged hospital stay. Routine screening for iron deficiency at admission in the cardiac rehabilitation unit is suggested.

National Economic Development Procedures Manual - Recreation. Volume 2. A Guide for Using the Contingent Value Methodology in Recreation Studies,

DTIC Science & Technology

1986-03-01

Directly from Sample Bid VI-16 Example 3 VI-16 Determining the Zero Price Qiantity Demanded VI-26 Summary VI -31 CHAPrER VII, THE DETERMINATION OF NED...While the standard deviation and variance are absolute measures of dispersion, a relative measure of dispersion can also be computed. This measure is...refers to the closeness of fit between the estimates obtained from Zli e and the true population value. The only way of being absolutely i: o-.iat the

Size Constancy in Bat Biosonar? Perceptual Interaction of Object Aperture and Distance

PubMed Central

Heinrich, Melina; Wiegrebe, Lutz

2013-01-01

Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. This phenomenon is termed “size constancy”. It is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. Recently, it was found that in echolocating bats, the ‘sonar aperture’, i.e., the range of angles from which sound is reflected from an object back to the bat, is unambiguously perceived and neurally encoded. Moreover, it is well known that object distance is accurately perceived and explicitly encoded in bat sonar. Here, we addressed size constancy in bat biosonar, recruiting virtual-object techniques. Bats of the species Phyllostomus discolor learned to discriminate two simple virtual objects that only differed in sonar aperture. Upon successful discrimination, test trials were randomly interspersed using virtual objects that differed in both aperture and distance. It was tested whether the bats spontaneously assigned absolute width information to these objects by combining distance and aperture. The results showed that while the isolated perceptual cues encoding object width, aperture, and distance were all perceptually well resolved by the bats, the animals did not assign absolute width information to the test objects. This lack of sonar size constancy may result from the bats relying on different modalities to extract size information at different distances. Alternatively, it is conceivable that familiarity with a behaviorally relevant, conspicuous object is required for sonar size constancy, as it has been argued for visual size constancy. Based on the current data, it appears that size constancy is not necessarily an essential feature of sonar perception in bats. PMID:23630598

Size constancy in bat biosonar? Perceptual interaction of object aperture and distance.

PubMed

Heinrich, Melina; Wiegrebe, Lutz

2013-01-01

Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. This phenomenon is termed "size constancy". It is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. Recently, it was found that in echolocating bats, the 'sonar aperture', i.e., the range of angles from which sound is reflected from an object back to the bat, is unambiguously perceived and neurally encoded. Moreover, it is well known that object distance is accurately perceived and explicitly encoded in bat sonar. Here, we addressed size constancy in bat biosonar, recruiting virtual-object techniques. Bats of the species Phyllostomus discolor learned to discriminate two simple virtual objects that only differed in sonar aperture. Upon successful discrimination, test trials were randomly interspersed using virtual objects that differed in both aperture and distance. It was tested whether the bats spontaneously assigned absolute width information to these objects by combining distance and aperture. The results showed that while the isolated perceptual cues encoding object width, aperture, and distance were all perceptually well resolved by the bats, the animals did not assign absolute width information to the test objects. This lack of sonar size constancy may result from the bats relying on different modalities to extract size information at different distances. Alternatively, it is conceivable that familiarity with a behaviorally relevant, conspicuous object is required for sonar size constancy, as it has been argued for visual size constancy. Based on the current data, it appears that size constancy is not necessarily an essential feature of sonar perception in bats.

Uncertainty in Population Estimates for Endangered Animals and Improving the Recovery Process

PubMed Central

Haines, Aaron M.; Zak, Matthew; Hammond, Katie; Scott, J. Michael; Goble, Dale D.; Rachlow, Janet L.

2013-01-01

Simple Summary The objective of our study was to evaluate the mention of uncertainty (i.e., variance) associated with population size estimates within U.S. recovery plans for endangered animals. To do this we reviewed all finalized recovery plans for listed terrestrial vertebrate species. We found that more recent recovery plans reported more estimates of population size and uncertainty. Also, bird and mammal recovery plans reported more estimates of population size and uncertainty. We recommend that updated recovery plans combine uncertainty of population size estimates with a minimum detectable difference to aid in successful recovery. Abstract United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery. The objective of our study was to evaluate whether recovery plans provide uncertainty (e.g., variance) with estimates of population size. We reviewed all finalized recovery plans for listed terrestrial vertebrate species to record the following data: (1) if a current population size was given, (2) if a measure of uncertainty or variance was associated with current estimates of population size and (3) if population size was stipulated for recovery. We found that 59% of completed recovery plans specified a current population size, 14.5% specified a variance for the current population size estimate and 43% specified population size as a recovery criterion. More recent recovery plans reported more estimates of current population size, uncertainty and population size as a recovery criterion. Also, bird and mammal recovery plans reported more estimates of population size and uncertainty compared to reptiles and amphibians. We suggest the use of calculating minimum detectable differences to improve confidence when delisting endangered animals and we identified incentives for individuals to get involved in recovery planning to improve access to quantitative data. PMID:26479531

Vehicle mass and injury risk in two-car crashes: A novel methodology.

PubMed

Tolouei, Reza; Maher, Mike; Titheridge, Helena

2013-01-01

This paper introduces a novel methodology based on disaggregate analysis of two-car crash data to estimate the partial effects of mass, through the velocity change, on absolute driver injury risk in each of the vehicles involved in the crash when absolute injury risk is defined as the probability of injury when the vehicle is involved in a two-car crash. The novel aspect of the introduced methodology is in providing a solution to the issue of lack of data on the speed of vehicles prior to the crash, which is required to calculate the velocity change, as well as a solution to the issue of lack of information on non-injury two-car crashes in national accident data. These issues have often led to focussing on relative measures of injury risk that are not independent of risk in the colliding cars. Furthermore, the introduced methodology is used to investigate whether there is any effect of vehicle size above and beyond that of mass ratio, and whether there are any effects associated with the gender and age of the drivers. The methodology was used to analyse two-car crashes to investigate the partial effects of vehicle mass and size on absolute driver injury risk. The results confirmed that in a two-car collision, vehicle mass has a protective effect on its own driver injury risk and an aggressive effect on the driver injury risk of the colliding vehicle. The results also confirmed that there is a protective effect of vehicle size above and beyond that of vehicle mass for frontal and front to side collisions. Copyright © 2012 Elsevier Ltd. All rights reserved.

Measurement of the photoionization cross section from the laser-populated 3D metastable levels in barium

NASA Technical Reports Server (NTRS)

Carlsten, J. L.; Mcilrath, T. J.; Parkinson, W. H.

1974-01-01

Measurements of the absolute photoionization cross section from the 6s5d 3D metastable level of barium are presented. The 3D levels were selectively populated with a high-power tuneable dye laser. The number density was determined by observing the resulting depopulation of the ground state when pumping occurred.

Investigating the case of human nose shape and climate adaptation

PubMed Central

Zaidi, Arslan A.; Claes, Peter; McEcoy, Brian; Shriver, Mark D.

2017-01-01

The evolutionary reasons for variation in nose shape across human populations have been subject to continuing debate. An import function of the nose and nasal cavity is to condition inspired air before it reaches the lower respiratory tract. For this reason, it is thought the observed differences in nose shape among populations are not simply the result of genetic drift, but may be adaptations to climate. To address the question of whether local adaptation to climate is responsible for nose shape divergence across populations, we use Qst–Fst comparisons to show that nares width and alar base width are more differentiated across populations than expected under genetic drift alone. To test whether this differentiation is due to climate adaptation, we compared the spatial distribution of these variables with the global distribution of temperature, absolute humidity, and relative humidity. We find that width of the nares is correlated with temperature and absolute humidity, but not with relative humidity. We conclude that some aspects of nose shape may indeed have been driven by local adaptation to climate. However, we think that this is a simplified explanation of a very complex evolutionary history, which possibly also involved other non-neutral forces such as sexual selection. PMID:28301464

Investigating the case of human nose shape and climate adaptation.

PubMed

Zaidi, Arslan A; Mattern, Brooke C; Claes, Peter; McEvoy, Brian; Hughes, Cris; Shriver, Mark D

2017-03-01

The evolutionary reasons for variation in nose shape across human populations have been subject to continuing debate. An import function of the nose and nasal cavity is to condition inspired air before it reaches the lower respiratory tract. For this reason, it is thought the observed differences in nose shape among populations are not simply the result of genetic drift, but may be adaptations to climate. To address the question of whether local adaptation to climate is responsible for nose shape divergence across populations, we use Qst-Fst comparisons to show that nares width and alar base width are more differentiated across populations than expected under genetic drift alone. To test whether this differentiation is due to climate adaptation, we compared the spatial distribution of these variables with the global distribution of temperature, absolute humidity, and relative humidity. We find that width of the nares is correlated with temperature and absolute humidity, but not with relative humidity. We conclude that some aspects of nose shape may indeed have been driven by local adaptation to climate. However, we think that this is a simplified explanation of a very complex evolutionary history, which possibly also involved other non-neutral forces such as sexual selection.

Blindness and low vision in Germany 1993-2009.

PubMed

Wolfram, Christian; Pfeiffer, Norbert

2012-02-01

To describe the development of the prevalence of blindness and low vision in the German population between 1993 and 2009 with respect to major demographic changes and to investigate how the prevalence of blindness would have developed without demographic aging. Investigation of the prevalence for blindness and low vision in the German population on the basis of the official German statistics for severely handicapped people and population statistics between 1993 and 2009. Age-specific prevalence rates and the prevalence based on a standardized population were calculated and the progression is demonstrated. The overall prevalence of blindness and low vision in Germany increased between 1993 and 2009 by 12.3% from 314,404 to 352,943 subjects. The absolute number of blind or visually impaired persons in the eldest group (75 years and above) has grown by 38.2% from 126,023 to 174,127 subjects. At the same time, both age-specific prevalence rates as well as the prevalence that was based on a standardized population decreased, matching more than 30,000 fewer cases of blindness in 2009 as compared to 1993. The increase in absolute prevalence numbers for blindness and low vision implies an increase in the ophthalmic workload. At the same time, the decrease in the age-specific and standardized prevalence indicates possible improvements in the overall eye health status of the population since 1993.

Evaluating the validity of using unverified indices of body condition

USGS Publications Warehouse

Schamber, J.L.; Esler, Daniel N.; Flint, Paul L.

2009-01-01

Condition indices are commonly used in an attempt to link body condition of birds to ecological variables of interest, including demographic attributes such as survival and reproduction. Most indices are based on body mass adjusted for structural body size, calculated as simple ratios or residuals from regressions. However, condition indices are often applied without confirming their predictive value (i.e., without being validated against measured values of fat and protein), which we term ‘unverified’ use. We evaluated the ability of a number of unverified indices frequently found in the literature to predict absolute and proportional levels of fat and protein across five species of waterfowl. Among indices we considered, those accounting for body size never predicted absolute protein more precisely than body mass, however, some indices improved predictability of fat, although the form of the best index varied by species. Further, the gain in precision by using a condition index to predict either absolute or percent fat was minimal (rise in r2≤0.13), and in many cases model fit was actually reduced. Our data agrees with previous assertions that the assumption that indices provide more precise indicators of body condition than body mass alone is often invalid. We strongly discourage the use of unverified indices, because subjectively selecting indices likely does little to improve precision and might in fact decrease predictability relative to using body mass alone.

Automated estimation of abdominal effective diameter for body size normalization of CT dose.

PubMed

Cheng, Phillip M

2013-06-01

Most CT dose data aggregation methods do not currently adjust dose values for patient size. This work proposes a simple heuristic for reliably computing an effective diameter of a patient from an abdominal CT image. Evaluation of this method on 106 patients scanned on Philips Brilliance 64 and Brilliance Big Bore scanners demonstrates close correspondence between computed and manually measured patient effective diameters, with a mean absolute error of 1.0 cm (error range +2.2 to -0.4 cm). This level of correspondence was also demonstrated for 60 patients on Siemens, General Electric, and Toshiba scanners. A calculated effective diameter in the middle slice of an abdominal CT study was found to be a close approximation of the mean calculated effective diameter for the study, with a mean absolute error of approximately 1.0 cm (error range +3.5 to -2.2 cm). Furthermore, the mean absolute error for an adjusted mean volume computed tomography dose index (CTDIvol) using a mid-study calculated effective diameter, versus a mean per-slice adjusted CTDIvol based on the calculated effective diameter of each slice, was 0.59 mGy (error range 1.64 to -3.12 mGy). These results are used to calculate approximate normalized dose length product values in an abdominal CT dose database of 12,506 studies.

Reconstruction of sediment transport pathways in modern microtidal sand flat by multiple classification analysis

NASA Astrophysics Data System (ADS)

Yamashita, S.; Nakajo, T.; Naruse, H.

2009-12-01

In this study, we statistically classified the grain size distribution of the bottom surface sediment on a microtidal sand flat to analyze the depositional processes of the sediment. Multiple classification analysis revealed that two types of sediment populations exist in the bottom surface sediment. Then, we employed the sediment trend model developed by Gao and Collins (1992) for the estimation of sediment transport pathways. As a result, we found that statistical discrimination of the bottom surface sediment provides useful information for the sediment trend model while dealing with various types of sediment transport processes. The microtidal sand flat along the Kushida River estuary, Ise Bay, central Japan, was investigated, and 102 bottom surface sediment samples were obtained. Then, their grain size distribution patterns were measured by the settling tube method, and each grain size distribution parameter (mud and gravel contents, mean grain size, coefficient of variance (CV), skewness, kurtosis, 5, 25, 50, 75, and 95 percentile) was calculated. Here, CV is the normalized sorting value divided by the mean grain size. Two classical statistical methods—principal component analysis (PCA) and fuzzy cluster analysis—were applied. The results of PCA showed that the bottom surface sediment of the study area is mainly characterized by grain size (mean grain size and 5-95 percentile) and the CV value, indicating predominantly large absolute values of factor loadings in primal component (PC) 1. PC1 is interpreted as being indicative of the grain-size trend, in which a finer grain-size distribution indicates better size sorting. The frequency distribution of PC1 has a bimodal shape and suggests the existence of two types of sediment populations. Therefore, we applied fuzzy cluster analysis, the results of which revealed two groupings of the sediment (Cluster 1 and Cluster 2). Cluster 1 shows a lower value of PC1, indicating coarse and poorly sorted sediments. Cluster 1 sediments are distributed around the branched channel from Kushida River and show an expanding distribution from the river mouth toward the northeast direction. Cluster 2 shows a higher value of PC1, indicating fine and well-sorted sediments; this cluster is distributed in a distant area from the river mouth, including the offshore region. Therefore, Cluster 1 and Cluster 2 are interpreted as being deposited by fluvial and wave processes, respectively. Finally, on the basis of this distribution pattern, the sediment trend model was applied in areas dominated separately by fluvial and wave processes. Resultant sediment transport patterns showed good agreement with those obtained by field observations. The results of this study provide an important insight into the numerical models of sediment transport.

Role of patch size, disease, and movement in rapid extinction of bighorn sheep

USGS Publications Warehouse

Singer, F.J.; Zeigenfuss, L.C.; Spicer, L.

2001-01-01

The controversy (Berger 1990, 1999; Wehausen 1999) over rapid extinction in bighorn sheep (Ovis canadensis) has focused on population size alone as a correlate to persistence time. We report on the persistence and population performance of 24 translocated populations of bighorn sheep. Persistence in these sheep was strongly correlated with larger patch sizes, greater distance to domestic sheep, higher population growth rates, and migratory movements, as well as to larger population sizes. Persistence was also positively correlated with larger average home-range size (p = 0.058, n = 10 translocated populations) and home-range size of rams (p = 0.087, n = 8 translocated populations). Greater home-range size and dispersal rates of bighorn sheep were positively correlated to larger patches. We conclude that patch size and thus habitat carrying capacity, not population size per se, is the primary correlate to both population performance and persistence. Because habitat carrying capacity defines the upper limit to population size, clearly the amount of suitable habitat in a patch is ultimately linked to population size. Larger populations (250+ animals) were more likely to recover rapidly to their pre-epizootic survey number following an epizootic (p = 0.019), although the proportion of the population dying in the epizootic also influenced the probability of recovery (p = 0.001). Expensive management efforts to restore or increase bighorn sheep populations should focus on large habitat patches located ≥23 km from domestic sheep, and less effort should be expended on populations in isolated, small patches of habitat.

Glutathione promoted expeditious green synthesis of silver nanoparticles in water using microwaves

EPA Science Inventory

Silver nanoparticles with size range 5-10 nm has been synthesized under microwave irradiation conditions using gluathione, an absolutely benign antioxidant that serves as the reducing as well as capping agent in aqueous medium. This rapid protocol yields the nanoparticles within ...

Absolute Effect of Prostate Cancer Screening: Balance of benefits and harms by center within the European Randomized Study of Prostate Cancer Screening

PubMed Central

Auvinen, Anssi; Moss, Sue M; Tammela, Teuvo L J; Taari, Kimmo; Roobol, Monique J; Schröder, Fritz H; Bangma, Chris H; Carlsson, Sigrid; Aus, Gunnar; Zappa, Marco; Puliti, Donella; Denis, Louis J; Nelen, Vera; Kwiatkowski, Maciej; Randazzo, Marco; Paez, Alvaro; Lujan, Marcos; Hugosson, Jonas

2016-01-01

Purpose The balance of benefits and harms in prostate cancer screening has not been sufficiently characterized. We related indicators of mortality reduction and overdetection by center within the European Randomized Study of Prostate Cancer Screening. Experimental Design We analyzed the absolute mortality reduction expressed as number needed to invite (NNI=1/absolute risk reduction; indicating how many men had to be randomized to screening arm to avert a prostate cancer death) for screening and the absolute excess of prostate cancer detection as number needed for overdetection (NNO=1/absolute excess incidence; indicating the number of men invited per additional prostate cancer case), and compared their relationship across the seven ERSPC centers. Results Both absolute mortality reduction (NNI) and absolute overdetection (NNO) varied widely between the centers: NNI 200-7000 and NNO 16-69. Extent of overdiagnosis and mortality reduction were closely associated (correlation coefficient r=0.76, weighted linear regression coefficient β=33, 95% 5-62, R2=0.72). For an averted prostate cancer death at 13 years of follow-up, 12-36 excess cases had to be detected in various centers. Conclusions The differences between the ERSPC centers likely reflect variations in prostate cancer incidence and mortality, as well as in screening protocol and performance. The strong interrelation between the benefits and harms suggests that efforts to maximize the mortality effect are bound to increase overdiagnosis, and might be improved by focusing on high-risk populations. The optimal balance between screening intensity and risk of overdiagnosis remains unclear. PMID:26289069

On the magnetic polarizability tensor of US coinage

NASA Astrophysics Data System (ADS)

Davidson, John L.; Abdel-Rehim, Omar A.; Hu, Peipei; Marsh, Liam A.; O'Toole, Michael D.; Peyton, Anthony J.

2018-03-01

The magnetic dipole polarizability tensor of a metallic object gives unique information about the size, shape and electromagnetic properties of the object. In this paper, we present a novel method of coin characterization based on the spectroscopic response of the absolute tensor. The experimental measurements are validated using a combination of tests with a small set of bespoke coin surrogates and simulated data. The method is applied to an uncirculated set of US coins. Measured and simulated spectroscopic tensor responses of the coins show significant differences between different coin denominations. The presented results are encouraging as they strongly demonstrate the ability to characterize coins using an absolute tensor approach.

Optimal quantum error correcting codes from absolutely maximally entangled states

NASA Astrophysics Data System (ADS)

Raissi, Zahra; Gogolin, Christian; Riera, Arnau; Acín, Antonio

2018-02-01

Absolutely maximally entangled (AME) states are pure multi-partite generalizations of the bipartite maximally entangled states with the property that all reduced states of at most half the system size are in the maximally mixed state. AME states are of interest for multipartite teleportation and quantum secret sharing and have recently found new applications in the context of high-energy physics in toy models realizing the AdS/CFT-correspondence. We work out in detail the connection between AME states of minimal support and classical maximum distance separable (MDS) error correcting codes and, in particular, provide explicit closed form expressions for AME states of n parties with local dimension \

Absolute phase estimation: adaptive local denoising and global unwrapping.

PubMed

Bioucas-Dias, Jose; Katkovnik, Vladimir; Astola, Jaakko; Egiazarian, Karen

2008-10-10

The paper attacks absolute phase estimation with a two-step approach: the first step applies an adaptive local denoising scheme to the modulo-2 pi noisy phase; the second step applies a robust phase unwrapping algorithm to the denoised modulo-2 pi phase obtained in the first step. The adaptive local modulo-2 pi phase denoising is a new algorithm based on local polynomial approximations. The zero-order and the first-order approximations of the phase are calculated in sliding windows of varying size. The zero-order approximation is used for pointwise adaptive window size selection, whereas the first-order approximation is used to filter the phase in the obtained windows. For phase unwrapping, we apply the recently introduced robust (in the sense of discontinuity preserving) PUMA unwrapping algorithm [IEEE Trans. Image Process.16, 698 (2007)] to the denoised wrapped phase. Simulations give evidence that the proposed algorithm yields state-of-the-art performance, enabling strong noise attenuation while preserving image details. (c) 2008 Optical Society of America

Scaling digital radiographs for templating in total hip arthroplasty using conventional acetate templates independent of calibration markers.

PubMed

Brew, Christopher J; Simpson, Philip M; Whitehouse, Sarah L; Donnelly, William; Crawford, Ross W; Hubble, Matthew J W

2012-04-01

We describe a scaling method for templating digital radiographs using conventional acetate templates independent of template magnification without the need for a calibration marker. The mean magnification factor for the radiology department was determined (119.8%; range, 117%-123.4%). This fixed magnification factor was used to scale the radiographs by the method described. Thirty-two femoral heads on postoperative total hip arthroplasty radiographs were then measured and compared with the actual size. The mean absolute accuracy was within 0.5% of actual head size (range, 0%-3%) with a mean absolute difference of 0.16 mm (range, 0-1 mm; SD, 0.26 mm). Intraclass correlation coefficient showed excellent reliability for both interobserver and intraobserver measurements with intraclass correlation coefficient scores of 0.993 (95% CI, 0.988-0.996) for interobserver measurements and intraobserver measurements ranging between 0.990 and 0.993 (95% CI, 0.980-0.997). Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

Chicken-sized oviraptorid dinosaurs from central China and their ontogenetic implications.

PubMed

Lü, Junchang; Currie, Philip J; Xu, Li; Zhang, Xingliao; Pu, Hanyong; Jia, Songhai

2013-02-01

Oviraptorids are a group of specialized non-avian theropod dinosaurs that were generally one to 8 m in body length. New specimens of baby oviraptorids from the Late Cretaceous of Henan Province are some of the smallest individuals known. They include diagnostic characters such as the relative position of the antorbital fenestra and the external naris, distinct opening in the premaxilla anteroventral to the external naris, antorbital fossa partly bordered by premaxilla posterodorsally, lacrimal process of premaxilla does not contact the anterodorsal process of the lacrimal, parietal almost as long as frontal; in dorsal view, posterior margin forms a straight line between the postzygapophyses in each of the fourth and fifth cervicals; femur longer than ilium. They also elucidate the ontogenetic processes of oviraptorids, including fusion of cranial elements and changes in relative body proportions. Hind limb proportions are constant in oviraptorids, regardless of absolute body size or ontogenetic stage. This suggests a sedentary lifestyle that did not involve the pursuit of similar-sized prey. The functional implications for bite force and therefore dietary preferences are better understood through the study of such small animals. The comparison of the measurements of 115 skeletons indicates that oviraptorids maintain their hind limb proportions regardless of ontogenetic stage or absolute size, which is a pattern seen more commonly in herbivores than in carnivores. This may weakly support the hypothesis that oviraptorids are herbivores rather than active carnivores.

Chicken-sized oviraptorid dinosaurs from central China and their ontogenetic implications

NASA Astrophysics Data System (ADS)

Lü, Junchang; Currie, Philip J.; Xu, Li; Zhang, Xingliao; Pu, Hanyong; Jia, Songhai

2013-02-01

Oviraptorids are a group of specialized non-avian theropod dinosaurs that were generally one to 8 m in body length. New specimens of baby oviraptorids from the Late Cretaceous of Henan Province are some of the smallest individuals known. They include diagnostic characters such as the relative position of the antorbital fenestra and the external naris, distinct opening in the premaxilla anteroventral to the external naris, antorbital fossa partly bordered by premaxilla posterodorsally, lacrimal process of premaxilla does not contact the anterodorsal process of the lacrimal, parietal almost as long as frontal; in dorsal view, posterior margin forms a straight line between the postzygapophyses in each of the fourth and fifth cervicals; femur longer than ilium. They also elucidate the ontogenetic processes of oviraptorids, including fusion of cranial elements and changes in relative body proportions. Hind limb proportions are constant in oviraptorids, regardless of absolute body size or ontogenetic stage. This suggests a sedentary lifestyle that did not involve the pursuit of similar-sized prey. The functional implications for bite force and therefore dietary preferences are better understood through the study of such small animals. The comparison of the measurements of 115 skeletons indicates that oviraptorids maintain their hind limb proportions regardless of ontogenetic stage or absolute size, which is a pattern seen more commonly in herbivores than in carnivores. This may weakly support the hypothesis that oviraptorids are herbivores rather than active carnivores.

The effects of particle size on the optical properties and surface roughness of a glass-balloon-filled black paint

NASA Technical Reports Server (NTRS)

Heslin, T.; Heaney, J.; Harper, M.

1974-01-01

The effects of particle size on the optical properties and surface roughness of a glass-balloon-filled, carbon-pigmented paint were studied in order to develop a diffuse-reflecting, low-total-reflectance, low-outgassing black paint. Particle sizes ranged between 20 microns and 74 microns. Surface roughness was found to increase with increasing particle size. Relative total reflectance at near-normal incidence (MgO standard) of the filled paints was less than for the unfilled paint between 230 nm and 1800 nm. Total absolute reflectance at 546 nm decreased with increasing particle size at grazing angles of incidence. Near-normal, total emittance was greater for the filled paints than for the unfilled paint. Specularity decreased with increasing particle size over the range studied.

A mapping of an ensemble of mitochondrial sequences for various organisms into 3D space based on the word composition.

PubMed

Aita, Takuyo; Nishigaki, Koichi

2012-11-01

To visualize a bird's-eye view of an ensemble of mitochondrial genome sequences for various species, we recently developed a novel method of mapping a biological sequence ensemble into Three-Dimensional (3D) vector space. First, we represented a biological sequence of a species s by a word-composition vector x(s), where its length [absolute value]x(s)[absolute value] represents the sequence length, and its unit vector x(s)/[absolute value]x(s)[absolute value] represents the relative composition of the K-tuple words through the sequence and the size of the dimension, N=4(K), is the number of all possible words with the length of K. Second, we mapped the vector x(s) to the 3D position vector y(s), based on the two following simple principles: (1) [absolute value]y(s)[absolute value]=[absolute value]x(s)[absolute value] and (2) the angle between y(s) and y(t) maximally correlates with the angle between x(s) and x(t). The mitochondrial genome sequences for 311 species, including 177 Animalia, 85 Fungi and 49 Green plants, were mapped into 3D space by using K=7. The mapping was successful because the angles between vectors before and after the mapping highly correlated with each other (correlation coefficients were 0.92-0.97). Interestingly, the Animalia kingdom is distributed along a single arc belt (just like the Milky Way on a Celestial Globe), and the Fungi and Green plant kingdoms are distributed in a similar arc belt. These two arc belts intersect at their respective middle regions and form a cross structure just like a jet aircraft fuselage and its wings. This new mapping method will allow researchers to intuitively interpret the visual information presented in the maps in a highly effective manner. Copyright © 2012 Elsevier Inc. All rights reserved.

A technique to measure the size of particles in laser Doppler velocimetry applications

NASA Technical Reports Server (NTRS)

Hess, C. F.

1985-01-01

A method to measure the size of particles in Laser Doppler Velocimeter (LDV) applications is discussed. Since in LDV the velocity of the flow is assocated with the velocity of particles to establish how well they follow the flow, in the present method the interferometric probe volume is surrounded by a larger beam of different polarization or wavelength. The particle size is then measured from the absolute intensity scattered from the large beam by particles crossing the fringes. Experiments using polystrene particles between 1.1 and 3.3 microns and larger glass beads are reported. It is shown that the method has an excellent size resolution and its accuracy is better than 10% for the particle size studied.

Sampling for area estimation: A comparison of full-frame sampling with the sample segment approach

NASA Technical Reports Server (NTRS)

Hixson, M.; Bauer, M. E.; Davis, B. J. (Principal Investigator)

1979-01-01

The author has identified the following significant results. Full-frame classifications of wheat and non-wheat for eighty counties in Kansas were repetitively sampled to simulate alternative sampling plans. Evaluation of four sampling schemes involving different numbers of samples and different size sampling units shows that the precision of the wheat estimates increased as the segment size decreased and the number of segments was increased. Although the average bias associated with the various sampling schemes was not significantly different, the maximum absolute bias was directly related to sampling size unit.

The Berg Balance Scale has high intra- and inter-rater reliability but absolute reliability varies across the scale: a systematic review.

PubMed

Downs, Stephen; Marquez, Jodie; Chiarelli, Pauline

2013-06-01

What is the intra-rater and inter-rater relative reliability of the Berg Balance Scale? What is the absolute reliability of the Berg Balance Scale? Does the absolute reliability of the Berg Balance Scale vary across the scale? Systematic review with meta-analysis of reliability studies. Any clinical population that has undergone assessment with the Berg Balance Scale. Relative intra-rater reliability, relative inter-rater reliability, and absolute reliability. Eleven studies involving 668 participants were included in the review. The relative intrarater reliability of the Berg Balance Scale was high, with a pooled estimate of 0.98 (95% CI 0.97 to 0.99). Relative inter-rater reliability was also high, with a pooled estimate of 0.97 (95% CI 0.96 to 0.98). A ceiling effect of the Berg Balance Scale was evident for some participants. In the analysis of absolute reliability, all of the relevant studies had an average score of 20 or above on the 0 to 56 point Berg Balance Scale. The absolute reliability across this part of the scale, as measured by the minimal detectable change with 95% confidence, varied between 2.8 points and 6.6 points. The Berg Balance Scale has a higher absolute reliability when close to 56 points due to the ceiling effect. We identified no data that estimated the absolute reliability of the Berg Balance Scale among participants with a mean score below 20 out of 56. The Berg Balance Scale has acceptable reliability, although it might not detect modest, clinically important changes in balance in individual subjects. The review was only able to comment on the absolute reliability of the Berg Balance Scale among people with moderately poor to normal balance. Copyright © 2013 Australian Physiotherapy Association. Published by .. All rights reserved.

Litter sex composition influences dominance status of Alpine marmots (Marmota marmota).

PubMed

Dupont, Pierre; Pradel, Roger; Lardy, Sophie; Allainé, Dominique; Cohas, Aurélie

2015-11-01

In social species, the hierarchical status of an individual has important consequences for its fitness. While many studies have focused on individual condition to explain access to dominance, very few have investigated the influence of the social environment, especially during early life. Yet it is known that environmental conditions early in life may influence several traits at adulthood. Here, we examine the influence of early social environment on accession to dominance by investigating the influence of litter size and sex composition on survival and the probability of ascending to dominance later in life using a 20-year dataset from a wild population of Alpine marmots (Marmota marmota). Although litter size had no effect on the fate of individuals, litter sex composition affected male juvenile survival and both male and female probabilities of reaching dominant status when adult. Male juveniles incur lower survival when the number of male juveniles in the litter increases, and individuals of both sexes from male-biased litters are more likely to become dominant than individuals from female-biased litters. However, the absolute number of sisters in the litter, rather than the sex ratio, seems to be an important predictor of the probability of acquiring dominant status: pups having more sisters are less likely to become dominant. Several potential mechanisms to explain these results are discussed.

Influence of inspiratory flow rate, particle size, and airway caliber on aerosolized drug delivery to the lung.

PubMed

Dolovich, M A

2000-06-01

A number of studies in the literature support the use of fine aerosols of drug, inhaled at low IFRs to target peripheral airways, with the objective of improving clinical responses to inhaled therapy (Fig. 8). Attempts have been made to separate response due to changes in total administered dose or the surface concentration of the dose from response due to changes in site of deposition--both are affected by the particle size of the aerosol, with IFR additionally influencing the latter. The tools for measuring dose and distribution have improved over the last 10-15 years, and thus we should expect greater accuracy in these measurements for assessing drug delivery to the lung. There are still issues, though, in producing radiolabeled (99m)technetium aerosols that are precise markers for the pharmaceutical product being tested and in quantitating absolute doses deposited in the lung. PET isotopes may provide the means for directly labelling a drug and perhaps can offer an alternative for making these measurements in the future, but deposition measurements should not be used in isolation; protocols should incorporate clinical tests to provide parallel therapeutic data in response to inhalation of the drug by the various patient populations being studied.

How many steps/day are enough? For older adults and special populations

PubMed Central

2011-01-01

Older adults and special populations (living with disability and/or chronic illness that may limit mobility and/or physical endurance) can benefit from practicing a more physically active lifestyle, typically by increasing ambulatory activity. Step counting devices (accelerometers and pedometers) offer an opportunity to monitor daily ambulatory activity; however, an appropriate translation of public health guidelines in terms of steps/day is unknown. Therefore this review was conducted to translate public health recommendations in terms of steps/day. Normative data indicates that 1) healthy older adults average 2,000-9,000 steps/day, and 2) special populations average 1,200-8,800 steps/day. Pedometer-based interventions in older adults and special populations elicit a weighted increase of approximately 775 steps/day (or an effect size of 0.26) and 2,215 steps/day (or an effect size of 0.67), respectively. There is no evidence to inform a moderate intensity cadence (i.e., steps/minute) in older adults at this time. However, using the adult cadence of 100 steps/minute to demark the lower end of an absolutely-defined moderate intensity (i.e., 3 METs), and multiplying this by 30 minutes produces a reasonable heuristic (i.e., guiding) value of 3,000 steps. However, this cadence may be unattainable in some frail/diseased populations. Regardless, to truly translate public health guidelines, these steps should be taken over and above activities performed in the course of daily living, be of at least moderate intensity accumulated in minimally 10 minute bouts, and add up to at least 150 minutes over the week. Considering a daily background of 5,000 steps/day (which may actually be too high for some older adults and/or special populations), a computed translation approximates 8,000 steps on days that include a target of achieving 30 minutes of moderate-to-vigorous physical activity (MVPA), and approximately 7,100 steps/day if averaged over a week. Measured directly and including these background activities, the evidence suggests that 30 minutes of daily MVPA accumulated in addition to habitual daily activities in healthy older adults is equivalent to taking approximately 7,000-10,000 steps/day. Those living with disability and/or chronic illness (that limits mobility and or/physical endurance) display lower levels of background daily activity, and this will affect whole-day estimates of recommended physical activity. PMID:21798044

Uncertainty in Population Estimates for Endangered Animals and Improving the Recovery Process.

PubMed

Haines, Aaron M; Zak, Matthew; Hammond, Katie; Scott, J Michael; Goble, Dale D; Rachlow, Janet L

2013-08-13

United States recovery plans contain biological information for a species listed under the Endangered Species Act and specify recovery criteria to provide basis for species recovery. The objective of our study was to evaluate whether recovery plans provide uncertainty (e.g., variance) with estimates of population size. We reviewed all finalized recovery plans for listed terrestrial vertebrate species to record the following data: (1) if a current population size was given, (2) if a measure of uncertainty or variance was associated with current estimates of population size and (3) if population size was stipulated for recovery. We found that 59% of completed recovery plans specified a current population size, 14.5% specified a variance for the current population size estimate and 43% specified population size as a recovery criterion. More recent recovery plans reported more estimates of current population size, uncertainty and population size as a recovery criterion. Also, bird and mammal recovery plans reported more estimates of population size and uncertainty compared to reptiles and amphibians. We suggest the use of calculating minimum detectable differences to improve confidence when delisting endangered animals and we identified incentives for individuals to get involved in recovery planning to improve access to quantitative data.

The demographic consequences of growing older and bigger in oyster populations.

