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1

Taxonomic and gene-centric metagenomics of the fecal microbiome of low and high feed conversion ratio (FCR) broilers.  

PubMed

Individual weight gain in broiler growers appears to vary, which may in part be due to variation in their gut microbiota. In this paper we analyse the fecal microbiota of low and high feed conversion ratio (FCR) broilers. After shotgun sequencing of the fecal microbiome, we used the SEED database to identify the microbial diversity and metabolic potential in low and high FCR birds. The domain-level breakdown of our samples was bacteria (>95 %), eukaryotes (>2 %), archaea (>0.2 %), and viruses (>0.2 %). At the phylum level, Proteobacteria (78.83 % in low and 52.04 % in high FCR), Firmicutes (11.97 % in low and 27.53 % in high FCR) and Bacteroidetes (7.10 % in low FCR and 17.53 % in high FCR) predominated in the fecal microbial community. Poultry fecal metagenomes revealed the sequences related to 33 genera in both low and high FCR with significantly different proportion. Functional analysis revealed that genes for the metabolism of carbohydrates, amino acids and derivatives and protein metabolism were most abundant in SEED subsystem in both samples. Genes associated with stress, virulence, cell wall and cell capsule were also abundant. Indeed, genes associated with sulphur assimilation, flagellum and flagellar motility were over represented in low FCR birds. This information could help in developing strategies to improve feed efficiency and feed formulation for broiler chickens. PMID:24136777

Singh, K M; Shah, T M; Reddy, Bhaskar; Deshpande, S; Rank, D N; Joshi, C G

2014-02-01

2

FcR and autoimmunity  

Microsoft Academic Search

\\u000a Human immunoglobulin receptors (FcR) provide an important link between the humoral and cellular branches of the immune response.\\u000a FcR engagement in autoimmune diseases may result in many biological responses including phagocytosis, endocytosis, antibody-dependent\\u000a cellular cytotoxicity (ADCC), release of inflammatory mediators, facilitation of antigen presentation and clearance of immune\\u000a complexes (IC). Most FcR belong to the family of multi-chain immune recognition

R. Repp; J. G. J. Winkel

3

Novel asymmetrically engineered antibody Fc variant with superior Fc?R binding affinity and specificity compared with afucosylated Fc variant.  

PubMed

Fc engineering is a promising approach to enhance the antitumor efficacy of monoclonal antibodies (mAbs) through antibody-dependent cell-mediated cytotoxicity (ADCC). Glyco- and protein-Fc engineering have been employed to enhance Fc?R binding and ADCC activity of mAbs; the drawbacks of previous approaches lie in their binding affinity to both Fc?RIIIa allotypes, the ratio of activating Fc?R binding to inhibitory Fc?R binding (A/I ratio) or the melting temperature (T(M)) of the C(H)2 domain. To date, no engineered Fc variant has been reported that satisfies all these points. Herein, we present a novel Fc engineering approach that introduces different substitutions in each Fc domain asymmetrically, conferring optimal binding affinity to Fc?R and specificity to the activating Fc?R without impairing the stability. We successfully designed an asymmetric Fc variant with the highest binding affinity for both Fc?RIIIa allotypes and the highest A/I ratio compared with previously reported symmetrically engineered Fc variants, and superior or at least comparable in vitro ADCC activity compared with afucosylated Fc variants. In addition, the asymmetric Fc engineering approach offered higher stability by minimizing the use of substitutions that reduce the T(M) of the C(H)2 domain compared with the symmetric approach. These results demonstrate that the asymmetric Fc engineering platform provides best-in-class effector function for therapeutic antibodies against tumor antigens. PMID:23406628

Mimoto, Futa; Igawa, Tomoyuki; Kuramochi, Taichi; Katada, Hitoshi; Kadono, Shojiro; Kamikawa, Takayuki; Shida-Kawazoe, Meiri; Hattori, Kunihiro

2013-01-01

4

[Evaluation of the 1Shot Phantom dedicated to the mammography system using FCR].  

PubMed

Currently daily quality control (QC) tests for mammography systems are generally evaluated by using visual analysis phantoms, which of course means subjective measurement. In our study, however, we evaluated a novel digital phantom, the 1Shot Phantom M plus (1Shot Phantom), together with automatic analysis software dedicated for mammography systems using Fuji computed radiography (FCR). The digital phantom enables objective evaluation by providing for actual physical measurement rather than subjective visual assessment. We measured 1) contrast to noise ratio (CNR), 2) image receptor homogeneity, 3) missed tissue at chest wall side, 4) modulation transfer function (MTF), and 5) geometric distortion utilizing the 1Shot Phantom. We then compared the values obtained using the 1Shot Phantom with values obtained from the European guidelines and International Electrotechnical Commission (IEC) standards. In addition, we evaluated the convenience of using the digital phantom. The values utilizing the 1Shot Phantom and those from the European guidelines and IEC standards were consistent, but the QC tests for the European guidelines and IEC standards methods took about six hours while the same QC tests using the 1Shot Phantom took 10 minutes or less including exposure of the phantom image, measurement, and analysis. In conclusion, the digital phantom and dedicated software proved very useful and produced improved analysis for mammography systems using FCR in clinical daily QC testing because of their objectivity and substantial time-saving convenience. PMID:19661726

Nagashima, Chieko; Uchiyama, Nachiko; Moriyama, Noriyuki; Nagata, Mio; Kobayashi, Hiroyuki; Sankoda, Katsuhiro; Saotome, Shigeru; Tagi, Masahiro; Kusunoki, Tetsurou

2009-07-20

5

School Administration: Optimal Ratio of Centralization to Decentralization.  

ERIC Educational Resources Information Center

Compares advantages and disadvantages of centralized and decentralized control in Soviet public schools. Recognizes that centralization concentrates the forces, funds, and available resources necessary for maximum achievement. Suggests that decentralization of administration can be optimized by delegating rights, duties, and responsibilities to…

Kapto, A. E.

1990-01-01

6

An investigation of transmission ratio distortion in the central region of the human MHC  

Microsoft Academic Search

Transmission ratio distortion (TRD) describes a significant departure from expected Mendelian inheritance ratios that is fundamental to both the biology of reproduction and statistical genetics. The relatively high fetal wastage in humans, with consequent selection of alleles in utero, makes it likely that TRD is prevalent in the human genome. The central region of the human major histocompatibility complex (MHC)

N Hanchard; K Rockett; I Udalova; J Wilson; B Keating; O Koch; A Nijnik; M Diakite; M Herbert; D Kwiatkowski

2006-01-01

7

Central Elemental Abundance Ratios in the Perseus Cluster: Resonant Scattering or SN Ia Enrichment?  

Microsoft Academic Search

We have determined elemental abundance ratios in the core of the Perseus\\u000acluster for several elements. These ratios indicate a central dominance of SN\\u000aIa ejecta similar to that found for A496, A2199 and A3571 (Dupke & White 2000).\\u000aSimultaneous analysis of ASCA spectra from SIS1, GIS 2&3 shows that the ratio\\u000aof Ni to Fe abundances is ~ (3.4

2000-01-01

8

Interaction of Obesity and Central Obesity on Elevated Urinary Albumin-to-Creatinine Ratio  

PubMed Central

Background Microalbuminuria was much more common among obese individuals indicating a probable association with obesity. However, association of microalbuminuria with interaction between obesity and central obesity has not yet been studied. Design and Methods A cross-sectional study was conducted in a 2889 general population aged ?30 years. Obesity was defined as body mass index ?28.0 kg/m2 and central obesity was defined as waist-to-hip ratio ?0.85 for females and ?0.90 for males. Both additive and multipliable interactions between obesity and central obesity on elevated urinary albumin-to-creatinine ratio (UACR) were evaluated. Results After controlling for potential covariates, participants with both obesity and central obesity have significantly increased risk for elevated UACR (OR?=?1.82 P<0.001) compared to those with neither. Additive interaction analysis indicated that about 43.9% of the risk of elevated UACR in participants with both obesity and central obesity was attributed to the interaction between obesity and central obesity (the attributable proportion because of the interaction: 0.439; 95% CI: 0.110–0.768). The multipliable interactive effect between obesity and central obesity on elevated UACR was not found significant (OR?=?1.82, P?=?0.078). Conclusions Microalbuminuria was significantly associated with the interaction between obesity and central obesity. Our results indicated that individuals with both obesity and central obesity should be intensively managed to prevent renal diseases.

Zhang, Qiu; Tian, Honggang; Li, Hongmei

2014-01-01

9

Electroretinogram b\\/a wave ratio improvement in central retinal vein obstruction  

Microsoft Academic Search

The electroretinogram (ERG), especially the b\\/a wave ratio, is considered a good indicator of retinal ischaemia in central retinal vein obstruction (CRVO). Seven CRVO patients who showed b\\/a wave ratio improvement from or = 1.0 and one from 1.07 to 1.53 were studied. Three mechanisms of change were observed: firstly, the b-wave amplitude increased without an a-wave amplitude decrease (group

Y Matsui; O Katsumi; H Sakaue; T Hirose

1994-01-01

10

Calves' sex ratio in naturally and artificially bred cattle in central Ethiopia.  

PubMed

A study was undertaken with the objective to identify some intrinsic (genotype of the cow, estrus time and parity) and extrinsic factors (service type, service time and estrus seasons) that affect calf sex ratio in naturally and artificially bred cattle in the central highlands of Ethiopia. A total of 4657 calving events were extracted from the long-term dairy cattle genetic improvement experiment at Holetta Agricultural Research Center. Factors that affect the logit of the probability of a female calf being born were obtained by using PROC GENMODE in Statistical Analysis System. Moreover, multivariate analysis was performed using PROC LOGISTIC procedure using forward selection procedure. Accordingly, genotype of the cow, parity, estrus season, and service type had considerable influences on calf sex ratio. However, estrus time and service time did not affect calf sex ratio (?(2) = 0.83 and 0.79, respectively). In Ethiopia, smallholder dairy farmers often complain that artificial insemination (AI) skewed to producing more male calves. However, our study showed that AI did not alter female-to-male calf sex ratio. On the contrary, natural mating increases the probability of female calves born (odds ratio 1.38) over AI. Heifer/cows that showed estrus and bred during the harsh seasons of the years produced more female calves than those that bred during the good seasons of the year. This strongly agreed with Trivers and Willard sex allocation theory. PMID:24908336

Delesa, Effa Kefena; Yohannes, Aster; Alemayehu, Mengistu; Samuel, Temesgen; Yehualaeshet, Teshome

2014-08-01

11

C/O and N/O ratios in planetary nebulae with [WC] central stars  

NASA Astrophysics Data System (ADS)

Planetary nebulae (PNe) around [WR] central stars (WRPNe) constitute a particular photoionized nebula class, representing about 10-15% of the PNe with known progenitor. We have studied 14 of them, detecting a large number of optical recombination lines (ORLs) from different ions of O and C (O+, O++, C++, C+3). This allows us to determine the C/O ratio, which is of paramount importance to constraint stellar evolution models. We have compared the obtained N/O and C/O ratios obtained with those derived from stellar evolution models, and we estimate that about half of our PNe have progenitors with initial masses similar to or larger than 4 Msun . These results are consistent with the results obtained from an independent analysis by Górny & García-Hernández (2014).

García-Rojas, J.; Peña, M.; Delgado-Inglada, G.; García-Hernández, D. A.; Morisset, C.

2014-04-01

12

An investigation of transmission ratio distortion in the central region of the human MHC.  

PubMed

Transmission ratio distortion (TRD) describes a significant departure from expected Mendelian inheritance ratios that is fundamental to both the biology of reproduction and statistical genetics. The relatively high fetal wastage in humans, with consequent selection of alleles in utero, makes it likely that TRD is prevalent in the human genome. The central region of the human major histocompatibility complex (MHC) is a strong TRD candidate, as it houses a number of immune and regulatory genes that may be important in pregnancy outcome. We used a nonhaplotype-based method to select 13 tagging SNPs from three central MHC candidate regions, and analysed their transmission in 380 newborns and their parents (1138 individuals). A TRD of 54:46 was noted in favour of the common allele of a promoter SNP in the CLIC1 gene (P = 0.025), with a similar distortion using haplotypes across the same gene region (P = 0.016). We also found evidence that markers in the CLIC1 gene region may have been subject to recent selection (P < 0.001). The study illustrates the potential benefits of screening for TRD and highlights the difficulties encountered therein. PMID:16341054

Hanchard, N; Rockett, K; Udalova, I; Wilson, J; Keating, B; Koch, O; Nijnik, A; Diakite, M; Herbert, M; Kwiatkowski, D

2006-01-01

13

Glomerular Fc?R expression and disease activity in IgA nephropathy  

Microsoft Academic Search

In this study, we examined the receptors for the Fc portion of immunoglobulin A (IgA) (Fc?R) in the glomeruli as well as circulating polymorphonuclear leukocytes and monocytes at the mRNA level by reverse transcription—polymerase chain reaction (RT-PCR) assay and at the protein level by an immunohistochemistry\\/flow cytometry technique using a specific anti-Fc?R monoclonal antibody (My 43). Glomeruli were isolated from

Abul Kashem; Masayuki Endoh; Naohiro Yano; Fumio Yamauchi; Yasuo Nomoto; Hideto Sakai; Kiyoshi Kurokawa

1997-01-01

14

Investigating Late Holocene Climate Variability in Central Mexico using Carbon Isotope Ratios in Organic Materials and Oxygen Isotope Ratios from Diatom Silica within Lacustrine Sediments  

Microsoft Academic Search

Previous studies have shown that moisture availability in the central highlands of Mexico during the last 3000 years has been highly variable, but evidence remains ambiguous since the climatic signal is partially masked by that of human activity. Here we use two isotope systems to provide evidence for environmental change in Laguna Zacapu, Michoacán covering this time period. Carbon isotope ratios

Melanie J. Leng; Sarah E. Metcalfe; Sarah J. Davies

2005-01-01

15

Genetic variants of the IgA Fc receptor (Fc?R, CD89) promoter in chronic hepatitis C patients  

Microsoft Academic Search

Fc receptor for IgA (Fc?R, CD89) is capable of triggering IgA-mediated immune responses to pathogens and has been proposed to function in circulating IgA clearance. Because inheritable variations modifying individual immune responses or immunoglobulin catabolism may affect the chronicity of viral infection, we investigated whether promoter polymorphisms of the Fc?R gene (FCAR) affect chronic hepatitis C virus (HCV) infection and

Azuma Watanabe; Toshibumi Shimokawa; Mitsuhiko Moriyama; Fumihiko Komine; Shuichi Amaki; Yasuyuki Arakawa; Chisei Ra

2006-01-01

16

Assessment of the statistics of the Strehl ratio: predictions of central limit theorem analysis  

NASA Astrophysics Data System (ADS)

For a beam propagating through turbulence, the statistics of the Strehl ratio are determined by recognizing that the real and imaginary parts of the on-axis far-field pattern can be represented as the sum of many contributions from the aperture. With this in mind, the central limit theorem (CLT) can be used to develop the statistics of the real and imaginary parts of the optical field, which through the appropriate mathematical manipulations as described here can then be used to develop the probability distribution of the far-field irradiance. The results obtained in this way (which we call the CLT theory or analysis) provide an analytic expression that agrees with the results of detailed wave-optics simulations. This provides an approach by which the statistics of the Strehl ratio can be rapidly determined. A key feature of this work is that the analytic results depend on the values of a few relevant turbulence parameters that include r0,fG, and ?2l. Therefore, a measurement of these parameters at various sites of interest allows us to rapidly assess the detailed nature of the statistical fluctuations of the far-field irradiance that will be experienced at these locations.