PubMed

Moore, Jacob L; Lipcius, Romuald N; Puckett, Brandon; Schreiber, Sebastian J

2016-10-01

Structured population models, particularly size- or age-structured, have a long history of informing conservation and natural resource management. While size is often easier to measure than age and is the focus of many management strategies, age-structure can have important effects on population dynamics that are not captured in size-only models. However, relatively few studies have included the simultaneous effects of both age- and size-structure. To better understand how population structure, particularly that of age and size, impacts restoration and management decisions, we developed and compared a size-structured integral projection model (IPM) and an age- and size-structured IPM, using a population of Crassostrea gigas oysters in the northeastern Pacific Ocean. We analyzed sensitivity of model results across values of local retention that give populations decreasing in size to populations increasing in size. We found that age- and size-structured models yielded the best fit to the demographic data and provided more reliable results about long-term demography. Elasticity analysis showed that population growth rate was most sensitive to changes in the survival of both large (>175 mm shell length) and small (<75 mm shell length) oysters, indicating that a maximum size limit, in addition to a minimum size limit, could be an effective strategy for maintaining a sustainable population. In contrast, the purely size-structured model did not detect the importance of large individuals. Finally, patterns in stable age and stable size distributions differed between populations decreasing in size due to limited local retention and populations increasing in size due to high local retention. These patterns can be used to determine population status and restoration success. The methodology described here provides general insight into the necessity of including both age- and size-structure into modeling frameworks when using population models to inform restoration and management decisions. © 2016 by the Ecological Society of America.

Indigenous and tribal peoples' health (The Lancet-Lowitja Institute Global Collaboration): a population study.

PubMed

Anderson, Ian; Robson, Bridget; Connolly, Michele; Al-Yaman, Fadwa; Bjertness, Espen; King, Alexandra; Tynan, Michael; Madden, Richard; Bang, Abhay; Coimbra, Carlos E A; Pesantes, Maria Amalia; Amigo, Hugo; Andronov, Sergei; Armien, Blas; Obando, Daniel Ayala; Axelsson, Per; Bhatti, Zaid Shakoor; Bhutta, Zulfiqar Ahmed; Bjerregaard, Peter; Bjertness, Marius B; Briceno-Leon, Roberto; Broderstad, Ann Ragnhild; Bustos, Patricia; Chongsuvivatwong, Virasakdi; Chu, Jiayou; Deji; Gouda, Jitendra; Harikumar, Rachakulla; Htay, Thein Thein; Htet, Aung Soe; Izugbara, Chimaraoke; Kamaka, Martina; King, Malcolm; Kodavanti, Mallikharjuna Rao; Lara, Macarena; Laxmaiah, Avula; Lema, Claudia; Taborda, Ana María León; Liabsuetrakul, Tippawan; Lobanov, Andrey; Melhus, Marita; Meshram, Indrapal; Miranda, J Jaime; Mu, Thet Thet; Nagalla, Balkrishna; Nimmathota, Arlappa; Popov, Andrey Ivanovich; Poveda, Ana María Peñuela; Ram, Faujdar; Reich, Hannah; Santos, Ricardo V; Sein, Aye Aye; Shekhar, Chander; Sherpa, Lhamo Y; Skold, Peter; Tano, Sofia; Tanywe, Asahngwa; Ugwu, Chidi; Ugwu, Fabian; Vapattanawong, Patama; Wan, Xia; Welch, James R; Yang, Gonghuan; Yang, Zhaoqing; Yap, Leslie

2016-07-09

International studies of the health of Indigenous and tribal peoples provide important public health insights. Reliable data are required for the development of policy and health services. Previous studies document poorer outcomes for Indigenous peoples compared with benchmark populations, but have been restricted in their coverage of countries or the range of health indicators. Our objective is to describe the health and social status of Indigenous and tribal peoples relative to benchmark populations from a sample of countries. Collaborators with expertise in Indigenous health data systems were identified for each country. Data were obtained for population, life expectancy at birth, infant mortality, low and high birthweight, maternal mortality, nutritional status, educational attainment, and economic status. Data sources consisted of governmental data, data from non-governmental organisations such as UNICEF, and other research. Absolute and relative differences were calculated. Our data (23 countries, 28 populations) provide evidence of poorer health and social outcomes for Indigenous peoples than for non-Indigenous populations. However, this is not uniformly the case, and the size of the rate difference varies. We document poorer outcomes for Indigenous populations for: life expectancy at birth for 16 of 18 populations with a difference greater than 1 year in 15 populations; infant mortality rate for 18 of 19 populations with a rate difference greater than one per 1000 livebirths in 16 populations; maternal mortality in ten populations; low birthweight with the rate difference greater than 2% in three populations; high birthweight with the rate difference greater than 2% in one population; child malnutrition for ten of 16 populations with a difference greater than 10% in five populations; child obesity for eight of 12 populations with a difference greater than 5% in four populations; adult obesity for seven of 13 populations with a difference greater than 10% in four populations; educational attainment for 26 of 27 populations with a difference greater than 1% in 24 populations; and economic status for 15 of 18 populations with a difference greater than 1% in 14 populations. We systematically collated data across a broader sample of countries and indicators than done in previous studies. Taking into account the UN Sustainable Development Goals, we recommend that national governments develop targeted policy responses to Indigenous health, improving access to health services, and Indigenous data within national surveillance systems. The Lowitja Institute. Copyright © 2016 Elsevier Ltd. All rights reserved.

Changing ethnic inequalities in mortality in New Zealand over 30 years: linked cohort studies with 68.9 million person-years of follow-up.

PubMed

Disney, George; Teng, Andrea; Atkinson, June; Wilson, Nick; Blakely, Tony

2017-01-01

Internationally, ethnic inequalities in mortality within countries are increasingly recognized as a public health concern. But few countries have data to monitor such inequalities. We aimed to provide a detailed description of ethnic inequalities (Māori [indigenous], Pacific, and European/Other) in mortality for a country with high quality ethnicity data, using both standard and novel visualization methods. Cohort studies of the entire New Zealand population were conducted, using probabilistically-linked Census and mortality data from 1981 to 2011 (68.9 million person years). Absolute (standardized rate difference) and relative (standardized rate ratio) inequalities were calculated, in 1-74-year-olds, for Māori and Pacific peoples in comparison to European/Other. All-cause mortality rates were highest for Māori, followed by Pacific peoples then European/Other, and declined in all three ethnic groups over time. Pacific peoples experienced the slowest annual percentage fall in mortality rates, then Māori, with European/Other having the highest percentage falls - resulting in widening relative inequalities. Absolute inequalities, however, for both Māori and Pacific males compared to European/Other have been falling since 1996. But for females, only Māori absolute inequalities (compared with European/Other) have been falling. Regarding cause of death, cancer is becoming a more important contributor than cardiovascular disease (CVD) to absolute inequalities, especially for Māori females. We found declines in all-cause mortality rates, over time, for each ethnic group of interest. Ethnic mortality inequalities are generally stable or even falling in absolute terms, but have increased on a relative scale. The drivers of these inequalities in mortality are transitioning over time, away from CVD to cancer and diabetes; such transitions are likely in other countries, and warrant further research. To address these inequalities, policymakers need to enhance prevention activities and health care delivery, but also support wider improvements in educational achievement and socioeconomic position for highest need populations.

Changing ethnic inequalities in mortality in New Zealand over 30 years: linked cohort studies with 68.9 million person-years of follow-up.

PubMed

Disney, George; Teng, Andrea; Atkinson, June; Wilson, Nick; Blakely, Tony

2017-04-26

Internationally, ethnic inequalities in mortality within countries are increasingly recognized as a public health concern. But few countries have data to monitor such inequalities. We aimed to provide a detailed description of ethnic inequalities (Māori [indigenous], Pacific, and European/Other) in mortality for a country with high quality ethnicity data, using both standard and novel visualization methods. Cohort studies of the entire New Zealand population were conducted, using probabilistically-linked Census and mortality data from 1981 to 2011 (68.9 million person years). Absolute (standardized rate difference) and relative (standardized rate ratio) inequalities were calculated, in 1-74-year-olds, for Māori and Pacific peoples in comparison to European/Other. All-cause mortality rates were highest for Māori, followed by Pacific peoples then European/Other, and declined in all three ethnic groups over time. Pacific peoples experienced the slowest annual percentage fall in mortality rates, then Māori, with European/Other having the highest percentage falls - resulting in widening relative inequalities. Absolute inequalities, however, for both Māori and Pacific males compared to European/Other have been falling since 1996. But for females, only Māori absolute inequalities (compared with European/Other) have been falling. Regarding cause of death, cancer is becoming a more important contributor than cardiovascular disease (CVD) to absolute inequalities, especially for Māori females. We found declines in all-cause mortality rates, over time, for each ethnic group of interest. Ethnic mortality inequalities are generally stable or even falling in absolute terms, but have increased on a relative scale. The drivers of these inequalities in mortality are transitioning over time, away from CVD to cancer and diabetes; such transitions are likely in other countries, and warrant further research. To address these inequalities, policymakers need to enhance prevention activities and health care delivery, but also support wider improvements in educational achievement and socioeconomic position for highest need populations.

Treatment decision-making and the form of risk communication: results of a factorial survey.

PubMed

Hembroff, Larry A; Holmes-Rovner, Margaret; Wills, Celia E

2004-11-16

Prospective users of preventive therapies often must evaluate complex information about therapeutic risks and benefits. The purpose of this study was to evaluate the effect of relative and absolute risk information on patient decision-making in scenarios typical of health information for patients. Factorial experiments within a telephone survey of the Michigan adult, non-institutionalized, English-speaking population. Average interview lasted 23 minutes. Subjects and sample design: 952 randomly selected adults within a random-digit dial sample of Michigan households. Completion rate was 54.3%. When presented hypothetical information regarding additional risks of breast cancer from a medication to prevent a bone disease, respondents reduced their willingness to recommend a female friend take the medication compared to the baseline rate (66.8% = yes). The decrease was significantly greater with relative risk information. Additional benefit information regarding preventing heart disease from the medication increased willingness to recommend the medication to a female friend relative to the baseline scenario, but did not differ between absolute and relative risk formats. When information about both increased risk of breast cancer and reduced risk of heart disease were provided, typical respondents appeared to make rational decisions consistent with Expected Utility Theory, but the information presentation format affected choices. Those 11% - 33% making decisions contrary to the medical indications were more likely to be Hispanic, older, more educated, smokers, and to have children in the home. In scenarios typical of health risk information, relative risk information led respondents to make non-normative decisions that were "corrected" when the frame used absolute risk information. This population sample made generally rational decisions when presented with absolute risk information, even in the context of a telephone interview requiring remembering rates given. The lack of effect of gender and race suggests that a standard strategy of presenting absolute risk information may improve patient decision-making.

Urbanization and physician maldistribution: a longitudinal study in Japan

PubMed Central

2011-01-01

Background The relative shortage of physicians in Japan's rural areas is an important issue in health policy. In the 1970s, the Japanese government began a policy to increase the number of medical students and to achieve a better distribution of physicians. Beginning in 1985, however, admissions to medical school were reduced to prevent a future oversupply of physicians. In 2007, medical school entrants equaled just 92% of their 1982 peers. The urban annual population growth rate is positive and the rural is negative, a trend that may affect denominator populations and physician distribution. Methods Our data cover six time points and span a decade: 1998, 2000, 2002, 2004, 2006, and 2008. The spatial units for analysis are the secondary tier of medical care (STM) as defined by the Medical Service Law and related legislation. We examined trends in the geographic disparities in population and physician distribution among 348 STMs in Japan. We compared populations and the number of physicians per 100,000 populations in each STM. To measure maldistribution quantitatively, we calculated Gini coefficients for physician distribution. Results Between 1998 and 2008, the total population and the number of practicing physicians for every 100,000 people increased by 0.95% and 13.6%, respectively. However, the inequality of physician distribution remained constant, although small and mostly rural areas experienced an increase in physician to population ratios. In contrast, as the maldistribution of population escalated during the same period, the Gini coefficient of population rose. Although the absolute number of practicing physicians in small STMs decreased, the fall in the denominator population of the STMs resulted in an increase in the number of practicing physicians per population in those located in rural areas. Conclusions A policy that increased the number of physicians and the physician to population ratios between 1998 and 2008 in all geographic areas of Japan, irrespective of size, did not lead to a more equal geographical distribution of physicians. The ratios of physicians to population in small rural STMs increased because of concurrent trends in urbanization and not because of a rise in the number of practicing physicians. PMID:21982582

Cost effectiveness analysis of screening for sight threatening diabetic eye disease

PubMed Central

James, Marilyn; Turner, David A; Broadbent, Deborah M; Vora, Jiten; Harding, Simon P

2000-01-01

Objective To measure the cost effectiveness of systematic photographic screening for sight threatening diabetic eye disease compared with existing practice. Design Cost effectiveness analysis Setting Liverpool. Subjects A target population of 5000 diabetic patients invited for screening. Main outcome measures Cost effectiveness (cost per true positive) of systematic and opportunistic programmes; incremental cost effectiveness of replacing opportunistic with systematic screening. Results Baseline prevalence of sight threatening eye disease was 14.1%. The cost effectiveness of the systematic programme was £209 (sensitivity 89%, specificity 86%, compliance 80%, annual cost £104 996) and of the opportunistic programme was £289 (combined sensitivity 63%, specificity 92%, compliance 78%, annual cost £99 981). The incremental cost effectiveness of completely replacing the opportunistic programme was £32. Absolute values of cost effectiveness were highly sensitive to varying prevalence, sensitivity and specificity, compliance, and programme size. Conclusion Replacing existing programmes with systematic screening for diabetic eye disease is justified. PMID:10856062

Continued investigation of LDEF's structural frame and thermal blankets by the Meteoroid and Debris Special Investigation Group

NASA Technical Reports Server (NTRS)

See, Thomas H.; Mack, Kimberly S.; Warren, Jack L.; Zolensky, Michael E.; Zook, Herbert A.

1993-01-01

This report focuses on the data acquired by detailed examination of LDEF intercostals, 68 of which are now in possession of the Meteoroid and Debris Special Investigation Group (M&D SIG) at JSC. In addition, limited data will be presented for several small sections from the A0178 thermal control blankets that were examined/counted prior to being shipped to Principal Investigators (PI's) for scientific study. The data presented here are limited to measurements of crater and penetration-hole diameters and their frequency of occurrence which permits, yet also constrains, more model-dependent, interpretative efforts. Such efforts will focus on the conversion of crater and penetration-hole sizes to projectile diameters (and masses), on absolute particle fluxes, and on the distribution of particle-encounter velocities. These are all complex issues that presently cannot be pursued without making various assumptions which relate, in part, to crater-scaling relationships, and to assumed trajectories of natural and man-made particle populations in LEO that control the initial impact conditions.

The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Cratering histories of the intercrater plains. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Leake, M. A.

1982-01-01

The intercrater plains of Mercury and the Moon are defined, in part, by their high densities of small craters. The crater size frequency statistics presented in this chapter may help constrain the relative ages and origins of these surfaces. To this end, the effects of common geologic processes on crater frequency statistics are compared with the diameter frequency distributions of the intercrater regions of the Moon and Mercury. Such analyses may determine whether secondary craters dominate the distribution at small diameters, and whether volcanic plains or ballistic deposits form the intercrater surface. Determining the mass frequency distribution and flux of the impacting population is a more difficult problem. The necessary information such as scaling relationships between projectile energy and crater diameter, the relative fluxes of solar system objects, and the absolute ages of surface units is model dependent and poorly constrained, especially for Mercury.

Triple galaxies and a hidden mass problem

NASA Technical Reports Server (NTRS)

Karachentsev, I. D.; Karachentseva, V. E.; Lebedev, V. S.

1990-01-01

The authors consider a homogeneous sample of 84 triple systems of galaxies with components brighter than m = 15.7, located in the northern sky and satisfying an isolation criterion with respect to neighboring galaxies in projection. The distributions of basic dynamical parameters for triplets have median values as follows: radial velocity dispersion 133 km/s, mean harmonic radius 63 kpc, absolute magnitude of galaxies M sub B equals -20.38, crossing time tau = 0.04 H(sup minus 1). For different ways of estimation the median mass-to-luminosity ratio is (20 - 30). A comparison of the last value with the ones for single and binary galaxies shows the presence of a virial mass excess for triplets by a factor 4. The mass-to-luminosity ratio is practically uncorrelated with linear size of triplets or with morphological types of their components. We note that a significant part of the virial excess may be explained by the presence of nonisolated triple configurations in the sample, which are produced by debris of more populous groups of galaxies.

Air Pollution and Stroke

PubMed Central

Lee, Kuan Ken; Miller, Mark R.; Shah, Anoop S. V.

2018-01-01

The adverse health effects of air pollution have long been recognised; however, there is less awareness that the majority of the morbidity and mortality caused by air pollution is due to its effects on the cardiovascular system. Evidence from epidemiological studies have demonstrated a strong association between air pollution and cardiovascular diseases including stroke. Although the relative risk is small at an individual level, the ubiquitous nature of exposure to air pollution means that the absolute risk at a population level is on a par with “traditional” risk factors for cardiovascular disease. Of particular concern are findings that the strength of this association is stronger in low and middle income countries where air pollution is projected to rise as a result of rapid industrialisation. The underlying biological mechanisms through which air pollutants exert their effect on the vasculature are still an area of intense discussion. A greater understanding of the effect size and mechanisms is necessary to develop effective strategies at individual and policy levels to mitigate the adverse cardiovascular effects of air pollution. PMID:29402072

Air Pollution and Stroke.

PubMed

Lee, Kuan Ken; Miller, Mark R; Shah, Anoop S V

2018-01-01

The adverse health effects of air pollution have long been recognised; however, there is less awareness that the majority of the morbidity and mortality caused by air pollution is due to its effects on the cardiovascular system. Evidence from epidemiological studies have demonstrated a strong association between air pollution and cardiovascular diseases including stroke. Although the relative risk is small at an individual level, the ubiquitous nature of exposure to air pollution means that the absolute risk at a population level is on a par with "traditional" risk factors for cardiovascular disease. Of particular concern are findings that the strength of this association is stronger in low and middle income countries where air pollution is projected to rise as a result of rapid industrialisation. The underlying biological mechanisms through which air pollutants exert their effect on the vasculature are still an area of intense discussion. A greater understanding of the effect size and mechanisms is necessary to develop effective strategies at individual and policy levels to mitigate the adverse cardiovascular effects of air pollution.

γδ T Cells Shape Pre-Immune Peripheral B Cell Populations

PubMed Central

Huang, Yafei; Getahun, Andrew; Heiser, Ryan A.; Detanico, Thiago O.; Aviszus, Katja; Kirchenbaum, Greg A.; Casper, Tamara L.; Huang, Chunjian; Aydintug, M. Kemal; Carding, Simon R.; Ikuta, Koichi; Huang, Hua; Wysocki, Lawrence J.; Cambier, John C.; O’Brien, Rebecca L.; Born, Willi K.

2015-01-01

We previously reported that selective ablation of certain γδ T cell subsets rather than removal of all γδ T cells, strongly affects serum antibody levels in non-immunized mice. This type of manipulation also changed T cells including residual γδ T cells, revealing some interdependence of γδ T cell populations. For example, in mice lacking Vγ4+ and Vγ6+ γδ T cells (B6.TCR-Vγ4−/−/6−/−), we observed expanded Vγ1+ cells, which changed in composition and activation and produced more IL-4 upon stimulation in vitro, increased IL-4 production by αβ T cells as well as spontaneous germinal center formation in the spleen, elevated serum Ig and autoantibodies. We therefore examined B cell populations in this and other γδ-deficient mouse strains. Whereas immature bone marrow B cells remained largely unchanged, peripheral B cells underwent several changes. Specifically, transitional and mature B cells in the spleen of B6.TCR-Vγ4−/−/6−/− mice and other peripheral B cell populations were diminished, most of all splenic marginal zone (MZ) B cells. However, relative frequencies and absolute numbers of antibody-producing cells, and serum levels of antibodies, IL-4 and BAFF, were increased. Cell transfers confirmed that these changes are directly dependent on the altered γδ T cells in this strain, and their enhanced potential of producing IL-4. Further evidence suggests the possibility of direct interactions between γδ T cells and B cells in the splenic MZ. Together, these data demonstrate the capability of γδ T cells of modulating size and productivity of pre-immune peripheral B cell populations. PMID:26582947

γδ T Cells Shape Preimmune Peripheral B Cell Populations.

PubMed

Huang, Yafei; Getahun, Andrew; Heiser, Ryan A; Detanico, Thiago O; Aviszus, Katja; Kirchenbaum, Greg A; Casper, Tamara L; Huang, Chunjian; Aydintug, M Kemal; Carding, Simon R; Ikuta, Koichi; Huang, Hua; Wysocki, Lawrence J; Cambier, John C; O'Brien, Rebecca L; Born, Willi K

2016-01-01

We previously reported that selective ablation of certain γδ T cell subsets, rather than removal of all γδ T cells, strongly affects serum Ab levels in nonimmunized mice. This type of manipulation also changed T cells, including residual γδ T cells, revealing some interdependence of γδ T cell populations. For example, in mice lacking Vγ4(+) and Vγ6(+) γδ T cells (B6.TCR-Vγ4(-/-)/6(-/-)), we observed expanded Vγ1(+) cells, which changed in composition and activation and produced more IL-4 upon stimulation in vitro, increased IL-4 production by αβ T cells as well as spontaneous germinal center formation in the spleen, and elevated serum Ig and autoantibodies. We therefore examined B cell populations in this and other γδ-deficient mouse strains. Whereas immature bone marrow B cells remained largely unchanged, peripheral B cells underwent several changes. Specifically, transitional and mature B cells in the spleen of B6.TCR-Vγ4(-/-)/6(-/-) mice and other peripheral B cell populations were diminished, most of all splenic marginal zone (MZ) B cells. However, relative frequencies and absolute numbers of Ab-producing cells, as well as serum levels of Abs, IL-4, and BAFF, were increased. Cell transfers confirmed that these changes are directly dependent on the altered γδ T cells in this strain and on their enhanced potential of producing IL-4. Further evidence suggests the possibility of direct interactions between γδ T cells and B cells in the splenic MZ. Taken together, these data demonstrate the capability of γδ T cells of modulating size and productivity of preimmune peripheral B cell populations. Copyright © 2015 by The American Association of Immunologists, Inc.

An High Resolution Near-Earth Objects Population Enabling Next-Generation Search Strategies

NASA Technical Reports Server (NTRS)

Tricaico, Pasquale; Beshore, E. C.; Larson, S. M.; Boattini, A.; Williams, G. V.

2010-01-01

Over the past decade, the dedicated search for kilometer-size near-Earth objects (NEOs), potentially hazardous objects (PHOs), and potential Earth impactors has led to a boost in the rate of discoveries of these objects. The catalog of known NEOs is the fundamental ingredient used to develop a model for the NEOs population, either by assessing and correcting for the observational bias (Jedicke et al., 2002), or by evaluating the migration rates from the NEOs source regions (Bottke et al., 2002). The modeled NEOs population is a necessary tool used to track the progress in the search of large NEOs (Jedicke et al., 2003) and to try to predict the distribution of the ones still undiscovered, as well as to study the sky distribution of potential Earth impactors (Chesley & Spahr, 2004). We present a method to model the NEOs population in all six orbital elements, on a finely grained grid, allowing us the design and test of targeted and optimized search strategies. This method relies on the observational data routinely reported to the Minor Planet Center (MPC) by the Catalina Sky Survey (CSS) and by other active NEO surveys over the past decade, to determine on a nightly basis the efficiency in detecting moving objects as a function of observable quantities including apparent magnitude, rate of motion, airmass, and galactic latitude. The cumulative detection probability is then be computed for objects within a small range in orbital elements and absolute magnitude, and the comparison with the number of know NEOs within the same range allows us to model the population. When propagated to the present epoch and projected on the sky plane, this provides the distribution of the missing large NEOs, PHOs, and potential impactors.

Measurement of absolute frequency of continuous-wave terahertz radiation in real time using a free-running, dual-wavelength mode-locked, erbium-doped fibre laser

PubMed Central

Hu, Guoqing; Mizuguchi, Tatsuya; Zhao, Xin; Minamikawa, Takeo; Mizuno, Takahiko; Yang, Yuli; Li, Cui; Bai, Ming; Zheng, Zheng; Yasui, Takeshi

2017-01-01

A single, free-running, dual-wavelength mode-locked, erbium-doped fibre laser was exploited to measure the absolute frequency of continuous-wave terahertz (CW-THz) radiation in real time using dual THz combs of photo-carriers (dual PC-THz combs). Two independent mode-locked laser beams with different wavelengths and different repetition frequencies were generated from this laser and were used to generate dual PC-THz combs having different frequency spacings in photoconductive antennae. Based on the dual PC-THz combs, the absolute frequency of CW-THz radiation was determined with a relative precision of 1.2 × 10−9 and a relative accuracy of 1.4 × 10−9 at a sampling rate of 100 Hz. Real-time determination of the absolute frequency of CW-THz radiation varying over a few tens of GHz was also demonstrated. Use of a single dual-wavelength mode-locked fibre laser, in place of dual mode-locked lasers, greatly reduced the size, complexity, and cost of the measurement system while maintaining the real-time capability and high measurement precision. PMID:28186148

The slippery slope from contraception to euthanasia.

PubMed

Kippley, J F

1978-01-01

The key element in natural family planning that keeps it from being the 1st to abortion is the emphasis on natural. A purely secular form of noncontraceptive birth control fails to avoid being the 1st step down the slippery slope toward abortion and then euthanasia. It is felt that the fundamental difference is in what is absolutized. The Western culture has absolutized family planning, thus, when people think that their right to plan the size of their family is an absolute right, and things do not go according to plans, they pursue their absolutized plans even if it means invading some other person's right to life. As Malcom Muggeridge has pointed out, as soon as a culture accepts the killing of the defenseless and innocent, the principle has been established for killing anyone who is socially inconvenient. However, when doing things according to God's laws, all individual plans are made relative. We do not attempt test-tube techniques and we do not resort to abortion or to sterilization. Some will reject the inherently religious overtones of the full meaning of natural (defined as acting in accord with the nature God has given each person), but at least, they have been given something to think about.

Absolute angular encoder based on optical diffraction

NASA Astrophysics Data System (ADS)

Wu, Jian; Zhou, Tingting; Yuan, Bo; Wang, Liqiang

2015-08-01

A new encoding method for absolute angular encoder based on optical diffraction was proposed in the present study. In this method, an encoder disc is specially designed that a series of elements are uniformly spaced in one circle and each element is consisted of four diffraction gratings, which are tilted in the directions of 30°, 60°, -60° and -30°, respectively. The disc is illuminated by a coherent light and the diffractive signals are received. The positions of diffractive spots are used for absolute encoding and their intensities are for subdivision, which is different from the traditional optical encoder based on transparent/opaque binary principle. Since the track's width in the disc is not limited in the diffraction pattern, it provides a new way to solve the contradiction between the size and resolution, which is good for minimization of encoder. According to the proposed principle, the diffraction pattern disc with a diameter of 40 mm was made by lithography in the glass substrate. A prototype of absolute angular encoder with a resolution of 20" was built up. Its maximum error was tested as 78" by comparing with a small angle measuring system based on laser beam deflection.

Introgression Makes Waves in Inferred Histories of Effective Population Size.

PubMed

Hawks, John

2017-01-01

Human populations have a complex history of introgression and of changing population size. Human genetic variation has been affected by both these processes, so inference of past population size depends upon the pattern of gene flow and introgression among past populations. One remarkable aspect of human population history as inferred from genetics is a consistent "wave" of larger effective population sizes, found in both African and non-African populations, that appears to reflect events prior to the last 100,000 years. I carried out a series of simulations to investigate how introgression and gene flow from genetically divergent ancestral populations affect the inference of ancestral effective population size. Both introgression and gene flow from an extinct, genetically divergent population consistently produce a wave in the history of inferred effective population size. The time and amplitude of the wave reflect the time of origin of the genetically divergent ancestral populations and the strength of introgression or gene flow. These results demonstrate that even small fractions of introgression or gene flow from ancient populations may have visible effects on the inference of effective population size.

Local extinction and recolonization, species effective population size, and modern human origins.

PubMed

Eller, Elise; Hawks, John; Relethford, John H

2004-10-01

A primary objection from a population genetics perspective to a multiregional model of modern human origins is that the model posits a large census size, whereas genetic data suggest a small effective population size. The relationship between census size and effective size is complex, but arguments based on an island model of migration show that if the effective population size reflects the number of breeding individuals and the effects of population subdivision, then an effective population size of 10,000 is inconsistent with the census size of 500,000 to 1,000,000 that has been suggested by archeological evidence. However, these models have ignored the effects of population extinction and recolonization, which increase the expected variance among demes and reduce the inbreeding effective population size. Using models developed for population extinction and recolonization, we show that a large census size consistent with the multiregional model can be reconciled with an effective population size of 10,000, but genetic variation among demes must be high, reflecting low interdeme migration rates and a colonization process that involves a small number of colonists or kin-structured colonization. Ethnographic and archeological evidence is insufficient to determine whether such demographic conditions existed among Pleistocene human populations, and further work needs to be done. More realistic models that incorporate isolation by distance and heterogeneity in extinction rates and effective deme sizes also need to be developed. However, if true, a process of population extinction and recolonization has interesting implications for human demographic history.

Genetic Diversity in Introduced Populations with an Allee Effect

PubMed Central

Wittmann, Meike J.; Gabriel, Wilfried; Metzler, Dirk

2014-01-01

A phenomenon that strongly influences the demography of small introduced populations and thereby potentially their genetic diversity is the demographic Allee effect, a reduction in population growth rates at small population sizes. We take a stochastic modeling approach to investigate levels of genetic diversity in populations that successfully overcame either a strong Allee effect, in which populations smaller than a certain critical size are expected to decline, or a weak Allee effect, in which the population growth rate is reduced at small sizes but not negative. Our results indicate that compared to successful populations without an Allee effect, successful populations with a strong Allee effect tend to (1) derive from larger founder population sizes and thus have a higher initial amount of genetic variation, (2) spend fewer generations at small population sizes where genetic drift is particularly strong, and (3) spend more time around the critical population size and thus experience more genetic drift there. In the case of multiple introduction events, there is an additional increase in diversity because Allee-effect populations tend to derive from a larger number of introduction events than other populations. Altogether, a strong Allee effect can either increase or decrease genetic diversity, depending on the average founder population size. By contrast, a weak Allee effect tends to decrease genetic diversity across the entire range of founder population sizes. Finally, we show that it is possible in principle to infer critical population sizes from genetic data, although this would require information from many independently introduced populations. PMID:25009147

Population dynamics in vasopressin cells.

PubMed

Leng, Gareth; Brown, Colin; Sabatier, Nancy; Scott, Victoria

2008-01-01

Most neurons sense and code change, and when presented with a constant stimulus they adapt, so as to be able to detect a fresh change. However, for some things it is important to know their absolute level; to encode such information, neurons must sustain their response to an unchanging stimulus while remaining able to respond to a change in that stimulus. One system that encodes the absolute level of a stimulus is the vasopressin system, which generates a hormonal signal that is proportional to plasma osmolality. Vasopressin cells sense plasma osmolality and secrete appropriate levels of vasopressin from the neurohypophysis as needed to control water excretion; this requires sustained secretion under basal conditions and the ability to increase (or decrease) secretion should plasma osmolality change. Here we explore the mechanisms that enable vasopressin cells to fulfill this function, and consider how coordination between the cells might distribute the secretory load across the population of vasopressin cells. 2008 S. Karger AG, Basel.

A Method to Compute Periodic Sums

DTIC Science & Technology

2013-10-15

the absolute performance of the present meth- ods with the smooth particle mesh Ewald ( SPME ) and other algorithms for periodic summation due to a...can be done using published data [14] comparing perfor- mance of the SPME and FMM-type PWA implementation for clusters, for relatively small size

Are great apes able to reason from multi-item samples to populations of food items?

PubMed

Eckert, Johanna; Rakoczy, Hannes; Call, Josep

2017-10-01

Inductive learning from limited observations is a cognitive capacity of fundamental importance. In humans, it is underwritten by our intuitive statistics, the ability to draw systematic inferences from populations to randomly drawn samples and vice versa. According to recent research in cognitive development, human intuitive statistics develops early in infancy. Recent work in comparative psychology has produced first evidence for analogous cognitive capacities in great apes who flexibly drew inferences from populations to samples. In the present study, we investigated whether great apes (Pongo abelii, Pan troglodytes, Pan paniscus, Gorilla gorilla) also draw inductive inferences in the opposite direction, from samples to populations. In two experiments, apes saw an experimenter randomly drawing one multi-item sample from each of two populations of food items. The populations differed in their proportion of preferred to neutral items (24:6 vs. 6:24) but apes saw only the distribution of food items in the samples that reflected the distribution of the respective populations (e.g., 4:1 vs. 1:4). Based on this observation they were then allowed to choose between the two populations. Results show that apes seemed to make inferences from samples to populations and thus chose the population from which the more favorable (4:1) sample was drawn in Experiment 1. In this experiment, the more attractive sample not only contained proportionally but also absolutely more preferred food items than the less attractive sample. Experiment 2, however, revealed that when absolute and relative frequencies were disentangled, apes performed at chance level. Whether these limitations in apes' performance reflect true limits of cognitive competence or merely performance limitations due to accessory task demands is still an open question. © 2017 Wiley Periodicals, Inc.

Minimum clinically important differences in chronic pain vary considerable by baseline pain and methodological factors: systematic review of empirical studies.

PubMed

Frahm Olsen, Mette; Bjerre, Eik; Hansen, Maria Damkjær; Tendal, Britta; Hilden, Jørgen; Hróbjartsson, Asbjørn

2018-05-21

The minimum clinically important difference (MCID) is used to interpret the relevance of treatment effects, e.g., when developing clinical guidelines, evaluating trial results or planning sample sizes. There is currently no agreement on an appropriate MCID in chronic pain and little is known about which contextual factors cause variation. This is a systematic review. We searched PubMed, EMBASE, and Cochrane Library. Eligible studies determined MCID for chronic pain based on a one-dimensional pain scale, a patient-reported transition scale of perceived improvement, and either a mean change analysis (mean difference in pain among minimally improved patients) or a threshold analysis (pain reduction associated with best sensitivity and specificity for identifying minimally improved patients). Main results were descriptively summarized due to considerable heterogeneity, which were quantified using meta-analyses and explored using subgroup analyses and metaregression. We included 66 studies (31.254 patients). Median absolute MCID was 23 mm on a 0-100 mm scale (interquartile range [IQR] 12-39) and median relative MCID was 34% (IQR 22-45) among studies using the mean change approach. In both cases, heterogeneity was very high: absolute MCID I 2  = 99% and relative MCID I 2  = 96%. High variation was also seen among studies using the threshold approach: median absolute MCID was 20 mm (IQR 15-30) and relative MCID was 32% (IQR 15-41). Absolute MCID was strongly associated with baseline pain, explaining approximately two-thirds of the variation, and to a lesser degree with the operational definition of minimum pain relief and clinical condition. A total of 15 clinical and methodological factors were assessed as possible causes for variation in MCID. MCID for chronic pain relief vary considerably. Baseline pain is strongly associated with absolute, but not relative, measures. To a much lesser degree, MCID is also influenced by the operational definition of relevant pain relief and possibly by clinical condition. Explicit and conscientious reflections on the choice of an MCID are required when classifying effect sizes as clinically important or trivial. Copyright © 2018 Elsevier Inc. All rights reserved.

[Reproductive biology of Lutjanus guttatus (Perciformes: Lutjanidae) in Utria National Park, Colombian Pacific].

PubMed

Correa-Herrera, Tatiana; Jiménez-Segura, Luz Fernanda

2013-06-01

Protected areas are important for natural population conservation since they work as refuge, feeding and breeding areas, where specimens should be exempt from human pressure. The generation of better criteria for management decisions and conservation of fishery resources, is based on the reproductive aspects of species that support fishing activities, since this information is related to the abundance, size and frequency of capture. With this aim, the reproductive biology of the spotted snapper Lutjanus guttatus was studied from April 2008 and February 2009 at the Utría National Park, Colombian Pacific. For this, we analyzed the volume of catch, size structure, sex ratio, fecundity, maturity size, breeding areas and seasons (n = 278), of daily landings of 21 units of artisanal fisheries in ten fishing grounds in the Park. Form all landings, we evaluated a total of 4319 individuals belonging to 84 species. Based on the number of individuals, Lutjanus guttatus ranked third in catches representing 6.4% (278 individuals), and 16th with 1.8% (95.79kg), based on catch biomass. The average weight was 0.34 kg +/- 0.25 kg, while 29 cm +/- 6.4 cm for total length. The total length-weight relationship had the best fit (Kruskal-Wallis, p < 0.05, n = 272) with the equation P(T) = 0.00000885* LT3.09. The occurrence of mature fish and high condition factors suggested a spawning season in June, September and October in sandy and rocky shores. This species showed an asynchronical gonadal development, with a mean sexual maturity size estimated in 23.5cm total length, and an absolute fecundity of 156 253.11 oocytes (mode of 4 microm diameter). We concluded that L. guttatus medium sizes observed indicated a fishing pressure on small size specimens (the minimum size being 18cm); thus, we recommend the implementation of minimum catch sizes based on the criterion of size at maturity LT100 (25.5 cm) and to apply seasonal fishing closures during the highest reproductive activity (June-October). However, it is necessary to obtain additional biological information with multi-year monitoring to improve fisheries management criteria in the area.

Effective population size of korean populations.

PubMed

Park, Leeyoung

2014-12-01

Recently, new methods have been developed for estimating the current and recent changes in effective population sizes. Based on the methods, the effective population sizes of Korean populations were estimated using data from the Korean Association Resource (KARE) project. The overall changes in the population sizes of the total populations were similar to CHB (Han Chinese in Beijing, China) and JPT (Japanese in Tokyo, Japan) of the HapMap project. There were no differences in past changes in population sizes with a comparison between an urban area and a rural area. Age-dependent current and recent effective population sizes represent the modern history of Korean populations, including the effects of World War II, the Korean War, and urbanization. The oldest age group showed that the population growth of Koreans had already been substantial at least since the end of the 19th century.

Absolute rather than relative income is a better socioeconomic predictor of chronic obstructive pulmonary disease in Swedish adults.

PubMed

Axelsson Fisk, Sten; Merlo, Juan

2017-05-04

While psychosocial theory claims that socioeconomic status (SES), acting through social comparisons, has an important influence on susceptibility to disease, materialistic theory says that socioeconomic position (SEP) and related access to material resources matter more. However, the relative role of SEP versus SES in chronic obstructive pulmonary disease (COPD) risk has still not been examined. We investigated the association between SES/SEP and COPD risk among 667 094 older adults, aged 55 to 60, residing in Sweden between 2006 and 2011. Absolute income in five groups by population quintiles depicted SEP and relative income expressed as quintile groups within each absolute income group represented SES. We performed sex-stratified logistic regression models to estimate odds ratios and the area under the receiver operator curve (AUC) to compare the discriminatory accuracy of SES and SEP in relation to COPD. Even though both absolute (SEP) and relative income (SES) were associated with COPD risk, only absolute income (SEP) presented a clear gradient, so the poorest had a three-fold higher COPD risk than the richest individuals. While the AUC for a model including only age was 0.54 and 0.55 when including relative income (SES), it increased to 0.65 when accounting for absolute income (SEP). SEP rather than SES demonstrated a consistent association with COPD. Our study supports the materialistic theory. Access to material resources seems more relevant to COPD risk than the consequences of low relative income.

Estimating the size of hidden populations using respondent-driven sampling data: Case examples from Morocco

PubMed Central

Johnston, Lisa G; McLaughlin, Katherine R; Rhilani, Houssine El; Latifi, Amina; Toufik, Abdalla; Bennani, Aziza; Alami, Kamal; Elomari, Boutaina; Handcock, Mark S

2015-01-01

Background Respondent-driven sampling is used worldwide to estimate the population prevalence of characteristics such as HIV/AIDS and associated risk factors in hard-to-reach populations. Estimating the total size of these populations is of great interest to national and international organizations, however reliable measures of population size often do not exist. Methods Successive Sampling-Population Size Estimation (SS-PSE) along with network size imputation allows population size estimates to be made without relying on separate studies or additional data (as in network scale-up, multiplier and capture-recapture methods), which may be biased. Results Ten population size estimates were calculated for people who inject drugs, female sex workers, men who have sex with other men, and migrants from sub-Sahara Africa in six different cities in Morocco. SS-PSE estimates fell within or very close to the likely values provided by experts and the estimates from previous studies using other methods. Conclusions SS-PSE is an effective method for estimating the size of hard-to-reach populations that leverages important information within respondent-driven sampling studies. The addition of a network size imputation method helps to smooth network sizes allowing for more accurate results. However, caution should be used particularly when there is reason to believe that clustered subgroups may exist within the population of interest or when the sample size is small in relation to the population. PMID:26258908

Changing population dynamics and uneven temperature emergence combine to exacerbate regional exposure to heat extremes under 1.5 °C and 2 °C of warming

NASA Astrophysics Data System (ADS)

Harrington, Luke J.; Otto, Friederike E. L.

2018-03-01

Understanding how continuing increases in global mean temperature will exacerbate societal exposure to extreme weather events is a question of profound importance. However, determining population exposure to the impacts of heat extremes at 1.5 °C and 2 °C of global mean warming requires not only (1) a robust understanding of the physical climate system response, but also consideration of (2) projected changes to overall population size, as well as (3) changes to where people will live in the future. This analysis introduces a new framework, adapted from studies of probabilistic event attribution, to disentangle the relative importance of regional climate emergence and changing population dynamics in the exposure to future heat extremes across multiple densely populated regions in Southern Asia and Eastern Africa (SAEA). Our results reveal that, when population is kept at 2015 levels, exposure to heat considered severe in the present decade across SAEA will increase by a factor of 4.1 (2.4-9.6) and 15.8 (5.0-135) under a 1.5°- and 2.0°-warmer world, respectively. Furthermore, projected population changes by the end of the century under an SSP1 and SSP2 scenario can further exacerbate these changes by a factor of 1.2 (1.0-1.3) and 1.5 (1.3-1.7), respectively. However, a large fraction of this additional risk increase is not related to absolute increases in population, but instead attributed to changes in which regions exhibit continued population growth into the future. Further, this added impact of population redistribution will be twice as significant after 2.0 °C of warming, relative to stabilisation at 1.5 °C, due to the non-linearity of increases in heat exposure. Irrespective of the population scenario considered, continued African population expansion will place more people in locations where emergent changes to future heat extremes are exceptionally severe.

The third population boom and corresponding macro-policies.

PubMed

Tian, X

1990-01-01

China's birth peak between 1962-1973, and the expected 3rd peak beginning in 1986 has and will create a need for better, stable family planning measures; economic planning between 1990 and 2020 needs to accommodate the working population which in 2010 is expected to be 71.4% of the population (956 million); and a macro-strategic policy needs to be developed of the elderly who may constitute 17.44% of the population. The aging trend in China's working age population is expected to rise so rapidly that in 48 years, between 1982 and 2040, the over 65 population will quadruple ( a process in developed countries usually taking 80 years), thus creating a significant impact on a society with a low level of economic development. It is suggested that along with the growth in the national economy should come a state-provided welfare and retirement system, with reforms necessary to generate the additional income for elderly support; it is important that the cultural pattern of family care of the elderly remain intact. Assisting the able elderly in earning income in the service sector is encouraged. China's population has historically undergone 2 peak growth periods, between 1685 and 1830 with a 1% growth rate and between 1949-89 with an annual growth rate of 1.8%. The 2nd period is marked by 2 smaller peaks, one between 1953- 1957 with a growth rate of 2.38% and 1962-73 with a growth rate of 2.56%. A decline after 1974 changed to another upward cycle in 1986 with an increase to a 1.43 % growth rate expected to continue to 1996. The 1st peak between 1953-57 has already affected population control and the job market, and the fecund population is of concern because of the absolute size of the population, and because the planned limit for population growth of 1.2 billion by the year 2000 may be exceeded; and the projected rates, which have been increasing as expected, mean a population of 1.5 billion by 2050.

Integrated Cuing Requirements (ICR) Study: Demonstration Data Base and Users Guide.

DTIC Science & Technology

1983-07-01

viewed with a servo-mounted televison camera and used to provide a visual scene for an observer in an ATD. Modulation: Mathematically, the absolute...i(b). CROSS REFERENCE The impact of stationary scene RESULTS. . details was also tested in this See (c) study. See Figure 33.5-1. Ial TEST APPARATUS...size. (See the discussion of * the impact of perceived distance on perceived size in Section 31._.) Figure 33.4-1 Perceived Distance and Velocity of Self

Immuno-analysis of microparticles: probing at the limits of detection

PubMed Central

Latham, Sharissa L.; Tiberti, Natalia; Gokoolparsadh, Naveena; Holdaway, Karen; Olivier Couraud, Pierre; Grau, Georges E. R.; Combes, Valery

2015-01-01

Microparticle (MP) research is clouded by debate regarding the accuracy and validity of flow cytometry (FCM) as an analytical methodology, as it is influenced by many variables including the pre-analytical conditions, instruments physical capabilities and detection parameters. This study utilises a simplistic in vitro system for generating MP, and through comparative analysis with immuno-electron microscopy (Immuno-EM) assesses the strengths and limitations of probe selection and high-sensitivity FCM. Of the markers examined, MP were most specifically labelled with phosphatidylserine ligands, annexin V and lactadherin, although only ~60% MP are PS positive. Whilst these two ligands detect comparable absolute MP numbers, they interact with the same population in distinct manners; annexin V binding is enhanced on TNF induced MP. CD105 and CD54 expression were, as expected, consistent and enhanced following TNF activation respectively. Their labelling however accounted for as few as 30–40% of MP. The greatest discrepancies between FCM and I-EM were observed in the population solely labelled for the surface antigen. These findings demonstrate that despite significant improvements in resolution, high-sensitivity FCM remains limited in detecting small-size MP expressing low antigen levels. This study highlights factors to consider when selecting endothelial MP probes, as well as interpreting and representing data. PMID:26553743

Absolute fracture risk assessment using lumbar spine and femoral neck bone density measurements: derivation and validation of a hybrid system.

PubMed

Leslie, William D; Lix, Lisa M

2011-03-01

The World Health Organization (WHO) Fracture Risk Assessment Tool (FRAX) computes 10-year probability of major osteoporotic fracture from multiple risk factors, including femoral neck (FN) T-scores. Lumbar spine (LS) measurements are not currently part of the FRAX formulation but are used widely in clinical practice, and this creates confusion when there is spine-hip discordance. Our objective was to develop a hybrid 10-year absolute fracture risk assessment system in which nonvertebral (NV) fracture risk was assessed from the FN and clinical vertebral (V) fracture risk was assessed from the LS. We identified 37,032 women age 45 years and older undergoing baseline FN and LS dual-energy X-ray absorptiometry (DXA; 1990-2005) from a population database that contains all clinical DXA results for the Province of Manitoba, Canada. Results were linked to longitudinal health service records for physician billings and hospitalizations to identify nontrauma vertebral and nonvertebral fracture codes after bone mineral density (BMD) testing. The population was randomly divided into equal-sized derivation and validation cohorts. Using the derivation cohort, three fracture risk prediction systems were created from Cox proportional hazards models (adjusted for age and multiple FRAX risk factors): FN to predict combined all fractures, FN to predict nonvertebral fractures, and LS to predict vertebral (without nonvertebral) fractures. The hybrid system was the sum of nonvertebral risk from the FN model and vertebral risk from the LS model. The FN and hybrid systems were both strongly predictive of overall fracture risk (p < .001). In the validation cohort, ROC analysis showed marginally better performance of the hybrid system versus the FN system for overall fracture prediction (p = .24) and significantly better performance for vertebral fracture prediction (p < .001). In a discordance subgroup with FN and LS T-score differences greater than 1 SD, there was a significant improvement in overall fracture prediction with the hybrid method (p = .025). Risk reclassification under the hybrid system showed better alignment with observed fracture risk, with 6.4% of the women reclassified to a different risk category. In conclusion, a hybrid 10-year absolute fracture risk assessment system based on combining FN and LS information is feasible. The improvement in fracture risk prediction is small but supports clinical interest in a system that integrates LS in fracture risk assessment. Copyright © 2011 American Society for Bone and Mineral Research.

Determining size and dispersion of minimum viable populations for land management planning and species conservation

NASA Astrophysics Data System (ADS)

Lehmkuhl, John F.

1984-03-01

The concept of minimum populations of wildlife and plants has only recently been discussed in the literature. Population genetics has emerged as a basic underlying criterion for determining minimum population size. This paper presents a genetic framework and procedure for determining minimum viable population size and dispersion strategies in the context of multiple-use land management planning. A procedure is presented for determining minimum population size based on maintenance of genetic heterozygosity and reduction of inbreeding. A minimum effective population size ( N e ) of 50 breeding animals is taken from the literature as the minimum shortterm size to keep inbreeding below 1% per generation. Steps in the procedure adjust N e to account for variance in progeny number, unequal sex ratios, overlapping generations, population fluctuations, and period of habitat/population constraint. The result is an approximate census number that falls within a range of effective population size of 50 500 individuals. This population range defines the time range of short- to long-term population fitness and evolutionary potential. The length of the term is a relative function of the species generation time. Two population dispersion strategies are proposed: core population and dispersed population.

Nonprobability Web Surveys to Measure Sexual Behaviors and Attitudes in the General Population: A Comparison With a Probability Sample Interview Survey

PubMed Central

Burkill, Sarah; Couper, Mick P; Conrad, Frederick; Clifton, Soazig; Tanton, Clare; Phelps, Andrew; Datta, Jessica; Mercer, Catherine H; Sonnenberg, Pam; Prah, Philip; Mitchell, Kirstin R; Wellings, Kaye; Johnson, Anne M; Copas, Andrew J

2014-01-01

Background Nonprobability Web surveys using volunteer panels can provide a relatively cheap and quick alternative to traditional health and epidemiological surveys. However, concerns have been raised about their representativeness. Objective The aim was to compare results from different Web panels with a population-based probability sample survey (n=8969 aged 18-44 years) that used computer-assisted self-interview (CASI) for sensitive behaviors, the third British National Survey of Sexual Attitudes and Lifestyles (Natsal-3). Methods Natsal-3 questions were included on 4 nonprobability Web panel surveys (n=2000 to 2099), 2 using basic quotas based on age and sex, and 2 using modified quotas based on additional variables related to key estimates. Results for sociodemographic characteristics were compared with external benchmarks and for sexual behaviors and opinions with Natsal-3. Odds ratios (ORs) were used to express differences between the benchmark data and each survey for each variable of interest. A summary measure of survey performance was the average absolute OR across variables. Another summary measure was the number of key estimates for which the survey differed significantly (at the 5% level) from the benchmarks. Results For sociodemographic variables, the Web surveys were less representative of the general population than Natsal-3. For example, for men, the average absolute OR for Natsal-3 was 1.14, whereas for the Web surveys the average absolute ORs ranged from 1.86 to 2.30. For all Web surveys, approximately two-thirds of the key estimates of sexual behaviors were different from Natsal-3 and the average absolute ORs ranged from 1.32 to 1.98. Differences were appreciable even for questions asked by CASI in Natsal-3. No single Web survey performed consistently better than any other did. Modified quotas slightly improved results for men, but not for women. Conclusions Consistent with studies from other countries on less sensitive topics, volunteer Web panels provided appreciably biased estimates. The differences seen with Natsal-3 CASI questions, where mode effects may be similar, suggest a selection bias in the Web surveys. The use of more complex quotas may lead to some improvement, but many estimates are still likely to differ. Volunteer Web panels are not recommended if accurate prevalence estimates for the general population are a key objective. PMID:25488851

Application of Individualized Speed Thresholds to Interpret Position Specific Running Demands in Elite Professional Rugby Union: A GPS Study

PubMed Central

Reardon, Cillian; Tobin, Daniel P.; Delahunt, Eamonn

2015-01-01

A number of studies have used GPS technology to categorise rugby union locomotive demands. However, the utility of the results of these studies is confounded by small sample sizes, sub-elite player status and the global application of absolute speed thresholds to all player positions. Furthermore, many of these studies have used GPS units with low sampling frequencies. The aim of the present study was to compare and contrast the high speed running (HSR) demands of professional rugby union when utilizing micro-technology units sampling at 10 Hz and applying relative or individualised speed zones. The results of this study indicate that application of individualised speed zones results in a significant shift in the interpretation of the HSR demands of both forwards and backs and positional sub-categories therein. When considering the use of an absolute in comparison to an individualised HSR threshold, there was a significant underestimation for forwards of HSR distance (HSRD) (absolute = 269 ± 172.02, individualised = 354.72 ± 99.22, p < 0.001), HSR% (absolute = 5.15 ± 3.18, individualised = 7.06 ± 2.48, p < 0.001) and HSR efforts (HSRE) (absolute = 18.81 ± 12.25; individualised = 24.78 ± 8.30, p < 0.001). In contrast, there was a significant overestimation of the same HSR metrics for backs with the use of an absolute threshold (HSRD absolute = 697.79 ± 198.11, individualised = 570.02 ± 171.14, p < 0.001; HSR% absolute = 10.85 ± 2.82, individualised = 8.95 ± 2.76, p < 0.001; HSRE absolute = 41.55 ± 11.25; individualised = 34.54 ± 9.24, p < 0.001). This under- or overestimation associated with an absolute speed zone applies to varying degrees across the ten positional sub-categories analyzed and also to individuals within the same positional sub-category. The results of the present study indicated that although use of an individulised HSR threshold improves the interpretation of the HSR demands on a positional basis, inter-individual variability in maximum velocity within positional sub-categories means that players need to be considered on an individual basis to accurately gauge the HSR demands of rugby union. PMID:26208315

Development and validation of a cerebral oximeter capable of absolute accuracy.

PubMed

MacLeod, David B; Ikeda, Keita; Vacchiano, Charles; Lobbestael, Aaron; Wahr, Joyce A; Shaw, Andrew D

2012-12-01

Cerebral oximetry may be a valuable monitor, but few validation data are available, and most report the change from baseline rather than absolute accuracy, which may be affected by individuals whose oximetric values are outside the expected range. The authors sought to develop and validate a cerebral oximeter capable of absolute accuracy. An in vivo research study. A university human physiology laboratory. Healthy human volunteers were enrolled in calibration and validation studies of 2 cerebral oximetric sensors, the Nonin 8000CA and 8004CA. The 8000CA validation study identified 5 individuals with atypical cerebral oxygenation values; their data were used to design the 8004CA sensor, which subsequently underwent calibration and validation. Volunteers were taken through a stepwise hypoxia protocol to a minimum saturation of peripheral oxygen. Arteriovenous saturation (70% jugular bulb venous saturation and 30% arterial saturation) at 6 hypoxic plateaus was used as the reference value for the cerebral oximeter. Absolute accuracy was defined using a combination of the bias and precision of the paired saturations (A(RMS)). In the validation study for the 8000CA sensor (n = 9, 106 plateaus), relative accuracy was an A(RMS) of 2.7, with an absolute accuracy of 8.1, meeting the criteria for a relative (trend) monitor, but not an absolute monitor. In the validation study for the 8004CA sensor (n = 11, 119 plateaus), the A(RMS) of the 8004CA was 4.1, meeting the prespecified success criterion of <5.0. The Nonin cerebral oximeter using the 8004CA sensor can provide absolute data on regional cerebral saturation compared with arteriovenous saturation, even in subjects previously shown to have values outside the normal population distribution curves. Copyright © 2012 Elsevier Inc. All rights reserved.

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

PubMed

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

2015-11-30

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

Postsettlement growth of two estuarine crab species, Chasmagnathus granulata and Cyrtograpsus angulatus (Crustacea, Decapoda, Grapsidae): laboratory and field investigations

NASA Astrophysics Data System (ADS)

Luppi, T. A.; Spivak, E. D.; Anger, K.

2002-02-01

The estuarine grapsid crabs Chasmagnathus granulata and Cyrtograpsus angulatus belong to the most typical and dominant inhabitants of brackish coastal lagoons in southeastern South America. In a combined laboratory and field investigation of juvenile growth, we measured the increase in body size in these species under controlled conditions as well as in field experiments (in Mar Chiquita lagoon, Argentina), seasonal changes in size frequency distribution of a natural population, and growth related changes in selected morphometric traits of male and female juveniles (relations between carapace width, carapace length, propodus height and length of the cheliped, and pleon width). At 24°C, Cy. angulatus grew faster than Ch. granulata; it reached the crab-9 instar (C9; 13 mm carapace width) after 92 days, while Ch. granulata required 107 days to reach the C8 instar (7.4 mm). At 12°C, growth ceased in both species. The pleon begins to show sexual differences in the C5 ( Cy. angulatus) and C8 instar ( Ch. granulata), respectively, while the chelae differentiate earlier in Ch. granulata than in Cy. angulatus (in C4 vs C6). In the field, growth was maximal in summer, and was generally faster than in laboratory cultures. However, there is great individual variability in size (about 25% even in the first crab instar) and in size increments at ecdysis, increasing throughout juvenile growth. Our data indicate that, in the field, small-scale and short-term variations in feeding conditions, temperature, and salinity account for an extremely high degree of variability in the absolute and relative rates of growth as well as in the time to sexual differentiation.

Reduced fecundity in small populations of the rare plant Gentianopsis ciliate (Gentianaceae)

USGS Publications Warehouse

Kery, M.; Matthies, D.

2004-01-01

Habitat destruction is the main cause for the biodiversity crisis. Surviving populations are often fragmented, i.e., small and isolated from each other. Reproduction of plants in small populations is often reduced, and this has been attributed to inbreeding depression, reduced attractiveness for pollinators, and reduced habitat quality in small populations. Here we present data on the effects of fragmentation on the rare, self-compatible perennial herb Gentianopsis ciliata (Gentianaceae), a species with very small and presumably well-dispersed seeds. We studied the relationship between population size, plant size, and the number of flowers produced in 63 populations from 1996-1998. In one of the years, leaf and flower size and the number of seeds produced per fruit was studied in a subset of 25 populations. Plant size, flower size, and the number of seeds per fruit and per plant increased with population size, whereas leaf length and the number of flowers per plant did not. The effects of population size on reproduction and on flower size remained significant if the effects were adjusted for differences in plant size, indicating that they could not be explained by differences in habitat quality. The strongly reduced reproduction in small populations may be due to pollination limitation, while the reduced flower size could indicate genetic effects.

Reduced fecundity in small populations of the rare plant Gentianopsis ciliate (Gentianaceae)

USGS Publications Warehouse

Robbins, C.S.

1983-01-01

Habitat destruction is the main cause for the biodiversity crisis. Surviving populations are often fragmented, i.e., small and isolated from each other. Reproduction of plants in small populations is often reduced, and this has been attributed to inbreeding depression, reduced attractiveness for pollinators, and reduced habitat quality in small populations. Here we present data on the effects of fragmentation on the rare, self-compatible perennial herb Gentianopsis ciliata (Gentianaceae), a species with very small and presumably well-dispersed seeds. We studied the relationship between population size, plant size, and the number of flowers produced in 63 populations from 1996-1998. In one of the years, leaf and flower size and the number of seeds produced per fruit was studied in a subset of 25 populations. Plant size, flower size, and the number of seeds per fruit and per plant increased with population size, whereas leaf length and the number of flowers per plant did not. The effects of population size on reproduction and on flower size remained significant if the effects were adjusted for differences in plant size, indicating that they could not be explained by differences in habitat quality. The strongly reduced reproduction in small populations may be due to pollination limitation, while the reduced flower size could indicate genetic effects.

Antiracism and the Level of Health Services: A Sociomedical Hypothesis

PubMed Central

Schatzkin, Arthur; Cooper, Richard; Green, Linda

1984-01-01

Little attention has been paid to the validity of the “reverse discrimination” position that antiracist initiatives in the health sector would be associated with reduced services for whites. This paper advances the sociomedical hypothesis that antiracism leads to an increase in the level of health services and opportunities available to both minority and white populations. Four types of US health care utilization and training data are explored: annual rates of discharge from short-stay hospitals, percent of population seeing a physician during the year, rates of hypertension treatment and control, and admissions to the first-year class of US medical schools. These data are examined according to race for years prior and subsequent to the upsurge of antiracist activity that characterized the Civil Rights Movement era. From the early or mid-1960s to the mid- or late 1970s, hospital discharges, physician visits, and hypertension treatment and control for minorities and whites increased substantially. Generally these increases were proportionally greater for minorities. Although the percentage of increase in minority medical school admissions was necessarily accompanied by a decline in percentage of admissions of whites, the absolute number of whites admitted rose substantially as overall class size grew. These data do not support the “reverse discrimination” notion of one racial group benefiting at the expense of another. The data are consistent with the hypothesis that antiracist efforts in the health sector lead to an expansion of services and opportunities for minority and majority populations. PMID:6737494

Identifying predictors of time-inhomogeneous viral evolutionary processes.

PubMed

Bielejec, Filip; Baele, Guy; Rodrigo, Allen G; Suchard, Marc A; Lemey, Philippe

2016-07-01

Various factors determine the rate at which mutations are generated and fixed in viral genomes. Viral evolutionary rates may vary over the course of a single persistent infection and can reflect changes in replication rates and selective dynamics. Dedicated statistical inference approaches are required to understand how the complex interplay of these processes shapes the genetic diversity and divergence in viral populations. Although evolutionary models accommodating a high degree of complexity can now be formalized, adequately informing these models by potentially sparse data, and assessing the association of the resulting estimates with external predictors, remains a major challenge. In this article, we present a novel Bayesian evolutionary inference method, which integrates multiple potential predictors and tests their association with variation in the absolute rates of synonymous and non-synonymous substitutions along the evolutionary history. We consider clinical and virological measures as predictors, but also changes in population size trajectories that are simultaneously inferred using coalescent modelling. We demonstrate the potential of our method in an application to within-host HIV-1 sequence data sampled throughout the infection of multiple patients. While analyses of individual patient populations lack statistical power, we detect significant evidence for an abrupt drop in non-synonymous rates in late stage infection and a more gradual increase in synonymous rates over the course of infection in a joint analysis across all patients. The former is predicted by the immune relaxation hypothesis while the latter may be in line with increasing replicative fitness during the asymptomatic stage.

Climate-based models for pulsed resources improve predictability of consumer population dynamics: outbreaks of house mice in forest ecosystems.

PubMed

Holland, E Penelope; James, Alex; Ruscoe, Wendy A; Pech, Roger P; Byrom, Andrea E

2015-01-01

Accurate predictions of the timing and magnitude of consumer responses to episodic seeding events (masts) are important for understanding ecosystem dynamics and for managing outbreaks of invasive species generated by masts. While models relating consumer populations to resource fluctuations have been developed successfully for a range of natural and modified ecosystems, a critical gap that needs addressing is better prediction of resource pulses. A recent model used change in summer temperature from one year to the next (ΔT) for predicting masts for forest and grassland plants in New Zealand. We extend this climate-based method in the framework of a model for consumer-resource dynamics to predict invasive house mouse (Mus musculus) outbreaks in forest ecosystems. Compared with previous mast models based on absolute temperature, the ΔT method for predicting masts resulted in an improved model for mouse population dynamics. There was also a threshold effect of ΔT on the likelihood of an outbreak occurring. The improved climate-based method for predicting resource pulses and consumer responses provides a straightforward rule of thumb for determining, with one year's advance warning, whether management intervention might be required in invaded ecosystems. The approach could be applied to consumer-resource systems worldwide where climatic variables are used to model the size and duration of resource pulses, and may have particular relevance for ecosystems where global change scenarios predict increased variability in climatic events.

Saturated fluorescence method for determination of atomic transition probabilities: Application to the Ar i 430.0-nm (1s4-3p8) transition and the lifetime determination of the upper level

NASA Astrophysics Data System (ADS)

Hirabayashi, A.; Okuda, S.; Nambu, Y.; Fujimoto, T.

1987-01-01

We have developed a new method for determination of atomic transition probabilities based on laser-induced-fluorescence spectroscopy (LIFS). In the method one produces a known population of atoms in the upper level under investigation and relates it to an observed absolute line intensity. We have applied this method to the argon 430.0-nm line (1s4-3p8): In an argon discharge plasma the 1s5-level population and spatial distribution are determined by the self-absorption method combined with LIFS under conditions where the 3p8-level population is much lower than that of the 1s5 level. When intense laser light of 419.1 nm (1s5-3p8) irradiates the plasma and saturates the 3p8-level population, the produced 3p8-level population and its alignment can be determined from the 1s5-level parameters as determined above, by solving the master equation on the basis of broad-line excitation. By comparing the observed absolute fluorescence intensity of the 430.0-nm line with the above population, we have determined the transition probability to be A=(3.94+/-0.60)×105 s-1. We also determined the 3p8-level lifetime by LIFS. Several factors which might affect the measurement are discussed. The result is τ=127+/-10 ns.

Does source population size affect performance in new environments?

PubMed Central

Yates, Matthew C; Fraser, Dylan J

2014-01-01

Small populations are predicted to perform poorly relative to large populations when experiencing environmental change. To explore this prediction in nature, data from reciprocal transplant, common garden, and translocation studies were compared meta-analytically. We contrasted changes in performance resulting from transplantation to new environments among individuals originating from different sized source populations from plants and salmonids. We then evaluated the effect of source population size on performance in natural common garden environments and the relationship between population size and habitat quality. In ‘home-away’ contrasts, large populations exhibited reduced performance in new environments. In common gardens, the effect of source population size on performance was inconsistent across life-history stages (LHS) and environments. When transplanted to the same set of new environments, small populations either performed equally well or better than large populations, depending on life stage. Conversely, large populations outperformed small populations within native environments, but only at later life stages. Population size was not associated with habitat quality. Several factors might explain the negative association between source population size and performance in new environments: (i) stronger local adaptation in large populations and antagonistic pleiotropy, (ii) the maintenance of genetic variation in small populations, and (iii) potential environmental differences between large and small populations. PMID:25469166

Analysis of Binary Multivariate Longitudinal Data via 2-Dimensional Orbits: An Application to the Agincourt Health and Socio-Demographic Surveillance System in South Africa

PubMed Central

Visaya, Maria Vivien; Sherwell, David; Sartorius, Benn; Cromieres, Fabien

2015-01-01

We analyse demographic longitudinal survey data of South African (SA) and Mozambican (MOZ) rural households from the Agincourt Health and Socio-Demographic Surveillance System in South Africa. In particular, we determine whether absolute poverty status (APS) is associated with selected household variables pertaining to socio-economic determination, namely household head age, household size, cumulative death, adults to minor ratio, and influx. For comparative purposes, households are classified according to household head nationality (SA or MOZ) and APS (rich or poor). The longitudinal data of each of the four subpopulations (SA rich, SA poor, MOZ rich, and MOZ poor) is a five-dimensional space defined by binary variables (questions), subjects, and time. We use the orbit method to represent binary multivariate longitudinal data (BMLD) of each household as a two-dimensional orbit and to visualise dynamics and behaviour of the population. At each time step, a point (x, y) from the orbit of a household corresponds to the observation of the household, where x is a binary sequence of responses and y is an ordering of variables. The ordering of variables is dynamically rearranged such that clusters and holes associated to least and frequently changing variables in the state space respectively, are exposed. Analysis of orbits reveals information of change at both individual- and population-level, change patterns in the data, capacity of states in the state space, and density of state transitions in the orbits. Analysis of household orbits of the four subpopulations show association between (i) households headed by older adults and rich households, (ii) large household size and poor households, and (iii) households with more minors than adults and poor households. Our results are compared to other methods of BMLD analysis. PMID:25919116

Absolute total and partial dissociative cross sections of pyrimidine at electron and proton intermediate impact velocities

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

Wolff, Wania, E-mail: wania@if.ufrj.br; Luna, Hugo; Sigaud, Lucas

Absolute total non-dissociative and partial dissociative cross sections of pyrimidine were measured for electron impact energies ranging from 70 to 400 eV and for proton impact energies from 125 up to 2500 keV. MOs ionization induced by coulomb interaction were studied by measuring both ionization and partial dissociative cross sections through time of flight mass spectrometry and by obtaining the branching ratios for fragment formation via a model calculation based on the Born approximation. The partial yields and the absolute cross sections measured as a function of the energy combined with the model calculation proved to be a useful toolmore » to determine the vacancy population of the valence MOs from which several sets of fragment ions are produced. It was also a key point to distinguish the dissociation regimes induced by both particles. A comparison with previous experimental results is also presented.« less

Oxygen-rich Mira variables: Near-infrared luminosity calibrations. Populations and period-luminosity relations

NASA Technical Reports Server (NTRS)

Alvarez, R.; Mennessier, M.-O.; Barthes, D.; Luri, X.; Mattei, J. A.

1997-01-01

Hipparcos astrometric and kinematical data of oxygen-rich Mira variables are used to calibrate absolute near-infrared magnitudes and kinematic parameters. Three distinct classes of stars with different kinematics and scale heights were identified. The two most significant groups present characteristics close to those usually assigned to extended/thick disk-halo populations and old disk populations, respectively, and thus they may differ by their metallicity abundance. Two parallel period-luminosity relations are found, one for each population. The shift between these relations is interpreted as the consequence of the effects of metallicity abundance on the luminosity.

[Karyological studies of two populations of Juniperus communis L. in west Siberia].

PubMed

Mikheeva, N A; Muratova, E N

2005-01-01

Results of a karyological study of Juniperus communis L. populations under swamp and dry conditions are presented. The chromosome number of J. communis are 2n = 22. Analysis of morphological chromosome parameters showed a similarity between karyotypes of both populations. It is possible to identify one pair of asymmetric chromosomes (VIII pair); this chromosome pair is close to submetacentric type. Three pairs of chromosomes (I, VII, VIII) have secondary constrictions. Other metacentric chromosomes form groups of five long (II--VI) and three short (IX-XI) pairs. Differences between two populations in absolute chromosomal length are observed.

Droplet Digital Enzyme-Linked Oligonucleotide Hybridization Assay for Absolute RNA Quantification.

PubMed

Guan, Weihua; Chen, Liben; Rane, Tushar D; Wang, Tza-Huei

2015-09-03

We present a continuous-flow droplet-based digital Enzyme-Linked Oligonucleotide Hybridization Assay (droplet digital ELOHA) for sensitive detection and absolute quantification of RNA molecules. Droplet digital ELOHA incorporates direct hybridization and single enzyme reaction via the formation of single probe-RNA-probe (enzyme) complex on magnetic beads. It enables RNA detection without reverse transcription and PCR amplification processes. The magnetic beads are subsequently encapsulated into a large number of picoliter-sized droplets with enzyme substrates in a continuous-flow device. This device is capable of generating droplets at high-throughput. It also integrates in-line enzymatic incubation and detection of fluorescent products. Our droplet digital ELOHA is able to accurately quantify (differentiate 40% difference) as few as ~600 RNA molecules in a 1 mL sample (equivalent to 1 aM or lower) without molecular replication. The absolute quantification ability of droplet digital ELOHA is demonstrated with the analysis of clinical Neisseria gonorrhoeae 16S rRNA to show its potential value in real complex samples.

Calibration of the Reflected Solar Instrument for the Climate Absolute Radiance and Refractivity Observatory

NASA Technical Reports Server (NTRS)

Thome, Kurtis; Barnes, Robert; Baize, Rosemary; O'Connell, Joseph; Hair, Jason

2010-01-01

The Climate Absolute Radiance and Refractivity Observatory (CLARREO) plans to observe climate change trends over decadal time scales to determine the accuracy of climate projections. The project relies on spaceborne earth observations of SI-traceable variables sensitive to key decadal change parameters. The mission includes a reflected solar instrument retrieving at-sensor reflectance over the 320 to 2300 nm spectral range with 500-m spatial resolution and 100-km swath. Reflectance is obtained from the ratio of measurements of the earth s surface to those while viewing the sun relying on a calibration approach that retrieves reflectance with uncertainties less than 0.3%. The calibration is predicated on heritage hardware, reduction of sensor complexity, adherence to detector-based calibration standards, and an ability to simulate in the laboratory on-orbit sources in both size and brightness to provide the basis of a transfer to orbit of the laboratory calibration including a link to absolute solar irradiance measurements.

Droplet Digital Enzyme-Linked Oligonucleotide Hybridization Assay for Absolute RNA Quantification

PubMed Central

Guan, Weihua; Chen, Liben; Rane, Tushar D.; Wang, Tza-Huei

2015-01-01

We present a continuous-flow droplet-based digital Enzyme-Linked Oligonucleotide Hybridization Assay (droplet digital ELOHA) for sensitive detection and absolute quantification of RNA molecules. Droplet digital ELOHA incorporates direct hybridization and single enzyme reaction via the formation of single probe-RNA-probe (enzyme) complex on magnetic beads. It enables RNA detection without reverse transcription and PCR amplification processes. The magnetic beads are subsequently encapsulated into a large number of picoliter-sized droplets with enzyme substrates in a continuous-flow device. This device is capable of generating droplets at high-throughput. It also integrates in-line enzymatic incubation and detection of fluorescent products. Our droplet digital ELOHA is able to accurately quantify (differentiate 40% difference) as few as ~600 RNA molecules in a 1 mL sample (equivalent to 1 aM or lower) without molecular replication. The absolute quantification ability of droplet digital ELOHA is demonstrated with the analysis of clinical Neisseria gonorrhoeae 16S rRNA to show its potential value in real complex samples. PMID:26333806

Droplet Digital Enzyme-Linked Oligonucleotide Hybridization Assay for Absolute RNA Quantification

NASA Astrophysics Data System (ADS)

Guan, Weihua; Chen, Liben; Rane, Tushar D.; Wang, Tza-Huei

2015-09-01

We present a continuous-flow droplet-based digital Enzyme-Linked Oligonucleotide Hybridization Assay (droplet digital ELOHA) for sensitive detection and absolute quantification of RNA molecules. Droplet digital ELOHA incorporates direct hybridization and single enzyme reaction via the formation of single probe-RNA-probe (enzyme) complex on magnetic beads. It enables RNA detection without reverse transcription and PCR amplification processes. The magnetic beads are subsequently encapsulated into a large number of picoliter-sized droplets with enzyme substrates in a continuous-flow device. This device is capable of generating droplets at high-throughput. It also integrates in-line enzymatic incubation and detection of fluorescent products. Our droplet digital ELOHA is able to accurately quantify (differentiate 40% difference) as few as ~600 RNA molecules in a 1 mL sample (equivalent to 1 aM or lower) without molecular replication. The absolute quantification ability of droplet digital ELOHA is demonstrated with the analysis of clinical Neisseria gonorrhoeae 16S rRNA to show its potential value in real complex samples.