Tyler, Glenn A.

2006-11-01

17

Changes in nutrients ratio along the central Bay of Bengal coast and its influence on chlorophyll distribution.  

PubMed

Elemental ratio of nutrients and its influence on chlorophyll a distribution was studied along the central coast of Bay of Bengal using multivariate statistical methods. High chlorophyll concentration was observed during summer (1.81 ?g l?¹) and premonsoon (1.95 ?gl?¹), however, it was high in top 20 m during premonsoon season in tandem with high nitrate (N) and silicate (Si) concentration. N:P (phosphate) ratio was less than Redfield ratio (16:1) during all seasons, indicating the Bay of Bengal as nitrate limited and confirmed the results of Principal ComponentAnalysis (PCA) with positive loading and multiple regression analysis showing negative correlation between this ratio and chlorophyll concentration during all seasons. Whereas, N:Si ratio was < 1 and Si:P ratio > 7 in top 20 m during all seasons explained the deficiency of phosphorus and enrichment of silicate in the central Bay of Bengal. Regression analysis between Si:P and N:Si ratios with chlorophyll showed negative correlation during premonsoon and summer respectively. Thus, the present results confirmed that nutrient molar ratios such as N:P<16; Si:P>7 and N:Si<1 was indicative of a potential N and Si limitation and are the primary limiting nutrients in the central Bay of Bengal in determining chlorophyll concentration. PMID:24813001

Thangaradjou, T; Sarangi, R K; Shanthi, R; Poornima, D; Raja, K; Saravanakumar, A; Balasubramanian, S T

2014-05-01

18

Intake-to-delivered-energy ratios for central station and distributed electricity generation in California  

NASA Astrophysics Data System (ADS)

In previous work, we showed that the intake fraction (iF) for nonreactive primary air pollutants was 20 times higher in central tendency for small-scale, urban-sited distributed electricity generation (DG) sources than for large-scale, central station (CS) power plants in California [Heath, G.A., Granvold, P.W., Hoats, A.S., Nazaroff, W.W., 2006. Intake fraction assessment of the air pollutant exposure implications of a shift toward distributed electricity generation. Atmospheric Environment 40, 7164-7177]. The present paper builds on that study, exploring pollutant- and technology-specific aspects of population inhalation exposure from electricity generation. We compare California's existing CS-based system to one that is more reliant on DG units sited in urban areas. We use Gaussian plume modeling and a GIS-based exposure analysis to assess 25 existing CSs and 11 DG sources hypothetically located in the downtowns of California's most populous cities. We consider population intake of three pollutants—PM 2.5, NO x and formaldehyde—directly emitted by five DG technologies—natural gas (NG)-fired turbines, NG internal combustion engines (ICE), NG microturbines, diesel ICEs, and fuel cells with on-site NG reformers. We also consider intake of these pollutants from existing CS facilities, most of which use large NG turbines, as well as from hypothetical facilities located at these same sites but meeting California's best-available control technology standards. After systematically exploring the sensitivity of iF to pollutant decay rate, the iFs for each of the three pollutants for all DG and CS cases are estimated. To efficiently compare the pollutant- and technology-specific exposure potential on an appropriate common basis, a new metric is introduced and evaluated: the intake-to-delivered-energy ratio (IDER). The IDER expresses the mass of pollutant inhaled by an exposed population owing to emissions from an electricity generation unit per quantity of electric energy delivered to the place of use. We find that the central tendency of IDER is much greater for almost every DG technology evaluated than for existing CS facilities in California.

Heath, Garvin A.; Nazaroff, William W.

19

Tpl2 kinase regulates Fc?R signaling and immune thrombocytopenia in mice.  

PubMed

The MAPK3 Tpl2 controls innate and adaptive immunity by regulating TLR, TNF-?, and GPCR signaling in a variety of cell types. Its ablation gives rise to an anti-inflammatory phenotype characterized by resistance to LPS-induced endotoxin shock, DSS-induced colitis, and TNF-?-induced IBD. Here, we address the role of Tpl2 in autoimmunity. Our data show that the ablation and the pharmacological inhibition of Tpl2 protect mice from antiplatelet antibody-induced thrombocytopenia, a model of ITP. Thrombocytopenia in this model and in ITP is caused by phagocytosis of platelets opsonized with antiplatelet antibodies and depends on Fc?R activation in splenic and hepatic myeloid cells. Further studies explained how Tpl2 inhibition protects from antibody-induced thrombocytopenia, by showing that Tpl2 is activated by Fc?R signals in macrophages and that its activation by these signals is required for ERK activation, cytoplasmic Ca(2+) influx, the induction of cytokine and coreceptor gene expression, and phagocytosis. PMID:23898046

Kyrmizi, Irene; Ioannou, Marianna; Hatziapostolou, Maria; Tsichlis, Philip N; Boumpas, Dimitrios T; Tassiulas, Ioannis

2013-10-01

20

Gas Compositions and He-C Isotopic Ratios of Fumarolic Samples from Negros Island, Central Philippines  

NASA Astrophysics Data System (ADS)

Four volcanoes that are distributed in the Negros Island, Central Philippines, include Kanlaon Volcano which is considered as one of the most active volcanoes in Philippines. All of these volcanoes are related to subduction system of Negros trench and form the Negros volcanic arc. Besides Kanlaon, from north to south, the volcanoes in Negros Island are Silay Volcano, Mandalagan Volcano and Cuernos de Negros Volcano. Although there is no eruption record of these three volcanoes in last 10,000 years, due to the ongoing solfataric/fumarolic activities, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) classifies these as 'potentially active' volcanoes. It means that there is still a considerable threat and risk of eruption. Fumarolic gas samples and bubbling gas samples of hot spring were collected in February 2007 and April 2008 to compare the compositions with others in the world. We analyzed the gas composition, carbon isotopes of CO2, and helium isotopes of these samples. The results of these samples show a similar composition as those of low-temperature fumaroles in other parts of the world, i.e., temperature < 200 oC, and H2S/SO2 >1. H2O is the major species of these gas samples, and CO2 is the dominant component after de-watering. Minor components include H2S, N2 and CH4. The gas composition of most of these samples falls in the range of affinity with convergent plate gases associated with groundwater based on the plot of N2-He-Ar diagram. The high 3He/4He ratios indicate a mantle-derived degassing source in origin, i.e., magma chambers could still exist beneath these volcanoes. Helium isotopes ratios show a decreasing trend from north to south, such distribution could be due to more crustal contamination caused by the collision event which happened in the northern part of the island. The carbon isotopic values of CO2 are far less negative than the values from a magma source. There are other carbon sources of CO2, most likely a thick sequence of limestone formation in Negros Island. When CO2 rise from magma to surface, it reacts with the limestone formation so that carbon isotopic values are changed. The outlet temperature of fumaroles and hot springs ranged between 28 ° and local boiling, and did not show significant variations between 2007 and 2008, which implies the de-gassing systems might be quite steady.

Lee, Hsiao-Fen; Yang, Tsanyao Frank; Faith Lan, Tefang; Chen, Yue-Gau; Sincioco, Jaime S.; Solidum, Renato U., Jr.

2010-05-01

21

The relationship between accommodative amplitude and the ratio of central lens thickness to its equatorial diameter in vertebrate eyes  

PubMed Central

Aim To determine the relationship between accommodative amplitude and central lens thickness/equatorial lens diameter (CLT/ELD) ratio in vertebrates. Methods Midsagittal sections of lenses from fixed, post mortem eyes from 125 different vertebrate species were photographed. Their CLT/ELD ratios were correlated with independently published measurements of their accommodative amplitudes. Using the non?linear finite element method (FEM), the efficiency of zonular traction (the absolute change in central radius of curvature per unit force [|?CR|/F]) for model lenses with CLT/ELD ratios from 0.45 to 0.9 was determined. Results Vertebrates with CLT/ELD ratios ?0.6 have high accommodative amplitudes. Zonular traction was found to be most efficient for those model lenses having CLT/ELD ratios ?0.6. Conclusions Vertebrates with lenses that have CLT/ELD ratios ?0.6 – i.e. “long oval” shapes – have the greatest accommodative amplitudes; e.g. primates, diving birds and diurnal birds of prey. Vertebrates that have oval or spherical shaped lenses, like owls and most mammals, have low accommodative amplitudes. Zonular traction was found to be most efficient when applied to model lenses with CLT/ELD ratios ?0.6. The implications of these findings on the mechanism of accommodation are discussed.

Schachar, Ronald A; Pierscionek, Barbara K; Abolmaali, Ali; Le, Tri

2007-01-01

22

Improved automatic adjustment of density and contrast in FCR system using neural network  

NASA Astrophysics Data System (ADS)

FCR system has an automatic adjustment of image density and contrast by analyzing the histogram of image data in the radiation field. Advanced image recognition methods proposed in this paper can improve the automatic adjustment performance, in which neural network technology is used. There are two methods. Both methods are basically used 3-layer neural network with back propagation. The image data are directly input to the input-layer in one method and the histogram data is input in the other method. The former is effective to the imaging menu such as shoulder joint in which the position of interest region occupied on the histogram changes by difference of positioning and the latter is effective to the imaging menu such as chest-pediatrics in which the histogram shape changes by difference of positioning. We experimentally confirm the validity of these methods (about the automatic adjustment performance) as compared with the conventional histogram analysis methods.

Takeo, Hideya; Nakajima, Nobuyoshi; Ishida, Masamitsu; Kato, Hisatoyo

1994-05-01

23

Search for quark compositeness with the dijet centrality ratio in pp collisions at ?s=7 TeV.  

PubMed

A search for quark compositeness in the form of quark contact interactions, based on hadronic jet pairs (dijets) produced in proton-proton collisions at ?s=7 TeV, is described. The data sample of the study corresponds to an integrated luminosity of 2.9 pb(-1) collected with the CMS detector at the LHC. The dijet centrality ratio, which quantifies the angular distribution of the dijets, is measured as a function of the invariant mass of the dijet system and is found to agree with the predictions of the standard model. A statistical analysis of the data provides a lower limit on the energy scale of quark contact interactions. The sensitivity of the analysis is such that the expected limit is 2.9 TeV; because the observed value of the centrality ratio at high invariant mass is below the expectation, the observed limit is 4.0 TeV at the 95% confidence level. PMID:21231646

Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Bergauer, T; Dragicevic, M; Erö, J; Fabjan, C; Friedl, M; Frühwirth, R; Ghete, V M; Hammer, J; Hänsel, S; Hartl, C; Hoch, M; Hörmann, N; Hrubec, J; Jeitler, M; Kasieczka, G; Kiesenhofer, W; Krammer, M; Liko, D; Mikulec, I; Pernicka, M; Rohringer, H; Schöfbeck, R; Strauss, J; Taurok, A; Teischinger, F; Waltenberger, W; Walzel, G; Widl, E; Wulz, C-E; Mossolov, V; Shumeiko, N; Gonzalez, J Suarez; Benucci, L; Ceard, L; De Wolf, E A; Janssen, X; Maes, T; Mucibello, L; Ochesanu, S; Roland, B; Rougny, R; Selvaggi, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Adler, V; Beauceron, S; Blyweert, S; D'Hondt, J; Devroede, O; Kalogeropoulos, A; Maes, J; Maes, M; Tavernier, S; Van Doninck, W; Van Mulders, P; Van Onsem, G P; Villella, I; Charaf, O; Clerbaux, B; De Lentdecker, G; Dero, V; Gay, A P R; Hammad, G H; Hreus, T; Marage, P E; Thomas, L; Vander Velde, C; Vanlaer, P; Wickens, J; Costantini, S; Grunewald, M; Klein, B; Marinov, A; Ryckbosch, D; Thyssen, F; Tytgat, M; Vanelderen, L; Verwilligen, P; Walsh, S; Zaganidis, N; Basegmez, S; Bruno, G; Caudron, J; De Favereau De Jeneret, J; Delaere, C; Demin, P; Favart, D; Giammanco, A; Grégoire, G; Hollar, J; Lemaitre, V; Militaru, O; Ovyn, S; Pagano, D; Pin, A; Piotrzkowski, K; Quertenmont, L; Schul, N; Beliy, N; Caebergs, T; Daubie, E; Alves, G A; De JesusDamiao, D; Pol, M E; Souza, M H G; Carvalho, W; Da Costa, E M; Martins, C De Oliveira; De Souza, S Fonseca; Mundim, L; Nogima, H; Oguri, V; Goicochea, J M Otalora; Da Silva, W L Prado; Santoro, A; Do Amaral, S M Silva; Sznajder, A; De Araujo, F Torres Da Silva; Dias, F A; Dias, M A F; Tomei, T R Fernandez Perez; Gregores, E M; Marinho, F; Novaes, S F; Padula, Sandra S; Darmenov, N; Dimitrov, L; Genchev, V; Iaydjiev, P; Piperov, S; Rodozov, M; Stoykova, S; Sultanov, G; Tcholakov, V; Trayanov, R; Vankov, I; Dyulendarova, M; Hadjiiska, R; Kozhuharov, V; Litov, L; Marinova, E; Mateev, M; Pavlov, B; Petkov, P; Bian, J G; Chen, G M; Chen, H S; Jiang, C H; Liang, D; Liang, S; Wang, J; Wang, J; Wang, X; Wang, Z; Yang, M; Zang, J; Zhang, Z; Ban, Y; Guo, S; Hu, Z; Li, W; Mao, Y; Qian, S J; Teng, H; Zhu, B; Cabrera, A; Moreno, B Gomez; Rios, A A Ocampo; Oliveros, A F Osorio; Sanabria, J C; Godinovic, N; Lelas, D; Lelas, K; Plestina, R; Polic, D; Puljak, I; Antunovic, Z; Dzelalija, M; Brigljevic, V; Duric, S; Kadija, K; Morovic, S; Attikis, A; Fereos, R; Galanti, M; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Rykaczewski, H; Abdel-basit, A; Assran, Y; Mahmoud, M A; Hektor, A; Kadastik, M; Kannike, K; Müntel, M; Raidal, M; Rebane, L; Azzolini, V; Eerola, P; Czellar, S; Härkönen, J; Heikkinen, A; Karimäki, V; Kinnunen, R; Klem, J; Kortelainen, M J; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Mäenpää, T; Tuominen, E; Tuominiemi, J; Tuovinen, E; Ungaro, D; Wendland, L; Banzuzi, K; Korpela, A; Tuuva, T; Sillou, D; Besancon, M; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Ferri, F; Ganjour, S; Gentit, F X; Givernaud, A; Gras, P; de Monchenault, G Hamel; Jarry, P; Locci, E; Malcles, J; Marionneau, M; Millischer, L; Rander, J; Rosowsky, A; Titov, M; Verrecchia, P; Baffioni, S; Bianchini, L; Bluj, M; Broutin, C; Busson, P; Charlot, C; Dobrzynski, L; de Cassagnac, R Granier; Haguenauer, M; Miné, P; Mironov, C; Ochando, C; Paganini, P; Sabes, D; Salerno, R; Sirois, Y; Thiebaux, C; Wyslouch, B; Zabi, A; Agram, J-L; Andrea, J; Besson, A; Bloch, D; Bodin, D; Brom, J-M; Cardaci, M; Chabert, E C; Collard, C; Conte, E; Drouhin, F; Ferro, C; Fontaine, J-C; Gelé, D; Goerlach, U; Greder, S; Juillot, P; Karim, M; Le Bihan, A-C; Mikami, Y; Van Hove, P; Fassi, F; Mercier, D; Baty, C; Beaupere, N; Bedjidian, M; Bondu, O; Boudoul, G; Boumediene, D; Brun, H; Chanon, N; Chierici, R; Contardo, D; Depasse, P; El Mamouni, H; Falkiewicz, A; Fay, J; Gascon, S; Ille, B; Kurca, T; Le Grand, T; Lethuillier, M; Mirabito, L; Perries, S; Sordini, V; Tosi, S; Tschudi, Y; Verdier, P; Xiao, H; Roinishvili, V; Anagnostou, G; Edelhoff, M; Feld, L; Heracleous, N; Hindrichs, O; Jussen, R; Klein, K; Merz, J; Mohr, N; Ostapchuk, A; Perieanu, A; Raupach, F; Sammet, J; Schael, S; Sprenger, D; Weber, H; Weber, M; Wittmer, B; Ata, M; Bender, W; Erdmann, M; Frangenheim, J; Hebbeker, T; Hinzmann, A; Hoepfner, K; Hof, C; Klimkovich, T; Klingebiel, D; Kreuzer, P; Lanske, D; Magass, C; Masetti, G; Merschmeyer, M; Meyer, A; Papacz, P; Pieta, H; Reithler, H; Schmitz, S A; Sonnenschein, L; Steggemann, J; Teyssier, D; Bontenackels, M; Davids, M; Duda, M; Flügge, G; Geenen, H; Giffels, M; Ahmad, W Haj; Heydhausen, D; Kress, T; Kuessel, Y; Linn, A; Nowack, A; Perchalla, L; Pooth, O; Rennefeld, J; Sauerland, P; Stahl, A; Thomas, M; Tornier, D; Zoeller, M H; Martin, M Aldaya; Behrenhoff, W; Behrens, U; Bergholz, M; Borras, K; Cakir, A; Campbell, A; Castro, E

2010-12-31

24

The Vioxx pharmaceutical scandal: Peterson v Merke Sharpe & Dohme (Aust) Pty Ltd (2010) 184 FCR 1.  

PubMed

In early March 2010, Federal Court Justice Jessup in Peterson v Merke Sharpe & Dohme (Aust) Pty Ltd (2010) 184 FCR 1 ruled that Merke Sharpe & Dohme Pty Ltd had produced a defective product contrary to the Trade Practices Act 1974 (Cth), the anti-arthritic drug Vioxx. Promoted as relieving arthritic pain without the side effect of gastric ulceration, the drug also doubled the risk of heart attack in those prescribed it. The court also heard that the manufacturing company had engaged in misleading practices to promote the prescription and usage of Vioxx, including "fake" journals and guidelines to "drug reps" that minimised the adverse cardiovascular risks. The manufacturer had already settled a class action in the United States for more than US$7 billion for those harmed by the drug but this was the first such case to be decided in Australia. The court awarded the applicant, Graeme Peterson, A$300,000 in damages. This column examines this judgment and analyses evidence there presented that Merck may have misled the scientific community, the medical profession and Australia's drug regulation system to get Vioxx on the market and keep it there. It considers whether the case reveals the need for more rigorous post-marketing surveillance and other changes to Australia's drug regulatory system, including a replacement of self-regulation in pharmaceutical promotion with a United States-style system of rewarded informant-led criminal penalties and civil damages claims. PMID:20977160

Faunce, Thomas; Townsend, Ruth; McEwan, Alexandra

2010-09-01

25

Arterial changes in the human vertebral body associated with aging. The ratios of peripheral to central arteries and arterial coiling.  

PubMed

Microarteriography with barium has shown the topgraphic distribution of intraosseous arteries in the cadaveric human vertebral body. Two types of intraosseous artery are found in the adult vertebral body, peripheral and central, whereas in children only central arteries are found. There is a close correlation (r = 0.79) between the ratios of peripheral: central arteries against age. The central arteries develop coils, which increase proportionately in number as age advances. The possible clinical significance of these observations is discussed. The increase in peripheral arteries alters the direction of flow from centrifugal to centripetal in the aged vertebral body; this has implications for the distribution of infected material, causing vertebral osteomyelitis, and for the distribution of electric surface charges, which will alter the mineralization of the vertebral body. The increase in coiling will alter intraosseous haemodynamics, potentially increasing resistance to flow resulting in ischaemia. The coils and their sheaths will modify the height of the pulse wave within the artery, increasing agitation of extracellular fluid, thus assisting the transport of metabolites. PMID:3715624

Ratcliffe, J F

1986-04-01

26

Broadly neutralizing hemagglutinin stalk-specific antibodies require Fc?R interactions for protection against influenza virus in vivo.  

PubMed

Neutralizing antibodies against influenza viruses have traditionally been thought to provide protection exclusively through their variable region; the contributions of mechanisms conferred by the Fc domain remain controversial. We investigated the in vivo contributions of Fc interactions with their cognate receptors for a collection of neutralizing anti-influenza antibodies. Whereas five broadly neutralizing monoclonal antibodies (bNAbs) targeting the conserved stalk region of hemagglutinin (HA) required interactions between the antibody Fc and Fc receptors for IgG (Fc?Rs) to confer protection from lethal H1N1 challenge, three strain-specific monoclonal Abs (mAbs) against the variable head domain of HA were equally protective in the presence or absence of Fc?R interactions. Although all antibodies blocked infection, only anti-stalk bNAbs were capable of mediating cytotoxicity of infected cells, which accounts for their Fc?R dependence. Immune complexes generated with anti-HA stalk mAb efficiently interacted with Fc?Rs, but anti-HA head immune complexes did not. These results suggest that Fc?R binding capacity by anti-HA antibodies was dependent on the interaction of the cognate Fab with antigen. We exploited these disparate mechanisms of mAb-mediated protection to reengineer an anti-stalk bNAb to selectively enhance Fc?R engagement to augment its protective activity. These findings reveal a previously uncharacterized property of bNAbs and guide an approach toward enhancing mAb-mediated antiviral therapeutics. PMID:24412922

DiLillo, David J; Tan, Gene S; Palese, Peter; Ravetch, Jeffrey V

2014-02-01

27

High aspect ratio template and method for producing same for central and peripheral nerve repair  

NASA Technical Reports Server (NTRS)

Millimeter to nano-scale structures manufactured using a multi-component polymer fiber matrix are disclosed. The use of dissimilar polymers allows the selective dissolution of the polymers at various stages of the manufacturing process. In one application, biocompatible matrixes may be formed with long pore length and small pore size. The manufacturing process begins with a first polymer fiber arranged in a matrix formed by a second polymer fiber. End caps may be attached to provide structural support and the polymer fiber matrix selectively dissolved away leaving only the long polymer fibers. These may be exposed to another product, such as a biocompatible gel to form a biocompatible matrix. The polymer fibers may then be selectively dissolved leaving only a biocompatible gel scaffold with the pores formed by the dissolved polymer fibers. The scaffolds may be used in, among other applications, the repair of central and peripheral nerves. Scaffolds for the repair of peripheral nerves may include a reservoir for the sustained release of nerve growth factor. The scaffolds may also include a multifunctional polyelectrolyte layer for the sustained release of nerve growth factor and enhance biocompatibility.

Sakamoto, Jeff S. (Inventor); Tuszynski, Mark Henry (Inventor); Gros, Thomas (Inventor); Chan, Christina (Inventor); Mehrotra, Sumit (Inventor)

2011-01-01

28

Ratios of effector to central memory antigen-specific CD4(+) T cells vary with antigen exposure in HIV+ patients.  

PubMed

The OX40/CD25 assay is a novel technique that assesses antigen-specific CD4(+) T-cell responses. To unequivocally demonstrate that responding cells are memory cells that become activated after secondary stimulation, naïve CD45RA(+) and memory CD45RO(+) populations were stimulated with cytomegalovirus (CMV) lysate and the combined expression of CD25 and OX40 measured. As expected, the naïve population showed very little response, whereas there was a higher response from the memory counterpart. To further elucidate CD4(+) memory T-cell subsets involved in recall responses, CD4(+) T cells were separated into central memory (Tcm) and effector memory (Tem) subsets and stimulated with antigen-pulsed antigen-presenting cells (APCs). CMV responses in healthy donors showed a Tem-dominant response with a Tem/Tcm ratio of 1.2, whereas the tetanus toxoid responses were dominated by a Tcm response with a Tem/Tcm ratio of 0.35. To determine memory response in the chronic of HIV infection, patient samples were used. A similar pattern to healthy donors was observed in seven chronic HIV+ patients at week 4 after anti-retroviral therapy who responded to CMV with a larger response coming from Tem. The pattern was similar after 48 weeks of therapy but the responses were lower in magnitude. In chronic HIV+ patients who respond to Gag peptides, following institution of therapy there was an inversion of the ratio of the responding memory subsets compared with week 4, with a greater response from Tcm at week 48. This result was concordant with reduction in antigen load. As immune activation decreased there was also a decrease in the percentage of responding effector memory cells and maintenance of long-term central memory. PMID:24492798

Phetsouphanh, Chansavath; Xu, Yin; Bailey, Michelle; Pett, Sarah; Zaunders, John; Seddiki, Nabila; Kelleher, Anthony D

2014-04-01

29

FUCHS ENDOTHELIAL CORNEAL DYSTROPHY: SUBJECTIVE GRADING VERSUS OBJECTIVE GRADING BASED ON THE CENTRAL TO PERIPHERAL THICKNESS RATIO  

PubMed Central

Purpose To assess inter-observer agreement between two corneal specialists grading Fuchs dystrophy clinically, and to determine if the corneal central to peripheral thickness ratio (CPTR) might be an alternative and objective metric of disease severity. Design Cross-sectional study. Participants Forty-five eyes (26 subjects) with mild and moderate Fuchs dystrophy, 73 eyes (60 subjects) with advanced Fuchs dystrophy, and 267 eyes (142 subjects) with normal corneas. Methods Corneas with Fuchs dystrophy were graded by two corneal specialists based on the confluence and area of guttae, and the presence or absence of edema. Central corneal thickness (CCT) and peripheral corneal thickness at 4 mm from the center (PCT4) were measured by using scanning-slit pachymetry. CPTR4 was the quotient of CCT and PCT4. Main Outcome Measures Inter-observer agreement for clinical grade; CPTR4. Results Inter-observer agreement for clinical grading of Fuchs dystrophy was moderate (?=0.32, 95% confidence interval, 0.19-0.45). In normal corneas, CCT was not correlated with age (r= -0.10, p=0.28, n=267), PCT4 decreased with age (r= -0.33, p<0.001, n=254), and CPTR4 increased with age (r= 0.59, p<0.001, n=254). CCT was higher in Fuchs dystrophy (652 ± 61 ?m, n=118) than in normal corneas (559 ± 31 ?m, n=267, p<0.001). PCT4 was higher in Fuchs dystrophy (650 ± 51 ?m, n=107) than in normal corneas (643 ± 43 ?m, n=254, p<0.001 after adjusting thickness for age). CPTR4 was higher in advanced Fuchs dystrophy (1.03 ± 0.07, n=65) than in mild and moderate Fuchs dystrophy (0.95 ± 0.07, n=42, age-adjusted p<0.001), which in turn was higher than in normal corneas (0.87 ± 0.05, n=254, age-adjusted p<0.001). CPTR4 was highly correlated with clinical grade of Fuchs dystrophy (r=0.77, p<0.001, n=361). CPTR4 was repeatable (median coefficient of variation, 1.3%), and provided excellent discrimination between Fuchs dystrophy and normal (area under the receiver operator characteristic curve, 0.93). Conclusions Agreement between corneal specialists for the subjective and morphologic clinical grading of Fuchs dystrophy is only moderate. The corneal CPTR is an objective, repeatable, and possibly functional, metric of severity of Fuchs dystrophy that warrants further investigation to determine its role in monitoring disease progression and predicting the need for keratoplasty.