[Ophthalmopathy caused by precision work of sorters of precious stones].

PubMed

Feĭgin, A A; Korniushina, T A; Rozenblium, Iu Z

1992-01-01

A total of 440 female workers aged 17 to 50, whose work records ranged from 1 to 29 years, engaged in grading the diamonds by the color, shape, size, and quality (a total of 24 to 33 positions) were examined. A random sample of 110 subjects was singled out; this sample was divided into 2 equal groups with or without asthenopic complaints. The refraction, absolute accommodation volume, and relative accommodation reserves were under study. Comparison of these two groups of workers has shown that subjects with precision ophthalmopathy show a trend to a higher incidence of myopia, reduction of the absolute accommodation volume by 1.6 diopters and of the relative accommodation reserves by 1.3 diopters.

Population demographics and genetic diversity in remnant and translocated populations of sea otters

USGS Publications Warehouse

Bodkin, James L.; Ballachey, Brenda E.; Cronin, M.A.; Scribner, K.T.

1999-01-01

The effects of small population size on genetic diversity and subsequent population recovery are theoretically predicted, but few empirical data are available to describe those relations. We use data from four remnant and three translocated sea otter (Enhydra lutris) populations to examine relations among magnitude and duration of minimum population size, population growth rates, and genetic variation. Metochondrial (mt)DNA haplotype diversity was correlated with the number of years at minimum population size (r = -0.741, p = 0.038) and minimum population size (r = 0.709, p = 0.054). We found no relation between population growth and haplotype diversity, altough growth was significantly greater in translocated than in remnant populations. Haplotype diversity in populations established from two sources was higher than in a population established from a single source and was higher than in the respective source populations. Haplotype frequencies in translocated populations of founding sizes of 4 and 28 differed from expected, indicating genetic drift and differential reproduction between source populations, whereas haplotype frequencies in a translocated population with a founding size of 150 did not. Relations between population demographics and genetic characteristics suggest that genetic sampling of source and translocated populations can provide valuable inferences about translocations.

Evidence for r- and K-selection in a wild bird population: a reciprocal link between ecology and evolution.

PubMed

Sæther, Bernt-Erik; Visser, Marcel E; Grøtan, Vidar; Engen, Steinar

2016-04-27

Understanding the variation in selection pressure on key life-history traits is crucial in our rapidly changing world. Density is rarely considered as a selective agent. To study its importance, we partition phenotypic selection in fluctuating environments into components representing the population growth rate at low densities and the strength of density dependence, using a new stochastic modelling framework. We analysed the number of eggs laid per season in a small song-bird, the great tit, and found balancing selection favouring large clutch sizes at small population densities and smaller clutches in years with large populations. A significant interaction between clutch size and population size in the regression for the Malthusian fitness reveals that those females producing large clutch sizes at small population sizes also are those that show the strongest reduction in fitness when population size is increased. This provides empirical support for ongoing r- and K-selection in this population, favouring phenotypes with large growth rates r at small population sizes and phenotypes with high competitive skills when populations are close to the carrying capacity K This selection causes long-term fluctuations around a stable mean clutch size caused by variation in population size, implying that r- and K-selection is an important mechanism influencing phenotypic evolution in fluctuating environments. This provides a general link between ecological dynamics and evolutionary processes, operating through a joint influence of density dependence and environmental stochasticity on fluctuations in population size. © 2016 The Author(s).

New crystal spectrograph designs and their application to plasma diagnostics (invited)

NASA Astrophysics Data System (ADS)

Förster, E.; Gäbel, K.; Uschmann, I.

1992-10-01

A special crystal monolith was fabricated for absolute measurements of x-ray wavelength. It consists of two flat quartz plates, accurately cut relative to reflecting net planes, with a fixed distance between them. Absolute wavelengths (i.e., without use of reference lines) of L-shell laser produced spectra of Cu, Ge, As, etc. have been measured in the 7.5-8.5 Å with an accuracy of Δλ/λ=10-5. Our Johann type x-ray spectrometer with a cylindrically bent quartz has been used to reveal line coincidences necessary for photopumping processes. In this scheme source-size influences are smaller, therefore, line profiles have been measured at a spectrometer resolution better than 5000. Because of its focusing in the sagittal plane, a von Hámos type x-ray spectrometer has been used to detect the small x-ray emission of subpicosecond laser-produced plasmas (E=2 mJ, t=100 fs). X-ray spectra of Al both Kα, Kβ lines and Heα-resonance line with its satellites. Finally, a multichannel x-ray microscope has been designed and fabricated. It consists of several two-dimensionally bent crystals where each of them images one x-ray line emitted by a laser-produced plasma. The spatial resolution of x-ray line images is about 5 μm, and the width of the spectral ranges is Δλ/λ=10-4 to 10-2. Thus, the spatial distribution of ions radiating in selected x-ray lines have been found being of interest in the study of population inversions.

Trends in educational inequalities in cause specific mortality in Norway from 1960 to 2010: a turning point for educational inequalities in cause specific mortality of Norwegian men after the millennium?

PubMed

Strand, Bjørn Heine; Steingrímsdóttir, Ólöf Anna; Grøholt, Else-Karin; Ariansen, Inger; Graff-Iversen, Sidsel; Næss, Øyvind

2014-11-24

Educational inequalities in total mortality in Norway have widened during 1960-2000. We wanted to investigate if inequalities have continued to increase in the post millennium decade, and which causes of deaths were the main drivers. All deaths (total and cause specific) in the adult Norwegian population aged 45-74 years over five decades, until 2010 were included; in all 708,449 deaths and over 62 million person years. Two indices of inequalities were used to measure inequality and changes in inequalities over time, on the relative scale (Relative Index of Inequality, RII) and on the absolute scale (Slope Index of Inequality, SII). Relative inequalities in total mortality increased over the five decades in both genders. Among men absolute inequalities stabilized during 2000-2010, after steady, significant increases each decade back to the 1960s, while in women, absolute inequalities continued to increase significantly during the last decade. The stabilization in absolute inequalities among men in the last decade was mostly due to a fall in inequalities in cardiovascular disease (CVD) mortality and lung cancer and respiratory disease mortality. Still, in this last decade, the absolute inequalities in cause-specific mortality among men were mostly due to cardiovascular diseases (CVD) (34% of total mortality inequality), lung cancer and respiratory diseases (21%). Among women the absolute inequalities in mortality were mostly due to lung cancer and chronic lower respiratory tract diseases (30%) and CVD (27%). In men, absolute inequalities in mortality have stopped increasing, seemingly due to reduction in inequalities in CVD mortality. Absolute inequality in mortality continues to widen among women, mostly due to death from lung cancer and chronic lung disease. Relative educational inequalities in mortality are still on the rise for Norwegian men and women.

Pneumonia diagnosis in childhood and incidence of leukaemia, lymphoma and brain cancer: a Danish nationwide cohort study.

PubMed

Søgaard, Kirstine Kobberøe; Farkas, Dóra Körmendiné; Sørensen, Henrik Toft

2017-12-29

There is an ongoing debate on the possible association between infections in early childhood and subsequent cancer risk, but it remains unclear if a hospital admission for infection is associated with risk of childhood cancer diagnosis. We examined if a hospital-based diagnosis of pneumonia was a clinical marker of the three most common childhood cancers. Population-based cohort study. Denmark, hospital diagnoses, 1994-2013. Using national health registries, we compared the observed incidence of leukaemia, lymphoma and brain cancer among 83 935 children with a hospital-based pneumonia diagnosis with that expected among children in the general population. We calculated absolute cancer risks and standardised incidence ratios (SIRs) as a measure of relative risk. The cancer SIRs were substantially increased during the first 6 months of follow-up; lymphoid leukaemia: 6.2 (95% CI 3.5 to 10.3); myeloid leukaemia: 14.8 (95% CI 6.0 to 30.6); Hodgkin's lymphoma: 60.8 (95% CI 26.2 to 120), non-Hodgkin's lymphoma: 15.9 (95% CI 5.2 to 37.2) and brain cancer: 4.4 (95% CI 1.9 to 8.7). The 6-month absolute risks of leukaemia, lymphoma and brain cancer were all low, reaching 0.05% when combined. An increased risk persisted beyond 5 years for non-Hodgkin's lymphoma and brain cancer. However, the 5-year absolute cancer risk was 0.14%. The short-term incidence of leukaemia, lymphoma and brain cancer was higher than expected and persisted beyond 5 years for non-Hodgkin's lymphoma and brain cancer. However, the absolute cancer risk was low. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Galaxy And Mass Assembly (GAMA): colour- and luminosity-dependent clustering from calibrated photometric redshifts

NASA Astrophysics Data System (ADS)

Christodoulou, L.; Eminian, C.; Loveday, J.; Norberg, P.; Baldry, I. K.; Hurley, P. D.; Driver, S. P.; Bamford, S. P.; Hopkins, A. M.; Liske, J.; Peacock, J. A.; Bland-Hawthorn, J.; Brough, S.; Cameron, E.; Conselice, C. J.; Croom, S. M.; Frenk, C. S.; Gunawardhana, M.; Jones, D. H.; Kelvin, L. S.; Kuijken, K.; Nichol, R. C.; Parkinson, H.; Pimbblet, K. A.; Popescu, C. C.; Prescott, M.; Robotham, A. S. G.; Sharp, R. G.; Sutherland, W. J.; Taylor, E. N.; Thomas, D.; Tuffs, R. J.; van Kampen, E.; Wijesinghe, D.

2012-09-01

We measure the two-point angular correlation function of a sample of 4289 223 galaxies with r < 19.4 mag from the Sloan Digital Sky Survey (SDSS) as a function of photometric redshift, absolute magnitude and colour down to Mr - 5 log h = -14 mag. Photometric redshifts are estimated from ugriz model magnitudes and two Petrosian radii using the artificial neural network package ANNz, taking advantage of the Galaxy And Mass Assembly (GAMA) spectroscopic sample as our training set. These photometric redshifts are then used to determine absolute magnitudes and colours. For all our samples, we estimate the underlying redshift and absolute magnitude distributions using Monte Carlo resampling. These redshift distributions are used in Limber's equation to obtain spatial correlation function parameters from power-law fits to the angular correlation function. We confirm an increase in clustering strength for sub-L* red galaxies compared with ˜L* red galaxies at small scales in all redshift bins, whereas for the blue population the correlation length is almost independent of luminosity for ˜L* galaxies and fainter. A linear relation between relative bias and log luminosity is found to hold down to luminosities L ˜ 0.03L*. We find that the redshift dependence of the bias of the L* population can be described by the passive evolution model of Tegmark & Peebles. A visual inspection of a random sample from our r < 19.4 sample of SDSS galaxies reveals that about 10 per cent are spurious, with a higher contamination rate towards very faint absolute magnitudes due to over-deblended nearby galaxies. We correct for this contamination in our clustering analysis.

Use of nonlinear models for describing scrotal circumference growth in Guzerat bulls raised under grazing conditions.

PubMed

Loaiza-Echeverri, A M; Bergmann, J A G; Toral, F L B; Osorio, J P; Carmo, A S; Mendonça, L F; Moustacas, V S; Henry, M

2013-03-15

The objective was to use various nonlinear models to describe scrotal circumference (SC) growth in Guzerat bulls on three farms in the state of Minas Gerais, Brazil. The nonlinear models were: Brody, Logistic, Gompertz, Richards, Von Bertalanffy, and Tanaka, where parameter A is the estimated testis size at maturity, B is the integration constant, k is a maturating index and, for the Richards and Tanaka models, m determines the inflection point. In Tanaka, A is an indefinite size of the testis, and B and k adjust the shape and inclination of the curve. A total of 7410 SC records were obtained every 3 months from 1034 bulls with ages varying between 2 and 69 months (<240 days of age = 159; 241-365 days = 451; 366-550 days = 1443; 551-730 days = 1705; and >731 days = 3652 SC measurements). Goodness of fit was evaluated by coefficients of determination (R(2)), error sum of squares, average prediction error (APE), and mean absolute deviation. The Richards model did not reach the convergence criterion. The R(2) were similar for all models (0.68-0.69). The error sum of squares was lowest for the Tanaka model. All models fit the SC data poorly in the early and late periods. Logistic was the model which best estimated SC in the early phase (based on APE and mean absolute deviation). The Tanaka and Logistic models had the lowest APE between 300 and 1600 days of age. The Logistic model was chosen for analysis of the environmental influence on parameters A and k. Based on absolute growth rate, SC increased from 0.019 cm/d, peaking at 0.025 cm/d between 318 and 435 days of age. Farm, year, and season of birth significantly affected size of adult SC and SC growth rate. An increase in SC adult size (parameter A) was accompanied by decreased SC growth rate (parameter k). In conclusion, SC growth in Guzerat bulls was characterized by an accelerated growth phase, followed by decreased growth; this was best represented by the Logistic model. The inflection point occurred at approximately 376 days of age (mean SC of 17.9 cm). We inferred that early selection of testicular size might result in smaller testes at maturity. Copyright © 2013 Elsevier Inc. All rights reserved.

Does who you know in the positional hierarchy protect or hurt? Social capital, comparative reference group, and depression in two societies.

PubMed

Song, Lijun

2015-07-01

Does the socioeconomic status (SES) that one's (ego's) network members (alters) occupy indicate social resources or social comparison standards in the dynamics of health across culture? Using nationally representative data simultaneously collected from the United States and urban China, this study examines two competing theories-social capital and comparative reference group-in the two societies and compares their different application across the two societies using two cultural explanations, relational dependence and self-evaluation motive. Social capital theory expects absolute accessed SES and the size of higher accessed socioeconomic positions to protect health, and the size of lower accessed socioeconomic positions to harm health. But comparative reference group theory predicts the opposite. Additionally, the relational dependence explanation anticipates social capital theory to be more applicable to urban China and comparative reference group theory to be more applicable to the United States. The self-evaluation motive explanation expects the same pattern across the two societies in the examination of the size of lower accessed socioeconomic positions but the opposite pattern in the analysis of absolute accessed SES and the size of higher accessed socioeconomic positions. This study focuses on depressive symptoms and measures accessed occupational status. Results are consistent with the self-evaluation motive explanation. They support both social capital theory and comparative reference group theory in the United States but only the latter theory in urban China. Copyright © 2015 Elsevier Ltd. All rights reserved.

Coevolution of cultural intelligence, extended life history, sociality, and brain size in primates

PubMed Central

Street, Sally E.; Navarrete, Ana F.; Laland, Kevin N.

2017-01-01

Explanations for primate brain expansion and the evolution of human cognition and culture remain contentious despite extensive research. While multiple comparative analyses have investigated variation in brain size across primate species, very few have addressed why primates vary in how much they use social learning. Here, we evaluate the hypothesis that the enhanced reliance on socially transmitted behavior observed in some primates has coevolved with enlarged brains, complex sociality, and extended lifespans. Using recently developed phylogenetic comparative methods we show that, across primate species, a measure of social learning proclivity increases with absolute and relative brain volume, longevity (specifically reproductive lifespan), and social group size, correcting for research effort. We also confirm relationships of absolute and relative brain volume with longevity (both juvenile period and reproductive lifespan) and social group size, although longevity is generally the stronger predictor. Relationships between social learning, brain volume, and longevity remain when controlling for maternal investment and are therefore not simply explained as a by-product of the generally slower life history expected for larger brained species. Our findings suggest that both brain expansion and high reliance on culturally transmitted behavior coevolved with sociality and extended lifespan in primates. This coevolution is consistent with the hypothesis that the evolution of large brains, sociality, and long lifespans has promoted reliance on culture, with reliance on culture in turn driving further increases in brain volume, cognitive abilities, and lifespans in some primate lineages. PMID:28739950

SU-E-T-68: A Quality Assurance System with a Web Camera for High Dose Rate Brachytherapy

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

Ueda, Y; Hirose, A; Oohira, S

Purpose: The purpose of this work was to develop a quality assurance (QA) system for high dose rate (HDR) brachytherapy to verify the absolute position of an 192Ir source in real time and to measure dwell time and position of the source simultaneously with a movie recorded by a web camera. Methods: A web camera was fixed 15 cm above a source position check ruler to monitor and record 30 samples of the source position per second over a range of 8.0 cm, from 1425 mm to 1505 mm. Each frame had a matrix size of 480×640 in the movie.more » The source position was automatically quantified from the movie using in-house software (built with LabVIEW) that applied a template-matching technique. The source edge detected by the software on each frame was corrected to reduce position errors induced by incident light from an oblique direction. The dwell time was calculated by differential processing to displacement of the source. The performance of this QA system was illustrated by recording simple plans and comparing the measured dwell positions and time with the planned parameters. Results: This QA system allowed verification of the absolute position of the source in real time. The mean difference between automatic and manual detection of the source edge was 0.04 ± 0.04 mm. Absolute position error can be determined within an accuracy of 1.0 mm at dwell points of 1430, 1440, 1450, 1460, 1470, 1480, 1490, and 1500 mm, in three step sizes and dwell time errors, with an accuracy of 0.1% in more than 10.0 sec of planned time. The mean step size error was 0.1 ± 0.1 mm for a step size of 10.0 mm. Conclusion: This QA system provides quick verifications of the dwell position and time, with high accuracy, for HDR brachytherapy. This work was supported by the Japan Society for the Promotion of Science Core-to-Core program (No. 23003)« less

On the absence of a correlation between population size and 'toolkit size' in ethnographic hunter-gatherers.

PubMed

Aoki, Kenichi

2018-04-05

In apparent contradiction to the theoretically predicted effect of population size on the quality/quantity of material culture, statistical analyses on ethnographic hunter-gatherers have shown an absence of correlation between population size and toolkit size. This has sparked a heated, if sometimes tangential, debate as to the usefulness of the theoretical models and as to what modes of cultural transmission humans are capable of and hunter-gatherers rely on. I review the directly relevant theoretical literature and argue that much of the confusion is caused by a mismatch between the theoretical variable and the empirical observable. I then confirm that a model incorporating the appropriate variable does predict a positive association between population size and toolkit size for random oblique, vertical, best-of- K , conformist, anticonformist, success bias and one-to-many cultural transmission, with the caveat that for all populations sampled, the population size has remained constant and toolkit size has reached the equilibrium for this population size. Finally, I suggest three theoretical scenarios, two of them involving variable population size, that would attenuate or eliminate this association and hence help to explain the empirical absence of correlation.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'. © 2018 The Author(s).

Population size is weakly related to quantitative genetic variation and trait differentiation in a stream fish.

PubMed

Wood, Jacquelyn L A; Tezel, Defne; Joyal, Destin; Fraser, Dylan J

2015-09-01

How population size influences quantitative genetic variation and differentiation among natural, fragmented populations remains unresolved. Small, isolated populations might occupy poor quality habitats and lose genetic variation more rapidly due to genetic drift than large populations. Genetic drift might furthermore overcome selection as population size decreases. Collectively, this might result in directional changes in additive genetic variation (VA ) and trait differentiation (QST ) from small to large population size. Alternatively, small populations might exhibit larger variation in VA and QST if habitat fragmentation increases variability in habitat types. We explored these alternatives by investigating VA and QST using nine fragmented populations of brook trout varying 50-fold in census size N (179-8416) and 10-fold in effective number of breeders, Nb (18-135). Across 15 traits, no evidence was found for consistent differences in VA and QST with population size and almost no evidence for increased variability of VA or QST estimates at small population size. This suggests that (i) small populations of some species may retain adaptive potential according to commonly adopted quantitative genetic measures and (ii) populations of varying sizes experience a variety of environmental conditions in nature, however extremely large studies are likely required before any firm conclusions can be made. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

Making It Count: Improving Estimates of the Size of Transgender and Gender Nonconforming Populations.

PubMed

Deutsch, Madeline B

2016-06-01

An accurate estimate of the number of transgender and gender nonconforming people is essential to inform policy and funding priorities and decisions. Historical reports of population sizes of 1 in 4000 to 1 in 50,000 have been based on clinical populations and likely underestimate the size of the transgender population. More recent population-based studies have found a 10- to 100-fold increase in population size. Studies that estimate population size should be population based, employ the two-step method to allow for collection of both gender identity and sex assigned at birth, and include measures to capture the range of transgender people with nonbinary gender identities.

[Study of public and private hospital care on a population basis, 1986-1996].

PubMed

Rocha, J S; Simões, B J

1999-02-01

The last decade saw the creation and implementation of the Brazilian National Health System (NHS)--public, universal and equalitarian--with the objective of offering wide coverage to meet the population's health needs. The objective of the study was the assessment of the evolution of public and private hospital care on a populational basis during the period of the implementation of the NHS. The 984,142 inpatients of the general hospitals of Ribeirão Preto, Brazil, during the period 1986 to 1996 were studied and those of them living in their own municipal district were selected. The inpatients are classified according to the financing system as private, pre-payment and NHS; the social situation of the patients and the profile of hospital morbidity are analysed. In the period studied a continuous growth in the number of hospitalizations is observed, both in absolute numbers and in coefficient per thousand inhabitants, increasing from 43,773 to 55,844 inpatients per year. Though when the categories of the hospitalizations are studied, it is seen that private inpatients present a reduction both in absolute numbers and as a coefficient from 3,181 (7.3%) to 2,215 (3.9%); the NHS inpatients decrease in absolute numbers and in a percentage by a third at the end of the period--falling from 33,254 (76.0%) to 29,373 (51.7%). On the other hand the pre-payment inpatient system triplicates in absolute numbers and duplicates by rate for inhabitant--from 7,338 (16.8%) to 25,256 (44.4%). The NHS hospital care attends mainly unskilled and semi-skilled manual workers; the professionals, technicians, non manual and skilled manual workers being assisted by the private services. The hospital morbidity of NHS inpatients is different from that of the private inpatient systems. The health policy in that period, limiting NHS financing, repressing demand and discouraging the private providers to work with NHS inpatients led to negative selectivity. The result was an increase in difference between standards of care as between the public and private services.

The population benefit of radiotherapy for gynaecological cancer: Local control and survival estimates.

PubMed

Hanna, Timothy P; Delaney, Geoffrey P; Barton, Michael B

2016-09-01

The population benefit of radiotherapy for gynaecological cancer (GC) if evidence-based guidelines were routinely followed is not known. This study's aim was to address this. Decision trees were utilised to estimate benefit. Radiotherapy alone (RT) benefit was the absolute proportional benefit of radiotherapy over no radiotherapy for radical indications, and over surgery alone for adjuvant indications. Chemoradiotherapy (CRT) benefit was the absolute incremental benefit of concurrent chemotherapy and RT over RT alone. Citation databases were systematically queried for the highest level of evidence defining 5-year Local Control (LC), and 2-year and 5-year Overall Survival (OS) benefit. Meta-analysis was performed if there were multiple sources of the same evidence level. Deterministic and probabilistic sensitivity analysis was performed. Guidelines supported 22 radiotherapy indications, of which 8 were for CRT. 21% of all GC had an adjuvant or curative radiotherapy indication. The absolute estimated population-based 5-year LC and OS benefits of RT, if all patients were treated according to guidelines, were: endometrial cancer LC 5.7% (95% CI (3.5%,8.2%)), OS 2.3% (1.2%,3.4%), ovarian cancer (nil), vulval cancer LC 10.0% (1.6%,18.2%), OS 8.5% (0.5%,15.9%). Combined with prior estimates for cervical cancer, RT benefits for all GC were LC 9.0% (7.8%,10.3%), OS 4.6% (3.8%,5.4%). The incremental benefit of CRT for all GC was LC 0.7% (0.4%,0.9%), OS 0.5% (0.2%,0.8%). Benefits were distinct from the contribution of other modalities. The model was robust in sensitivity analysis. Most radiotherapy benefit was irreplaceable by other modalities. Radiotherapy provides important and irreplaceable LC and OS benefits for GC when optimally utilised. The population model provided a robust means for estimating this benefit. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

The metabolism of plant sterols is disturbed in postmenopausal women with coronary artery disease.

PubMed

Gylling, Helena; Hallikainen, Maarit; Rajaratnam, Radhakrishnan A; Simonen, Piia; Pihlajamäki, Jussi; Laakso, Markku; Miettinen, Tatu A

2009-03-01

In postmenopausal coronary artery disease (CAD) women, serum plant sterols are elevated. Thus, we investigated further whether serum plant sterols reflect absolute cholesterol metabolism in CAD as in other populations and whether the ABCG5 and ABCG8 genes, associated with plant sterol metabolism, were related to the risk of CAD. In free-living postmenopausal women with (n = 47) and without (n = 62) CAD, serum noncholesterol sterols including plant sterols were analyzed with gas-liquid chromatography, cholesterol absorption with peroral isotopes, absolute cholesterol synthesis with sterol balance technique, and bile acid synthesis with quantitating fecal bile acids. In CAD women, serum plant sterol ratios to cholesterol were 21% to 26% (P < .05) higher than in controls despite similar cholesterol absorption efficiency. Absolute cholesterol and bile acid synthesis were reduced. Only in controls were serum plant sterols related to cholesterol absorption (eg, sitosterol; in controls: r = 0.533, P < .001; in CAD: r = 0.296, P = not significant). However, even in CAD women, serum lathosterol (relative synthesis marker) and lathosterol-cholestanol (relative synthesis-absorption marker) were related to absolute synthesis and absorption percentage (P range from .05 to <.001) similarly to controls. Frequencies of the common polymorphisms of ABCG5 and ABCG8 genes did not differ between coronary and control women. In conclusion, plant sterol metabolism is disturbed in CAD women; so serum plant sterols only tended to reflect absolute cholesterol absorption. Other relative markers of cholesterol metabolism were related to the absolute ones in both groups. ABCG5 and ABCG8 genes were not associated with the risk of CAD.

Reproducibility of forearm vasodilator response to intra-arterial infusion of calcitonin gene-related peptide assessed by venous occlusion plethysmography

PubMed Central

Vanmolkot, Floris H M; de Hoon, Jan N J M

2005-01-01

Aims To assess the reproducibility of the forearm blood flow (FBF) response to intra-arterial infusion of calcitonin-gene related peptide (CGRP), measured by venous occlusion plethysmography. In addition, to compare different ways of expressing the FBF response and perform sample size calculations. Methods On two separate visits, CGRP (10 ng min−1 dl−1 forearm) was infused for 45 min into the brachial artery of six healthy subjects. Reproducibility was assessed by calculating mean difference, repeatability coefficient, within-subject coefficient of variation (WCV) and intraclass correlation coefficient. Results CGRP increased FBF from 2.8 ± 0.4 and 3.2 ± 0.7 (at baseline) to 15.4 ± 1.4 and 15.2 ± 1.5 ml min−1 dl−1 forearm (at 45 min) on visits 1 and 2, respectively (P < 0.0001 for both visits). Mean difference in FBF at 45 min between both visits was 0.3 ml min−1 dl−1 forearm (repeatability coefficient: 4.1 ml min−1 dl−1 forearm). This FBF response appeared to be more reproducible when expressed as absolute FBF in the infused arm (WCV 11%) compared with absolute FBF-ratio between both arms (WCV 37%), percentage change from baseline in FBF in the infused arm (WCV 29%) and percentage change from baseline in FBF-ratio (WCV 40%). When expressed as absolute FBF, a sample size of five (95% confidence interval: 2–12) subjects gives 90% power at a type I error probability of 0.05 to detect a 25% shift in FBF response. Conclusions Intra-arterial infusion of CGRP results in a forearm vasodilator response which is reproducible between days. This response is most reproducible when expressed as absolute FBF. The presented methodology provides a suitable pharmacodynamic model to assess the in vivo activity of CGRP-receptor antagonists in a small number of subjects. PMID:15801933

Delayed-type hypersensitivity to fragrance materials in a select North American population.

PubMed

Belsito, Donald V; Fowler, Joseph F; Sasseville, Denis; Marks, James G; De Leo, Vincent A; Storrs, Frances J

2006-03-01

In published reports from Europe, 3- and 4-(4-hydroxy-4-methylpentyl)cyclohexene-1-carboxaldehyde (HMPCC) (Lyral) has been described as a common cause of allergic contact dermatitis (ACD). In Europe, the rates of reaction to HMPCC among patients undergoing patch testing for suspected ACD have varied from 1.2 to 17.0%, depending on the country. Data on the incidence of sensitivity to HMPCC among North Americans with suspected ACD have not been reported. The goals of this study were (1) to assess the incidence of delayed-type hypersensitivity reactions to HMPCC among patients undergoing patch testing for evaluation of eczematous dermatitis at six centers throughout North America; (2) to determine the most appropriate concentration of HMPCC to use in performing patch tests; and (3) to compare and contrast the incidence rates for HMPCC hypersensitivity to those for other fragrance materials screened with the North American Contact Dermatitis Group (NACDG) screening tray, which includes fragrance mix, Myroxilon pereirae (balsam of Peru), cinnamic aldehyde, ylang ylang oil, jasmine absolute, and tea tree oil. This report represents the prospective multicenter data on patients tested with the fragrance-related allergens on the NACDG standard screening tray and with HMPCC at 5%, 1.5%, and 0.5% concentrations in petrolatum. Statistical analyses were performed with Student's t-test (two tailed) and the chi-square test. Data from 1,603 patients evaluated at five US sites and one Canadian site were analyzed. Most patients (87.8%) were Caucasian. The majority (67%) were women, and 26.2% had a history consistent with atopic dermatitis. The patients ranged in age from 1 to 88 years, and the mean +/- standard deviation was 46.3 +/- 16.5 years. Myroxilon pereirae (balsam of Peru) and fragrance mix were the most frequent patch-test-positive fragrance allergens (6.6% and 5.9%, respectively). Cinnamic aldehyde (1.7%), ylang ylang oil (0.6%), jasmine absolute (0.4%), HMPCC (0.4% for 5% HMPCC, 0.3% for 1.5% HMPCC, and 0.2% for 0.5% HMPCC), and tea tree oil (0.3%) less frequently yielded positive reactions. Men were more likely than women to be allergic to cinnamic aldehyde. Women were more likely than men to be allergic to jasmine absolute. Atopic patients were no more likely to react to fragrance materials than were nonatopic patients. Patients who reacted to jasmine absolute tended to be older than the general population whereas those who reacted to tea tree oil tended to be younger than the general population. There were no other demographic differences between patients who reacted to a given fragrance material and the entire population studied. Testing with fragrance mix and balsam of Peru failed to identify the majority of patients in this study who were found to be sensitized to jasmine absolute, HMPCC, or tea tree oil. HMPCC is an uncommon allergen in the North American population. We recommend testing with 5% HMPCC in petrolatum for those patients suspected of having a fragrance allergy.

Impact resistant electrolytes

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

Veith, Gabriel M.; Armstrong, Beth L.; Tenhaeff, Wyatt E.

A passively impact resistant composite electrolyte composition includes an electrolyte solvent, up to 2M of an electrolyte salt, and shear thickening ceramic particles having a polydispersity index of no greater than 0.1, an average particle size of in a range of 50 nm to 1 .mu.m, and an absolute zeta potential of greater than .+-.40 mV.

Pharmacological activity and toxicity of some neurotropic agents under conditions of experimental hypodynamia

NASA Technical Reports Server (NTRS)

Kirichek, L. T.

1980-01-01

The indices of pharmacological range, risk coefficients, ED50, LD50, the size of the area of toxic activity, and maximal tolerated and absolute lethal doses were compared in hypodynamic mice. The pharmacological activity of the test neurotropic agents exhibiting a central action underwent change, but their toxicity remained unchanged.

Corpus Callosum Morphometrics in Young Children with Autism Spectrum Disorder

ERIC Educational Resources Information Center

Boger-Megiddo, Inbal; Shaw, Dennis W. W.; Friedman, Seth D.; Sparks, Bobbi F.; Artru, Alan A.; Giedd, Jay N.; Dawson, Geraldine; Dager, Stephen R.

2006-01-01

This study assessed digital corpus callosum cross sectional areas in 3-4 year olds with autism spectrum disorder (ASD) compared to typically developing (TD) and developmentally delayed (DD) children. Though not different in absolute size compared to TD, ASD callosums were disproportionately small adjusted for increased ASD cerebral volume. ASD…

A Meta-Analysis of Growth Trends from Vertically Scaled Assessments

ERIC Educational Resources Information Center

Dadey, Nathan; Briggs, Derek C.

2012-01-01

A vertical scale, in principle, provides a common metric across tests with differing difficulties (e.g., spanning multiple grades) so that statements of "absolute" growth can be made. This paper compares 16 states' 2007-2008 effect size growth trends on vertically scaled reading and math assessments across grades 3 to 8. Two patterns…

Methods for estimating confidence intervals in interrupted time series analyses of health interventions.

PubMed

Zhang, Fang; Wagner, Anita K; Soumerai, Stephen B; Ross-Degnan, Dennis

2009-02-01

Interrupted time series (ITS) is a strong quasi-experimental research design, which is increasingly applied to estimate the effects of health services and policy interventions. We describe and illustrate two methods for estimating confidence intervals (CIs) around absolute and relative changes in outcomes calculated from segmented regression parameter estimates. We used multivariate delta and bootstrapping methods (BMs) to construct CIs around relative changes in level and trend, and around absolute changes in outcome based on segmented linear regression analyses of time series data corrected for autocorrelated errors. Using previously published time series data, we estimated CIs around the effect of prescription alerts for interacting medications with warfarin on the rate of prescriptions per 10,000 warfarin users per month. Both the multivariate delta method (MDM) and the BM produced similar results. BM is preferred for calculating CIs of relative changes in outcomes of time series studies, because it does not require large sample sizes when parameter estimates are obtained correctly from the model. Caution is needed when sample size is small.

Calibrated Tully-fisher Relations For Improved Photometric Estimates Of Disk Rotation Velocities

NASA Astrophysics Data System (ADS)

Reyes, Reinabelle; Mandelbaum, R.; Gunn, J. E.; Pizagno, J.

2011-01-01

We present calibrated scaling relations (also referred to as Tully-Fisher relations or TFRs) between rotation velocity and photometric quantities-- absolute magnitude, stellar mass, and synthetic magnitude (a linear combination of absolute magnitude and color)-- of disk galaxies at z 0.1. First, we selected a parent disk sample of 170,000 galaxies from SDSS DR7, with redshifts between 0.02 and 0.10 and r band absolute magnitudes between -18.0 and -22.5. Then, we constructed a child disk sample of 189 galaxies that span the parameter space-- in absolute magnitude, color, and disk size-- covered by the parent sample, and for which we have obtained kinematic data. Long-slit spectroscopy were obtained from the Dual Imaging Spectrograph (DIS) at the Apache Point Observatory 3.5 m for 99 galaxies, and from Pizagno et al. (2007) for 95 galaxies (five have repeat observations). We find the best photometric estimator of disk rotation velocity to be a synthetic magnitude with a color correction that is consistent with the Bell et al. (2003) color-based stellar mass ratio. The improved rotation velocity estimates have a wide range of scientific applications, and in particular, in combination with weak lensing measurements, they enable us to constrain the ratio of optical-to-virial velocity in disk galaxies.

Asteroid Airbursts: Risk Assessment and Reduction

NASA Astrophysics Data System (ADS)

Boslough, M.