Repp, Daniel J.; Hodge, David O.; Baratz, Keith H.; McLaren, Jay W.; Patel, Sanjay V.

2012-01-01

30

Central axis tissue-air ratios as a function of area\\/perimeter at depth and their applicability to irregularly shaped fields  

Microsoft Academic Search

Families of central axis tissue-air ratio (TAR) curves as a function of area at depth, divided by perimeter (A\\/P) for fixed values of depth, were plotted and tabulated using the original data of Gupta and Cunningham for square fields. By means of an isodose plotter, values of TAR were experimentally obtained up to depths of 30 cm for mantle field,

D E Wrede

1972-01-01

31

Chemoimmunotherapy with oral low-dose fludarabine, cyclophosphamide and rituximab (old-FCR) as treatment for elderly patients with chronic lymphocytic leukaemia.  

PubMed

Median age at diagnosis for chronic lymphocytic leukaemia (CLL) patients is now 72 years, thus a consistent number of patients may not tolerate standard doses i.v. of fludarabine, cyclophosphamide and rituximab (FCR), the best available therapy, due to unacceptable myelotoxicity and risk of severe infections. We studied safety and efficacy of the addition of rituximab to the oral low-dose FC regimen (old-FCR) in a selected population of 30 elderly (median age 75, 15 untreated, 15 treated with 1 prior therapy) CLL patients. Complete remission (CR) rate was 80% in the untreated patients (overall response rate, ORR 93%), and 30% in pretreated patients (ORR 74%). Progression free survivals (PFS) were 45 months and 30 months in the untreated and treated patients, respectively. In patients achieving CR, old-FCR led to PFS of 67 months. Moreover, haematological toxicity was mild (grade 3-4: 15%) and patients were treated mostly in outpatient clinic. Old-FCR could be a good therapy option for elderly CLL patients outside clinical trials, larger studies are needed to confirm our findings. PMID:24934847

Gozzetti, Alessandro; Candi, Veronica; Fabbri, Alberto; Schiattone, Luana; Cencini, Emanuele; Lauria, Francesco; Frasconi, Adele; Crupi, Rosaria; Raspadori, Donatella; Papini, Giulia; Defina, Marzia; Bartalucci, Giulia; Bocchia, Monica

2014-08-01

32

Explanation of the Central Charge Ratio 27/32 in Four-Dimensional Renormalization Group Flows between Superconformal Theories  

SciTech Connect

We show that when a four-dimensional N=2 superconformal field theory (SCFT) flows to an N=1 SCFT via giving a mass to the adjoint chiral superfield in a vector multiplet with marginal coupling, the central charges a and c of the N=2 theory are related to those of the N=1 theory by a universal linear transformation as long as there are no accidental symmetries in the infrared. In the large N limit, this relationship implies that the central charges obey a{sub IR}/a{sub UV}=c{sub IR}/c{sub UV}=27/32. This gives a physical explanation to many examples of this number found in the literature, and also suggests the existence of a flow between some theories not previously thought to be connected.

Tachikawa, Yuji; Wecht, Brian [School of Natural Sciences, Institute for Advanced Study, Princeton, New Jersey 08450 (United States)

2009-08-07

33

Ratios of Peripheral-to-Central Airway Lumen Area and Percentage Wall Area as Predictors of Severity of Chronic Obstructive Pulmonary Disease.  

PubMed

OBJECTIVE. The purpose of this study was to assess the ability of the ratios of peripheral-to-central airway lumen area (hereafter referred to as LA) and percentage wall area (hereafter referred to as %WA) to predict the severity of chronic obstructive pulmonary disease (COPD) according to Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines. SUBJECTS AND METHODS. We examined 32 patients (27 men and five women; mean age ± SD, 70.0 ± 6.8 years; seven GOLD stage 0 [at risk for COPD], 19 GOLD stage 1-2 [mild to moderate airflow limitation], and six GOLD stage 3-4 [severe to very severe airflow limitation]) using inspiratory CT. Mean LA and %WA were measured for the first (main bronchi), third, and fifth generations of five bronchi in each lobe and the ratios of peripheral to central airways were calculated (third to first, fifth to first, and fifth to third) and statistically compared. RESULTS. The fifth-generation LA, LA fifth to first, and LA fifth to third significantly decreased and fifth %WA, %WA fifth to first, and %WA fifth to third also increased with progression of GOLD stage (p < 0.05), but central measurements, including first and third generations, did not. There were significant differences between GOLD 0 and GOLD 1-2 for %WA fifth to third and LA fifth to third and between GOLD 0 and GOLD 3-4 for all six parameters (p < 0.05); %WA fifth to third had the best cutoff value of 1.02 (sensitivity, 92%; specificity, 86%) for diagnosis of COPD (GOLD 1-4). The %WA fifth to first of 1.51 (sensitivity, 83%; specificity, 89%) was best for diagnosis of GOLD 3-4. CONCLUSION. Ratios of peripheral-to-central airway LA and %WA show improved correlation with COPD severity. PMID:24951198

Sasaki, Tomoaki; Takahashi, Koji; Takada, Nobuhisa; Ohsaki, Yoshinobu

2014-07-01

34

Age, growth, sex ratio, and maturity of the whitefish in central Green Bay and adjacent waters of Lake Michigan  

USGS Publications Warehouse

This study is based on 1,023 whitefish, Coregonus clupeaformis (Mitchill)--819 in seven samples from five localitites in central Green Bay in 1948-49 and 1851-52 and 204 in a single 1948 collection from northwestern Lake Michigan proper. Records of age indicated unusual strength for only one year class--1943 which strongly dominated the 1948 sample from Lake Michigan and the 1949 sample from Green Bay and was well represented in the 1948 collection from green Bay. Collection of 1951-52 without exception were dominated by age group III. Length distributions of samples varied widely according to the age composition. Among fish more than 2 years old, the length distributions of age groups overlapped broadly. Several 1-inch intervals included fish of four age groups. The length-weight relation varied considerably among central Green Bay samples, but differences among localitites were nearly equalled by the year-to-year difference at a single locality. Lake Michigan whitefish were generally lighter than those from Green Bay. Weight increased to the 3.386 power of length in Green Bay (combined samples) and the 3.359 power in Lake Michigan. Growth in length, calculated by direct proportion from diameter measurements of growth fields on scales, differed among localities in central Green Bay and between samples of different years at a single locality. If permanent locality differences exist they are not large and can be obscured by the evident annual fluctuations of growth. The grand average calculated length of Green Bay whitefish (combined collections) exceeded that of Lake Michigan fish in all years of life. The advantage was greatest (2.2 inches) at 3 years (calculated lengths of 16.0 inches and 13.8 inches) and subsequently declined to 0.5 inch at 9 years (lengths of 24.6 and 24.1 inches). Both groups reached the minimum legal length of 17 inches during the fourth growing season. Green Bay whitefish also had the larger calculated weights. The advantage reached 9.3 ounces in 3 years (calculated weights of 22.4 and 13.1 ounces). In years of life 4-9, the weight advantage over Lake Michigan fish ranged from 8.7 ounces, (seventh year; weights of 74.4 and 65.7 ounces) to 12.2 ounces (ninth year; weights of 96.2 and 84.0 ounces). Comparison of growth of whitefish at four localities in northern Lake Michigan indicates that fastest growth is in central Green Bay and slowest near the Fox Islands. Growth is intermediate and similar in northwestern Lake Michigan proper and sorthern Green Bay. Youngest mature male whitefish in green Bay belonged to age group II and youngest mature females to age group III. All IV-group fish were mature. Shortest mature males were at 14.5-14.9 inches and shortest mature females at 16.5-16.9 inches. All males longer than 17.9 inches and all females longer than 18.4 inches were mature.

Mraz, Donald

1964-01-01

35

A PKC-SHP1 signaling axis desensitizes Fc? receptor signaling by reducing the tyrosine phosphorylation of CBL and regulates Fc?R mediated phagocytosis  

PubMed Central

Background Fc? receptors mediate important biological signals in myeloid cells including the ingestion of microorganisms through a process of phagocytosis. It is well-known that Fc? receptor (Fc?R) crosslinking induces the tyrosine phosphorylation of CBL which is associated with Fc?R mediated phagocytosis, however how signaling molecules coordinate to desensitize these receptors is unclear. An investigation of the mechanisms involved in receptor desensitization will provide new insight into potential mechanisms by which signaling molecules may downregulate tyrosine phosphorylation dependent signaling events to terminate important signaling processes. Results Using the U937IF cell line, we observed that Fc?R1 crosslinking induces the tyrosine phosphorylation of CBL, which is maximal at 5 min. followed by a kinetic pattern of dephosphorylation. An investigation of the mechanisms involved in receptor desensitization revealed that pretreatment of U937IF or J774 cells with PMA followed by Fc? receptor crosslinking results in the reduced tyrosine phosphorylation of CBL and the abrogation of downstream signals, such as CBL-CRKL binding, Rac-GTP activation and the phagocytic response. Pretreatment of J774 cells with GF109203X, a PKC inhibitor was observed to block dephosphorylation of CBL and rescued the phagocytic response. We demonstrate that the PKC induced desensitization of Fc?R/ phagocytosis is associated with the inactivation of Rac-GTP, which is deactivated in a hematopoietic specific phosphatase SHP1 dependent manner following ITAM stimulation. The effect of PKC on Fc?R signaling is augmented by the transfection of catalytically active SHP1 and not by the transfection of catalytic dead SHP1 (C124S). Conclusions Our results suggest a functional model by which PKC interacts with SHP1 to affect the phosphorylation state of CBL, the activation state of Rac and the negative regulation of ITAM signaling i.e. Fc? receptor mediated phagocytosis. These findings suggest a mechanism for Fc? receptor desensitization by which a serine-threonine kinase e.g. PKC downregulates tyrosine phosphorylation dependent signaling events via the reduced tyrosine phosphorylation of the complex adapter protein, CBL.

2014-01-01

36

Temporal evolution of lead isotope ratios in sediments of the Central Portuguese Margin: a fingerprint of human activities.  

PubMed

Stable Pb isotope ratios ((206)Pb/(207)Pb, (208)Pb/(206)Pb), (210)Pb, Pb, Al, Ca, Fe, Mn and Si concentrations were measured in 7 sediment cores from the west coast of the Iberian Peninsula to assess the Pb contamination throughout the last 200 years. Independently of their locations, all cores are characterized by increasing Pb/Al rends not related to grain-size changes. Conversely, decreasing trends of (206)Pb/(207)Pb were found towards the present. This tendency suggest a change in Pb sources reflecting an increased proportion derived from anthropogenic activities. The highest anthropogenic Pb inventories for sediments younger than 1950s were found in the two shallowest cores of Cascais and Lisboa submarine canyons, reflecting the proximity of the Tagus estuary. Lead isotope signatures also help demonstrate that sediments contaminated with Pb are not constrained to estuarine-coastal areas and upper parts of submarine canyons, but are also to transferred to a lesser extent to deeper parts of the Portuguese Margin. PMID:23871578

Mil-Homens, Mário; Caetano, Miguel; Costa, Ana M; Lebreiro, Susana; Richter, Thomas; de Stigter, Henko; Trancoso, Maria A; Brito, Pedro

2013-09-15

37

Loss of DAP12 and FcR? Drives Exaggerated IL-12 Production and CD8+ T Cell Response by CCR2+ Mo-DCs  

PubMed Central

Dap12 and FcR?, the two transmembrane ITAM-containing signaling adaptors expressed in dendritic cells (DC), are implicated in the regulation of DC function. Several activating and adhesion receptors including integrins require these chains for their function in triggering downstream signaling and effector pathways, however the exact role(s) for Dap12 and FcR? remains elusive as their loss can lead to both attenuating and enhancing effects. Here, we report that mice congenitally lacking both Dap12 and FcR? chains (DF) show a massively enhanced effector CD8+ T cell response to protein antigen immunization or West Nile Virus (WNV) infection. Thus, immunization of DF mice with MHCI-restricted OVA peptide leads to accumulation of IL-12-producing monocyte-derived dendritic cells (Mo-DC) in draining lymph nodes, followed by vastly enhanced generation of antigen-specific IFN?-producing CD8+ T cells. Moreover, DF mice show increased viral clearance in the WNV infection model. Depletion of CCR2+ monocytes/macrophages in vivo by administration anti-CCR2 antibodies or clodronate liposomes completely prevents the exaggerated CD8+ T cell response in DF mice. Mechanistically, we show that the loss of Dap12 and FcR?-mediated signals in Mo-DC leads to a disruption of GM-CSF receptor-induced STAT5 activation resulting in upregulation of expression of IRF8, a transcription factor. Consequently, Dap12- and FcR?-deficiency exacerbates GM-CSF-driven monocyte differentiation and production of inflammatory Mo-DC. Our data suggest a novel cross-talk between DC-ITAM and GM-CSF signaling pathways, which controls Mo-DC differentiation, IL-12 production, and CD8+ T cell responses.

Gmyrek, Grzegorz B.; Akilesh, Holly M.; Graham, Daniel B.; Fuchs, Anja; Yang, Lihua; Miller, Mark J.; Sandoval, Gabriel J.; Sheehan, Kathleen C. F.; Schreiber, Robert D.; Diamond, Michael S.; Swat, Wojciech

2013-01-01

38

How to determine post-FCR therapy for cytogenetic risk-tailored elderly patients with chronic lymphocytic leukemia, maintenance rituximab or observation.  

PubMed

The open-label, prospective, observational study aimed to evaluate whether the addition of maintenance rituximab (MR) improved progression-free survival (PFS) and overall survival (OS), after fludarabine, cyclophosphamide, and rituximab (FCR) for cytogenetic risk-tailored elderly patients with chronic lymphocytic leukemia (CLL). Enrolled 201 patients (ages 65-84 years) who received FCR and gained an overall response. One hundred and four of 201 patients were in the observation (OBS) arm while 97/201 patients continued to receive MR therapy. After FCR, no more benefits were provided by MR versus OBS in cytogenetic better intermediate-risk cohort. PFS at 10 years reached 68.6 versus 58.1 % (P > 0.05). Ten-year OS was 81.8 versus 74.6 % (P > 0.05). However, the improvement of PFS and OS were as dramatic as the improvements of being MR treating versus OBS mainly in the poor-risk cohort. PFS at 10 years reached 57.1 versus 22.7 % (P < 0.01), and 10-year OS was 71.2 versus 41.7 % (P < 0.01). Compared with OBS, no severe hematologic adverse events (AEs) (Grades 3-4) appeared in patients with MR; only some mild non-hematologic AEs incurred (nausea-vomiting 0.96 %, allergy 1.9 % and infection 1.9 %) during the maintenance treatment. The study showed that MR improved 10-year RFS and OS for cytogenetic poor-risk patients with CLL. PMID:24985882

Huang, Bin-Tao; Zeng, Qing-Chun; Zhao, Wei-Hong; Li, Bing-Sheng; Chen, Rui-Lin

2014-08-01

39

From emissions to ambient mixing ratios: on-line seasonal field measurements of volatile organic compounds over a Norway spruce dominated forest in central Germany  

NASA Astrophysics Data System (ADS)

Biogenic volatile organic compounds (BVOC) are substantial contributors to atmospheric chemistry and physics and demonstrate the close relationship between biosphere and atmosphere. Their emission rates are highly sensitive to meteorological and environmental changes with concomitant impacts on atmospheric chemistry. We have investigated seasonal isoprenoid and oxygenated VOC (oxVOC) fluxes from a Norway spruce (Picea abies) tree in Central Germany and explored the emission responses under various atmospheric conditions. Emission rates were quantified by using dynamic branch enclosure and Proton Transfer Reaction-Mass Spectrometry (PTR-MS) techniques. Additionally, ambient mixing ratios were derived through application of a new box model treatment on the dynamic chamber measurements. These are compared in terms of abundance and origin with the corresponding emissions. Isoprenoids govern the BVOC emissions from Norway spruce, with monoterpenes and sesquiterpenes accounting for 50.8 ± 7.2% and 19.8 ± 8.1% respectively of the total emissions. Normalizing the VOC emission rates, we have observed a trend of reduction of carbon containing emissions from April to November, with an enhancement of oxVOC. Highest emission rates were observed in June for all measured species, with the exception of sesquiterpenes that were emitted most strongly in April. We exploit the wide range of conditions experienced at the site to filter the dataset with a combination of temperature, ozone and absolute humidity values in order to derive the emission potential and temperature dependency development for the major chemical species investigated. A profound reduction of monoterpene emission potential (E30) and temperature dependency (?) was found under low temperature regimes, combined with low ozone levels (E30MT, LTLO3=56 ± 9.1 ng g(dw)-1 h-1, ?MT,LTLO3=0.03±0.01 K-1) while a combination of both stresses was found to alter their emissions responses with respect to temperature substantially (E30MT,HTHO3=1420.1 ± 191.4 ng g(dw)-1 h-1, ?MT,HTHO3=0.15 ± 0.02 K-1). Moreover, we have explored compound relationships under different atmospheric condition sets, addressing possible co-occurrence of emissions under specific conditions. Finally, we evaluate the temperature dependent algorithm that seems to describe the temperature dependent emissions. Highest emission deviations were observed for monoterpenes and these emission fluctuations were attributed to a fraction which is triggered by an additional light dependency.

Bourtsoukidis, E.; Williams, J.; Kesselmeier, J.; Jacobi, S.; Bonn, B.

2013-11-01

40

IgE receptors (FcR epsilon) modifications. I. Effect of regulator soluble factors of human IgE synthesis isolated by affinity chromatography.  

PubMed

After isolating the soluble factors and observing their biological activity of "in vitro" IgE synthesis, we decided to study the changes these molecules exercise on the expression of lymphocytes of IgE (FcR epsilon). We saw that the fractions from healthy subjects inhibited the expression of receptors quantified by immunofluorescence, reducing it to 15.5 and 15.75 (p less than 0.01). Three of the fractions from atopic individuals also inhibited this expression, with some average values of 13.75, 11.25 and 15.25, against 23 as the basal levels. Material from pollinic patients acted similarly, obtaining expression percentages of 13 and 14.5 (p less than 0.01). These findings, along with those obtained in the experiment of IgE synthesis, confirmed the presence of regulator factors in IgE synthesis in the 3 population groups, quantitatively different. These factors will be isotype specific and just as what happened in IgG synthesis, there was no modification in the expression of the mentioned immunoglobulin. PMID:2143350

Tabar, A I; Sanz, M L; Oehling, A

1990-01-01

41

Estimation of the Optimal Ratio of Standardized Ileal Digestible Threonine to Lysine for Finishing Barrows Fed Low Crude Protein Diets  

PubMed Central

Two experiments were conducted to determine the standardized ileal digestible (SID) lysine (Lys) requirement and the ideal SID threonine (Thr) to Lys ratio for finishing barrows. In Exp. 1, 120 barrows with an average body weight of 72.8±3.6 kg were allotted to one of six dietary treatments in a randomized complete block design conducted for 35 d. Each diet was fed to five pens of pigs containing four barrows. A normal crude protein (CP) diet providing 15.3% CP and 0.71% SID Lys and five low CP diets providing 12% CP with SID Lys concentrations of 0.51, 0.61, 0.71, 0.81 and 0.91% were formulated. Increasing the SID Lys content of the diet resulted in an increase in weight gain (linear effect p = 0.04 and quadratic effect p = 0.08) and an improvement in feed conversion ratio (FCR) (linear effect p = 0.02 and quadratic effect p = 0.02). For weight gain and FCR, the estimated SID Lys requirement of finishing barrows were 0.71 and 0.71% (linear broken-line analysis), 0.79 and 0.78% (quadratic analysis), respectively. Exp. 2 was a 26 d dose-response study using SID Thr to Lys ratios of 0.56, 0.61, 0.67, 0.72 and 0.77. A total of 138 barrows weighing 72.5±4.4 kg were randomly allotted to receive one of the five diets. All diets were formulated to contain 0.61% SID Lys (10.5% CP), which is slightly lower than the pig’s requirement. Weight gain was quadratically (p = 0.03) affected by SID Thr to Lys ratio while FCR was linearly improved (p = 0.02). The SID Thr to Lys ratios for maximal weight gain and minimal FCR and serum urea nitrogen (SUN) were 0.67, 0.71 and 0.64 using a linear broken-line model and 0.68, 0.78 and 0.70 using a quadratic model, respectively. Based on the estimates obtained from the broken-line and quadratic analysis, we concluded that the dietary SID Lys requirement for both maximum weight gain and minimum FCR was 0.75%, and an optimum SID Thr to Lys ratio was 0.68 to maximize weight gain, 0.75 to optimize FCR and 0.67 to minimize SUN for finishing barrows.

Xie, Chunyuan; Zhang, Shihai; Zhang, Guijie; Zhang, Fengrui; Chu, Licui; Qiao, Shiyan

2013-01-01

42

First Measurement of the Ratio of Central-Electron to Forward-Electron W Partial Cross Sections in p anti-p Collisions at s**(1/2) = 1.96 TeV  

SciTech Connect

We present a measurement of {sigma}(p{bar p} {yields} W) x {Beta}(W {yields} e{nu}) at {radical}s = 1.96 TeV, using electrons identified in the forward region (1.2 < |{eta}| < 2.8) of the CDF II detector. The data correspond to an integrated luminosity of 223 pb{sup -1}. We measure {sigma} x {Beta} = 2796 {+-} 13(stat){sub -90}{sup +95}(syst){+-}162 (lum) pb. Combining this result with a previous CDF measurement obtained using electrons in the central region (|{eta}| {approx}< 1), we present the first measurement of the ratio of central-electron to forward-electron W partial cross sections R{sub exp} = 0.925 {+-} 0.006(stat){+-}0.032(syst), consistent with theoretical predictions using CTEQ and MRST parton distribution functions.

Abulencia, A.; Adelman, J.; Affolder, T.; Akimoto, T.; Albrow, M.G.; Ambrose, D.; Amerio, S.; Amidei, D.; Anastassov, A.; Anikeev, K.; Annovi, A.; /Taiwan, Inst. Phys. /Argonne /Barcelona, IFAE /Baylor U. /INFN, Bologna /Bologna U. /Brandeis U. /UC, Davis /UCLA /UC, San Diego /UC, Santa Barbara

2007-02-01

43

Relationship between hypocentral distributions and Vp/Vs ratio structures inferred from dense seismic array data: a case study of the 1984 western Nagano Prefecture earthquake, central Japan  

NASA Astrophysics Data System (ADS)

We conducted a three-dimensional traveltime tomographic reconstruction in and around the source region of the 1984 western Nagano Prefecture earthquake to investigate the generation process for the main shock and associated swarm activity. Up to 220 000 high-resolution traveltime records (2 ms error) were compiled from a dense seismic network. From these records, we performed accurate, high-resolution calculations to estimate hypocentre distributions and three-dimensional velocity structure. Most hypocentres aligned along the same path or within the same plane, rather than in three-dimensional clusters. Hypocentres in the swarm region are located in regions with low Vp/Vs ratios, while few earthquakes occurred in regions with high or normal Vp/Vs ratios. We suggest that differences in the number of small fractures and fluid content between these two regions influenced the seismic activity. Rupture propagation associated with the main shock appears to be confined by relatively higher Vp/Vs surroundings, and a low-velocity region which limits its vertical extent.

Doi, Issei; Noda, Shunta; Iio, Yoshihisa; Horiuchi, Shigeki; Sekiguchi, Shoji

2013-11-01

44

Lipid D/H Ratios from Multiple Sources and Deposits Indicate Drier Little Ice Age at Washington Island (4°43`N, 160°25`W), Central Pacific  

NASA Astrophysics Data System (ADS)

To compare the sensitivity of biomarker D/H ratios from two distinct climate archives, a lake and a peat bog on the Tropical Pacific Island of Terrania, compound-specific hydrogen isotope ratios (expressed as ?D values) were determined on lipid biomarkers from various biological sources deposited in the two climate archives. At present, Terrania or Washington Island (4°43`N, 160°25`W) permanently lies in the intertropical convergence zone (ITCZ) and receives an annual precipitation of 2,903 mm. The interior of this lens shaped island contains a freshwater lake and peat bogs. Previous studies on the lake sediments found evidence for a substantially drier climate at times during the Little Ice Age (AD 1400-1850) based on the lithologic transition from modern freshwater sediments to a sequence of pure cyanobacterial mat in concert with ?D values from total lipid extracts (Sachs et al., 2009). Here we report on ?D values from lipids of various sources: dinoflagellate algae (dinosterol and a saturated C30 sterol (4? -methyl-24-ethyl-5? -cholestan-3?-ol), microbial sources (diploptene and nC21 alkane) and higher plants (fern-7-ene, ?-sitosterol and stigmastanol). Mean ?D values from all lipids, measured in both archives, are significantly enriched in deuterium by between 22 and 86‰ during previously inferred drier climate conditions and simultaneously record the transition towards a freshwater lake at around AD1550. Measured ?D values of all lipids cover a wide range from -281‰ to -105‰ during freshwater deposition and from -185‰ to -50‰ when climate was drier. In agreement with the observed isotopic difference between lipids produced via the acetogenic and the mevalonic acid biosynthetic pathway ?D values for algae and higher plant sterols are depleted in deuterium relative to the nC21 alkane by 150‰ on average. The consistent ?D values from dinosterol and 4? -methyl-24-ethyl-5? -cholestan-3?-ol from the lake and peat deposits signify the robustness of these lipid ?D values to indicate hydrologic changes in the sedimentary record. ?D values among lipids of similar and disparate sources and/or biosynthetic origin from Washington Island lake (AD ~ 800-1550) and peat bog (AD~1200-1660) sediments are significantly enriched in deuterium prior to AD 1560/1640 and thus both suggest drier climate conditions resembling today’s environmental and depositional setting at Christmas Island which is located 300km SSE of Washington Island beyond the influence of the ITCZ.

Muegler, I.; Sachse, D.; Sachs, J. P.

2010-12-01

45

Further Evidence for Large Central Mass-to-light Ratios in Early-type Galaxies: The Case of Ellipticals and Lenticulars in the A262 Cluster  

NASA Astrophysics Data System (ADS)

We present new radially resolved spectroscopy of eight early-type galaxies in the A262 cluster. The measurements include stellar rotation, velocity dispersion, H 3 and H 4 coefficients of the line-of-sight velocity distribution along the major and minor axes and an intermediate axis as well as line-strength index profiles of Mg, Fe, and H?. The ionized-gas velocity and velocity dispersion is measured for six sample galaxies along different axes. We derive dynamical mass-to-light ratios and dark matter densities from orbit-based dynamical models, complemented by the galaxies' ages, metallicities, and ?-element abundances from single stellar-population models. The ionized-gas kinematics give a valuable consistency check for the model assumptions about orientation and intrinsic shape of the galaxies. Four galaxies have a significant detection of dark matter and their halos are about 10 times denser than in spirals of the same stellar mass. By calibrating dark matter densities to cosmological simulations we find assembly redshifts of z DM ? 1-3, as previously reported for the Coma Cluster. The dynamical mass that follows the light is larger than expected for a Kroupa stellar initial mass function (IMF), especially in galaxies with high velocity dispersion ?eff inside the effective radius r eff. This could indicate a "massive" IMF in massive galaxies. Alternatively, some of the dark matter in massive galaxies could follow the light very closely. In combination with our comparison sample of Coma early-type galaxies, we now have 5 of 24 galaxies where (1) mass follows light to 1-3 r eff, (2) the dynamical mass-to-light ratio of all the mass that follows the light is large (?8-10 in the Kron-Cousins R band), and (3) the dark matter fraction is negligible to 1-3 r eff. Unless the IMF in these galaxies is particularly "massive" and somehow coupled to the dark matter content, there seems to be a significant degeneracy between luminous and dark matter in at least some early-type galaxies. The role of violent relaxation is briefly discussed. Based on data collected with the 2.4 m Hiltner Telescope.

Wegner, G. A.; Corsini, E. M.; Thomas, J.; Saglia, R. P.; Bender, R.; Pu, S. B.