2015-12-01

Airbursts are events in which small (meters to tens-of-meters in diameter) asteroids deposit most of their energy in the atmosphere with a total energy greater than small nuclear explosions (>0.1 kilotons of TNT). The airburst risk is higher than previous assessments for two reasons. First, they are more frequent than previously thought. The Tunguska-class (~40 meters) population estimate has doubled, and Chelyabinsk-class (~20 meters) has increased by a factor of 2.6. Second, asteroid airbursts are significantly more damaging than previously assumed. In most cases, they more efficiently couple energy to the surface than nuclear explosions of the same yield. Past Near-Earth Object (NEO) risk assessments concluded that the largest asteroids (> 1 km) dominated the hazard. Large NEOs represent only a tiny fraction of the population but the potential for global catastrophe means that the contribution from low-probability, high-consequence events is large. Nearly 90% of these objects, none of which is on a collision course, have been catalogued. This has reduced their assessed near-term statistical risk by more than an order of magnitude because completion is highest for the largest and most dangerous. The relative risk from small objects would therefore be increasing even if their absolute assessed risk were not. Uncertainty in the number of small NEOs remains large and can only be reduced by expanded surveys. One strategy would be to count small NEOs making close passes in statistically significant numbers. For example, there are about 25 times as many objects of a given size that pass within the distance of geosynchronous orbit than collide with the earth, and 2000 times as many pass within a lunar distance (accounting for gravitational focusing). An asteroid the size of the Chelyabinsk impactor (~20 m) could potentially be observed within geosynchronous orbit every two years and within lunar orbit nearly once a week. A Tunguska-sized asteroid (~40 m) passes within a lunar distance several times a year. A survey optimized to discover and count these objects would rapidly reduce the uncertainty in their populations. An additional benefit would be early warning of an imminent impact to give authorities time to issue evacuation or take-cover instructions in circumstances for which there would be no time the prevent an impact.

How Many Ultra-Low Delta-v Near Earth Objects Remain Undiscovered? Implications for missions.

NASA Astrophysics Data System (ADS)

Elvis, Martin; Ranjan, Sukrit; Galache, Jose Luis; Murphy, Max

2015-08-01

The past decade has witnessed considerable growth of interest in missions to Near-Earth Objects (NEOs). NEOs are considered prime targets for manned and robotic missions, for both scientific objectives as well as in-situ resource utilization including harvesting of water for propellant and life support and mining of high-value elements for sale on Earth. Appropriate targets are crucial to such missions. Hence, ultra-low delta-v mission targets are strongly favored. Some mission architectures rely on the discovery of more ultra-low delta-v NEOs. In fact the approved and executed NEO missions have all targeted asteroids with ultra-low LEO to asteroid rendezvous delta-v <5.5 km/s.In this paper, we estimate the total NEO population as a function of delta-v, and how many remain to be discovered in various size ranges down to ~100m. We couple the NEOSSat-1 model (Greenstreet et al., 2012) to the NEO size distribution derived from the NEOWISE survey (Mainzer et al., 2011b) to compute an absolute NEO population model. We compare the Minor Planet Center (MPC) catalog of known NEOs to this NEO population model. We compute the delta-v from LEO to asteroid rendezvous orbits using a modified Shoemaker-Helin (S-H) formalism that empirically removes biases found comparing S-H with the results from NHATS. The median delta-v of the known NEOs is 7.3 km/s, the median delta-v predicted by our NEO model is 9.8 km/s, suggesting that undiscovered objects are biased to higher delta-v. The survey of delta-v <10.3 km/s NEOs is essentially complete for objects with diameter D >300 m. However, there are tens of thousands of objects with delta-v <10.3 km/s to be discovered in the D = 50 - 300 m size class (H = 20.4 - 24.3). Our work suggests that there are 100 yet-undiscovered NEOs with delta-v < 5:8 km/s, and 1000 undiscovered NEOs with v < 6.3 km/s. We conclude that, even with complete NEO surveys, the selection of good (i.e. ultra-low delta-v) mission targets is limited given current propulsion technology. Visiting the full range of NEO sub-types will likely require improved propulsion systems.

Effect of age, decentration, aberrations and pupil size on subjective image quality with concentric bifocal optics.

PubMed

Rio, David; Woog, Kelly; Legras, Richard

2016-07-01

We investigated the impact of lens centration, wearer aberrations, pupil size and age on the optics of two bifocal contact lenses using image simulation. Fourteen conditions (i.e. two optical profiles with two and eight concentric zones; two conditions of centration: centred and 0.77 mm decentred; and three conditions of aberrations: 0, 0.15 and 0.35 μm RMS; three pupil sizes: 3, 4.5 and 6 mm) were tested on two populations (i.e. 20-40 and 40-60 years old) using a numerical simulation method. For each condition, images were calculated for proximities ranging from -4D to + 2D with steps of 0.25D. Subjects graded the quality of each simulated image (i.e. a target 'HEV' of 0.4 logMAR) on a continuous scale from 0 to 5. To limit the effect of the observer's own aberrations, subjects viewed the displayed images through a 3-mm pupil and their optimal correction. Both populations reported similar image quality (i.e. average absolute difference of 0.23) except for sharp and low contrast images, which obtained slightly higher grades with younger subjects, probably due to a better contrast sensitivity in this population. Typical decentration had no effect on bifocal contact lenses wearers' vision, as the ratio between areas dedicated to near and distance vision did not change. Aberrations (i.e. mainly 0.24 μm of spherical aberration on a 4.5-mm pupil) reduced the addition of the two radial zones bifocal optics and introduced a hyperopic shift (i.e. 0.50D) of the through-focus image quality for the eight radial zone bifocal lens. The combination of typical aberrations with typical decentration created the same effect as typical aberrations alone, meaning that aberration impact was stronger than decentration impact. The two radial zone bifocal lens was dependent on the pupil whereas the eight radial zone lens was not. When fitting new bifocal optics, the aberrations of the patients, as well as their pupil diameter, are the main subject dependent parameters influencing quality of vision. Typical contact lens decentration and lower cortical treatment efficiency of retinal images of older subjects had relatively little impact. © 2016 The Authors Ophthalmic & Physiological Optics © 2016 The College of Optometrists.

Population Growth, Energy Use, and Pollution: Understanding the Driving Forces of Global Change. Hands-On! Developing Active Learning Modules on the Human Dimensions of Global Change.

ERIC Educational Resources Information Center

Kuby, Michael

Since the beginning of the scientific revolution in the 1700s, the absolute scale of the human economy has increased many times over, and, with it, the impact on the natural environment. This learning module's activities introduce the student to linkages among population growth, energy use, level of economic and technological development and their…

Calibration of a time-resolved hard-x-ray detector using radioactive sources

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

Stoeckl, C., E-mail: csto@lle.rochester.edu; Theobald, W.; Regan, S. P.

A four-channel, time-resolved, hard x-ray detector (HXRD) has been operating at the Laboratory for Laser Energetics for more than a decade. The slope temperature of the hot-electron population in direct-drive inertial confinement fusion experiments is inferred by recording the hard x-ray radiation generated in the interaction of the electrons with the target. Measuring the energy deposited by hot electrons requires an absolute calibration of the hard x-ray detector. A novel method to obtain an absolute calibration of the HXRD using single photons from radioactive sources was developed, which uses a thermoelectrically cooled, low-noise, charge-sensitive amplifier.

Social and spatial patterns of obesity diffusion over three decades in a Norwegian county population: the HUNT Study

PubMed Central

2013-01-01

Background In order to develop effective preventive strategies, knowledge of trends in socioeconomic and geographical differences in risk factor levels is important. The objective of this study was to examine social and spatial patterns of obesity diffusion in a Norwegian population during three decades. Methods Data on adults aged 30–69 years from three cross-sectional health surveys eleven years apart in the Nord-Trøndelag Health Study, Norway, HUNT1 (1984–1986), HUNT2 (1995–1997) and HUNT3 (2006–2008) were utilized. Body mass index (BMI) was used as a measure of obesity. Height and weight were measured clinically. Age standardized prevalences, absolute prevalence differences and ratios, prevalence odds ratios for BMI and the Relative Index of Inequality (RII) were calculated. Multilevel statistical models were fitted for analysing geographical patterns. Results The prevalence of obesity was systematically higher in groups with lower socio-economic status and increased successively in all groups in the population during the three decades. The relative socioeconomic inequalities in obesity measured by level of education did not change substantially in the period. In HUNT1 (1984–86) obesity was most prevalent among low educated women (14.1%) and in HUNT3 (2006–08) among low educated men (30.4%). The RII for men changed from 2.60 to 1.91 and 2.36 in HUNT1, HUNT2 and HUNT3. In women the RIIs were 1.71, 2.28 and 2.30 correspondingly. However, the absolute obesity prevalence inequalities increased, and a geographical diffusion from central to distal districts was observed from HUNT2 to HUNT3. Conclusions The prevalence of obesity increased in all socioeconomic groups in this Norwegian adult county population from the 1980ies up to present time. The data did not suggest increasing relative inequalities, but increasing absolute socioeconomic differences and a geographical diffusion towards rural districts. Public health preventive strategies should be oriented to counteract the obesity epidemic in the population. PMID:24138786

Relative and Absolute Availability of Healthier Food and Beverage Alternatives Across Communities in the United States

PubMed Central

Powell, Lisa M.; Rimkus, Leah; Isgor, Zeynep; Barker, Dianne C.; Ohri-Vachaspati, Punam; Chaloupka, Frank

2014-01-01

Objectives. We examined associations between the relative and absolute availability of healthier food and beverage alternatives at food stores and community racial/ethnic, socioeconomic, and urban–rural characteristics. Methods. We analyzed pooled, annual cross-sectional data collected in 2010 to 2012 from 8462 food stores in 468 communities spanning 46 US states. Relative availability was the ratio of 7 healthier products (e.g., whole-wheat bread) to less healthy counterparts (e.g., white bread); we based absolute availability on the 7 healthier products. Results. The mean healthier food and beverage ratio was 0.71, indicating that stores averaged 29% fewer healthier than less healthy products. Lower relative availability of healthier alternatives was associated with low-income, Black, and Hispanic communities. Small stores had the largest differences: relative availability of healthier alternatives was 0.61 and 0.60, respectively, for very low-income Black and very low-income Hispanic communities, and 0.74 for very high-income White communities. We found fewer associations between absolute availability of healthier products and community characteristics. Conclusions. Policies to improve the relative availability of healthier alternatives may be needed to improve population health and reduce disparities. PMID:25211721

Why to compare absolute numbers of mitochondria.

PubMed

Schmitt, Sabine; Schulz, Sabine; Schropp, Eva-Maria; Eberhagen, Carola; Simmons, Alisha; Beisker, Wolfgang; Aichler, Michaela; Zischka, Hans

2014-11-01

Prompted by pronounced structural differences between rat liver and rat hepatocellular carcinoma mitochondria, we suspected these mitochondrial populations to differ massively in their molecular composition. Aiming to reveal these mitochondrial differences, we came across the issue on how to normalize such comparisons and decided to focus on the absolute number of mitochondria. To this end, fluorescently stained mitochondria were quantified by flow cytometry. For rat liver mitochondria, this approach resulted in mitochondrial protein contents comparable to earlier reports using alternative methods. We determined similar protein contents for rat liver, heart and kidney mitochondria. In contrast, however, lower protein contents were determined for rat brain mitochondria and for mitochondria from the rat hepatocellular carcinoma cell line McA 7777. This result challenges mitochondrial comparisons that rely on equal protein amounts as a typical normalization method. Exemplarily, we therefore compared the activity and susceptibility toward inhibition of complex II of rat liver and hepatocellular carcinoma mitochondria and obtained significant discrepancies by either normalizing to protein amount or to absolute mitochondrial number. Importantly, the latter normalization, in contrast to the former, demonstrated a lower complex II activity and higher susceptibility toward inhibition in hepatocellular carcinoma mitochondria compared to liver mitochondria. These findings demonstrate that solely normalizing to protein amount may obscure essential molecular differences between mitochondrial populations. Copyright © 2014 Elsevier B.V. and Mitochondria Research Society. All rights reserved.

Temperature-dependent body size effects determine population responses to climate warming.

PubMed

Lindmark, Max; Huss, Magnus; Ohlberger, Jan; Gårdmark, Anna

2018-02-01

Current understanding of animal population responses to rising temperatures is based on the assumption that biological rates such as metabolism, which governs fundamental ecological processes, scale independently with body size and temperature, despite empirical evidence for interactive effects. Here, we investigate the consequences of interactive temperature- and size scaling of vital rates for the dynamics of populations experiencing warming using a stage-structured consumer-resource model. We show that interactive scaling alters population and stage-specific responses to rising temperatures, such that warming can induce shifts in population regulation and stage-structure, influence community structure and govern population responses to mortality. Analysing experimental data for 20 fish species, we found size-temperature interactions in intraspecific scaling of metabolic rate to be common. Given the evidence for size-temperature interactions and the ubiquity of size structure in animal populations, we argue that accounting for size-specific temperature effects is pivotal for understanding how warming affects animal populations and communities. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

A case-control study to assess the impact of mammographic density on breast cancer risk in women aged 40-49 at intermediate familial risk.

PubMed

Assi, Valentina; Massat, Nathalie J; Thomas, Susan; MacKay, James; Warwick, Jane; Kataoka, Masako; Warsi, Iqbal; Brentnall, Adam; Warren, Ruth; Duffy, Stephen W

2015-05-15

Mammographic density is a strong risk factor for breast cancer, but its potential application in risk management is not clear, partly due to uncertainties about its interaction with other breast cancer risk factors. We aimed to quantify the impact of mammographic density on breast cancer risk in women aged 40-49 at intermediate familial risk of breast cancer (average lifetime risk of 23%), in particular in premenopausal women, and to investigate its relationship with other breast cancer risk factors in this population. We present the results from a case-control study nested with the FH01 cohort study of 6,710 women mostly aged 40-49 at intermediate familial risk of breast cancer. One hundred and three cases of breast cancer were age-matched to one or two controls. Density was measured by semiautomated interactive thresholding. Absolute density, but not percent density, was a significant risk factor for breast cancer in this population after adjusting for area of nondense tissue (OR per 10 cm(2) = 1.07, 95% CI 1.00-1.15, p = 0.04). The effect was stronger in premenopausal women, who made up the majority of the study population. Absolute density remained a significant predictor of breast cancer risk after adjusting for age at menarche, age at first live birth, parity, past or present hormone replacement therapy, and the Tyrer-Cuzick 10-year relative risk estimate of breast cancer. Absolute density can improve breast cancer risk stratification and delineation of high-risk groups alongside the Tyrer-Cuzick 10-year relative risk estimate. © 2014 UICC.

A nationwide study of ovarian serous borderline tumors in Denmark 1978-2002. Risk of recurrence, and development of ovarian serous carcinoma.

PubMed

Hannibal, Charlotte Gerd; Vang, Russell; Junge, Jette; Frederiksen, Kirsten; Kurman, Robert J; Kjaer, Susanne K

2017-01-01

Absolute risk and risk factors for recurrence and ovarian serous carcinoma following ovarian serous borderline tumors (SBTs) is not well-established. We included all women with SBTs in Denmark, 1978-2002. Diagnoses were confirmed by centralized pathology review and classified as atypical proliferative serous tumor (APST) or noninvasive low-grade serous carcinoma (LGSC). Implants were classified as noninvasive or invasive. Medical records were collected and reviewed, and follow-up was obtained. Subsequent diagnoses were also confirmed by centralized pathology review. We examined absolute risk and risk factors for recurrent APST and serous carcinoma using Cox regression. The absolute serous carcinoma risk after, respectively, 5 and 20years was 5.0% and 13.9% for noninvasive LGSC, and 0.9% and 3.7% for APST. Serous carcinoma risk was significantly higher following noninvasive LGSC compared with APST among stage I patients/patients without implants (HR=5.3; 95% CI: 1.7-16.3), whereas no significant association with tumor type was found in advanced stage patients/patients with implants. Advanced stage - notably invasive implants - bilaterality, surface involvement, and residual disease increased serous carcinoma risk. However, women with stage I APST also had a higher risk than the general population. This largest population-based cohort of verified SBTs revealed that women with noninvasive LGSC are significantly more likely to develop serous carcinoma than women with APST, which could not entirely be explained by invasive implants. Although invasive implants was a strong risk factor for serous carcinoma, even women with stage I APST were at increased risk compared with the general population. Copyright © 2016 Elsevier Inc. All rights reserved.

Pharmacokinetics and absolute bioavailability of phenobarbital in neonates and young infants, a population pharmacokinetic modelling approach.

PubMed

Marsot, Amélie; Brevaut-Malaty, Véronique; Vialet, Renaud; Boulamery, Audrey; Bruguerolle, Bernard; Simon, Nicolas

2014-08-01

Phenobarbital is widely used for treatment of neonatal seizures. Its optimal use in neonates and young infants requires information regarding pharmacokinetics. The objective of this study is to characterize the absolute bioavailability of phenobarbital in neonates and young infants, a pharmacokinetic parameter which has not yet been investigated. Routine clinical pharmacokinetic data were retrospectively collected from 48 neonates and infants (weight: 0.7-10 kg; patient's postnatal age: 0-206 days; GA: 27-42 weeks) treated with phenobarbital, who were administered as intravenous or suspension by oral routes and hospitalized in a paediatric intensive care unit. Total mean dose of 4.6 mg/kg (3.1-10.6 mg/kg) per day was administered by 30-min infusion or by oral route. Pharmacokinetic analysis was performed using a nonlinear mixed-effect population model software). Data were modelled with an allometric pharmacokinetic model, using three-fourths scaling exponent for clearance (CL). The population typical mean [per cent relative standard error (%RSE)] values for CL, apparent volume of distribution (Vd ) and bioavailability (F) were 0.0054 L/H/kg (7%), 0.64 L/kg (15%) and 48.9% (22%), respectively. The interindividual variability of CL, Vd , F (%RSE) and residual variability (%RSE) was 17% (31%), 50% (27%), 39% (27%) and 7.2 mg/L (29%), respectively. The absolute bioavailability of phenobarbital in neonates and infants was estimated. The dose should be increased when switching from intravenous to oral administration. © 2013 Société Française de Pharmacologie et de Thérapeutique. Published by John Wiley & Sons Ltd.

Altitudinal variation in age and body size in Yunnan pond frog (Pelophylax pleuraden).

PubMed

Lou, Shang Ling; Jin, Long; Liu, Yan Hong; Mi, Zhi Ping; Tao, Gang; Tang, Yu Mei; Liao, Wen Bo

2012-08-01

Large-scale systematic patterns of body size are a basic concern of evolutionary biology. Identifying body size variation along altitudinal gradients may help us to understand the evolution of life history of animals. In this study, we investigated altitudinal variation in body size, age and growth rate in Chinese endemic frog, Pelophylax pleuraden. Data sampled from five populations covering an altitudinal span of 1413 to 1935 m in Sichuan province revealed that body size from five populations did not co-vary with altitudes, not following Bergmann's rule. Average adult SVL differed significantly among populations in males, but not in females. For both sexes, average adult age differed significantly among populations. Post-metamorphic growth rate did not co-vary with altitude, and females grew faster than males in all populations. When controlling the effect of age, body size did not differ among populations in both sexes, suggesting that age did not affect variation in body size among populations. For females, there may be other factors, such as the allocation of energy between growth and reproduction, that eliminated the effect of age on body size. To our minds, the major reason of body size variation among populations in male frogs may be related to individual longevity. Our findings also suggest that factors other than age and growth rate may contribute to size differences among populations.

Both population size and patch quality affect local extinctions and colonizations.

PubMed

Franzén, Markus; Nilsson, Sven G

2010-01-07

Currently, the habitat of many species is fragmented, resulting in small local populations with individuals occasionally dispersing between the remaining habitat patches. In a solitary bee metapopulation, extinction probability was related to both local bee population sizes and pollen resources measured as host plant population size. Patch size, on the other hand, had no additional predictive power. The turnover rate of local bee populations in 63 habitat patches over 4 years was high, with 72 extinction events and 31 colonization events, but the pollen plant population was stable with no extinctions or colonizations. Both pollen resources and bee populations had strong and independent effects on extinction probability, but connectivity was not of importance. Colonizations occurred more frequently within larger host plant populations. For metapopulation survival of the bee, large pollen plant populations are essential, independent of current bee population size.

The Effects of Population Size Histories on Estimates of Selection Coefficients from Time-Series Genetic Data

PubMed Central

Jewett, Ethan M.; Steinrücken, Matthias; Song, Yun S.

2016-01-01

Many approaches have been developed for inferring selection coefficients from time series data while accounting for genetic drift. These approaches have been motivated by the intuition that properly accounting for the population size history can significantly improve estimates of selective strengths. However, the improvement in inference accuracy that can be attained by modeling drift has not been characterized. Here, by comparing maximum likelihood estimates of selection coefficients that account for the true population size history with estimates that ignore drift by assuming allele frequencies evolve deterministically in a population of infinite size, we address the following questions: how much can modeling the population size history improve estimates of selection coefficients? How much can mis-inferred population sizes hurt inferences of selection coefficients? We conduct our analysis under the discrete Wright–Fisher model by deriving the exact probability of an allele frequency trajectory in a population of time-varying size and we replicate our results under the diffusion model. For both models, we find that ignoring drift leads to estimates of selection coefficients that are nearly as accurate as estimates that account for the true population history, even when population sizes are small and drift is high. This result is of interest because inference methods that ignore drift are widely used in evolutionary studies and can be many orders of magnitude faster than methods that account for population sizes. PMID:27550904

Understanding Past Population Dynamics: Bayesian Coalescent-Based Modeling with Covariates

PubMed Central

Gill, Mandev S.; Lemey, Philippe; Bennett, Shannon N.; Biek, Roman; Suchard, Marc A.

2016-01-01

Effective population size characterizes the genetic variability in a population and is a parameter of paramount importance in population genetics and evolutionary biology. Kingman’s coalescent process enables inference of past population dynamics directly from molecular sequence data, and researchers have developed a number of flexible coalescent-based models for Bayesian nonparametric estimation of the effective population size as a function of time. Major goals of demographic reconstruction include identifying driving factors of effective population size, and understanding the association between the effective population size and such factors. Building upon Bayesian nonparametric coalescent-based approaches, we introduce a flexible framework that incorporates time-varying covariates that exploit Gaussian Markov random fields to achieve temporal smoothing of effective population size trajectories. To approximate the posterior distribution, we adapt efficient Markov chain Monte Carlo algorithms designed for highly structured Gaussian models. Incorporating covariates into the demographic inference framework enables the modeling of associations between the effective population size and covariates while accounting for uncertainty in population histories. Furthermore, it can lead to more precise estimates of population dynamics. We apply our model to four examples. We reconstruct the demographic history of raccoon rabies in North America and find a significant association with the spatiotemporal spread of the outbreak. Next, we examine the effective population size trajectory of the DENV-4 virus in Puerto Rico along with viral isolate count data and find similar cyclic patterns. We compare the population history of the HIV-1 CRF02_AG clade in Cameroon with HIV incidence and prevalence data and find that the effective population size is more reflective of incidence rate. Finally, we explore the hypothesis that the population dynamics of musk ox during the Late Quaternary period were related to climate change. [Coalescent; effective population size; Gaussian Markov random fields; phylodynamics; phylogenetics; population genetics. PMID:27368344

Effects of constant immigration on the dynamics and persistence of stable and unstable Drosophila populations

PubMed Central

Dey, Snigdhadip; Joshi, Amitabh

2013-01-01

Constant immigration can stabilize population size fluctuations but its effects on extinction remain unexplored. We show that constant immigration significantly reduced extinction in fruitfly populations with relatively stable or unstable dynamics. In unstable populations with oscillations of amplitude around 1.5 times the mean population size, persistence and constancy were unrelated. Low immigration enhanced persistence without affecting constancy whereas high immigration increased constancy without enhancing persistence. In relatively stable populations with erratic fluctuations of amplitude close to the mean population size, both low and high immigration enhanced persistence. In these populations, the amplitude of fluctuations relative to mean population size went down due to immigration, and their dynamics were altered to low-period cycles. The effects of immigration on the population size distribution and intrinsic dynamics of stable versus unstable populations differed considerably, suggesting that the mechanisms by which immigration reduced extinction risk depended on underlying dynamics in complex ways. PMID:23470546

Genome size differentiates co-occurring populations of the planktonic diatom Ditylum brightwellii (Bacillariophyta)

PubMed Central

2010-01-01

Background Diatoms are one of the most species-rich groups of eukaryotic microbes known. Diatoms are also the only group of eukaryotic micro-algae with a diplontic life history, suggesting that the ancestral diatom switched to a life history dominated by a duplicated genome. A key mechanism of speciation among diatoms could be a propensity for additional stable genome duplications. Across eukaryotic taxa, genome size is directly correlated to cell size and inversely correlated to physiological rates. Differences in relative genome size, cell size, and acclimated growth rates were analyzed in isolates of the diatom Ditylum brightwellii. Ditylum brightwellii consists of two main populations with identical 18s rDNA sequences; one population is distributed globally at temperate latitudes and the second appears to be localized to the Pacific Northwest coast of the USA. These two populations co-occur within the Puget Sound estuary of WA, USA, although their peak abundances differ depending on local conditions. Results All isolates from the more regionally-localized population (population 2) possessed 1.94 ± 0.74 times the amount of DNA, grew more slowly, and were generally larger than isolates from the more globally distributed population (population 1). The ITS1 sequences, cell sizes, and genome sizes of isolates from New Zealand were the same as population 1 isolates from Puget Sound, but their growth rates were within the range of the slower-growing population 2 isolates. Importantly, the observed genome size difference between isolates from the two populations was stable regardless of time in culture or the changes in cell size that accompany the diatom life history. Conclusions The observed two-fold difference in genome size between the D. brightwellii populations suggests that whole genome duplication occurred within cells of population 1 ultimately giving rise to population 2 cells. The apparent regional localization of population 2 is consistent with a recent divergence between the populations, which are likely cryptic species. Genome size variation is known to occur in other diatom genera; we hypothesize that genome duplication may be an active and important mechanism of genetic and physiological diversification and speciation in diatoms. PMID:20044934

Dating Tectonic Activity on Mercury’s Large-Scale Lobate-Scarp Thrust Faults

NASA Astrophysics Data System (ADS)

Barlow, Nadine G.; E Banks, Maria

2017-10-01

Mercury’s widespread large-scale lobate-scarp thrust faults reveal that the planet’s tectonic history has been dominated by global contraction, primarily due to cooling of its interior. Constraining the timing and duration of this contraction provides key insight into Mercury’s thermal and geologic evolution. We combine two techniques to enhance the statistical validity of size-frequency distribution crater analyses and constrain timing of the 1) earliest and 2) most recent detectable activity on several of Mercury’s largest lobate-scarp thrust faults. We use the sizes of craters directly transected by or superposed on the edge of the scarp face to define a count area around the scarp, a method we call the Modified Buffered Crater Counting Technique (MBCCT). We developed the MBCCT to avoid the issue of a near-zero scarp width since feature widths are included in area calculations of the commonly used Buffered Crater Counting Technique (BCCT). Since only craters directly intersecting the scarp face edge conclusively show evidence of crosscutting relations, we increase the number of craters in our analysis (and reduce uncertainties) by using the morphologic degradation state (i.e. relative age) of these intersecting craters to classify other similarly degraded craters within the count area (i.e., those with the same relative age) as superposing or transected. The resulting crater counts are divided into two categories: transected craters constrain the earliest possible activity and superposed craters constrain the most recent detectable activity. Absolute ages are computed for each population using the Marchi et al. [2009] model production function. A test of the Blossom lobate scarp indicates the MBCCT gives statistically equivalent results to the BCCT. We find that all scarps in this study crosscut surfaces Tolstojan or older in age (>~3.7 Ga). The most recent detectable activity along lobate-scarp thrust faults ranges from Calorian to Kuiperian (~3.7 Ga to present). Our results complement previous relative-age studies with absolute ages and indicate global contraction continued over the last ~3-4 Gyr. At least some thrust fault activity occurred on Mercury in relatively recent times (<280 Ma).

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

Usui, Fumihiko; Hasegawa, Sunao; Matsuhara, Hideo

We present an analysis of the albedo properties of main belt asteroids (MBAs) detected by the All-Sky Survey of the infrared astronomical satellite AKARI. The characteristics of 5120 asteroids detected by the survey, including their sizes and albedos, were cataloged in the Asteroid Catalog Using AKARI (AcuA). Size and albedo measurements were based on the standard thermal model, using inputs of infrared fluxes and absolute magnitudes measured at optical wavelengths. MBAs, which account for 4722 of the 5120 AcuA asteroids, have semimajor axes of 2.06-3.27 AU, except for the near-Earth asteroids. AcuA provides a complete data set of all MBAsmore » brighter than the absolute magnitude of H < 10.3, which corresponds to the diameter of d > 20 km. We confirmed that the albedo distribution of the MBAs is strongly bimodal as was already known from the past observations, and that the bimodal distribution occurs not only in the total population, but also within inner, middle, and outer regions of the main belt. The bimodal distribution in each group consists of low-albedo components in C-type asteroids and high-albedo components in S-type asteroids. We found that the small asteroids have much more variety in albedo than the large asteroids. In spite of the albedo transition process like space weathering, the heliocentric distribution of the mean albedo of asteroids in each taxonomic type is nearly flat. The mean albedo of the total, on the other hand, gradually decreases with an increase in semimajor axis. This can be explained by the compositional ratio of taxonomic types; that is, the proportion of dark asteroids such as C- and D-types increases, while that of bright asteroids such as S-type decreases, with increasing heliocentric distance. The heliocentric distributions of X-subclasses: E-, M-, and P-types, which can be divided based on albedo values, are also examined. P-types, which are the major component in X-types, are distributed throughout the main belt regions, and the abundance of P-types increases beyond 3 AU. This distribution is similar to that of C- or D-types.« less

Effect of Surgical Approach on Pulmonary Function in Adolescent Idiopathic Scoliosis Patients: A Systemic Review and Meta-analysis.

PubMed

Lee, Andy C H; Feger, Mark A; Singla, Anuj; Abel, Mark F

2016-11-15

Systemic review and meta-analysis. To analyze the effect of spinal fusion and instrumentation for adolescent idiopathic scoliosis (AIS) on absolute pulmonary function test (PFTs). Pulmonary function is correlated with severity of deformity in AIS patients and studies that have analyzed the effect of spinal fusion and instrumentation on PFTs for AIS have reported inconsistent results. There is a need to analyze the effect of spinal fusion on PFTs with stratification by surgical approach. Our analysis included 22 studies. Cohen's d effect sizes were calculated for absolute PFT outcome measures with 95% confidence intervals (CI). Meta-analyses were performed at each postoperative time frame for six homogeneous surgical approaches: (i) combined anterior release and posterior fusion with instrumentation; (ii) combined video assisted anterior release and posterior fusion with instrumentation without thoracoplasty; (iii) posterior fusion with instrumentation without thoracoplasty; (iv) anterior fusion with instrumentation and without thoracoplasty; (v) video assisted anterior fusion with instrumentation without thoracoplasty; and (vi) any scoliosis surgery with additional thoracoplasty. Anterior spinal fusion with instrumentation, any scoliosis surgery with concomitant thoracoplasty, or video-assisted anterior fusion with instrumentation for AIS had similar absolute PFTs at their 2 year postoperative follow up compared with their preoperative PFTs (effect sizes ranging from -0.2-0.2 with all CI crossing "0"). Posterior spinal fusion with instrumentation (with or without an anterior release) demonstrated small to moderate increases in PFTs 2 years postoperatively (effect sizes ranging from 0.35-0.65 with all CI not crossing "0"). Anterior fusion with instrumentation, regardless of the approach, and any scoliosis surgery with concomitant thoracoplasty do not lead to significant change in pulmonary functions 2 year after surgery. Posterior spinal fusion with instrumentation (with or without an anterior release) resulted in small to moderate increases in PFTs. N/A.

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

Wen, N; Lu, S; Qin, Y

Purpose: To evaluate the dosimetric uncertainty associated with Gafchromic (EBT3) films and establish an absolute dosimetry protocol for Stereotactic Radiosurgery (SRS) and Stereotactic Body Radiotherapy (SBRT). Methods: EBT3 films were irradiated at each of seven different dose levels between 1 and 15 Gy with open fields, and standard deviations of dose maps were calculated at each color channel for evaluation. A scanner non-uniform response correction map was built by registering and comparing film doses to the reference diode array-based dose map delivered with the same doses. To determine the temporal dependence of EBT3 films, the average correction factors of differentmore » dose levels as a function of time were evaluated up to four days after irradiation. An integrated film dosimetry protocol was developed for dose calibration, calibration curve fitting, dose mapping, and profile/gamma analysis. Patient specific quality assurance (PSQA) was performed for 93 SRS/SBRT treatment plans. Results: The scanner response varied within 1% for the field sizes less than 5 × 5 cm{sup 2}, and up to 5% for the field sizes of 10 × 10 cm{sup 2}. The scanner correction method was able to remove visually evident, irregular detector responses found for larger field sizes. The dose response of the film changed rapidly (∼10%) in the first two hours and plateaued afterwards, ∼3% change between 2 and 24 hours. The mean uncertainties (mean of the standard deviations) were <0.5% over the dose range 1∼15Gy for all color channels for the OD response curves. The percentage of points passing the 3%/1mm gamma criteria based on absolute dose analysis, averaged over all tests, was 95.0 ± 4.2. Conclusion: We have developed an absolute film dose dosimetry protocol using EBT3 films. The overall uncertainty has been established to be approximately 1% for SRS and SBRT PSQA. The work was supported by a Research Scholar Grant, RSG-15-137-01-CCE from the American Cancer Society.« less

Adaptively resizing populations: Algorithm, analysis, and first results

NASA Technical Reports Server (NTRS)

Smith, Robert E.; Smuda, Ellen

1993-01-01

Deciding on an appropriate population size for a given Genetic Algorithm (GA) application can often be critical to the algorithm's success. Too small, and the GA can fall victim to sampling error, affecting the efficacy of its search. Too large, and the GA wastes computational resources. Although advice exists for sizing GA populations, much of this advice involves theoretical aspects that are not accessible to the novice user. An algorithm for adaptively resizing GA populations is suggested. This algorithm is based on recent theoretical developments that relate population size to schema fitness variance. The suggested algorithm is developed theoretically, and simulated with expected value equations. The algorithm is then tested on a problem where population sizing can mislead the GA. The work presented suggests that the population sizing algorithm may be a viable way to eliminate the population sizing decision from the application of GA's.

A guide to calculating habitat-quality metrics to inform conservation of highly mobile species

USGS Publications Warehouse

Bieri, Joanna A.; Sample, Christine; Thogmartin, Wayne E.; Diffendorfer, James E.; Earl, Julia E.; Erickson, Richard A.; Federico, Paula; Flockhart, D. T. Tyler; Nicol, Sam; Semmens, Darius J.; Skraber, T.; Wiederholt, Ruscena; Mattsson, Brady J.

2018-01-01

Many metrics exist for quantifying the relative value of habitats and pathways used by highly mobile species. Properly selecting and applying such metrics requires substantial background in mathematics and understanding the relevant management arena. To address this multidimensional challenge, we demonstrate and compare three measurements of habitat quality: graph-, occupancy-, and demographic-based metrics. Each metric provides insights into system dynamics, at the expense of increasing amounts and complexity of data and models. Our descriptions and comparisons of diverse habitat-quality metrics provide means for practitioners to overcome the modeling challenges associated with management or conservation of such highly mobile species. Whereas previous guidance for applying habitat-quality metrics has been scattered in diversified tracks of literature, we have brought this information together into an approachable format including accessible descriptions and a modeling case study for a typical example that conservation professionals can adapt for their own decision contexts and focal populations.Considerations for Resource ManagersManagement objectives, proposed actions, data availability and quality, and model assumptions are all relevant considerations when applying and interpreting habitat-quality metrics.Graph-based metrics answer questions related to habitat centrality and connectivity, are suitable for populations with any movement pattern, quantify basic spatial and temporal patterns of occupancy and movement, and require the least data.Occupancy-based metrics answer questions about likelihood of persistence or colonization, are suitable for populations that undergo localized extinctions, quantify spatial and temporal patterns of occupancy and movement, and require a moderate amount of data.Demographic-based metrics answer questions about relative or absolute population size, are suitable for populations with any movement pattern, quantify demographic processes and population dynamics, and require the most data.More real-world examples applying occupancy-based, agent-based, and continuous-based metrics to seasonally migratory species are needed to better understand challenges and opportunities for applying these metrics more broadly.

Relative populations of excited levels within the ground configuration of Si-like Cu, Zn, Ge and Se ions

NASA Technical Reports Server (NTRS)

Datla, R. U.; Roberts, J. R.; Bhatia, A. K.

1991-01-01

Populations of 3p2 1D2, 3P1, 3P2 levels in Si-like Cu, Zn, Ge, and Se ions have been deduced from the measurements of absolute intensities of magnetic dipole transitions within the 3s2 3p2 ground configuration. The measured population ratios are compared with theoretical calculations based on the distorted-wave approximation for the electron collisions and a semiclassical approximation for the proton collisions. The observed deviation from the statistical distribution for the excited-level populations within the ground configuration along the silicon isoelectronic sequence is in agreement with theoretical prediction.

Population growth, agrarian peasant economy and environmental degradation in Tanzania.