2012-09-01

46

The fate of atmospherically derived pb in central European catchments: insights from spatial and temporal pollution gradients and pb isotope ratios.  

PubMed

Soils in polluted regions are generally regarded as a delayed, long-lasting source for Pb contamination of aquatic systems. Lead deposited on topsoil is slowly transported downward with particulate and colloidal organic matter, driven by infiltrating precipitation. Then, Pb is tightly retained in mineral soil. Lead export from catchments is extremely low and decoupled from the atmospheric input. We tested this hypothesis in 11 small catchments, differing in pollution levels. Input/ouput Pb fluxes were monitored for 14-15 years in an era of decreasing industrial Pb emission rates. Between 1996/1997 and 2010, Pb deposition fluxes decreased significantly, on average by 80%. At the beginning of the monitoring, Pb export constituted 2 to 58% of Pb input. At the end of the monitoring, Pb export constituted 2 to 95% of Pb input. Highly polluted sites in the northeast exported significantly more Pb than less polluted sites further south. The (206)Pb/(207)Pb isotope ratios of runoff (1.16) were identical to those of topsoil and present-day deposition, and different from mineral soil and bedrock. Lead isotope systematics and between-site flux comparisons indicated that a portion of the incoming Pb had a relatively short residence time in the catchments, on the order of decades. PMID:24660842

Bohdalkova, Leona; Novak, Martin; Stepanova, Marketa; Fottova, Daniela; Chrastny, Vladislav; Mikova, Jitka; Kubena, Ales A

2014-04-15

47

Lightning Ratios  

NSDL National Science Digital Library

Using satellites and ground-based detection instruments, researchers have now mapped out lightning ratios for the continental United States. The Lightning Ratios site, from Space Science News (NASA), provides recent data in the form of a vibrant color map (.pdf or .jpg) of cloud-to-cloud lightning to cloud-to-ground lightning over the continental United States.

48

Dietary methionine and n-6/n-3 polyunsaturated fatty acid ratio reduce adverse effects of infectious bursal disease in broilers.  

PubMed

This study was carried out to investigate the modulatory effects of dietary methionine and n-6/n-3 polyunsaturated fatty acids (PUFA) ratio on immune response and performance of infectious bursal disease (IBD)-challenged broiler chickens. In total, 350 one-day-old male broiler chicks were assigned to 1 of the 6 dietary treatment groups in a 3 × 2 factorial arrangement. There were 3 n-6/n-3 PUFA ratios (45, 5.5, and 1.5) and 2 levels of methionine (NRC recommendation and twice NRC recommendation). The results showed that birds fed with dietary n-6/n-3 PUFA ratio of 5.5 had higher BW, lower feed intake, and superior FCR than other groups. However, the highest antibody response was observed in birds with dietary n-6/n-3 PUFA ratio of 1.5. Lowering n-6/n-3 PUFA ratio reduced bursa lesion score equally in birds fed with n-6/n-3 PUFA ratio of 5.5 and 1.5. Supplementation of methionine by twice the recommendation also improved FCR and reduced feed intake and bursa lesion score. However, in this study, the optimum performance (as measured by BW, feed intake, and FCR) did not coincide with the optimum immune response (as measured by antibody titer). It seems that dietary n-3 PUFA modulates the broiler chicken performance and immune response in a dose-dependent but nonlinear manner. Therefore, it can be suggested that a balance of moderate level of dietary n-6/n-3 PUFA ratio (5.5) and methionine level (twice recommendation) might enhance immune response together with performance in IBD-challenged broiler chickens. PMID:22912451

Maroufyan, E; Kasim, A; Ebrahimi, M; Loh, T C; Hair-Bejo, M; Soleimani, A F

2012-09-01

49

Energy dependence of kaon-to-proton ratio fluctuations in central Pb+Pb collisions from {radical}(s{sub NN})=6.3 to 17.3 GeV  

SciTech Connect

Kaons and protons carry large parts of two conserved quantities: strangeness and baryon number. It is argued that their correlation and thus also fluctuations are sensitive to conditions prevailing at the anticipated parton-hadron phase boundary. Fluctuations of the (K{sup +}+K{sup -})/(p+p) and K{sup +}/p ratios have been measured for the first time by NA49 in central Pb+Pb collisions at five CERN Super Proton Synchrotron energies between {radical}(s{sub N{sub N}})=6.3 and {radical}(s{sub N{sub N}})=17.3 GeV. Both ratios exhibit a change of sign in {sigma}{sub dyn}, a measure of nonstatistical fluctuations, around {radical}(s{sub N{sub N}})=8 GeV. Below this energy, {sigma}{sub dyn} is positive, indicating higher fluctuation compared to a mixed event background sample, while for higher energies, {sigma}{sub dyn} is negative, indicating correlated emission of kaons and protons. The results are compared to hadronic transport model calculations which fail to reproduce the energy dependence.

Anticic, T.; Kadija, K.; Nicolic, V.; Susa, T. [Rudjer Boskovic Institute, Zagreb (Croatia); Baatar, B.; Kolesnikov, V. I.; Malakhov, A. I.; Melkumov, G. L. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Barna, D.; Fodor, Z.; Laszlo, A.; Palla, G.; Sikler, F.; Veres, G. I.; Vesztergombi, G. [KFKI Research Institute for Particle and Nuclear Physics, Budapest (Hungary); Bartke, J.; Kowalski, M.; Rybicki, A. [H. Niewodniczanski Institute of Nuclear Physics, Polish Academy of Sciences, Cracow (Poland); Beck, H.; Blume, C. [Fachbereich Physik der Universitaet, Frankfurt (Germany)

2011-06-15

50

Radius Ratio  

NSDL National Science Digital Library

This is a set of animations that demonstrates properties of the spherical holes formed when uniform spheres are packed. Cubic, octahedral and tetrahedral packing arrangements may be examined without anything in the holes,and with the repective holes filled. The sizes of the various holes relative to the spheres being packed are shown, which can lead students into an exploration of the radius ratio concept. An example is given of computing the relative size of an octahedral hole.

51

Absence of Fc epsilonRI alpha chain results in upregulation of Fc gammaRIII-dependent mast cell degranulation and anaphylaxis. Evidence of competition between Fc epsilonRI and Fc gammaRIII for limiting amounts of FcR beta and gamma chains.  

PubMed Central

In mouse mast cells, both Fc epsilonRI and Fc gammaRIII are alpha beta gamma2 tetrameric complexes in which different alpha chains confer IgE or IgG ligand recognition while the signaling FcR beta and gamma chains are identical. We used primarily noninvasive techniques (changes in body temperature, dye extravasation) to assess systemic anaphylactic responses in nonanesthetized wild-type, Fc epsilonRI alpha chain -/- and FcR gamma chain -/- mice. We confirm that systemic anaphylaxis in mice can be mediated largely through IgG1 and Fc gammaRIII and we provide direct evidence that these responses reflect activation of Fc gammaRIII rather than Fc gammaRI. Furthermore, we show that Fc gammaRIII-dependent responses are more intense in normal than in congenic mast cell-deficient KitW/KitW-v mice, indicating that Fc gammaRIII responses have mast cell-dependent and -independent components. Finally, we demonstrate that the upregulation of cell surface expression of Fc gammaRIII seen in Fc epsilonRI alpha chain -/- mice corresponds to an increased association of Fc gammaRIII alpha chains with FcR beta and gamma chains and is associated with enhanced Fc gammaRIII-dependent mast cell degranulation and systemic anaphylactic responses. Therefore, the phenotype of the Fc epsilonRI alpha chain -/- mice suggests that expression of Fc epsilonRI and Fc gammaRIII is limited by availability of the FcR beta and gamma chains and that, in normal mice, changes in the expression of one receptor (Fc epsilonRI) may influence the expression of functional responses dependent on the other (Fc gammaRIII).

Dombrowicz, D; Flamand, V; Miyajima, I; Ravetch, J V; Galli, S J; Kinet, J P

1997-01-01

52

Freedom of information applications as an "evergreening" tactic: Secretary, Department of Health and Ageing v iNOVA Pharmaceuticals (Australia) Pty Ltd (2010) 191 FCR 573; [2010] FCA 1442.  

PubMed

A recent decision of the Federal Court of Australia illustrates how patent-holding pharmaceutical companies are attempting to use Australia's Freedom of Information Act 1982 (Cth) to force Australian safety, quality and efficacy regulators to disclose whether generic competitors are attempting to enter the market. In Secretary, Department of Health and Ageing v iNova Pharmaceuticals (Australia) Pty Ltd (2010) 191 FCR 573; [2010] FCA 1442 a single judge of the Federal Court overturned a decision of the Administrative Appeals Tribunal (AAT) that would have compelled the Australian Therapeutic Goods Administration (TGA) to reveal whether they were in possession of an application to register generic versions of two iNova products: imiquimod and phentermine. In its justification to the AAT for refusing to confirm or deny the existence of any application, the TGA argued that to reveal the existence of such a document would prejudice the proper administration of the National Health Act 1953 (Cth) as it could compromise the listing of a generic on the Pharmaceutical Benefits Scheme. The AAT failed to appreciate the extent to which this revelation to a competitor would have undercut 2004 amendments to the Therapeutic Goods Act 1989 (Cth) that provided penalties for evergreening tactics involving TGA notifications to drug patent-holders and 2006 amendments to the Patents Act 1990 (Cth) which protected the right of generic manufacturers to "springboard". The decision of the Federal Court is one of the first to explore the use of freedom of information legislation by patent-holders as a potential "evergreening" technique to prolong royalties by marginalising generic competition. Because of the significant amounts of money involved in ensuring rapid market entry of low-cost generic products, the issue has considerable public health significance. PMID:21988009

Vines, Tim; Faunce, Thomas

2011-09-01

53

Platinum ratio search versus golden ratio search  

Microsoft Academic Search

In this simulation study, we examine the traditional golden ratio search in view of cost minimization and search risk, and propose an alternative search plan with what we call “platinum ratio”. The golden ratio search has been thought the best for unimodal optimization. However, our study shows that the golden ratio search is the best only in the sense of

Xia Pan

2008-01-01

54

Learning About Ratios  

NSDL National Science Digital Library

Ratios appear in everyday life, but what exactly is a ratio. This lesson will help you understand what is a ratio and what to do with a ratio. What is a ratio? Dr. Math gives a pretty good explanation on these sites What is a ratio? Ratios as Fractions Figuring Ratios Writing Ratios Ratios Use this site to explore ratios using pictures All About Ratios Now that you have a little understanding here are some in-class activities that your teacher can help you with ...

Hadley, Mrs.

2005-06-17

55

Energy and centrality dependence of p¯ and p production and the Lambda¯\\/p¯ ratio in Pb+Pb collisions between 20A GeV and 158A GeV  

Microsoft Academic Search

The transverse mass mt distributions for antiprotons are measured at midrapidity for minimum bias Pb+Pb collisions at 158A GeV and for central Pb+Pb collisions at 20A, 30A, 40A, and 80A GeV beam energies in the fixed target experiment NA49 at the CERN SPS. The rapidity density dn\\/dy, inverse slope parameter T, and mean transverse mass derived from the mt

C. Alt; T. Anticic; B. Baatar; D. Barna; J. Bartke; L. Betev; H. Bialkowska; C. Blume; B. Boimska; M. Botje; J. Bracinik; R. Bramm; P. Buncic; V. Cerny; P. Christakoglou; O. Chvala; J. G. Cramer; P. Csató; P. Dinkelaker; V. Eckardt; D. Flierl; Z. Fodor; P. Foka; V. Friese; J. Gál; M. Gazdzicki; V. Genchev; G. Georgopoulos; E. Gladysz; K. Grebieszkow; S. Hegyi; C. Höhne; K. Kadija; A. Karev; M. Kliemant; S. Kniege; V. I. Kolesnikov; E. Kornas; R. Korus; M. Kowalski; I. Kraus; M. Kreps; A. Laslo; M. Van Leeuwen; P. Lévai; L. Litov; B. Lungwitz; M. Makariev; A. I. Malakhov; M. Mateev; G. L. Melkumov; A. Mischke; M. Mitrovski; J. Molnár; V. Nicolic; G. Pálla; A. D. Panagiotou; D. Panayotov; A. Petridis; M. Pikna; D. Prindle; F. Pühlhofer; R. Renfordt; C. Roland; G. Roland; M. Rybczynski; A. Rybicki; A. Sandoval; N. Schmitz; T. Schuster; P. Seyboth; F. Siklér; B. Sitar; E. Skrzypczak; G. Stefanek; R. Stock; C. Strabel; H. Ströbele; T. Susa; I. Szentpétery; J. Sziklai; P. Szymanski; V. Trubnikov; D. Varga; M. Vassiliou; G. I. Veres; G. Vesztergombi; D. Vranic; A. Wetzler; Z. Wlodarczyk; I. K. Yoo; J. Zimányi

2006-01-01

56

The Golden Ratio  

NSDL National Science Digital Library

In this lesson, "students learn about ratios, including the 'Golden Ratio', a ratio of length to width that can be found in art, architecture, and nature. Students examine different ratios to determine whether the Golden Ratio can be found in the human body." (from NCTM's Illuminations) This is lesson 3 in a 7-lesson unit called "Measuring Up"

Mathematics, Illuminations N.

2009-02-18

57

The Strehl Ratio in Adaptive Optics Images: Statistics and Estimation  

Microsoft Academic Search

Statistical properties of the intensity in adaptive optics images are usually modeled with a Rician distribution. We study the central point of the image, where this model is inappropriate for high to very high correction levels. The central point is an important problem because it gives the Strehl ratio distribution. We show that the central point distribution can be modeled

Rémi Soummer; André Ferrari

2007-01-01

58

Bicycle Gears- Ratios  

NSDL National Science Digital Library

Students experiment with and learn about the gear ratios on a bicycleâthus enhancing their understanding of circumference of a circle, proportions, etc. Actual gear ratio would be the ratio between the front and rear sprocket, NOT between pedal and rear wheel.