PubMed

Madulu, N F

1995-03-01

Population strategies to relieve the density pressures on land and resources in Tanzania have not considered the basic causes of population growth. Resettlement results in the same environmental degradation as in the original settlement. There should be a reduction in the population growth and planning of proper land use and resource exploitation before resettlement. Rural development must include a decline in the dependency on subsistence agriculture. Population in Tanzania increased by 213% during 1948-88. An absolute increase in population size during 1978-88 is recorded despite a slight decline in the rate of growth. Death rates declined, but birth rates were relatively stable at around 50 per 1000 population. Regions with the highest growth rates were Dar es Salaam (4.8%), Rukwa (4.3%), Arusha (3.8%), Mbeya (3.1%), and Ruvuma (3.2%). The regions with the lowest rates were Tanga and Kilimanjaro (2.1%), Coast (2.1%), Lindi (2%), and Mtwara (1.4%). Low growth rates are attributed to low fertility and high infertility. Other factors affecting high growth rates are culture, rates of natural increase, intensity of internal and international migration, climatic conditions, and availability of resources. In 1988 46% of the population was under 15 years old. Per capita land availability declined from 11.8 hectares in 1948 to 3.8 hectares in 1988. The number of landless peasants increased. Productivity declined, and distances to farms increased. The total fertility rate was 6.5 children per woman in 1988 and 6.1 during 1991-92. Slight declines were apparent in the crude birth rate also. High fertility was a response to universal marriage, low contraceptive use (7% using modern methods during 1991-92), declining lactation periods, high mortality rates, and old traditions favoring large families. Children were used extensively in time-consuming and labor-intensive activities, such as fetching water. The mean number of children ever born was higher among women with 1-4 years of schooling compared to women with no formal education and women with 5 or more years of education. Population growth contributes to deforestation, soil erosion, desertification, famine, drought, flooding, and demand for firewood.

Rapid population divergence in thermal reaction norms for an invading species: breaking the temperature-size rule.

PubMed

Kingsolver, J G; Massie, K R; Ragland, G J; Smith, M H

2007-05-01

The temperature-size rule is a common pattern of phenotypic plasticity in which higher temperature during development results in a smaller adult body size (i.e. a thermal reaction norm with negative slope). Examples and exceptions to the rule are known in multiple groups of organisms, but rapid population differentiation in the temperature-size rule has not been explored. Here we examine the genetic and parental contributions to population differentiation in thermal reaction norms for size, development time and survival in the Cabbage White Butterfly Pieris rapae, for two geographical populations that have likely diverged within the past 150 years. We used split-sibship experiments with two temperature treatments (warm and cool) for P. rapae from Chapel Hill, NC, and from Seattle, WA. Mixed-effect model analyses demonstrate significant genetic differences between NC and WA populations for adult size and for thermal reaction norms for size. Mean adult mass was 12-24% greater in NC than in WA populations for both temperature treatments; mean size was unaffected or decreased with temperature (the temperature-size rule) for the WA population, but size increased with temperature for the NC population. Our study shows that the temperature-size rule and related thermal reaction norms can evolve rapidly within species in natural field conditions. Rapid evolutionary divergence argues against the existence of a simple, general mechanistic constraint as the underlying cause of the temperature-size rule.

Trends in educational differentials in suicide mortality between 1993-2006 in Korea.

PubMed

Lee, Weon Young; Khang, Young-Ho; Noh, Manegseok; Ryu, Jae-In; Son, Mia; Hong, Yeon-Pyo

2009-08-31

This study aims to examine how inequalities in suicide by education changed during and after macroeconomic restructuring following the economic crisis of 1997 in South Korea. Using Korea's 1995, 2000, and 2005 census data aggregately linked to mortality data (1993-2006), relative and absolute differentials in suicide mortality by education were calculated by gender and age among Korean population aged 35 and over. Average annual suicide mortality rates have steadily increased from 1993-1997 to 2003-2006 in almost all sociodemographic groups stratified by gender, age, and education. Based on the relative index of inequality (RII) and slope index of inequality (SII), educational differentials in suicide mortality generally increased over time in men and women aged 45 years+. Although RII did not increase with year among men and women aged 35 - 44 years, SII showed a significantly increasing trend in this age group. These worsening absolute inequalities in suicide mortality indicate that the governmental suicide prevention policy should be directed toward socially disadvantaged groups of the Korean population.

Physical properties of the ionized gas and brightness distribution in NGC4736

NASA Astrophysics Data System (ADS)

Rodrigues, I.; Dottori, H.; Cepa, J.; Vilchez, J.

1998-03-01

In this work we study the galaxy NGC4736, using narrow band interference filters imaging centered at the emission lines {Oii} {3727+3729}, Hβ, {Oiii} {5007}, Hα, {Sii} {6716+6730} and {Siii} {9070} and nearby continua. We have obtained sizes, positions, emission line absolute fluxes, and continua intensities for 90 Hii regions, mainly distributed in a ring-like structure of 3.2kpc in diameter. The Hα luminosities are in the range 37.3 <= log L_Hα <= 39.4 ergs(-1) . The Hii regions size distribution presents a characteristic diameter D_0 = 115pc and verifies the relation log (L_Hα ) ~D(3) . The temperature of the ionizing sources and the metallicity of the Hii regions are respectively in the ranges 3.410(4) <~T_⋆ <~ 4.010(4) K and 8.5 <~12 + log (O/H) <~9.3. The masses of the ionizing clusters are in the range 510(3) <~M_T/M_sun <~210(5) . The continua radial surface brightness distribution is better fitted by the superposition of a de Vaucouleurs', a thin and a thick exponential disk laws. The monochromatic colors show that outside the star forming ring the disk presents a younger stellar population than inside it. Tables 3 and 4 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

Methodological choices affect cancer incidence rates: a cohort study.

PubMed

Brooke, Hannah L; Talbäck, Mats; Feychting, Maria; Ljung, Rickard

2017-01-19

Incidence rates are fundamental to epidemiology, but their magnitude and interpretation depend on methodological choices. We aimed to examine the extent to which the definition of the study population affects cancer incidence rates. All primary cancer diagnoses in Sweden between 1958 and 2010 were identified from the national Cancer Register. Age-standardized and age-specific incidence rates of 29 cancer subtypes between 2000 and 2010 were calculated using four definitions of the study population: persons resident in Sweden 1) based on general population statistics; 2) with no previous subtype-specific cancer diagnosis; 3) with no previous cancer diagnosis except non-melanoma skin cancer; and 4) with no previous cancer diagnosis of any type. We calculated absolute and relative differences between methods. Age-standardized incidence rates calculated using general population statistics ranged from 6% lower (prostate cancer, incidence rate difference: -13.5/100,000 person-years) to 8% higher (breast cancer in women, incidence rate difference: 10.5/100,000 person-years) than incidence rates based on individuals with no previous subtype-specific cancer diagnosis. Age-standardized incidence rates in persons with no previous cancer of any type were up to 10% lower (bladder cancer in women) than rates in those with no previous subtype-specific cancer diagnosis; however, absolute differences were <5/100,000 person-years for all cancer subtypes. For some cancer subtypes incidence rates vary depending on the definition of the study population. For these subtypes, standardized incidence ratios calculated using general population statistics could be misleading. Moreover, etiological arguments should be used to inform methodological choices during study design.

Method and apparatus for making absolute range measurements

DOEpatents

Earl, Dennis D [Knoxville, TN; Allison, Stephen W [Knoxville, TN; Cates, Michael R [Oak Ridge, TN; Sanders, Alvin J [Knoxville, TN

2002-09-24

This invention relates to a method and apparatus for making absolute distance or ranging measurements using Fresnel diffraction. The invention employs a source of electromagnetic radiation having a known wavelength or wavelength distribution, which sends a beam of electromagnetic radiation through a screen at least partially opaque at the wavelength. The screen has an aperture sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector spaced some distance from the screen. The detector detects the central intensity of the beam as well as a set of intensities displaced from a center of the aperture. The distance from the source to the target can then be calculated based upon the known wavelength, aperture radius, and beam intensity.

Neighbourhood socioeconomic inequalities in incidence of acute myocardial infarction: a cohort study quantifying age- and gender-specific differences in relative and absolute terms.

PubMed

Koopman, Carla; van Oeffelen, Aloysia A M; Bots, Michiel L; Engelfriet, Peter M; Verschuren, W M Monique; van Rossem, Lenie; van Dis, Ineke; Capewell, Simon; Vaartjes, Ilonca

2012-08-07

Socioeconomic status has a profound effect on the risk of having a first acute myocardial infarction (AMI). Information on socioeconomic inequalities in AMI incidence across age-gender-groups is lacking. Our objective was to examine socioeconomic inequalities in the incidence of AMI considering both relative and absolute measures of risk differences, with a particular focus on age and gender. We identified all patients with a first AMI from 1997 to 2007 through linked hospital discharge and death records covering the Dutch population. Relative risks (RR) of AMI incidence were estimated by mean equivalent household income at neighbourhood-level for strata of age and gender using Poisson regression models. Socioeconomic inequalities were also shown within the stratified age-gender groups by calculating the total number of events attributable to socioeconomic disadvantage. Between 1997 and 2007, 317,564 people had a first AMI. When comparing the most deprived socioeconomic quintile with the most affluent quintile, the overall RR for AMI was 1.34 (95 % confidence interval (CI): 1.32-1.36) in men and 1.44 (95 % CI: 1.42-1.47) in women. The socioeconomic gradient decreased with age. Relative socioeconomic inequalities were most apparent in men under 35 years and in women under 65 years. The largest number of events attributable to socioeconomic inequalities was found in men aged 45-74 years and in women aged 65-84 years. The total proportion of AMIs that was attributable to socioeconomic inequalities in the Dutch population of 1997 to 2007 was 14 % in men and 18 % in women. Neighbourhood socioeconomic inequalities were observed in AMI incidence in the Netherlands, but the magnitude across age-gender groups depended on whether inequality was expressed in relative or absolute terms. Relative socioeconomic inequalities were high in young persons and women, where the absolute burden of AMI was low. Absolute socioeconomic inequalities in AMI were highest in the age-gender groups of middle-aged men and elderly women, where the number of cases was largest.

Neighbourhood socioeconomic inequalities in incidence of acute myocardial infarction: a cohort study quantifying age- and gender-specific differences in relative and absolute terms

PubMed Central

2012-01-01

Background Socioeconomic status has a profound effect on the risk of having a first acute myocardial infarction (AMI). Information on socioeconomic inequalities in AMI incidence across age- gender-groups is lacking. Our objective was to examine socioeconomic inequalities in the incidence of AMI considering both relative and absolute measures of risk differences, with a particular focus on age and gender. Methods We identified all patients with a first AMI from 1997 to 2007 through linked hospital discharge and death records covering the Dutch population. Relative risks (RR) of AMI incidence were estimated by mean equivalent household income at neighbourhood-level for strata of age and gender using Poisson regression models. Socioeconomic inequalities were also shown within the stratified age-gender groups by calculating the total number of events attributable to socioeconomic disadvantage. Results Between 1997 and 2007, 317,564 people had a first AMI. When comparing the most deprived socioeconomic quintile with the most affluent quintile, the overall RR for AMI was 1.34 (95 % confidence interval (CI): 1.32 – 1.36) in men and 1.44 (95 % CI: 1.42 – 1.47) in women. The socioeconomic gradient decreased with age. Relative socioeconomic inequalities were most apparent in men under 35 years and in women under 65 years. The largest number of events attributable to socioeconomic inequalities was found in men aged 45–74 years and in women aged 65–84 years. The total proportion of AMIs that was attributable to socioeconomic inequalities in the Dutch population of 1997 to 2007 was 14 % in men and 18 % in women. Conclusions Neighbourhood socioeconomic inequalities were observed in AMI incidence in the Netherlands, but the magnitude across age-gender groups depended on whether inequality was expressed in relative or absolute terms. Relative socioeconomic inequalities were high in young persons and women, where the absolute burden of AMI was low. Absolute socioeconomic inequalities in AMI were highest in the age-gender groups of middle-aged men and elderly women, where the number of cases was largest. PMID:22870916

Estimating population sizes for elusive animals: the forest elephants of Kakum National Park, Ghana.

PubMed

Eggert, L S; Eggert, J A; Woodruff, D S

2003-06-01

African forest elephants are difficult to observe in the dense vegetation, and previous studies have relied upon indirect methods to estimate population sizes. Using multilocus genotyping of noninvasively collected samples, we performed a genetic survey of the forest elephant population at Kakum National Park, Ghana. We estimated population size, sex ratio and genetic variability from our data, then combined this information with field observations to divide the population into age groups. Our population size estimate was very close to that obtained using dung counts, the most commonly used indirect method of estimating the population sizes of forest elephant populations. As their habitat is fragmented by expanding human populations, management will be increasingly important to the persistence of forest elephant populations. The data that can be obtained from noninvasively collected samples will help managers plan for the conservation of this keystone species.

Determination of the optimal sample size for a clinical trial accounting for the population size.

PubMed

Stallard, Nigel; Miller, Frank; Day, Simon; Hee, Siew Wan; Madan, Jason; Zohar, Sarah; Posch, Martin

2017-07-01

The problem of choosing a sample size for a clinical trial is a very common one. In some settings, such as rare diseases or other small populations, the large sample sizes usually associated with the standard frequentist approach may be infeasible, suggesting that the sample size chosen should reflect the size of the population under consideration. Incorporation of the population size is possible in a decision-theoretic approach either explicitly by assuming that the population size is fixed and known, or implicitly through geometric discounting of the gain from future patients reflecting the expected population size. This paper develops such approaches. Building on previous work, an asymptotic expression is derived for the sample size for single and two-arm clinical trials in the general case of a clinical trial with a primary endpoint with a distribution of one parameter exponential family form that optimizes a utility function that quantifies the cost and gain per patient as a continuous function of this parameter. It is shown that as the size of the population, N, or expected size, N∗ in the case of geometric discounting, becomes large, the optimal trial size is O(N1/2) or O(N∗1/2). The sample size obtained from the asymptotic expression is also compared with the exact optimal sample size in examples with responses with Bernoulli and Poisson distributions, showing that the asymptotic approximations can also be reasonable in relatively small sample sizes. © 2016 The Author. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phenotypic plasticity in clutch size regulation among populations of a potential invasive fruit fly from environments that vary in host heterogeneity and isolation.

PubMed

Aluja, M; Birke, A; Díaz-Fleischer, F; Rull, J

2018-05-21

Phenotypic plasticity is thought to evolve in response to environmental unpredictability and can shield genotypes from selection. However, selection can also act on plastic traits. Egg-laying behaviour, including clutch size regulation, is a plastic behavioural trait among tephritid fruit flies. We compared plasticity in clutch size regulation among females of Anastrepha ludens populations stemming from environments that differed in the degree of predictability in egg-laying opportunities. Clutch size regulation in response to hosts of different sizes was compared among flies from (a) a wild, highly isolated population, (b) a wild population that switches seasonally from a small wild host fruit that varies greatly in abundance to an abundant large-sized commercial host, and (c) a laboratory population. Flies from all three populations adjusted clutch number and size according to host size. However, flies from the heterogeneous wild environment were more plastic in adjusting clutch size than flies from agricultural settings that also laid fewer eggs; yet both populations were more plastic in adjusting clutch size in line with host size when compared with laboratory females. When wild and orchard females encountered the largest host, clutch size was extremely variable and egg regulation did not follow the same trend. Heterogeneity in host availability in space and time appears to be as important as seasonal variation in host size in maintaining plastic clutch size regulation behaviour. In stable environments, there was a clear reduction in the plasticity of these traits.

Sampling for area estimation: A comparison of full-frame sampling with the sample segment approach. [Kansas

NASA Technical Reports Server (NTRS)

Hixson, M. M.; Bauer, M. E.; Davis, B. J.

1979-01-01

The effect of sampling on the accuracy (precision and bias) of crop area estimates made from classifications of LANDSAT MSS data was investigated. Full-frame classifications of wheat and non-wheat for eighty counties in Kansas were repetitively sampled to simulate alternative sampling plants. Four sampling schemes involving different numbers of samples and different size sampling units were evaluated. The precision of the wheat area estimates increased as the segment size decreased and the number of segments was increased. Although the average bias associated with the various sampling schemes was not significantly different, the maximum absolute bias was directly related to sampling unit size.

Dynamics of domain coverage of the protein sequence universe.

PubMed

Rekapalli, Bhanu; Wuichet, Kristin; Peterson, Gregory D; Zhulin, Igor B

2012-11-16

The currently known protein sequence space consists of millions of sequences in public databases and is rapidly expanding. Assigning sequences to families leads to a better understanding of protein function and the nature of the protein universe. However, a large portion of the current protein space remains unassigned and is referred to as its "dark matter". Here we suggest that true size of "dark matter" is much larger than stated by current definitions. We propose an approach to reducing the size of "dark matter" by identifying and subtracting regions in protein sequences that are not likely to contain any domain. Recent improvements in computational domain modeling result in a decrease, albeit slowly, in the relative size of "dark matter"; however, its absolute size increases substantially with the growth of sequence data.

Homoplasy and mutation model at microsatellite loci and their consequences for population genetics analysis.

PubMed

Estoup, Arnaud; Jarne, Philippe; Cornuet, Jean-Marie

2002-09-01

Homoplasy has recently attracted the attention of population geneticists, as a consequence of the popularity of highly variable stepwise mutating markers such as microsatellites. Microsatellite alleles generally refer to DNA fragments of different size (electromorphs). Electromorphs are identical in state (i.e. have identical size), but are not necessarily identical by descent due to convergent mutation(s). Homoplasy occurring at microsatellites is thus referred to as size homoplasy. Using new analytical developments and computer simulations, we first evaluate the effect of the mutation rate, the mutation model, the effective population size and the time of divergence between populations on size homoplasy at the within and between population levels. We then review the few experimental studies that used various molecular techniques to detect size homoplasious events at some microsatellite loci. The relationship between this molecularly accessible size homoplasy size and the actual amount of size homoplasy is not trivial, the former being considerably influenced by the molecular structure of microsatellite core sequences. In a third section, we show that homoplasy at microsatellite electromorphs does not represent a significant problem for many types of population genetics analyses realized by molecular ecologists, the large amount of variability at microsatellite loci often compensating for their homoplasious evolution. The situations where size homoplasy may be more problematic involve high mutation rates and large population sizes together with strong allele size constraints.

The Effects of Population Size Histories on Estimates of Selection Coefficients from Time-Series Genetic Data.

PubMed

Jewett, Ethan M; Steinrücken, Matthias; Song, Yun S

2016-11-01

Many approaches have been developed for inferring selection coefficients from time series data while accounting for genetic drift. These approaches have been motivated by the intuition that properly accounting for the population size history can significantly improve estimates of selective strengths. However, the improvement in inference accuracy that can be attained by modeling drift has not been characterized. Here, by comparing maximum likelihood estimates of selection coefficients that account for the true population size history with estimates that ignore drift by assuming allele frequencies evolve deterministically in a population of infinite size, we address the following questions: how much can modeling the population size history improve estimates of selection coefficients? How much can mis-inferred population sizes hurt inferences of selection coefficients? We conduct our analysis under the discrete Wright-Fisher model by deriving the exact probability of an allele frequency trajectory in a population of time-varying size and we replicate our results under the diffusion model. For both models, we find that ignoring drift leads to estimates of selection coefficients that are nearly as accurate as estimates that account for the true population history, even when population sizes are small and drift is high. This result is of interest because inference methods that ignore drift are widely used in evolutionary studies and can be many orders of magnitude faster than methods that account for population sizes. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Research on Grid Size Suitability of Gridded Population Distribution in Urban Area: A Case Study in Urban Area of Xuanzhou District, China.

PubMed

Dong, Nan; Yang, Xiaohuan; Cai, Hongyan; Xu, Fengjiao

2017-01-01

The research on the grid size suitability is important to provide improvement in accuracies of gridded population distribution. It contributes to reveal the actual spatial distribution of population. However, currently little research has been done in this area. Many well-modeled gridded population dataset are basically built at a single grid scale. If the grid cell size is not appropriate, it will result in spatial information loss or data redundancy. Therefore, in order to capture the desired spatial variation of population within the area of interest, it is necessary to conduct research on grid size suitability. This study summarized three expressed levels to analyze grid size suitability, which include location expressed level, numeric information expressed level, and spatial relationship expressed level. This study elaborated the reasons for choosing the five indexes to explore expression suitability. These five indexes are consistency measure, shape index rate, standard deviation of population density, patches diversity index, and the average local variance. The suitable grid size was determined by constructing grid size-indicator value curves and suitable grid size scheme. Results revealed that the three expressed levels on 10m grid scale are satisfying. And the population distribution raster data with 10m grid size provide excellent accuracy without loss. The 10m grid size is recommended as the appropriate scale for generating a high-quality gridded population distribution in our study area. Based on this preliminary study, it indicates the five indexes are coordinated with each other and reasonable and effective to assess grid size suitability. We also suggest choosing these five indexes in three perspectives of expressed level to carry out the research on grid size suitability of gridded population distribution.

Research on Grid Size Suitability of Gridded Population Distribution in Urban Area: A Case Study in Urban Area of Xuanzhou District, China

PubMed Central

Dong, Nan; Yang, Xiaohuan; Cai, Hongyan; Xu, Fengjiao

2017-01-01

The research on the grid size suitability is important to provide improvement in accuracies of gridded population distribution. It contributes to reveal the actual spatial distribution of population. However, currently little research has been done in this area. Many well-modeled gridded population dataset are basically built at a single grid scale. If the grid cell size is not appropriate, it will result in spatial information loss or data redundancy. Therefore, in order to capture the desired spatial variation of population within the area of interest, it is necessary to conduct research on grid size suitability. This study summarized three expressed levels to analyze grid size suitability, which include location expressed level, numeric information expressed level, and spatial relationship expressed level. This study elaborated the reasons for choosing the five indexes to explore expression suitability. These five indexes are consistency measure, shape index rate, standard deviation of population density, patches diversity index, and the average local variance. The suitable grid size was determined by constructing grid size-indicator value curves and suitable grid size scheme. Results revealed that the three expressed levels on 10m grid scale are satisfying. And the population distribution raster data with 10m grid size provide excellent accuracy without loss. The 10m grid size is recommended as the appropriate scale for generating a high-quality gridded population distribution in our study area. Based on this preliminary study, it indicates the five indexes are coordinated with each other and reasonable and effective to assess grid size suitability. We also suggest choosing these five indexes in three perspectives of expressed level to carry out the research on grid size suitability of gridded population distribution. PMID:28122050

Association between different phases of menstrual cycle and body image measures of perceived size, ideal size, and body dissatisfaction.

PubMed

Teixeira, André Luiz S; Dias, Marcelo Ricardo C; Damasceno, Vinícius O; Lamounier, Joel A; Gardner, Rick M

2013-12-01

The association between phases of the menstrual cycle and body image was investigated. 44 university women (M age = 23.3 yr., SD = 4.7) judged their perceived and ideal body size, and body dissatisfaction was calculated at each phase of the menstrual cycle, including premenstrual, menstrual, and intermenstrual. Participants selected one of nine figural drawings ranging from very thin to obese that represented their perceived size and ideal size. Body dissatisfaction was measured as the absolute difference between scores on perceived and ideal figural drawings. During each menstrual phase, anthropometric measures of weight, height, body mass index, circumference of waist and abdomen, and body composition were taken. There were no significant differences in any anthropometric measures between the three menstrual cycle phases. Perceived body size and body dissatisfaction were significantly different between menstrual phases, with the largest perceived body size and highest body dissatisfaction occurring during the menstrual phase. Ideal body size did not differ between menstrual phases, although participants desired a significantly smaller ideal size as compared to the perceived size.

The impact of obesity on skeletal muscle strength and structure through adolescence to old age.

PubMed

Tomlinson, D J; Erskine, R M; Morse, C I; Winwood, K; Onambélé-Pearson, Gladys

2016-06-01

Obesity is associated with functional limitations in muscle performance and increased likelihood of developing a functional disability such as mobility, strength, postural and dynamic balance limitations. The consensus is that obese individuals, regardless of age, have a greater absolute maximum muscle strength compared to non-obese persons, suggesting that increased adiposity acts as a chronic overload stimulus on the antigravity muscles (e.g., quadriceps and calf), thus increasing muscle size and strength. However, when maximum muscular strength is normalised to body mass, obese individuals appear weaker. This relative weakness may be caused by reduced mobility, neural adaptations and changes in muscle morphology. Discrepancies in the literature remain for maximal strength normalised to muscle mass (muscle quality) and can potentially be explained through accounting for the measurement protocol contributing to muscle strength capacity that need to be explored in more depth such as antagonist muscle co-activation, muscle architecture, a criterion valid measurement of muscle size and an accurate measurement of physical activity levels. Current evidence demonstrating the effect of obesity on muscle quality is limited. These factors not being recorded in some of the existing literature suggest a potential underestimation of muscle force either in terms of absolute force production or relative to muscle mass; thus the true effect of obesity upon skeletal muscle size, structure and function, including any interactions with ageing effects, remains to be elucidated.

[A Quality Assurance (QA) System with a Web Camera for High-dose-rate Brachytherapy].

PubMed

Hirose, Asako; Ueda, Yoshihiro; Oohira, Shingo; Isono, Masaru; Tsujii, Katsutomo; Inui, Shouki; Masaoka, Akira; Taniguchi, Makoto; Miyazaki, Masayoshi; Teshima, Teruki

2016-03-01

The quality assurance (QA) system that simultaneously quantifies the position and duration of an (192)Ir source (dwell position and time) was developed and the performance of this system was evaluated in high-dose-rate brachytherapy. This QA system has two functions to verify and quantify dwell position and time by using a web camera. The web camera records 30 images per second in a range from 1,425 mm to 1,505 mm. A user verifies the source position from the web camera at real time. The source position and duration were quantified with the movie using in-house software which was applied with a template-matching technique. This QA system allowed verification of the absolute position in real time and quantification of dwell position and time simultaneously. It was evident from the verification of the system that the mean of step size errors was 0.31±0.1 mm and that of dwell time errors 0.1±0.0 s. Absolute position errors can be determined with an accuracy of 1.0 mm at all dwell points in three step sizes and dwell time errors with an accuracy of 0.1% in more than 10.0 s of the planned time. This system is to provide quick verification and quantification of the dwell position and time with high accuracy at various dwell positions without depending on the step size.

VizieR Online Data Catalog: WISE/NEOWISE Mars-crossing asteroids (Ali-Lagoa+, 2017)

NASA Astrophysics Data System (ADS)

Ali-Lagoa, V.; Delbo, M.

2017-07-01

We fitted the near-Earth asteroid thermal model of Harris (1998, Icarus, 131, 29) to WISE/NEOWISE thermal infrared data (see, e.g., Mainzer et al. 2011ApJ...736..100M, and Masiero et al. 2014, Cat. J/ApJ/791/121). The table contains the best-fitting values of size and beaming parameter. We note that the beaming parameter is a strictly positive quantity, but a negative sign is given to indicate whenever we could not fit it and had to assume a default value. We also provide the visible geometric albedos computed from the diameter and the tabulated absolute magnitudes. Minimum relative errors of 10, 15, and 20 percent should be considered for size, beaming parameter and albedo in those cases for which the beaming parameter could be fitted. Otherwise, the minimum relative errors in size and albedo increase to 20 and 40 percent (see, e.g., Mainzer et al. 2011ApJ...736..100M). The asteroid absolute magnitudes and slope parameters retrieved from the Minor Planet Center (MPC) are included, as well as the number of observations used in each WISE band (nW2, nW3, nW4) and the corresponding average values of heliocentric and geocentric distances and phase angle of the observations. The ephemerides were retrieved from the MIRIADE service (http://vo.imcce.fr/webservices/miriade/?ephemph). (1 data file).

First light measurements of the Total Solar Irradiance experiment CLARA on NORSAT-1

NASA Astrophysics Data System (ADS)

Schmutz, Werner

2016-07-01

NORSAT-1 is a Norwegian micro-satellite, which will be launched April 22, 2016. (In the future at the time of writing this abstract.) The satellite carries two scientific instruments and an AIS receiver for performing ship detection from space. One of the scientific instruments is a Compact Light-weight Absolute RAdiometer (CLARA) and the other is a Langmuir Probe instrument comprising four probes mounted on booms. The latter experiment will measure electron density and the platform's floating potential along the orbit. The University of Oslo provides the Langmuir probes. The radiometer experiment CLARA has been built by PMOD/WRC funded through the Swiss PRODEX program. It will measure Total Solar Irradiance with an instrument of novel design that is optimized for minimizing mass and size by still ensuring highest measuring accuracy and thermal stability. The radiometers of CLARA have been fully characterized as well as calibrated at the TRF facility. It is expected that the first light accuracy of the absolute measurement of Total Solar Irradiance will be better than pm0.3 W/m^{2, allowing to probe the current TSI composite for its absolute level. The presentation will give an overview of the CLARA instrument and its calibration. It is expected that at the time of the COSPAR conference the first light TSI value of CLARA/NORSAT-1 is ready for publication. Together with a previous absolute TSI measurements available for July 27, 2010 measured by PREMOS/PICARD the new absolute TSI measurement will be used to test the accuracy of long term TSI trend given by the relative TSI composite.

Quantification of absolute blood velocity using LDA

NASA Astrophysics Data System (ADS)

Borozdova, M. A.; Fedosov, I. V.; Tuchin, V. V.

2018-04-01

We developed novel schematics of a Laser Doppler anemometer where measuring volume is comparable with the red blood cell (RBC) size and a small period of interference fringes improves device resolution. The technique was used to estimate Doppler frequency shift at flow velocity measurements. It has been shown that technique is applicable for measurements in whole blood.

From Chebyshev to Bernstein: A Tour of Polynomials Small and Large

ERIC Educational Resources Information Center

Boelkins, Matthew; Miller, Jennifer; Vugteveen, Benjamin

2006-01-01

Consider the family of monic polynomials of degree n having zeros at -1 and +1 and all their other real zeros in between these two values. This article explores the size of these polynomials using the supremum of the absolute value on [-1, 1], showing that scaled Chebyshev and Bernstein polynomials give the extremes.

SOA Does Not Reveal the Absolute Time Course of Cognitive Processing in Fast Priming Experiments

ERIC Educational Resources Information Center

Tzur, Boaz; Frost, Ram

2007-01-01

Applying Bloch's law to visual word recognition research, both exposure duration of the prime and its luminance determine the prime's overall energy, and consequently determine the size of the priming effect. Nevertheless, experimenters using fast-priming paradigms traditionally focus only on the SOA between prime and target to reflect the…

Landsat continuity: issues and opportunities for land cover monitoring

Treesearch

Michael A. Wulder; Joanne C. White; Samuel N. Goward; Jeffrey G. Masek; James R. Irons; Martin Herold; Warren B. Cohen; Thomas R. Loveland; Curtis E. Woodcock

2008-01-01

Initiated in 1972, the Landsat program has provided a continuous record of Earth observation for 35 years. The assemblage of Landsat spatial, spectral, and temporal resolutions, over a reasonably sized image extent, results in imagery that can be processed to represent land cover over large areas with an amount of spatial detail that is absolutely unique and...

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Science.gov Websites

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Association between absolute tumor burden and serum bone-specific alkaline phosphatase in canine appendicular osteosarcoma.

PubMed

Sternberg, R A; Pondenis, H C; Yang, X; Mitchell, M A; O'Brien, R T; Garrett, L D; Helferich, W G; Hoffmann, W E; Fan, T M

2013-01-01

In dogs with appendicular osteosarcoma (OSA), increased pretreatment serum bone-specific alkaline phosphatase (BALP) activity is a negative prognostic factor, associated with shorter disease-free intervals and survival times, but a biologic basis for observed differential serum BALP activities in canine OSA patients remains incompletely defined. Serum BALP activity will correlate with absolute tumor burden in dogs with OSA. This study included 96 client-owned dogs with appendicular OSA. In canine OSA cell lines, the expression and membranous release of BALP was evaluated in vitro. The correlation between serum BALP activity and radiographic primary tumor size was evaluated in OSA-bearing dogs. In dogs developing visceral OSA metastases, serial changes in serum BALP activities were evaluated in relation to progression of macroscopic metastases, and visceral metastatic OSA cells were evaluated for BALP expression. In vitro, BALP expression was not associated with either tumorigenic or metastatic phenotype, rather the quantity of membranous BALP released was proportional with cell density. In dogs devoid of macroscopic metastases, there was a positive correlation between serum BALP activity and absolute primary tumor size. In dogs with progressive OSA metastases, serum BALP activity increased and coincided with the development of macroscopic metastases. OSA cells derived from visceral metastatic lesions retained BALP expression. Tumor burden is a determinant of serum BALP activity in dogs with appendicular OSA. The association between increased pretreatment BALP activity and negative clinical prognosis may simply be attributed to greater initial tumor burden, and consequently more advanced tumor stage. Copyright © 2013 by the American College of Veterinary Internal Medicine.

Is governance, gross domestic product, inequality, population size or country surface area associated with coverage and equity of health interventions? Ecological analyses of cross-sectional surveys from 80 countries.

PubMed

Wehrmeister, Fernando C; da Silva, Inácio Crochemore M; Barros, Aluisio J D; Victora, Cesar G

2017-01-01

To assess associations between national characteristics, including governance indicators, with a proxy for universal health coverage in reproductive, maternal, newborn and child health (RMNCH). Ecological analysis based on data from national standardised cross-sectional surveys. Low-income and middle-income countries with a Demographic and Health Survey or a Multiple Indicator Cluster Survey since 2005. 1 246 710 mothers and 2 129 212 children from 80 national surveys. Gross domestic product (GDP), country surface area, population, Gini index and six governance indicators (control of corruption, political stability and absence of violence, government effectiveness, regulatory quality, rule of law, and voice and accountability). Levels and inequality in the composite coverage index (CCI), a weighted average of eight RMNCH interventions. Relative and absolute inequalities were measured through the concentration index (CIX) and slope index of inequality (SII) for CCI, respectively. The average values of CCI (70.5% (SD=13.3)), CIX (5.3 (SD=5.1)) and mean slope index (19.8 (SD=14.7)) were calculated. In the unadjusted analysis, all governance variables and GDP were positively associated with the CCI and negatively with inequalities. Country surface showed inverse associations with both inequality indices. After adjustment, among the governance indicators, only political stability and absence of violence was directly related to CCI (β=6.3; 95% CI 3.6 to 9.1; p<0.001) and inversely associated with relative (CIX; β=-1.4; 95% CI -2.4 to -0.4; p=0.007) and absolute (SII; β=-5.3; 95% CI -8.9 to -1.7; p=0.005) inequalities. The strongest associations with governance indicators were found in the poorest wealth quintile. Similar patterns were observed for GDP. Country surface area was inversely related to inequalities on CCI. Levels and equity in RMNCH interventions are positively associated with political stability and absence of violence, and with GDP, and inversely associated with country surface area.

Spatial and Temporal Characteristics of the 2009 A/H1N1 Influenza Pandemic in Peru

PubMed Central

Chowell, Gerardo; Viboud, Cécile; Munayco, Cesar V.; Gómez, Jorge; Simonsen, Lone; Miller, Mark A.; Tamerius, James; Fiestas, Victor; Halsey, Eric S.; Laguna-Torres, Victor A.