2011-01-01

59

The Golden Ratio  

ERIC Educational Resources Information Center

The Golden Ratio is sometimes called the "Golden Section" or the "Divine Proportion", in which three points: A, B, and C, divide a line in this proportion if AC/AB = AB/BC. "Donald in Mathmagicland" includes a section about the Golden Ratio and the ratios within a five-pointed star or pentagram. This article presents two computing exercises that…

Hyde, Hartley

2004-01-01

60

High pressure ratio turbocharger  

Microsoft Academic Search

This patent describes a turbocharger system for an internal combustion engine. It comprises means forming a turbine adapted to be driven by exhaust gas from an internal combustion engine comprising: a turbine wheel having a central core and outwardly extending vanes, the turbine wheel being rotatable about a central axis; a meridionally divided volute for exhaust gas surrounding the turbine

Woollenweber

1991-01-01

61

Maximum ratio transmission  

Microsoft Academic Search

This paper presents the concept, principles, and analysis of maximum ratio transmission for wireless communications, where multiple antennas are used for both transmission and reception. The principles and analysis are applicable to general cases, including maximum-ratio combining. Simulation results agree with the analysis. The analysis shows that the average overall signal-to-mise ratio (SNR) is proportional to the cross correlation between

Titus K. Y. Lo

1999-01-01

62

Recursion Formulas of Central Configurations.  

NASA Astrophysics Data System (ADS)

This paper analyzes central configurations which are special configurations leading to homothetic solutions of the n-body problem. For the planar central configurations, these solutions also provide periodic solutions of the n-body problem. Chapter 1 defines the problem and provides an overview of the area. There is historical interest in knowing the total number of these central configurations. For n >= 4 the problem remains unsolved. Furthermore, a different mass ratio between the n bodies will produce a different total number of central configurations. This paper will provide the total number of central configurations which has a special mass ratio. For the planar central configurations the total number of central configurations grows at the speed n!2n, and the three dimensional case is n!3^{n }. Chapters 2, 3 and 5 give details and proofs of the analytical continuation method. This method begins with three bodies, then creates the central configurations with four bodies with one small mass, using the implicit function theorem. If the process is repeated, the total number of central configurations for any n-body problem may be calculated, provided (n-3) masses are sufficiently small. In Chapters 4 and 7, the formulas are derived for the total number of central configurations of the n-body problem with special mass ratio (m _1,m_2,m_3,epsilon_1, ...,epsilonn) in both planar and three-dimensional cases. Examples of formulas provided are: n!(2^{n+1} + 1) , n!((n^2 - n + 4)2^{n+1 } - n - 7), and (n!/6) ((n ^3 + 11n - 12)2^{n+2} + 6n + 54). Chapter 6 solves a very special degenerate case during the continuation process. The Morse Index of these central configurations is discussed in Chapter 8.

Tien, Fangcheng

1993-01-01

63

Compression Ratio Adjuster  

NASA Technical Reports Server (NTRS)

New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.

Akkerman, J. W.

1982-01-01

64

Likelihood Ratio Tests  

NSDL National Science Digital Library

This page, created by Kyle Siegrist of the University of Alabama - Huntsville, introduces likelihood ratio tests by giving the Neyman-Pearson lemma and several examples. The examples include a gamma model, a binomial model, and a nonparametric model. The page concludes with a definition of the generalized likelihood ratio test.

Siegrist, Kyle

2009-01-12

65

Directional Gear Ratio Transmission.  

National Technical Information Service (NTIS)

Epicyclic gear transmissions which transmit output at a gear ratio dependent only upon the input's direction are considered. A transmission housing envelops two epicyclic gear assemblies, and has shafts extending from it. One shaft is attached to a sun ge...

A. E. Lefever

1982-01-01

66

Inelastic Ratio of ARALL.  

National Technical Information Service (NTIS)

The inelastic ratio (IR) of ARALL was determined in bending tests on four configurations with varying length, width, thickness, fiber orientation, and number of layers. The IR is 65%, differences between the configurations are negligibly small. The small ...

M. L. C. E. Verbruggen

1984-01-01

67

The Small Tight Aspect Ratio Tokamak experiment  

SciTech Connect

Low-aspect-ratio tokamaks offer both the economic advantage of smaller size and a number of physics advantages which are not available at conventional aspect ratio. The Small Tight Aspect Ratio Tokamak (START) [[ital Fusion] [ital Technology] 1990, edited by B. E. Keen, M. Huguet, and R. Hemsworth (North-Holland, Amsterdam, 1991), Vol. 1, p. 353] was conceived as a first substantial test of tokamak plasma behavior at low aspect ratio. It has achieved plasma currents up to 200 kA, peak densities of [similar to]2[times]10[sup 20] m[sup [minus]3] and central electron temperatures of [similar to]500 eV at an aspect ratio of 1.3--1.5. Central beta values of [similar to]13% have been measured and the volume-averaged beta [l angle][beta][r angle] can approach the Troyon limit. Plasmas are naturally elongated ([kappa][approx lt]2.0) and are vertically stable without feedback control. Major disruptions have not been observed at low aspect ratios ([ital A][le]2.0).

Colchin, R.J.; Carolan, P.G.; Duck, R.; Edlington, T.; Erents, S.K.; Ferreira, J.; Fielding, S.J.; Gibson, K.; Goodall, D.H.J.; Gryaznevich, M.; Hender, T.C.; Hugill, J.; Jenkins, I.; Li, J.; Manhood, S.J.; Parham, B.J.; Robinson, D.C.; Singleton, M.; Sykes, A.; Todd, T.N.; Turner, M.F.; Valovic, M.; Walsh, M.; Wilson, H.R. (AEA Fusion Technology, Culham Laboratory (EURATOM/UKAEA Association), Abingdon, Oxon (United Kingdom))

1993-07-01

68

Isotope Ratio Mass Spectrometry.  

PubMed

Isotope Ratio Mass Spectrometry (IRMS) is a specialized technique used to provide information about the geographic, chemical, and biological origins of substances. The ability to determine the source of an organic substance stems from the relative isotopic abundances of the elements which comprise the material. Because the isotope ratios of elements such as carbon, hydrogen, oxygen, sulfur, and nitrogen can become locally enriched or depleted through a variety of kinetic and thermodynamic factors, measurement of the isotope ratios can be used to differentiate between samples which otherwise share identical chemical compositions. Several sample introduction methods are now available for commercial isotope ratio mass spectrometers. Combustion is most commonly used for bulk isotopic analysis, whereas gas and liquid chromatography are predominately used for the real-time isotopic analysis of specific compounds within a mixture. Here, highlights of advances in instrumentation and applications within the last three years are provided to illustrate the impact of this rapidly growing area of research. Some prominent new applications include authenticating organic food produce, ascertaining whether or not African elephants are guilty of night-time raids on farmers' crops, and linking forensic drug and soil samples from a crime scene to a suspected point of origin. For the sake of brevity, we focus this Minireview on the isotope ratio measurements of lighter-elements common to organic sources; we do not cover the equally important field of inorganic isotope ratio mass spectrometry. PMID:19173039

Muccio, Zeland; Jackson, Glen P

2009-02-01

69

@central park  

NSDL National Science Digital Library

The Central Park Conservancy, a not-for-profit organization dedicated to restoring, improving, and managing Central Park's grounds and facilities, offers this "official" site, which contains a wealth of information about what is arguably the world's most famous city park. Each of the site's sections contains useful or interesting information; the Then & Now section, for instance, offers an overview of Central Park's history, a bibliography with 43 entries for those seeking further information, and a list of movies with scenes set in the park. Another highlight of the site is the Virtual Park, which consists of a set of clickable maps through which users can explore 72 points of interest, each described in the affectionate style of a travel guidebook. The site's other sections include such features as events schedules, press releases, information on when and where particular varieties of flowers bloom, and a section devoted entirely to activities for families and children. This site will be especially useful to those who are planning a visit to Central Park, but other users will likely find it informative and entertaining as well.

70

Halloween Central  

NSDL National Science Digital Library

Halloween is coming up, and this site will help readers prepare for an evening of ghouls, goblins, and other nasties. Halloween Central is a fairly extensive metasite with links to a wide variety of Halloween resources, including costumes, clip art, recipes, haunted houses, Halloween safety, and pumpkins, among many others.

71

Analysis of Ratios in Multivariate Morphometry  

PubMed Central

The analysis of ratios of body measurements is deeply ingrained in the taxonomic literature. Whether for plants or animals, certain ratios are commonly indicated in identification keys, diagnoses, and descriptions. They often provide the only means for separation of cryptic species that mostly lack distinguishing qualitative characters. Additionally, they provide an obvious way to study differences in body proportions, as ratios reflect geometric shape differences. However, when it comes to multivariate analysis of body measurements, for instance, with linear discriminant analysis (LDA) or principal component analysis (PCA), interpretation using body ratios is difficult. Both techniques are commonly applied for separating similar taxa or for exploring the structure of variation, respectively, and require standardized raw or log-transformed variables as input. Here, we develop statistical procedures for the analysis of body ratios in a consistent multivariate statistical framework. In particular, we present algorithms adapted to LDA and PCA that allow the interpretation of numerical results in terms of body proportions. We first introduce a method called the “LDA ratio extractor,” which reveals the best ratios for separation of two or more groups with the help of discriminant analysis. We also provide measures for deciding how much of the total differences between individuals or groups of individuals is due to size and how much is due to shape. The second method, a graphical tool called the “PCA ratio spectrum,” aims at the interpretation of principal components in terms of body ratios. Based on a similar idea, the “allometry ratio spectrum” is developed which can be used for studying the allometric behavior of ratios. Because size can be defined in different ways, we discuss several concepts of size. Central to this discussion is Jolicoeur's multivariate generalization of the allometry equation, a concept that was derived only with a heuristic argument. Here we present a statistical derivation of the allometric size vector using the method of least squares. The application of the above methods is extensively demonstrated using published data sets from parasitic wasps and rock crabs.

Baur, Hannes; Leuenberger, Christoph

2011-01-01

72

Rod centralizer  

SciTech Connect

This patent describes a well tool. It includes a pump rod and a centralizer having a single piece cylindrical body rigidly mounted on the rod, an upper pair of ribs integral with an upper portion of the body and extending outwardly therefrom in opposite directions, and a lower pair of ribs integral with a lower portion of the body and extending outwardly therefrom in opposite directions. The lower pair of ribs being displaced on the body from the upper pair of ribs ninety degrees about the central longitudinal axis of the rod, the body having a circumferential intermediate portion integral with the upper and lower portions between the top ends of the lower ribs and the bottom ends of the upper pair of ribs, the intermediate portion of the body being of lower mechanical strength than the portions thereof provided with the ribs.

Sable, D.E.

1991-03-05

73

Central Africa  

NSDL National Science Digital Library

Begun in 1996, the International Crisis Group's (ICG) Central Africa Project analyzes political and ethnic conflict within and between the nations that straddle mid-Africa, including the Democratic Republic of Congo (DRC), Burundi, Angola, Uganda, and Rwanda. As part of that effort ICG has released over twelve full text reports in the last year (a few in French only). The two most recent in-depth reports are: "Africa's Seven-Nation War," which examines how the armies of seven African nations have been drawn into the rebellion against DRC President Laurent Dsir Kabila; and "How Kabila Lost His Way," which traces the foundation of the Kabila regime and seeks to discover why it has engendered both internal and external opposition. Well-researched and fully footnoted, yet written with a non-specialist audience in mind, these reports are a good resource for both students and general readers with an interest in the current situation in Central Africa.

1996-01-01

74

The Golden Ratio  

NSDL National Science Digital Library

This Web site provides a "basic introduction to one of the most amazing discoveries in mathematics: the Golden Ratio." Created by David L. Narain, this site offers a particularly engaging way to bring together math and the natural sciences in the classroom. Seven straightforward activities have students construct a golden rectangle and spiral, and also explore the Golden Ratio in nature and in other contexts. The site also includes a quiz; answers are not provided, though. The activities are designed for 9th and 10th graders, but would also be appropriate for middle school students.

Narain, David L.

2001-01-01

75

PE Central  

NSDL National Science Digital Library

The Virginia Polytechnic Institute Health and Physical Education Program developed this site, a clearinghouse of information about K-12 physical education and health. An extensive list of lesson plans and assessment ideas, arranged topically and by grade level, is the focal point of this site; the Classroom Teacher Lesson Ideas uses PE "across the curriculum" to help students learn concepts in other subjects. PE Central provides information for PE professionals on relevant journals, job announcements, and equipment purchases, among other topics.

1996-01-01

76

A Recipe for Ratio  

ERIC Educational Resources Information Center

Many learners still struggled to appreciate, and understand the difference between, the concepts of fractions and ratio. This is not just a UK phenomenon, which is demonstrated here by the use of a resource developed by the Wisconsin Centre for Education, in association with the Freudenthal Institute of the University of Utrecht, with a group of…

Moffett, Pamela

2012-01-01

77

Digit ratio in birds.  

PubMed

The Homeobox (Hox) genes direct the development of tetrapod digits. The expression of Hox genes may be influenced by endogenous sex steroids during development. Manning (Digit ratio. New Brunswick, NJ: Rutgers University Press, 2002) predicted that the ratio between the lengths of digits 2 (2D) and 4 (4D) should be sexually dimorphic because prenatal exposure to estrogens and androgens positively influence the lengths of 2D and 4D, respectively. We measured digits and other morphological traits of birds from three orders (Passeriformes, house sparrow, Passer domesticus; tree swallow, Tachycineta bicolor; Pscittaciformes, budgerigar, Melopsittacus undulates; Galliformes, chicken, Gallus domesticus) to test this prediction. None were sexually dimorphic for 2D:4D and there were no associations between 2D:4D and other sexually dimorphic traits. When we pooled data from all four species after we averaged right and left side digits from each individual and z-transformed the resulting digit ratios, we found that males had significantly larger 2D:4D than did females. Tetrapods appear to be sexually dimorphic for 2D:4D with 2D:4D larger in males as in some birds and reptiles and 2D:4D smaller in males as in some mammals. The differences between the reptile and mammal lineages in the directionality of 2D:4D may be related to the differences between them in chromosomal sex determination. We suggest that (a) natural selection for a perching foot in the first birds may have overridden the effects of hormones on the development of digit ratio in this group of vertebrates and (b) caution be used in making inferences about prenatal exposure to hormones and digit ratio in birds. PMID:18833568

Lombardo, Michael P; Thorpe, Patrick A; Brown, Barbara M; Sian, Katie

2008-12-01

78

Sonnet Central  

NSDL National Science Digital Library

Created by a dedicated sonnet aficionado, Sonnet Central is not intended for the scholar, per se, but for the reader, the Internaut with a weakness for poetry. The site contains a collection of English-language sonnets, grouped by period and region or by author, and modernized for contemporary readers. Pictures, contemporaneous critical works, a bibliography, and audio files of readings of selected poems complement the sonnets, some of which are maintained off-site (many at the University of Toronto). From Shakespeare to Wilfred Owen, selections from many well-known sonneteers are here alongside those of their less famous contemporaries.