2011-01-01

Background Highly refined surveillance data on the 2009 A/H1N1 influenza pandemic are crucial to quantify the spatial and temporal characteristics of the pandemic. There is little information about the spatial-temporal dynamics of pandemic influenza in South America. Here we provide a quantitative description of the age-specific morbidity pandemic patterns across administrative areas of Peru. Methods We used daily cases of influenza-like-illness, tests for A/H1N1 influenza virus infections, and laboratory-confirmed A/H1N1 influenza cases reported to the epidemiological surveillance system of Peru's Ministry of Health from May 1 to December 31, 2009. We analyzed the geographic spread of the pandemic waves and their association with the winter school vacation period, demographic factors, and absolute humidity. We also estimated the reproduction number and quantified the association between the winter school vacation period and the age distribution of cases. Results The national pandemic curve revealed a bimodal winter pandemic wave, with the first peak limited to school age children in the Lima metropolitan area, and the second peak more geographically widespread. The reproduction number was estimated at 1.6–2.2 for the Lima metropolitan area and 1.3–1.5 in the rest of Peru. We found a significant association between the timing of the school vacation period and changes in the age distribution of cases, while earlier pandemic onset was correlated with large population size. By contrast there was no association between pandemic dynamics and absolute humidity. Conclusions Our results indicate substantial spatial variation in pandemic patterns across Peru, with two pandemic waves of varying timing and impact by age and region. Moreover, the Peru data suggest a hierarchical transmission pattern of pandemic influenza A/H1N1 driven by large population centers. The higher reproduction number of the first pandemic wave could be explained by high contact rates among school-age children, the age group most affected during this early wave. PMID:21712984

Endovascular therapy for acute ischaemic stroke: the Pragmatic Ischaemic Stroke Thrombectomy Evaluation (PISTE) randomised, controlled trial

PubMed Central

Muir, Keith W; Ford, Gary A; Messow, Claudia-Martina; Ford, Ian; Murray, Alicia; Clifton, Andrew; Brown, Martin M; Madigan, Jeremy; Lenthall, Rob; Robertson, Fergus; Dixit, Anand; Cloud, Geoffrey C; Wardlaw, Joanna; Freeman, Janet; White, Philip

2017-01-01

Objective The Pragmatic Ischaemic Thrombectomy Evaluation (PISTE) trial was a multicentre, randomised, controlled clinical trial comparing intravenous thrombolysis (IVT) alone with IVT and adjunctive intra-arterial mechanical thrombectomy (MT) in patients who had acute ischaemic stroke with large artery occlusive anterior circulation stroke confirmed on CT angiography (CTA). Design Eligible patients had IVT started within 4.5 hours of stroke symptom onset. Those randomised to additional MT underwent thrombectomy using any Conformité Européene (CE)-marked device, with target interval times for IVT start to arterial puncture of <90 min. The primary outcome was the proportion of patients achieving independence defined by a modified Rankin Scale (mRS) score of 0–2 at day 90. Results Ten UK centres enrolled 65 patients between April 2013 and April 2015. Median National Institutes of Health Stroke Scale score was 16 (IQR 13–21). Median stroke onset to IVT start was 120 min. In the intention-to-treat analysis, there was no significant difference in disability-free survival at day 90 with MT (absolute difference 11%, adjusted OR 2.12, 95% CI 0.65 to 6.94, p=0.20). Secondary analyses showed significantly greater likelihood of full neurological recovery (mRS 0–1) at day 90 (OR 7.6, 95% CI 1.6 to 37.2, p=0.010). In the per-protocol population (n=58), the primary and most secondary clinical outcomes significantly favoured MT (absolute difference in mRS 0–2 of 22% and adjusted OR 4.9, 95% CI 1.2 to 19.7, p=0.021). Conclusions The trial did not find a significant difference between treatment groups for the primary end point. However, the effect size was consistent with published data and across primary and secondary end points. Proceeding as fast as possible to MT after CTA confirmation of large artery occlusion on a background of intravenous alteplase is safe, improves excellent clinical outcomes and, in the per-protocol population, improves disability-free survival. Trial registration number NCT01745692; Results. PMID:27756804

Is governance, gross domestic product, inequality, population size or country surface area associated with coverage and equity of health interventions? Ecological analyses of cross-sectional surveys from 80 countries

PubMed Central

Wehrmeister, Fernando C; da Silva, Inácio Crochemore M; Barros, Aluisio J D; Victora, Cesar G

2017-01-01

Objective To assess associations between national characteristics, including governance indicators, with a proxy for universal health coverage in reproductive, maternal, newborn and child health (RMNCH). Design Ecological analysis based on data from national standardised cross-sectional surveys. Setting Low-income and middle-income countries with a Demographic and Health Survey or a Multiple Indicator Cluster Survey since 2005. Participants 1 246 710 mothers and 2 129 212 children from 80 national surveys. Exposures of interest Gross domestic product (GDP), country surface area, population, Gini index and six governance indicators (control of corruption, political stability and absence of violence, government effectiveness, regulatory quality, rule of law, and voice and accountability). Main outcomes Levels and inequality in the composite coverage index (CCI), a weighted average of eight RMNCH interventions. Relative and absolute inequalities were measured through the concentration index (CIX) and slope index of inequality (SII) for CCI, respectively. Results The average values of CCI (70.5% (SD=13.3)), CIX (5.3 (SD=5.1)) and mean slope index (19.8 (SD=14.7)) were calculated. In the unadjusted analysis, all governance variables and GDP were positively associated with the CCI and negatively with inequalities. Country surface showed inverse associations with both inequality indices. After adjustment, among the governance indicators, only political stability and absence of violence was directly related to CCI (β=6.3; 95% CI 3.6 to 9.1; p<0.001) and inversely associated with relative (CIX; β=−1.4; 95% CI −2.4 to −0.4; p=0.007) and absolute (SII; β=−5.3; 95% CI –8.9 to −1.7; p=0.005) inequalities. The strongest associations with governance indicators were found in the poorest wealth quintile. Similar patterns were observed for GDP. Country surface area was inversely related to inequalities on CCI. Conclusions Levels and equity in RMNCH interventions are positively associated with political stability and absence of violence, and with GDP, and inversely associated with country surface area. PMID:29225951

Population growth enhances the mean fixation time of neutral mutations and the persistence of neutral variation.

PubMed

Waxman, D

2012-06-01

A fundamental result of population genetics states that a new mutation, at an unlinked neutral locus in a randomly mating diploid population, has a mean time of fixation of ∼4N(e) generations, where N(e) is the effective population size. This result is based on an assumption of fixed population size, which does not universally hold in natural populations. Here, we analyze such neutral fixations in populations of changing size within the framework of the diffusion approximation. General expressions are derived for the mean and variance of the fixation time in changing populations. Some explicit results are given for two cases: (i) the effective population size undergoes a sudden change, representing a sudden population expansion or a sudden bottleneck; (ii) the effective population changes linearly for a limited period of time and then remains constant. Additionally, a lower bound for the mean time of fixation is obtained for an effective population size that increases with time, and this is applied to exponentially growing populations. The results obtained in this work show, among other things, that for populations that increase in size, the mean time of fixation can be enhanced, sometimes substantially so, over 4N(e,0) generations, where N(e,0) is the effective population size at the time the mutation arises. Such an enhancement is associated with (i) an increased probability of neutral polymorphism in a population and (ii) an enhanced persistence of high-frequency neutral variation, which is the variation most likely to be observed.

Estimation of population size using open capture-recapture models

USGS Publications Warehouse

McDonald, T.L.; Amstrup, Steven C.

2001-01-01

One of the most important needs for wildlife managers is an accurate estimate of population size. Yet, for many species, including most marine species and large mammals, accurate and precise estimation of numbers is one of the most difficult of all research challenges. Open-population capture-recapture models have proven useful in many situations to estimate survival probabilities but typically have not been used to estimate population size. We show that open-population models can be used to estimate population size by developing a Horvitz-Thompson-type estimate of population size and an estimator of its variance. Our population size estimate keys on the probability of capture at each trap occasion and therefore is quite general and can be made a function of external covariates measured during the study. Here we define the estimator and investigate its bias, variance, and variance estimator via computer simulation. Computer simulations make extensive use of real data taken from a study of polar bears (Ursus maritimus) in the Beaufort Sea. The population size estimator is shown to be useful because it was negligibly biased in all situations studied. The variance estimator is shown to be useful in all situations, but caution is warranted in cases of extreme capture heterogeneity.

The role of serum non-cholesterol sterols as surrogate markers of absolute cholesterol synthesis and absorption.

PubMed

Miettinen, T A; Gylling, H; Nissinen, M J

2011-10-01

To study the whole-body cholesterol metabolism in man, cholesterol synthesis and absorption need to be measured. Because of the complicated methods of the measurements, new approaches were developed including the analysis of serum non-cholesterol sterols. In current lipidologic papers and even in intervention studies, serum non-cholesterol sterols are frequently used as surrogate markers of cholesterol metabolism without any validation to the absolute metabolic variables. The present review compares serum non-cholesterol sterols with absolute measurements of cholesterol synthesis and absorption in published papers to find out whether the serum markers are valid indicators of cholesterol metabolism in various conditions. During statin treatment, during interventions of dietary fat, and in type 2 diabetes the relative and absolute variables of cholesterol synthesis and absorption were frequently but not constantly correlated with each other. In some occasions, especially in subjects with apolipoprotein E3/4 and E4/4 phenotypes, the relative metabolic markers were even more sensitive than the absolute ones to reflect changes in cholesterol metabolism during dietary interventions. Even in general population at very high absorption the homeostasis of cholesterol metabolism is disturbed damaging the validity of the serum markers. It is worth using several instead of only one precursor and absorption sterol marker for making conclusions of altered synthesis or absorption of cholesterol, and even then the presence of at least some absolute measurement is valuable. During consumption of plant sterol-enriched diets and in situations of interfered cholesterol homeostasis the relative markers do not adequately reflect cholesterol metabolism. Accordingly, the validity of the relative markers of cholesterol metabolism should not be considered as self-evident. Copyright © 2011 Elsevier B.V. All rights reserved.

Absolute change in fasting plasma glucose over 12 months is associated with 2-year and 5-year major adverse cardiovascular events in patients with drug-eluting stent implants.

PubMed

Kang, Dong Oh; Seo, Hong Seog; Choi, Byung Geol; Lee, Eunmi; Kim, Ji Park; Lee, Sun Ki; Im, Sung Il; Na, Jin Oh; Choi, Cheol Ung; Lim, Hong Euy; Kim, Jin Won; Kim, Eung Ju; Rha, Seung-Woon; Park, Chang Gyu; Oh, Dong Joo

2015-01-20

Major adverse cardiovascular events (MACEs) in patients with or without cardiovascular disease (CVD) are greatly affected by various factors associated with metabolism and inflammation. To determine which clinical parameters at treatment are associated with the development of 2-year and 5-year MACEs in high-risk patients with CVD who have undergone drug-eluting stent (DES) implantation. The present study involved a total of 432 patients who underwent percutaneous coronary intervention with DES. Variables representing the average and absolute amount of change in clinical parameters over the 12-month follow-up were assessed for association with 2-year and 5-year development of MACE. The study population was divided into quartiles for the variable showing the highest correlation to MACE development. Estimated incidence of 2-year and 5-year MACEs for each of the quartiles was determined by survival curve analysis, and subgroup analysis was performed for patients with diabetes and statin users. Absolute change in fasting plasma glucose (FPG) over 12 months showed the highest correlation with 2-year and 5-year MACE development. The estimated incidence of MACE increased with increasing quartiles for absolute change in FPG. The association between absolute change in FPG and MACE development exhibited a stronger relationship for the specific subgroups of patients with diabetes and statin users. Increases and decreases in FPG had a comparable contribution to MACE development. A greater absolute change in FPG over 12 months post-PCI is an independent risk factor for 2-year and 5-year MACE development in DES-implanted patients, especially in the diabetes and statin users. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Repeated Habitat Disturbances by Fire Decrease Local Effective Population Size

PubMed Central

Ragsdale, Alexandria K.; McCoy, Earl D.; Mushinsky, Henry R.

2016-01-01

Effective population size is a fundamental parameter in population genetics, and factors that alter effective population size will shape the genetic characteristics of populations. Habitat disturbance may have a large effect on genetic characteristics of populations by influencing immigration and gene flow, particularly in fragmented habitats. We used the Florida Sand Skink (Plestiodon reynoldsi) to investigate the effect of fire-based habitat disturbances on the effective population size in the highly threatened, severely fragmented, and fire dependent Florida scrub habitat. We screened 7 microsatellite loci in 604 individuals collected from 12 locations at Archbold Biological Station. Archbold Biological Station has an active fire management plan and detailed records of fires dating to 1967. Our objective was to determine how the timing, number, and intervals between fires affect effective population size, focusing on multiple fires in the same location. Effective population size was higher in areas that had not been burned for more than 10 years and decreased with number of fires and shorter time between fires. A similar pattern was observed in abundance: increasing abundance with time-since-fire and decreasing abundance with number of fires. The ratio of effective population size to census size was higher at sites with more recent fires and tended to decrease with time-since-last-fire. These results suggest that habitat disturbances, such as fire, may have a large effect in the genetic characteristics of local populations and that Florida Sand Skinks are well adapted to the natural fire dynamics required to maintain Florida scrub. PMID:26976940

Veridical mapping in savant abilities, absolute pitch, and synesthesia: an autism case study

PubMed Central

Bouvet, Lucie; Donnadieu, Sophie; Valdois, Sylviane; Caron, Chantal; Dawson, Michelle; Mottron, Laurent

2014-01-01

An enhanced role and autonomy of perception are prominent in autism. Furthermore, savant abilities, absolute pitch, and synesthesia are all more commonly found in autistic individuals than in the typical population. The mechanism of veridical mapping has been proposed to account for how enhanced perception in autism leads to the high prevalence of these three phenomena and their structural similarity. Veridical mapping entails functional rededication of perceptual brain regions to higher order cognitive operations, allowing the enhanced detection and memorization of isomorphisms between perceptual and non-perceptual structures across multiple scales. In this paper, we present FC, an autistic individual who possesses several savant abilities in addition to both absolute pitch and synesthesia-like associations. The co-occurrence in FC of abilities, some of them rare, which share the same structure, as well as FC’s own accounts of their development, together suggest the importance of veridical mapping in the atypical range and nature of abilities displayed by autistic people. PMID:24600416

Mapping the absolute magnetic field and evaluating the quadratic Zeeman-effect-induced systematic error in an atom interferometer gravimeter

NASA Astrophysics Data System (ADS)

Hu, Qing-Qing; Freier, Christian; Leykauf, Bastian; Schkolnik, Vladimir; Yang, Jun; Krutzik, Markus; Peters, Achim

2017-09-01

Precisely evaluating the systematic error induced by the quadratic Zeeman effect is important for developing atom interferometer gravimeters aiming at an accuracy in the μ Gal regime (1 μ Gal =10-8m /s2 ≈10-9g ). This paper reports on the experimental investigation of Raman spectroscopy-based magnetic field measurements and the evaluation of the systematic error in the gravimetric atom interferometer (GAIN) due to quadratic Zeeman effect. We discuss Raman duration and frequency step-size-dependent magnetic field measurement uncertainty, present vector light shift and tensor light shift induced magnetic field measurement offset, and map the absolute magnetic field inside the interferometer chamber of GAIN with an uncertainty of 0.72 nT and a spatial resolution of 12.8 mm. We evaluate the quadratic Zeeman-effect-induced gravity measurement error in GAIN as 2.04 μ Gal . The methods shown in this paper are important for precisely mapping the absolute magnetic field in vacuum and reducing the quadratic Zeeman-effect-induced systematic error in Raman transition-based precision measurements, such as atomic interferometer gravimeters.

Early diagnosis of severe combined immunodeficiency (SCID) in Turkey: a pilot study.

PubMed

Can, Ceren; Hamilçıkan, Şahin; Can, Emrah

2017-08-29

Severe combined immunodeficiency (SCID) is a neonatal emergency. As the T-cell receptor excision circles (TREC) test is not cost effective for neonatal screening of SCID in developing countries, this pilot study's objective aimed at identifying preliminary data to enable SCID identification in the general population. This observational study was performed in Bagcılar Training and Research Hospital, Istanbul, Turkey. Cord-blood complete blood count (CBC) was recorded in all neonates included in the study. Absolute lymphopenia was considered in cord-blood samples if the absolute lymphocyte count was less than 2500/mm 3 . A control blood count was performed 1-month later for cases with detected lymphopenia. A total of 2945 term neonates were included in the study. Absolute lymphopenia was found in nine (0.3%) neonates, while 2936 (99.7%) had an absolute lymphocytic count above 2.5 × 10 3 /mm 3 . The mean counts of red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), platelets (PLT), and monocytes in the lymphopenia group were not found to significantly differ from the non-lymphopenia group. However, there were significantly lower mean white blood cell (WBC), lymphocyte, and neutrophil counts between the groups (p < .05). Absolute lymphopenia detected using CBC analysis is a simple, easier, more non-invasive, and cheaper method than the TREC method for detection of SCID neonates, and this method may prove to be a useful alternative, especially in developing countries.

An Observational Upper Limit on the Interstellar Number Density of Asteroids and Comets

NASA Astrophysics Data System (ADS)

Engelhardt, Toni; Jedicke, Robert; Vereš, Peter; Fitzsimmons, Alan; Denneau, Larry; Beshore, Ed; Meinke, Bonnie

2017-03-01

We derived 90% confidence limits (CLs) on the interstellar number density ({ρ }{IS}{CL}) of interstellar objects (ISOs; comets and asteroids) as a function of the slope of their size-frequency distribution (SFD) and limiting absolute magnitude. To account for gravitational focusing, we first generated a quasi-realistic ISO population to ˜ 750 {au} from the Sun and propagated it forward in time to generate a steady state population of ISOs with heliocentric distance < 50 {au}. We then simulated the detection of the synthetic ISOs using pointing data for each image and average detection efficiencies for each of three contemporary solar system surveys—Pan-STARRS1, the Mt. Lemmon Survey, and the Catalina Sky Survey. These simulations allowed us to determine the surveys’ combined ISO detection efficiency under several different but realistic modes of identifying ISOs in the survey data. Some of the synthetic detected ISOs had eccentricities as small as 1.01, which is in the range of the largest eccentricities of several known comets. Our best CL of {ρ }{IS}{CL}=1.4× {10}-4 {{au}}-3 implies that the expectation that extra-solar systems form like our solar system, eject planetesimals in the same way, and then distribute them throughout the Galaxy, is too simplistic, or that the SFD or behavior of ISOs as they pass through our solar system is far from expectation.

Abundance ratios in dwarf elliptical galaxies

NASA Astrophysics Data System (ADS)

Şen, Ş.; Peletier, R. F.; Boselli, A.; den Brok, M.; Falcón-Barroso, J.; Hensler, G.; Janz, J.; Laurikainen, E.; Lisker, T.; Mentz, J. J.; Paudel, S.; Salo, H.; Sybilska, A.; Toloba, E.; van de Ven, G.; Vazdekis, A.; Yesilyaprak, C.

2018-04-01

We determine abundance ratios of 37 dwarf ellipticals (dEs) in the nearby Virgo cluster. This sample is representative of the early-type population of galaxies in the absolute magnitude range -19.0 < Mr < -16.0. We analyse their absorption line-strength indices by means of index-index diagrams and scaling relations and use the stellar population models to interpret them. We present ages, metallicities, and abundance ratios obtained from these dEs within an aperture size of Re/8. We calculate [Na/Fe] from NaD, [Ca/Fe] from Ca4227, and [Mg/Fe] from Mgb. We find that [Na/Fe] is underabundant with respect to solar, whereas [Mg/Fe] is around solar. This is exactly opposite to what is found for giant ellipticals, but follows the trend with metallicity found previously for the Fornax dwarf NGC 1396. We discuss possible formation scenarios that can result in such elemental abundance patterns, and we speculate that dEs have disc-like star formation history (SFH) favouring them to originate from late-type dwarfs or small spirals. Na-yields appear to be very metal-dependent, in agreement with studies of giant ellipticals, probably due to the large dependence on the neutron-excess in stars. We conclude that dEs have undergone a considerable amount of chemical evolution, they are therefore not uniformly old, but have extended SFH, similar to many of the Local Group galaxies.

[Congenital bladder diverticula and vesicoureteral reflux].

PubMed

Garat, José María; Angerri, Oriol; Caffaratti, Jorge; Moscatiello, Pietro

2008-03-01

To analyze our series of primary congenital diverticula (PCD) and their association with vesicoureteral reflux. We have taken care of 23 children with PCD. Eleven of them had big diverticula (> 2 cm) and twelve small. In the first group, 4 children had vesicoureteral reflux and 5 in the second group. In group A, ureteral reimplantation was performed at the time of diverticulum excision. Nor diverticula neither refluxes were operated in group B. We analyze separately results in both groups. Group A: Patients were operated including diverticulum excision. There were not recurrences except in one case with Ehler-Danlos Syndrome. No reimplanted ureter showed postoperative reflux. Nevertheless, one case with multiple bladder diverticula without reflux presented reflux after the excision of several diverticula without reimplantation. Group B: Small diverticula did not undergo surgery Spontaneous outcome of reflux was similar to that of the general population without diverticula. Bladder diverticula are frequently associated with vesicoureteral reflux. The presence of reflux is not an absolute condition for surgical or endoscopic treatment. When diverticula are big in size (Group A) the indication for surgery comes from recurrent infection or voiding disorders, not from reflux. If they undergo surgery, ureteral reimplantation is performed in the case they had reflux or for technical reasons like bladder wall weakness. When diverticula are small (Group B) the presence of reflux does not condition treatment, being the rate of spontaneous resolution similar to the general population.

The Influence of Solid Rocket Motor Retro-Burns on the Space Debris Environment

NASA Astrophysics Data System (ADS)

Stabroth, S.; Homeister, M.; Oswald, M.; Wiedemann, C.; Klinkrad, H.; Vörsmann, P.

The ESA space debris population model MASTER Meteoroid and Space Debris Terrestrial Environment Reference considers firings of solid rocket motors SRM as a debris source with the associated generation of slag and dust particles The resulting slag and dust population is a major contribution to the sub-millimetre size debris environment in Earth orbit The current model version MASTER-2005 is based on the simulation of 1 076 orbital SRM firings which contributed to the long-term debris environment A comparison of the modelled flux with impact data from returned surfaces shows that the shape and quantity of the modelled SRM dust distribution matches that of recent Hubble Space Telescope HST solar array measurements very well However the absolute flux level for dust is under-predicted for some of the analysed Long Duration Exposure Facility LDEF surfaces This points into the direction of some past SRM firings not included in the current event database The most suitable candidates for these firings are the large number of SRM retro-burns of return capsules Objects released by those firings have highly eccentric orbits with perigees in the lower regions of the atmosphere Thus they produce no long-term effect on the debris environment However a large number of those firings during the on-orbit time frame of LDEF might lead to an increase of the dust population for some of the LDEF surfaces In this paper the influence of SRM retro-burns on the short- and long-term debris environment is analysed The existing firing database is updated with gathered

mtDNA variation predicts population size in humans and reveals a major Southern Asian chapter in human prehistory.

PubMed

Atkinson, Quentin D; Gray, Russell D; Drummond, Alexei J

2008-02-01

The relative timing and size of regional human population growth following our expansion from Africa remain unknown. Human mitochondrial DNA (mtDNA) diversity carries a legacy of our population history. Given a set of sequences, we can use coalescent theory to estimate past population size through time and draw inferences about human population history. However, recent work has challenged the validity of using mtDNA diversity to infer species population sizes. Here we use Bayesian coalescent inference methods, together with a global data set of 357 human mtDNA coding-region sequences, to infer human population sizes through time across 8 major geographic regions. Our estimates of relative population sizes show remarkable concordance with the contemporary regional distribution of humans across Africa, Eurasia, and the Americas, indicating that mtDNA diversity is a good predictor of population size in humans. Plots of population size through time show slow growth in sub-Saharan Africa beginning 143-193 kya, followed by a rapid expansion into Eurasia after the emergence of the first non-African mtDNA lineages 50-70 kya. Outside Africa, the earliest and fastest growth is inferred in Southern Asia approximately 52 kya, followed by a succession of growth phases in Northern and Central Asia (approximately 49 kya), Australia (approximately 48 kya), Europe (approximately 42 kya), the Middle East and North Africa (approximately 40 kya), New Guinea (approximately 39 kya), the Americas (approximately 18 kya), and a second expansion in Europe (approximately 10-15 kya). Comparisons of relative regional population sizes through time suggest that between approximately 45 and 20 kya most of humanity lived in Southern Asia. These findings not only support the use of mtDNA data for estimating human population size but also provide a unique picture of human prehistory and demonstrate the importance of Southern Asia to our recent evolutionary past.

Influence of Population Density on Offspring Number and Size in Burying Beetles

ERIC Educational Resources Information Center

Rauter, Claudia M.

2010-01-01

This laboratory exercise investigates the influence of population density on offspring number and size in burying beetles. Students test the theoretical predictions that brood size declines and offspring size increases when competition over resources becomes stronger with increasing population density. Students design the experiment, collect and…

Development and psychometric evaluation of the breast size satisfaction scale.

PubMed

Pahlevan Sharif, Saeed

2017-10-09

Purpose The purpose of this paper is to develop and evaluate psychometrically an instrument named the Breast Size Satisfaction Scale (BSSS) to assess breast size satisfaction. Design/methodology/approach The present scale was developed using a set of 16 computer-generated 3D images of breasts to overcome some of the limitations of existing instruments. The images were presented to participants and they were asked to select the figure that most accurately depicted their actual breast size and the figure that most closely represented their ideal breast size. Breast size satisfaction was computed by subtracting the absolute value of the difference between ideal and actual perceived size from 16, such that higher values indicate greater breast size satisfaction. Findings Study 1 ( n=65 female undergraduate students) showed good test-retest reliability and study 2 ( n=1,000 Iranian women, aged 18 years and above) provided support for convergent validity using a nomological network approach. Originality/value The BSSS demonstrated good psychometric properties and thus can be used in future studies to assess breast size satisfaction among women.

Reconstruction of Sensory Stimuli Encoded with Integrate-and-Fire Neurons with Random Thresholds

PubMed Central

Lazar, Aurel A.; Pnevmatikakis, Eftychios A.

2013-01-01

We present a general approach to the reconstruction of sensory stimuli encoded with leaky integrate-and-fire neurons with random thresholds. The stimuli are modeled as elements of a Reproducing Kernel Hilbert Space. The reconstruction is based on finding a stimulus that minimizes a regularized quadratic optimality criterion. We discuss in detail the reconstruction of sensory stimuli modeled as absolutely continuous functions as well as stimuli with absolutely continuous first-order derivatives. Reconstruction results are presented for stimuli encoded with single as well as a population of neurons. Examples are given that demonstrate the performance of the reconstruction algorithms as a function of threshold variability. PMID:24077610

Anomalous gain in an isotopically mixed CO2 laser and application to absolute wavelength calibration

NASA Technical Reports Server (NTRS)

Hewagama, Tilak; Oppenheim, Uri P.; Mumma, Michael J.

1991-01-01

Measurements are reported on a grating-tuned CO2 laser, containing an isotropic mixture of O-16C-12O-16, O-16C-12O-18, and O-18C-12O-18. The P6 and R14 lines of O-16C-12O-16 were found to have anomalously high intensities. These anomalies are produced by the near coincidence of the transition frequencies in two distinct isotopes, permitting them to act as a single indistinguishable population. These two lines can be used to identify the rotational quantum numbers in the P and R branch spectra, thereby permitting absolute wavelength calibration to be achieved.

A Precision Determination of the Effect of Metallicity on Cepheid Absolute Magnitudes in VIJHK Bands from Magellanic Cloud Cepheids

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

Wielgórski, Piotr; Pietrzyński, Grzegorz; Zgirski, Bartłomiej

Using high-quality observed period–luminosity ( P – L ) relations in both Magellanic Clouds in the VIJHK s bands and optical and near-infrared Wesenheit indices, we determine the effect of metallicity on Cepheid P – L relations by comparing the relative distance between the LMC and SMC as determined from the Cepheids to the difference in distance between the Clouds that has been derived with very high accuracy from late-type eclipsing binary systems. Within an uncertainty of 3%, which is dominated by the uncertainty on the mean difference in metallicity between the Cepheid populations in the LMC and SMC, wemore » find metallicity effects smaller than 2% in all bands and in the Wesenheit indices, consistent with a zero metallicity effect. This result is valid for the metallicity range from −0.35 dex to −0.75 dex corresponding to the mean [Fe/H] values for classical Cepheids in the LMC and SMC, respectively. Yet most Cepheids in galaxies beyond the Local Group and located in the less crowded outer regions of these galaxies do fall into this metallicity regime, making our result important for applications to determine the distances to spiral galaxies well beyond the Local Group. Our result supports previous findings that indicated a very small metallicity effect on the near-infrared absolute magnitudes of classical Cepheids, and resolves the dispute about the size and sign of the metallicity effect in the optical spectral range. It also resolves one of the most pressing problems in the quest toward a measurement of the Hubble constant with an accuracy of 1% from the Cepheid–supernova Ia method.« less

Fusobacterium nucleatum as a prognostic marker of colorectal cancer in a Japanese population.

PubMed

Yamaoka, Yuko; Suehiro, Yutaka; Hashimoto, Shinichi; Hoshida, Tomomi; Fujimoto, Michiyo; Watanabe, Michiya; Imanaga, Daiki; Sakai, Kouhei; Matsumoto, Toshihiko; Nishioka, Mitsuaki; Takami, Taro; Suzuki, Nobuaki; Hazama, Shoichi; Nagano, Hiroaki; Sakaida, Isao; Yamasaki, Takahiro

2018-04-01

Accumulating evidence shows an overabundance of Fusobacterium nucleatum in colorectal tumor tissues. However, the correlation between the absolute copy number of F. nucleatum in colorectal cancer tissues and colorectal cancer progression is unclear from previous reports. Therefore, we performed a study to compare the abundance of F. nucleatum in colorectal tissues with clinicopathologic and molecular features of colorectal cancer. We collected 100 colorectal cancer tissues and 72 matched normal-appearing mucosal tissues. Absolute copy numbers of F. nucleatum were measured by droplet digital PCR. The detection rates of F. nucleatum were 63.9% (46/72) in normal-appearing mucosal tissues and 75.0% (75/100) in CRC tissue samples. The median copy number of F. nucleatum was 0.4/ng DNA in the normal-appearing colorectal mucosa in patients with colorectal cancer and 1.9/ng DNA in the colorectal cancer tissues (P = 0.0031). F. nucleatum copy numbers in stage IV colorectal cancer tissues were significantly higher than those in the normal-appearing mucosa in patients with colorectal cancer (P = 0.0016). The abundance of F. nucleatum in colorectal cancer tissues correlated with tumor size and KRAS mutation and was significantly associated with shorter overall survival times; this trend was notable in the patients with stage IV colorectal cancer. Focusing on normal-appearing mucosa in the patients with colorectal cancer, the F. nucleatum copy number was significantly higher in the patients with stage IV rather than stages I-III. These results suggest that determining F. nucleatum levels may help predict clinical outcomes in colorectal cancer patients. Further confirmatory studies using independent datasets are required to confirm our findings.

Comparison of glomerular filtration rate determined by use of single-slice dynamic computed tomography and scintigraphy in cats.

PubMed

Schmidt, David M; Scrivani, Peter V; Dykes, Nathan L; Goldstein, Richard M; Erb, Hollis N; Reeves, Anthony P

2012-04-01

To compare estimation of glomerular filtration rate determined via conventional methods (ie, scintigraphy and plasma clearance of technetium Tc 99m pentetate) and dynamic single-slice computed tomography (CT). 8 healthy adult cats. Scintigraphy, plasma clearance testing, and dynamic CT were performed on each cat on the same day; order of examinations was randomized. Separate observers performed GFR calculations for scintigraphy, plasma clearance testing, or dynamic CT. Methods were compared via Bland-Altman plots and considered interchangeable and acceptable when the 95% limits of agreement (mean difference between methods ± 1.96 SD of the differences) were ≤ 0.7 mL/min/kg. Global GFR differed < 0.7 mL/min/kg in 5 of 8 cats when comparing plasma clearance testing and dynamic CT; the limits of agreement were 1.4 and -1.7 mL/min/kg. The mean ± SD difference was -0.2 ± 0.8 mL/min/kg, and the maximum difference was 1.6 mL/min/kg. The mean ± SD difference (absolute value) for percentage filtration by individual kidneys was 2.4 ± 10.5% when comparing scintigraphy and dynamic CT; the maximum difference was 20%, and the limits of agreement were 18% and 23% (absolute value). GFR estimation via dynamic CT exceeded the definition for acceptable clinical use, compared with results for conventional methods, which was likely attributable to sample size and preventable technical complications. Because 5 of 8 cats had comparable values between methods, further investigation of dynamic CT in a larger sample population with a wide range of GFR values should be performed.

Plasticity in hydraulic architecture of Scots pine across Eurasia.

PubMed

Poyatos, R; Martínez-Vilalta, J; Cermák, J; Ceulemans, R; Granier, A; Irvine, J; Köstner, B; Lagergren, F; Meiresonne, L; Nadezhdina, N; Zimmermann, R; Llorens, P; Mencuccini, M

2007-08-01

Widespread tree species must show physiological and structural plasticity to deal with contrasting water balance conditions. To investigate these plasticity mechanisms, a meta-analysis of Pinus sylvestris L. sap flow and its response to environmental variables was conducted using datasets from across its whole geographical range. For each site, a Jarvis-type, multiplicative model was used to fit the relationship between sap flow and photosynthetically active radiation, vapour pressure deficit (D) and soil moisture deficit (SMD); and a logarithmic function was used to characterize the response of stomatal conductance (G(s)) to D. The fitted parameters of those models were regressed against climatic variables to study the acclimation of Scots pine to dry/warm conditions. The absolute value of sap flow and its sensitivity to D and SMD increased with the average summer evaporative demand. However, relative sensitivity of G(s) to D (m/G (s,ref), where m is the slope and G(s,ref) is reference G(s) at D = 1 kPa) did not increase with evaporative demand across populations, and transpiration per unit leaf area at a given D increased accordingly in drier/warmer climates. This physiological plasticity was linked to the previously reported climate- and size-related structural acclimation of leaf to sapwood area ratios. G (s,ref), and its absolute sensitivity to D(m), tended to decrease with age/height of the trees as previously reported for other pine species. It is unclear why Scots pines have higher transpiration rates at drier/warmer sites, at the expense of lower water-use efficiency. In any case, our results suggest that these structural adjustments may not be enough to prevent lower xylem tensions at the driest sites.

Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate.

PubMed

Sarangi, Manaswini; Nagarajan, Archana; Dey, Snigdhadip; Bose, Joy; Joshi, Amitabh

2016-09-01

Multiple experimental evolution studies on Drosophila melanogaster in the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies.We recently showed that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through a combination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very different suite of traits than that seen to evolve under similar selection in D. melanogaster and was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates of greater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term laboratory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we show that long-term laboratory populations of D. melanogaster, descended from some of the populations used in the earlier studies, evolve essentially the same set of traits as the D. ananassae and D. n. nasuta crowding-adapted populations when subjected to a similar larval density at low absolute volumes of food. As in the case of D. ananassae and D. n. nasuta, and in stark contrast to earlier studies with D. melanogaster, these crowding-adapted populations of D. melanogaster did not evolve greater larval feeding rates as a correlate of increased competitive ability. The present results clearly suggest that the suite of phenotypes through which the evolution of greater competitive ability is achieved in fruitflies depends critically not just on larval density per unit volume of food, but also on the total amount of food available in the culture vials. We discuss these results in the context of an hypothesis about how larval density and the height of the food column in culture vials might interact to alter the fitness costs and benefits of increased larval feeding rates, thus resulting in different routes to the evolution of greater competitive ability, depending on the details of exactly how the larval crowding was implemented.

Andean Condor (Vultur gryphus) in Ecuador: Geographic Distribution, Population Size and Extinction Risk.

PubMed

Naveda-Rodríguez, Adrián; Vargas, Félix Hernán; Kohn, Sebastián; Zapata-Ríos, Galo

2016-01-01

The Andean Condor (Vultur gryphus) in Ecuador is classified as Critically Endangered. Before 2015, standardized and systematic estimates of geographic distribution, population size and structure were not available for this species, hampering the assessment of its current status and hindering the design and implementation of effective conservation actions. In this study, we performed the first quantitative assessment of geographic distribution, population size and population viability of Andean Condor in Ecuador. We used a methodological approach that included an ecological niche model to study geographic distribution, a simultaneous survey of 70 roosting sites to estimate population size and a population viability analysis (PVA) for the next 100 years. Geographic distribution in the form of extent of occurrence was 49 725 km2. During a two-day census, 93 Andean Condors were recorded and a population of 94 to 102 individuals was estimated. In this population, adult-to-immature ratio was 1:0.5. In the modeled PVA scenarios, the probability of extinction, mean time to extinction and minimum population size varied from zero to 100%, 63 years and 193 individuals, respectively. Habitat loss is the greatest threat to the conservation of Andean Condor populations in Ecuador. Population size reduction in scenarios that included habitat loss began within the first 15 years of this threat. Population reinforcement had no effects on the recovery of Andean Condor populations given the current status of the species in Ecuador. The population size estimate presented in this study is the lower than those reported previously in other countries where the species occur. The inferences derived from the population viability analysis have implications for Condor management in Ecuador. This study highlights the need to redirect efforts from captive breeding and population reinforcement to habitat conservation.

Andean Condor (Vultur gryphus) in Ecuador: Geographic Distribution, Population Size and Extinction Risk

PubMed Central

Naveda-Rodríguez, Adrián; Vargas, Félix Hernán; Kohn, Sebastián; Zapata-Ríos, Galo

2016-01-01

The Andean Condor (Vultur gryphus) in Ecuador is classified as Critically Endangered. Before 2015, standardized and systematic estimates of geographic distribution, population size and structure were not available for this species, hampering the assessment of its current status and hindering the design and implementation of effective conservation actions. In this study, we performed the first quantitative assessment of geographic distribution, population size and population viability of Andean Condor in Ecuador. We used a methodological approach that included an ecological niche model to study geographic distribution, a simultaneous survey of 70 roosting sites to estimate population size and a population viability analysis (PVA) for the next 100 years. Geographic distribution in the form of extent of occurrence was 49 725 km2. During a two-day census, 93 Andean Condors were recorded and a population of 94 to 102 individuals was estimated. In this population, adult-to-immature ratio was 1:0.5. In the modeled PVA scenarios, the probability of extinction, mean time to extinction and minimum population size varied from zero to 100%, 63 years and 193 individuals, respectively. Habitat loss is the greatest threat to the conservation of Andean Condor populations in Ecuador. Population size reduction in scenarios that included habitat loss began within the first 15 years of this threat. Population reinforcement had no effects on the recovery of Andean Condor populations given the current status of the species in Ecuador. The population size estimate presented in this study is the lower than those reported previously in other countries where the species occur. The inferences derived from the population viability analysis have implications for Condor management in Ecuador. This study highlights the need to redirect efforts from captive breeding and population reinforcement to habitat conservation. PMID:26986004

The evolutionary legacy of size-selective harvesting extends from genes to populations

PubMed Central

Uusi-Heikkilä, Silva; Whiteley, Andrew R; Kuparinen, Anna; Matsumura, Shuichi; Venturelli, Paul A; Wolter, Christian; Slate, Jon; Primmer, Craig R; Meinelt, Thomas; Killen, Shaun S; Bierbach, David; Polverino, Giovanni; Ludwig, Arne; Arlinghaus, Robert

2015-01-01

Size-selective harvesting is assumed to alter life histories of exploited fish populations, thereby negatively affecting population productivity, recovery, and yield. However, demonstrating that fisheries-induced phenotypic changes in the wild are at least partly genetically determined has proved notoriously difficult. Moreover, the population-level consequences of fisheries-induced evolution are still being controversially discussed. Using an experimental approach, we found that five generations of size-selective harvesting altered the life histories and behavior, but not the metabolic rate, of wild-origin zebrafish (Danio rerio). Fish adapted to high positively size selective fishing pressure invested more in reproduction, reached a smaller adult body size, and were less explorative and bold. Phenotypic changes seemed subtle but were accompanied by genetic changes in functional loci. Thus, our results provided unambiguous evidence for rapid, harvest-induced phenotypic and evolutionary change when harvesting is intensive and size selective. According to a life-history model, the observed life-history changes elevated population growth rate in harvested conditions, but slowed population recovery under a simulated moratorium. Hence, the evolutionary legacy of size-selective harvesting includes populations that are productive under exploited conditions, but selectively disadvantaged to cope with natural selection pressures that often favor large body size. PMID:26136825

Spatial variation in egg size of a top predator: Interplay of body size and environmental factors?

NASA Astrophysics Data System (ADS)

Louzao, Maite; Igual, José M.; Genovart, Meritxell; Forero, Manuela G.; Hobson, Keith A.; Oro, Daniel

2008-09-01

It is expected that nearby populations are constrained by the same ecological features shaping in turn similarity in their ecological traits. Here, we studied the spatio-temporal variability in egg size among local populations of the critically endangered Balearic shearwater Puffinus mauretanicus, a top marine predator endemic to the western Mediterranean region. Specifically we assessed whether this trait was influenced by maternal body size, as an indicator of a genetic component, and feeding ecology (through stable-carbon and nitrogen-isotope measurements), as an indicator of environmental factors. We found that egg size varied among local populations, an unexpected result at such a small spatial scale. Body size differences at the local population level only partially explained such differences. Blood isotope measurements also differed among local populations. Values of δ 15N suggested inter-population differences in trophic level, showing a similar general pattern with egg size, and suggesting a nutritional link between them whereby egg size was affected by differences in feeding resources and/or behaviour. Values of δ 13C suggested that local populations did not differ in foraging habits with respect to benthic- vs. pelagic-based food-webs. Egg size did not vary among years as did breeding performance, suggesting that a differential temporal window could affect both breeding parameters in relation to food availability. The absence of a relationship between breeding performance and egg size suggested that larger eggs might only confer an advantage during harsh conditions. Alternatively parental quality could greatly affect breeding performance. We showed that inter-population differences in egg size could be influenced by both body size and environmental factors.

A projection of lesser prairie chicken (Tympanuchus pallidicinctus) populations range-wide

USGS Publications Warehouse

Cummings, Jonathan W.; Converse, Sarah J.; Moore, Clinton T.; Smith, David R.; Nichols, Clay T.; Allan, Nathan L.; O'Meilia, Chris M.

2017-08-09

We built a population viability analysis (PVA) model to predict future population status of the lesser prairie-chicken (Tympanuchus pallidicinctus, LEPC) in four ecoregions across the species’ range. The model results will be used in the U.S. Fish and Wildlife Service's (FWS) Species Status Assessment (SSA) for the LEPC. Our stochastic projection model combined demographic rate estimates from previously published literature with demographic rate estimates that integrate the influence of climate conditions. This LEPC PVA projects declining populations with estimated population growth rates well below 1 in each ecoregion regardless of habitat or climate change. These results are consistent with estimates of LEPC population growth rates derived from other demographic process models. Although the absolute magnitude of the decline is unlikely to be as low as modeling tools indicate, several different lines of evidence suggest LEPC populations are declining.

Repeated Habitat Disturbances by Fire Decrease Local Effective Population Size.

PubMed

Schrey, Aaron W; Ragsdale, Alexandria K; McCoy, Earl D; Mushinsky, Henry R

2016-07-01

Effective population size is a fundamental parameter in population genetics, and factors that alter effective population size will shape the genetic characteristics of populations. Habitat disturbance may have a large effect on genetic characteristics of populations by influencing immigration and gene flow, particularly in fragmented habitats. We used the Florida Sand Skink (Plestiodon reynoldsi) to investigate the effect of fire-based habitat disturbances on the effective population size in the highly threatened, severely fragmented, and fire dependent Florida scrub habitat. We screened 7 microsatellite loci in 604 individuals collected from 12 locations at Archbold Biological Station. Archbold Biological Station has an active fire management plan and detailed records of fires dating to 1967. Our objective was to determine how the timing, number, and intervals between fires affect effective population size, focusing on multiple fires in the same location. Effective population size was higher in areas that had not been burned for more than 10 years and decreased with number of fires and shorter time between fires. A similar pattern was observed in abundance: increasing abundance with time-since-fire and decreasing abundance with number of fires. The ratio of effective population size to census size was higher at sites with more recent fires and tended to decrease with time-since-last-fire. These results suggest that habitat disturbances, such as fire, may have a large effect in the genetic characteristics of local populations and that Florida Sand Skinks are well adapted to the natural fire dynamics required to maintain Florida scrub. © The American Genetic Association. 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Fitness and Activity Assessments among U.S. Army Populations: Implications for NCHS General Population Surveys,

DTIC Science & Technology

1986-01-01

and in some cases -body fat ), are measured twice yearly in the U.S. Army through age 60. Field measures are defined as those conducted by army units...weight and fat standards were originally part of the fitness program and fitness regulations. Because of a considerable increase in emphasis in this...service. Absolute b max is 4/0% less in women but only15% less when adjusted for difference in fat free weight. The relatively small overlap between

The role of immigration in Canada's demographic outlook.

PubMed

Passaris, C

1998-01-01

"Canada's contemporary demographic profile has been profoundly influenced by the end of the baby boom, decline in the fertility rate, ageing of the population and prospects for an absolute decline in population shortly after the turn of the century. These demographic characteristics necessitate an enhanced role for immigration and the need for a more proactive immigration policy in order to correct and fine-tune demographic trends and to come to grips with the social and economic challenges and opportunities of the next few decades." (EXCERPT)

Population size dependency of measles epidemic that was scalable from Japanese prefectures to European countries.

PubMed

Yoshikura, Hiroshi

2018-04-27

Relation between number of measles patients (y) and population size (x) was expressed by an equation y = ax s , where a is a constant and s the slope of the plot; s was 2.04-2.17 for prefectures in Japan, i.e., the number of patients was proportional to square of the prefecture population size. For European countries that joined European Union no later than 2009, the slope was 1.43-1.87. The measles' population dependency found among prefectures in Japan was thus scalable up to European countries. It was surprising because, unlike Japan, population density in EU countries was not uniform and not proportional to the population size. The population size dependency was not observed among Western Pacific and South-East Asian countries probably on account of confounding interacting socioeconomic factors. Correlation between measles incidence and birth rate, infant mortality or GDP per capita was almost insignificant.Size distribution of local infection clusters (LICs) of measles and rubella in Japan followed power law. For measles, though the population dependency remained unchanged after "elimination", there was change in the Zipf-type plot of LIC sizes. After the "elimination", LICs linked to importation-related outbreaks in less populated prefectures emerged as the top-ranked LICs.

Independent coding of absolute duration and distance magnitudes in the prefrontal cortex

PubMed Central

Marcos, Encarni; Tsujimoto, Satoshi

2016-01-01

The estimation of space and time can interfere with each other, and neuroimaging studies have shown overlapping activation in the parietal and prefrontal cortical areas. We used duration and distance discrimination tasks to determine whether space and time share resources in prefrontal cortex (PF) neurons. Monkeys were required to report which of two stimuli, a red circle or blue square, presented sequentially, were longer and farther, respectively, in the duration and distance tasks. In a previous study, we showed that relative duration and distance are coded by different populations of neurons and that the only common representation is related to goal coding. Here, we examined the coding of absolute duration and distance. Our results support a model of independent coding of absolute duration and distance metrics by demonstrating that not only relative magnitude but also absolute magnitude are independently coded in the PF. NEW & NOTEWORTHY Human behavioral studies have shown that spatial and duration judgments can interfere with each other. We investigated the neural representation of such magnitudes in the prefrontal cortex. We found that the two magnitudes are independently coded by prefrontal neurons. We suggest that the interference among magnitude judgments might depend on the goal rather than the perceptual resource sharing. PMID:27760814

Using Israel's National Cancer Registry Database to Track Progress in the War against Cancer: A Challenge for Health Services.

PubMed

Robinson, Eliezer; Silverman, Barbara G; Keinan-Boker, Lital

2017-04-01

The number of cancer survivors has been increasing worldwide and is now approximately 32.6 million and growing. Cancer survivors present a challenge to health care providers because of their higher susceptibility to long-term health outcomes related to their primary disease and treatment. To report on the number of cancer survivors and incident cancer cases in the period 1960-2009 in Israel, in order to provide data on the scope of the challenge Israel's health care funds face. The Israel National Cancer Registry (INCR) database was used to identify new cancer cases diagnosed during the period 1960-2009. Lifetable analysis was used to assess changes in cumulative survival and population prevalence of cancer survivors throughout the 50 year study period. Almost 600,000 invasive cancer cases were diagnosed during the period 1960-2009 (overall absolute survival rate 54%). Within this time period, the number of new patients diagnosed with cancer increased fivefold and that of cancer survivors ninefold. The absolute survival of cancer patients and the prevalence of cancer survivors in the general population significantly increased with time from 34% and 0.5%, respectively (1960-1969), to 62% and 1.9%, respectively (2000-2009). Cumulative absolute survival for 5, 10 and 15 years following diagnosis increased with time as well. The INCR database is useful to assess progress in the war against cancer. The growing numbers of cancer survivors in Israel present a challenge to the national health and social services system.

Socioeconomic inequalities in cause specific mortality among older people in France.

PubMed

Menvielle, Gwenn; Leclerc, Annette; Chastang, Jean-François; Luce, Danièle

2010-05-19

European comparative studies documented a clear North-South divide in socioeconomic inequalities with cancer being the most important contributor to inequalities in total mortality among middle aged men in Latin Europe (France, Spain, Portugal, Italy). The aim of this paper is to investigate educational inequalities in mortality by gender, age and causes of death in France, with a special emphasis on people aged 75 years and more. We used data from a longitudinal population sample that includes 1% of the French population. Risk of death (total and cause specific) in the period 1990-1999 according to education was analysed using Cox regression models by age group (45-59, 60-74, and 75+). Inequalities were quantified using both relative (ratio) and absolute (difference) measures. Relative inequalities decreased with age but were still observed in the oldest age group. Absolute inequalities increased with age. This increase was particularly pronounced for cardiovascular diseases. The contribution of different causes of death to absolute inequalities in total mortality differed between age groups. In particular, the contribution of cancer deaths decreased substantially between the age groups 60-74 years and 75 years and more, both in men and in women. This study suggests that the large contribution of cancer deaths to the excess mortality among low educated people that was observed among middle aged men in Latin Europe is not observed among French people aged 75 years and more. This should be confirmed among other Latin Europe countries.

Testing the 'island rule' for a tenebrionid beetle (Coleoptera, Tenebrionidae)

NASA Astrophysics Data System (ADS)

Palmer, Miquel

2002-05-01

Insular populations and their closest mainland counterparts commonly display body size differences that are considered to fit the island rule, a theoretical framework to explain both dwarfism and gigantism in isolated animal populations. The island rule is used to explain the pattern of change of body size at the inter-specific level. But the model implicitly makes also a prediction for the body size of isolated populations of a single species. It suggests that, for a hypothetical species covering a wide range of island sizes, there exists a specific island size where this species reaches the largest body size. Body size would be small (in relative terms) in the smallest islets of the species range. It would increase with island size, and reach a maximum at some specific island size. However, additional increases from such a specific island size would instead promote body size reduction, and small (in relative terms) body sizes would be found again on the largest islands. The biogeographical patterns predicted by the island rule have been described and analysed for vertebrates only (mainly mammals), but remain largely untested for insects or other invertebrates. I analyse here the pattern of body size variation between seven isolated insular populations of a flightless beetle, Asida planipennis (Coleoptera, Tenebrionidae). This is an endemic species of Mallorca, Menorca and a number of islands and islets in the Balearic archipelago (western Mediterranean). The study covers seven of the 15 known populations (i.e., there are only 15 islands or islets inhabited by the species). The populations studied fit the pattern advanced above and we could, therefore, extrapolate the island rule to a very different kind of organism. However, the small sample size of some of the populations invites some caution at this early stage.

A New Method for Estimating the Effective Population Size from Allele Frequency Changes

PubMed Central

Pollak, Edward

1983-01-01

A new procedure is proposed for estimating the effective population size, given that information is available on changes in frequencies of the alleles at one or more independently segregating loci and the population is observed at two or more separate times. Approximate expressions are obtained for the variances of the new statistic, as well as others, also based on allele frequency changes, that have been discussed in the literature. This analysis indicates that the new statistic will generally have a smaller variance than the others. Estimates of effective population sizes and of the standard errors of the estimates are computed for data on two fly populations that have been discussed in earlier papers. In both cases, there is evidence that the effective population size is very much smaller than the minimum census size of the population. PMID:17246147

Colonial, more widely distributed and less abundant bird species undergo wider population fluctuations independent of their population trend

PubMed Central

Møller, Anders P.

2017-01-01

Understanding temporal variability in population size is important for conservation biology because wide population fluctuations increase the risk of extinction. Previous studies suggested that certain ecological, demographic, life-history and genetic characteristics of species might be related to the degree of their population fluctuations. We checked whether that was the case in a large sample of 231 European breeding bird species while taking a number of potentially confounding factors such as population trends or similarities among species due to common descent into account. When species-specific characteristics were analysed one by one, the magnitude of population fluctuations was positively related to coloniality, habitat, total breeding range, heterogeneity of breeding distribution and natal dispersal, and negatively related to urbanisation, abundance, relative number of subspecies, parasitism and proportion of polymorphic loci. However, when abundance (population size) was included in the analyses of the other parameters, only coloniality, habitat, total breeding range and abundance remained significantly related to population fluctuations. The analysis including all these predictors simultaneously showed that population size fluctuated more in colonial, less abundant species with larger breeding ranges. Other parameters seemed to be related to population fluctuations only because of their association with abundance or coloniality. The unexpected positive relationship between population fluctuations and total breeding range did not seem to be mediated by abundance. The link between population fluctuations and coloniality suggests a previously unrecognized cost of coloniality. The negative relationship between population size and population fluctuations might be explained by at least three types of non-mutually exclusive stochastic processes: demographic, environmental and genetic stochasticity. Measurement error in population indices, which was unknown, may have contributed to the negative relationship between population size and fluctuations, but apparently only to a minor extent. The association between population size and fluctuations suggests that populations might be stabilized by increasing population size. PMID:28253345

A preliminary report on the magnetic measurements of samples 72275 and 72255. [direction and magnitude of remanent magnetization

NASA Technical Reports Server (NTRS)

Banerjee, S. K.

1974-01-01

The direction and magnitude of natural remanent magnetization of five approximately 3-g subsamples of 72275 and 72255 and the high field saturation magnetization, coercive force, and isothermal remanent magnetization of 100-mg chip from each of these samples, were studied. Given an understanding of the magnetization processes, group 1 experiments provide information about the absolute direction of the ancient magnetizing field and a qualitative estimate of its size (paleointensity). The group 2 experiments yield a quantitative estimate of the iron content and a qualitative ideal of the grain sizes.

Assessment of errors in static electrical impedance tomography with adjacent and trigonometric current patterns.

PubMed

Kolehmainen, V; Vauhkonen, M; Karjalainen, P A; Kaipio, J P

1997-11-01

In electrical impedance tomography (EIT), difference imaging is often preferred over static imaging. This is because of the many unknowns in the forward modelling which make it difficult to obtain reliable absolute resistivity estimates. However, static imaging and absolute resistivity values are needed in some potential applications of EIT. In this paper we demonstrate by simulation the effects of different error components that are included in the reconstruction of static EIT images. All simulations are carried out in two dimensions with the so-called complete electrode model. Errors that are considered are the modelling error in the boundary shape of an object, errors in the electrode sizes and localizations and errors in the contact impedances under the electrodes. Results using both adjacent and trigonometric current patterns are given.

Ratioing methods for in-flight response calibration of space-based spectro-radiometers, operating in the solar spectral region

NASA Astrophysics Data System (ADS)

Lobb, Dan

2017-11-01

One of the most significant problems for space-based spectro-radiometer systems, observing Earth from space in the solar spectral band (UV through short-wave IR), is in achievement of the required absolute radiometric accuracy. Classical methods, for example using one or more sun-illuminated diffusers as reflectance standards, do not generally provide methods for monitoring degradation of the in-flight reference after pre-flight characterisation. Ratioing methods have been proposed that provide monitoring of degradation of solar attenuators in flight, thus in principle allowing much higher confidence in absolute response calibration. Two example methods are described. It is shown that systems can be designed for relatively low size and without significant additions to the complexity of flight hardware.

Population estimates of Nearctic shorebirds

USGS Publications Warehouse

Morrison, R.I.G.; Gill, Robert E.; Harrington, B.A.; Skagen, S.K.; Page, G.W.; Gratto-Trevor, C. L.; Haig, S.M.

2000-01-01

Estimates are presented for the population sizes of 53 species of Nearctic shorebirds occurring regularly in North America, plus four species that breed occasionally. Shorebird population sizes were derived from data obtained by a variety of methods from breeding, migration and wintering areas, and formal assessments of accuracy of counts or estimates are rarely available. Accurate estimates exist only for a few species that have been the subject of detailed investigation, and the likely accuracy of most estimates is considered poor or low. Population estimates range from a few tens to several millions. Overall, population estimates most commonly fell in the range of hundreds of thousands, particularly the low hundreds of thousands; estimated population sizes for large shorebird species currently all fall below 500,000. Population size was inversely related to size (mass) of the species, with a statistically significant negative regression between log (population size) and log (mass). Two outlying groups were evident on the regression graph: one, with populations lower than predicted, included species considered either to be "at risk" or particularly hard to count, and a second, with populations higher than predicted, included two species that are hunted. Population estimates are an integral part of conservation plans being developed for shorebirds in the United States and Canada, and may be used to identify areas of key international and regional importance.

Estimates of shorebird populations in North America

USGS Publications Warehouse

Morrison, R.I.G.; Gill, Robert E.; Harrington, B.A.; Skagen, S.K.; Page, G.W.; Gratto-Trevor, C. L.; Haig, S.M.

2001-01-01

Estimates are presented for the population sizes of 53 species of Nearctic shorebirds occurring regularly in North America, plus four species that breed occasionally. Population estimates range from a few tens to several millions. Overall, population estimates most commonly fall in the range of hundreds of thousands, particularly the low hundreds of thousands; estimated population sizes for large shorebird species currently all fall below 500 000. Population size is inversely related to size (mass) of the species, with a statistically significant negative regression between log(population size) and log(mass). Two outlying groups are evident on the regression graph: one, with populations lower than predicted, includes species considered to be either “at risk” or particularly hard to count, and a second, with populations higher than predicted, includes two species that are hunted. Shorebird population sizes were derived from data obtained by a variety of methods from breeding, migration, and wintering areas, and formal assessments of accuracy of counts or estimates are rarely available. Accurate estimates exist only for a few species that have been the subject of detailed investigation, and the likely accuracy of most estimates is considered poor or low. Population estimates are an integral part of conservation plans being developed for shorebirds in the United States and Canada and may be used to identify areas of key international and regional importance.

Effects of spatial structure of population size on the population dynamics of barnacles across their elevational range.

PubMed

Fukaya, Keiichi; Okuda, Takehiro; Nakaoka, Masahiro; Noda, Takashi

2014-11-01

Explanations for why population dynamics vary across the range of a species reflect two contrasting hypotheses: (i) temporal variability of populations is larger in the centre of the range compared to the margins because overcompensatory density dependence destabilizes population dynamics and (ii) population variability is larger near the margins, where populations are more susceptible to environmental fluctuations. In both of these hypotheses, positions within the range are assumed to affect population variability. In contrast, the fact that population variability is often related to mean population size implies that the spatial structure of the population size within the range of a species may also be a useful predictor of the spatial variation in temporal variability of population size over the range of the species. To explore how population temporal variability varies spatially and the underlying processes responsible for the spatial variation, we focused on the intertidal barnacle Chthamalus dalli and examined differences in its population dynamics along the tidal levels it inhabits. Changes in coverage of barnacle populations were monitored for 10.5 years at 25 plots spanning the elevational range of this species. Data were analysed by fitting a population dynamics model to estimate the effects of density-dependent and density-independent processes on population growth. We also examined the temporal mean-variance relationship of population size with parameters estimated from the population dynamics model. We found that the relative variability of populations tended to increase from the centre of the elevational range towards the margins because of an increase in the magnitude of stochastic fluctuations of growth rates. Thus, our results supported hypothesis (2). We also found that spatial variations in temporal population variability were well characterized by Taylor's power law, the relative population variability being inversely related to the mean population size. Results suggest that understanding the population dynamics of a species over its range may be facilitated by taking the spatial structure of population size into account as well as by considering changes in population processes as a function of position within the range of the species. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Dynamics of domain coverage of the protein sequence universe

PubMed Central

2012-01-01

Background The currently known protein sequence space consists of millions of sequences in public databases and is rapidly expanding. Assigning sequences to families leads to a better understanding of protein function and the nature of the protein universe. However, a large portion of the current protein space remains unassigned and is referred to as its “dark matter”. Results Here we suggest that true size of “dark matter” is much larger than stated by current definitions. We propose an approach to reducing the size of “dark matter” by identifying and subtracting regions in protein sequences that are not likely to contain any domain. Conclusions Recent improvements in computational domain modeling result in a decrease, albeit slowly, in the relative size of “dark matter”; however, its absolute size increases substantially with the growth of sequence data. PMID:23157439

Martian planetwide crater distributions - Implications for geologic history and surface processes

NASA Technical Reports Server (NTRS)

Soderblom, L. A.; Condit, C. D.; West, R. A.; Herman, B. M.; Kreidler, T. J.

1974-01-01

Three different diameter size ranges are considered in connection with the Martian crater distribution, taking into account small craters from 0.6 to 1.2 km, intermediate-sized craters from 4 to 10 km, and large craters with diameters exceeding 20 km. One of the objectives of the investigation reported is to establish the effects of eolian processes in the modification of craters in the different size ranges. Another objective is concerned with a description of the genetic relationships among the three size ranges of craters. Observables related to the relative age of geologic provinces are to be separated from observables related to geographic variations in eolian transport and deposition. Lunar and Martian cratering histories are compared as a basis for establishing relative and absolute time scales for the geological evolution of Mars.

SU-F-T-76: Total Skin Electron Therapy: An-End-To-End Examination of the Absolute Dosimetry with a Rando Phantom

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

Cui, G; Ha, J; Zhou, S

Purpose: To examine and validate the absolute dose for total skin electron therapy (TSET) through an end-to-end test with a Rando phantom using optically stimulated luminescent dosimeters (OSLDs) and EBT3 radiochromic films. Methods: A Varian Trilogy linear accelerator equipped with the special procedure 6 MeV HDTSe- was used to perform TSET irradiations using a modified Stanford 6-dual-field technique. The absolute dose was calibrated using a Markus ion chamber at a reference depth of 1.3cm at 100 cm SSD with a field size of 36 × 36 cm at the isocenter in solid water slabs. The absolute dose was cross validatedmore » by a farmer ion chamber. Then the dose rate in the unit of cGy/Mu was calibrated using the Markus chamber at the treatment position. OSLDs were used to independently verify the dose using the calibrated dose rate. Finally, a patient treatment plan (200 cGy/cycle) was delivered in the QA mode to a Rando phantom, which had 16 pairs of OSLDs and EBT3 films taped onto its surface at different anatomical positions. The doses recorded were read out to validate the absolute dosimetry for TSET. Results: The OSLD measurements were within 7% agreement with the planned dose except the shoulder areas, where the doses recorded were 23% lower on average than those of the planned. The EBT3 film measurements were within 10% agreement with the planned dose except the shoulder and the scalp vertex areas, where the respective doses recorded were 18% and 14% lower on average than those of the planned. The OSLDs gave more consistent dose measurements than those of the EBT3 films. Conclusion: The absolute dosimetry for TSET was validated by an end-to-end test with a Rando phantom using the OSLDs and EBT3 films. The beam calibration and monitor unit calculations were confirmed.« less

Population size estimation of men who have sex with men through the network scale-up method in Japan.

PubMed

Ezoe, Satoshi; Morooka, Takeo; Noda, Tatsuya; Sabin, Miriam Lewis; Koike, Soichi

2012-01-01

Men who have sex with men (MSM) are one of the groups most at risk for HIV infection in Japan. However, size estimates of MSM populations have not been conducted with sufficient frequency and rigor because of the difficulty, high cost and stigma associated with reaching such populations. This study examined an innovative and simple method for estimating the size of the MSM population in Japan. We combined an internet survey with the network scale-up method, a social network method for estimating the size of hard-to-reach populations, for the first time in Japan. An internet survey was conducted among 1,500 internet users who registered with a nationwide internet-research agency. The survey participants were asked how many members of particular groups with known population sizes (firepersons, police officers, and military personnel) they knew as acquaintances. The participants were also asked to identify the number of their acquaintances whom they understood to be MSM. Using these survey results with the network scale-up method, the personal network size and MSM population size were estimated. The personal network size was estimated to be 363.5 regardless of the sex of the acquaintances and 174.0 for only male acquaintances. The estimated MSM prevalence among the total male population in Japan was 0.0402% without adjustment, and 2.87% after adjusting for the transmission error of MSM. The estimated personal network size and MSM prevalence seen in this study were comparable to those from previous survey results based on the direct-estimation method. Estimating population sizes through combining an internet survey with the network scale-up method appeared to be an effective method from the perspectives of rapidity, simplicity, and low cost as compared with more-conventional methods.

75 FR 48815 - Medicaid Program and Children's Health Insurance Program (CHIP); Revisions to the Medicaid...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-11

... size may be reduced by the finite population correction factor. The finite population correction is a statistical formula utilized to determine sample size where the population is considered finite rather than... program may notify us and the annual sample size will be reduced by the finite population correction...

Estimation of census and effective population sizes: the increasing usefulness of DNA-based approaches

Treesearch

Gordon Luikart; Nils Ryman; David A. Tallmon; Michael K. Schwartz; Fred W. Allendorf

2010-01-01

Population census size (NC) and effective population sizes (Ne) are two crucial parameters that influence population viability, wildlife management decisions, and conservation planning. Genetic estimators of both NC and Ne are increasingly widely used because molecular markers are increasingly available, statistical methods are improving rapidly, and genetic estimators...

Population Genetics of the São Tomé Caecilian (Gymnophiona: Dermophiidae: Schistometopum thomense) Reveals Strong Geographic Structuring

PubMed Central

Stoelting, Ricka E.; Measey, G. John; Drewes, Robert C.

2014-01-01

Islands provide exciting opportunities for exploring ecological and evolutionary mechanisms. The oceanic island of São Tomé in the Gulf of Guinea exhibits high diversity of fauna including the endemic caecilian amphibian, Schistometopum thomense. Variation in pigmentation, morphology and size of this taxon over its c. 45 km island range is extreme, motivating a number of taxonomic, ecological, and evolutionary hypotheses to explain the observed diversity. We conducted a population genetic study of S. thomense using partial sequences of two mitochondrial DNA genes (ND4 and 16S), together with morphological examination, to address competing hypotheses of taxonomic or clinal variation. Using Bayesian phylogenetic analysis and Spatial Analysis of Molecular Variance, we found evidence of four geographic clades, whose range and approximated age (c. 253 Kya – 27 Kya) are consistent with the spread and age of recent volcanic flows. These clades explained 90% of variation in ND4 (φCT = 0.892), and diverged by 4.3% minimum pairwise distance at the deepest node. Most notably, using Mismatch Distributions and Mantel Tests, we identified a zone of population admixture that dissected the island. In the northern clade, we found evidence of recent population expansion (Fu's Fs = −13.08 and Tajima's D = −1.80) and limited dispersal (Mantel correlation coefficient = 0.36, p = 0.01). Color assignment to clades was not absolute. Paired with multinomial regression of chromatic data, our analyses suggested that the genetic groups and a latitudinal gradient together describe variation in color of S. thomense. We propose that volcanism and limited dispersal ability are the likely proximal causes of the observed genetic structure. This is the first population genetic study of any caecilian and demonstrates that these animals have deep genetic divisions over very small areas in accordance with previous speculations of low dispersal abilities. PMID:25171066

Use of an Anatomical Scalar to Control for Sex-Based Size Differences in Measures of Hyoid Excursion during Swallowing

ERIC Educational Resources Information Center

Molfenter, Sonja M.; Steele, Catriona M.

2014-01-01

Purpose: Traditional methods for measuring hyoid excursion from dynamic videofluoroscopy recordings involve calculating changes in position in absolute units (mm). This method shows a high degree of variability across studies but agreement that greater hyoid excursion occurs inmen than in women. Given that men are typically taller than women, the…

Changes in product recovery between live and dead lodgepole pine: a compendium.

Treesearch

Thomas D. Fahey; Thomas A. Snellgrove; Marlin E. Plank

1986-01-01

Six studies were used to compare differences in recovery of volume and value among live, recent dead, and older dead lodgepole pine (Pinus contorts Dougl. ex Loud.) in the Western United States. The products studied included boards, random-length dimension, studs, and veneer. For the average size log (12 cubic feet) absolute values were highest for boards, followed by...

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Science.gov Websites

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VizieR Online Data Catalog: Veritas family members Yarkovsky drift rates (Carruba+, 2017)

NASA Astrophysics Data System (ADS)

Carruba, V.; Vokrouhlicky, D.; Nesvorny, D.

2017-05-01

Data about 274 identified Veritas members, their absolute magnitude, proper a, e, sin(i), g, and s, Lyapunov exponent (multiplied by a factor 10+6), and estimated mean Yarkovsky drift speed, in AU/Myr (no such value is available for (1086) Nata itself, that because of its relative large size has very limited Yarkovsky mobility). (1 data file).

Psychophysical Criteria for Visual Simulation Systems.

DTIC Science & Technology

1980-05-01

definitive data were found to estab- lish detection thresholds; therefore, this is one area where a psycho- physical study was recommended. Differential size...The specific functional relationships needinq quantification were the following: 1. The effect of Horizontal Aniseikonia on Target Detection and...Transition Technique 6. The Effects of Scene Complexity and Separation on the Detection of Scene Misalignment 7. Absolute Brightness Levels in

Cross-Regional Differences in Meeting the Challenge of Teacher Salary Increase

ERIC Educational Resources Information Center

Derkachev, P. V.

2015-01-01

This paper presents an overview of studies on the correlations of teacher pay to regional economics and to regional factors affecting the size of teacher salaries. It describes the basic pay indicators for teachers in the regions: absolute salary, teacher pay level as compared to the average regional salary, and ratio of salary to the cost of a…

--No Title--

Science.gov Websites

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Paper and pencil vs online self-administered food frequency questionnaire (FFQ) applied to university population: a pilot study.

PubMed

González Carrascosa, R; García Segovia, P; Martínez Monzó, J

2011-01-01

To test the reliability of dietary intake data measured with an online food frequency questionnaires (FFQ) applied to a university population by comparing the results with those from a paper and pencil version. A total of 50 students were recruited from the second-year Food Technology course at the Universitat Politècnica de València (Comunidad Valenciana, Spain) in the academic year 2008-2009. The students were between the ages of 20-32. The participants completed both presentation modes of the FFQ (paper and pencil and online) in a cross-over study with a time interval of 3-week. To study the effect of ordering of the questionnaires, participants were randomly assigned to group A (paper and pencil FFQ first) and group B (online FFQ first). Both self-administered semi-quantitative presentations of the FFQ included 84 food items divided into six groups (dairy products; eggs, meat and fish; vegetables, legumes and fruits; bread, cereals and similar; oils, fats and sweets; beverages and pre-cooked). Participants were asked how frequently and how much each food item they had consumed in the previous year. The response rate was 78% (39 students, 23% men and 77% women). For the total sample, the median dietary intakes were higher for the paper and pencil FFQ than the online version for energy (2,077 vs. 1,635 kcal/day), proteins (96 vs. 88 g/day), carbohydrates (272 vs. 211 g/day), and fat (70 vs. 58 g/day), respectively. These differences were statistically significant. However, there were not significant differences between the two presentations when the consumption by groups of food was calculated, except for "beverages and pre-cooked" group. The pilot testing showed that this online FFQ is a useful tool for estimating the intake of food groups in this university population. On the other hand, the differences found in the results of the absolute quantities of energy and nutrients intakes were not clear. These differences could be due to the problems that the participants had for reporting portion size in the paper and pencil FFQ as photographs of portion sizes were not presented.

Determination of Residual Stress Distributions in Polycrystalline Alumina using Fluorescence Microscopy

PubMed Central

Michaels, Chris A.; Cook, Robert F.

2016-01-01

Maps of residual stress distributions arising from anisotropic thermal expansion effects in a polycrystalline alumina are generated using fluorescence microscopy. The shifts of both the R1 and R2 ruby fluorescence lines of Cr in alumina are used to create maps with sub-µm resolution of either the local mean and shear stresses or local crystallographic a- and c-stresses in the material, with approximately ± 1 MPa stress resolution. The use of single crystal control materials and explicit correction for temperature and composition effects on line shifts enabled determination of the absolute values and distributions of values of stresses. Temperature correction is shown to be critical in absolute stress determination. Experimental determinations of average stress parameters in the mapped structure are consistent with assumed equilibrium conditions and with integrated large-area measurements. Average crystallographic stresses of order hundreds of MPa are determined with characteristic distribution widths of tens of MPa. The stress distributions reflect contributions from individual clusters of stress in the structure; the cluster size is somewhat larger than the grain size. An example application of the use of stress maps is shown in the calculation of stress-intensity factors for fracture in the residual stress field. PMID:27563163

Dripping and jetting regimes in co-flowing capillary jets: unforced measurements and response to driving

NASA Astrophysics Data System (ADS)

Baroud, Charles; Cordero, Maria-Luisa; Gallaire, Francois

2011-11-01

We study the breakup of drops in a co-flowing jet, within the confinement of a microfluidic channel. The breakup can occur right after the nozzle (dripping) or through the generation of a liquid jet that breaks up a long distance from the nozzle (jetting). Traditionally, these two regimes have been considered to reflect an absolutely unstable jet or a convectively unstable jet, respectively. We first provide measurements of the frequency of oscillation and breakup of the liquid jet; the dispersion relation thus obtained compares well with existing theories for convective instabilities in the case of the jetting regime. However, the theories in the absolutely unstable mode fail to predict the evolution of the frequency and drop size in the dripping regime. We also test the jet response to an external forcing, using a focused laser to locally heat the jet. The dripping regime is found to be insensitive to the perturbation and the frequency of drop formation remains unaltered. In contrast, the jetting regime locks to the external frequency, which translates into a modification of the drop size in agreement with the dispersion relations. This confirms the convective nature of the jetting regime. Permanent address: Universidad de Chile.