79

Some Statistical Characteristics of a Peak to Average Ratio  

Microsoft Academic Search

The peak to average ratio is a measure used in engineering design. Peak refers TV the greatest observation of a population or sample and average refers to one of the familiar measures of central tendency. The density function of the peak to median ratio is derived in general for non-negative variates using applicable order statistics techniques. It is then derived

Milton Morrison; Filbert Tobias

1965-01-01

80

What's My Ratio?  

NSDL National Science Digital Library

In this activity, students use linear measurement and calculators to investigate proportionality and determine the constant ratio between similar figures. In it, students draw a figure on centimeter graph paper, increase or decrease the size, and predict the dimensions. Then students compare the ratio of two pictures by measuring, recording their data, and discussing their findings to draw conclusions. Suggested guidelines for instruction and classroom discussion are included, as well as data collection worksheets for students, and centimeter graph paper to print. The lesson may be introduced by reading appropriate sections from "GoosebumpsâMonster Blood III" (Chapters 15 and 16) by R.L. Stine, or "The Shrinking of Treehorn" by F. Heide.

2003-01-01

81

Displacement and Velocity Ratios  

NSDL National Science Digital Library

This interactive presentation, created by James Bourassa and John Rosz for the Electromechanical Digital Library, discusses displacement and velocity ratios. Bourassa and Rosz begin by providing detailed definitions of both topics and then provide mathematical examples of each. Once this basic explanation is complete, the authors allow students to practice these theories in a set of self-correcting quiz questions. Bourassa and Rosz explain each using helpful interactive flash animations. These are not only useful in explanation, but they allow the student to more fully engage with the topic. Overall, this is a nice introduction to the physical and mathematical concepts of displacement and velocity ratios. This could be a valuable learning resource in everything from a physics to a technical education classroom.

Bourassa, James; Rosz, John

2011-04-05

82

Health Resources in South Central Connecticut.  

National Technical Information Service (NTIS)

Health resource data are presented for use as a baseline in planning and developing health services in south central Connecticut. Primary care resources are considered, including physicians and acceptable physician-to-population ratios, comprehensive heal...

1975-01-01

83

PROPORTIONS and RATIOS  

NSDL National Science Digital Library

Using what you already know and the text, can you solve these problems? Just by looking at the titles below, describe in your journal what you think each activity is going to be about and how it relates to proportions and ratios. Which tastes juicier? Statue of Liberty : is the Statue of Liberty's nose too long? Describe in your journal how your favorite question above was answered. Also, include any fun facts you learned along the way. What ...

Squire, Mrs.

2009-04-13

84

Ratio Word Problems  

NSDL National Science Digital Library

This lesson begins with a word problem in which students must figure how much money Erica and Tim each earn when they split $480 by a ratio of 5:3. After the problem, students watch a video in which the problem is solved using division and multiplication and again using fractions. Students then click the Try It button to complete a problem on their own. There are also embedded tools, a calculator and scratchpad, for students to use as they solve.

2006-01-01

85

The Golden Ratio Encoder  

Microsoft Academic Search

This paper proposes a novel Nyquist-rate analog-to-digital (A\\/D) conversion algorithm which achieves exponential accuracy in the bit-rate despite using imperfe ct components. The proposed algorithm is based on a robust implementation of a beta-encoder with ? = ? = (1 + ? 5)\\/2, the golden ratio. It was previously shown that beta-encoders can be implemented in such a way that

Ingrid Daubechies; C. Sinan Güntürk; Yang Wang; Özgür Yilmaz

2008-01-01

86

Thinking Blocks: Ratios  

NSDL National Science Digital Library

This set of six interactive Flash activities gives students an opportunity to visually model and calculate the unknown quantity from ratios and other information, all in the context of solving word problems. A video demonstration introduces each method, and then students work on modeling and solving five problems. Students can check their modeling of the problem at intermediate stages. Teachers can track a student's progress throughout the problem set.

2012-01-01

87

Odor Concentration Invariance by Chemical Ratio Coding  

PubMed Central

Many animal species rely on chemical signals to extract ecologically important information from the environment. Yet in natural conditions chemical signals will frequently undergo concentration changes that produce differences in both level and pattern of activation of olfactory receptor neurons. Thus, a central problem in olfactory processing is how the system is able to recognize the same stimulus across different concentrations. To signal species identity for mate recognition, some insects use the ratio of two components in a binary chemical mixture to produce a code that is invariant to dilution. Here, using psychophysical methods, we show that rats also classify binary odor mixtures according to the molar ratios of their components, spontaneously generalizing over at least a tenfold concentration range. These results indicate that extracting chemical ratio information is not restricted to pheromone signaling and suggest a general solution for concentration-invariant odor recognition by the mammalian olfactory system.

Uchida, Naoshige; Mainen, Zachary F.

2007-01-01

88

Central hypothyroidism  

PubMed Central

Central hypothyroidism is defined as hypothyroidism due to insufficient stimulation by thyroid stimulating hormone (TSH) of an otherwise normal thyroid gland. It has an estimated prevalence of approximately 1 in 80,000 to 1 in 120,000. It can be secondary hypothyroidism (pituitary) or tertiary hypothyroidism (hypothalamus) in origin. In children, it is usually caused by craniopharyngiomas or previous cranial irradiation for brain tumors or hematological malignancies. In adults, it is usually due to pituitary macroadenomas, pituitary surgeries or post-irradiation. Fatigue and peripheral edema are the most specific clinical features. Diagnosis is established by the presence of normal to low-normal TSH on the background of low-normal thyroid hormones, confirmed by the thyrotropin releasing hormone stimulation test. Therapy includes use of levothyroxine titrated to improvement in symptomology and keeping free T4 in the upper limit of normal reference range.

Gupta, Vishal; Lee, Marilyn

2011-01-01

89

Peak power ratio generator  

DOEpatents

A peak power ratio generator is described for measuring, in combination with a conventional power meter, the peak power level of extremely narrow pulses in the gigahertz radio frequency bands. The present invention in a preferred embodiment utilizes a tunnel diode and a back diode combination in a detector circuit as the only high speed elements. The high speed tunnel diode provides a bistable signal and serves as a memory device of the input pulses for the remaining, slower components. A hybrid digital and analog loop maintains the peak power level of a reference channel at a known amount. Thus, by measuring the average power levels of the reference signal and the source signal, the peak power level of the source signal can be determined.

Moyer, Robert D. (Albuquerque, NM)

1985-01-01

90

Debate Central  

NSDL National Science Digital Library

Courtesy of the National Center for Policy Analysis (NCPA), Debate-Central.org offers resources related to this year's National Forensic League high school debate topic: "Resolved: That the United States federal government should establish a foreign policy significantly limiting the use of weapons of mass destruction." The site, which is updated daily, features a wealth of links sorted into ten categories (each of which is further divided into subcategories). Resources are collected from periodicals, think tanks, and other sources, and the collection should be useful not just for debaters but for anyone looking for authoritative resources on these topics. Other debate topics are listed on the right-hand side of the page, though these are covered in a less comprehensive manner. Also at the site is a bulletin board, through which users can ask questions of experts such as Dr. Hans Mark, former Secretary of the Air Force and Deputy Administrator of NASA, and a link to NCPA's Terrorism in America site. NCPA's mission is "to develop and promote private alternatives to government regulation and control, solving problems by relying on the strength of the competitive, entrepreneurial private sector."

2001-01-01

91

Characteristic of Bennett's acceptance ratio method  

NASA Astrophysics Data System (ADS)

A powerful and well-established tool for free-energy estimation is Bennett’s acceptance ratio method. Central properties of this estimator, which employs samples of work values of a forward and its time-reversed process, are known: for given sets of measured work values, it results in the best estimate of the free-energy difference in the large sample limit. Here we state and prove a further characteristic of the acceptance ratio method: the convexity of its mean-square error. As a two-sided estimator, it depends on the ratio of the numbers of forward and reverse work values used. Convexity of its mean-square error immediately implies that there exists a unique optimal ratio for which the error becomes minimal. Further, it yields insight into the relation of the acceptance ratio method and estimators based on the Jarzynski equation. As an application, we study the performance of a dynamic strategy of sampling forward and reverse work values.

Hahn, Aljoscha M.; Then, Holger

2009-09-01

92

{Omega}/{Xi} production ratio in S-W  

SciTech Connect

We have measured the ({Omega}{sup {minus}}+{bar {Omega}}{sup +})/({Xi}{sup {minus}}+{bar {Xi}}{sup +}) production ratio in central S-W collisions to be 0.8{plus_minus}0.4 at central rapidity and p{sub T}{gt}1.6 GeV/{ital c}. {copyright} 1995 {ital American} {ital Institute} {ital of} {ital Physics}.

Abatzis, S. [Nuclear Physics Department, Athens University, GR-15771 Athens (Greece); Andrighetto, A.; Antinori, F.; Barnes, R.P.; Bayes, A.C.; Benayoun, M.; Beusch, W.; Carney, J.N.; de la Cruz, B.; Di Bari, D.; Dufey, J.P.; Davies, J.P.; Elia, D.; Evans, D.; Fini, R.; French, B.R.; Ghidini, B.; Helstrup, H.; Holme, A.K.; Jacholkowski, A.; Kahane, J.; Kinson, J.B.; Kirk, A.; Knudson, K.; Lassalle, J.C.; Lenti, V.; Leruste, P.; Manzari, V.; Narjoux, J.L.; Navach, F.; Quercigh, E.; Rossi, L.; Safarik, K.; Sene, M.; Sene, R.; Storas, T.; Vassiliadis, G.; Villalobos Baillie, O.; Volte, A.; Votruba, M.F.; Federico Antinori /CERN & Genova for WA85 Collaboration

1995-07-20

93

Poisson's ratio and crustal seismology  

Microsoft Academic Search

New measurements of compressional and shear wave velocities to hydrostatic pressures of 1 GPa are summarized for 678 rocks. Emphasis was placed on obtaining high-accuracy velocity measurements, which are shown to be critical in calculating Poisson's ratios from velocities. The rocks have been divided into 29 major groups for which velocities, velocity ratios, and Poisson's ratios are presented at several

Nikolas I. Christensen

1996-01-01

94

Increased skeletal:renal uptake ratio. [Bone-seekers  

SciTech Connect

Twenty-four patients with increased skeletal:renal uptake ratios of /sup 99m/Tc-methylene diphosphonate were studied. Increased uptake was central in metastatic prostate carcinoma, peripheral in hematologic disorders, and heterogeneous in Paget disease and fibrous dysplasia. There was no discernible redistribution of skeletal uptake in patients with renal failure. Absence of both renal and bladder activity was not observed in patients with normal renal function. An increased ratio was always abnormal and frequently indicated diffuse bone disease.

Cheng, T.H.; Holman, B.L.

1980-08-01

95

Oxygen isotope ratios of the Icelandic crust  

NASA Astrophysics Data System (ADS)

Oxygen isotope ratios of hydrothermally altered basalts from depths of up to ˜3 km are reported from three localities in Iceland: International Research Drilling Project (IRDP) core at Reydarfjordur, eastern Iceland (Tertiary age); drill cuttings from Reykjavik (Plio-Pleistocene age); and Holocene drill cuttings from the active Krafla central volcano. Whole rock samples from these three localities have ?18O values averaging +3.9±1.3, +2.4±1.1, and -7.7±2.4‰, respectively. The observed values in the deeper samples from Krafla are as low as the values for any rocks previously reported. There seems to be a slight negative gradient in ?18O with depth at the former two localities and a more pronounced one at Krafla. Oxygen isotope fractionations between epidote and quartz and those between calcite and fluid suggest that the basalts were altered at temperatures of 300°-400°C. Low ?D and ?18O of epidote and low ?34S of anhydrite indicate that the altering fluids in all three areas originated as meteoric waters and have undergone varied `oxygen shifts.' Differences in the 18O shift of the fluids are attributed to differences in hydrothermal systems; low water/rock ratios (?0.1) are found in the IRDP core and the Reykjavik hole, but high water/rock ratios (>5) at Krafla. The convective hydrothermal activity, which is probably driven by silicic magma beneath the central volcanoes, has caused strong subsolidus depletion of 18O in the rocks. The primary-magmatic ?18O value of the rocks in the Tertiary IRDP core was about +3.9‰, which is lower than that obtained for fresh basalt from other places. Such exceptionally low ?18O magmas are common in Iceland and may occur as the result of oxygen isotope exchange with or assimilation of altered rocks that form a thick sequence beneath the island due to isostatic subsidence.

Hattori, Keiko; Muehlenbachs, Karlis

1982-08-01

96

Central bank Financial Independence  

Microsoft Academic Search

Central bank independence is a multifaceted institutional design. The financial component has been seldom analysed. This paper intends to set a comprehensive conceptual background for central bank financial independence. Quite often central banks are modelled as robot like maximizers of some goal. This perspective neglects the fact that central bank functions are inevitably deployed on its balance sheet and have

J. Ramon Martinez-Resano

2004-01-01

97

The dynamics of operational sex ratios and competition for mates  

Microsoft Academic Search

In sexually reproducing animals, individuals of one sex may have to compete for access to mating partners of the opposite sex. The operational sex ratio (OSR) is central in predicting the intensity of mating competition and which sex is competing for which. Thanks to recent theoretical and empirical advances, particularly by exploring the concept of OSR, sexual selection studies today

Charlotta Kvarnemo; Ingrid Ahnesjo

1996-01-01

98

The sex ratio in anencephaly  

Microsoft Academic Search

A review of the data supports the suggestion of Knox (1974) that the sex ratio and incidence of anencephalics vary together within populations, as they are known to do between populations. There seems some doubts, though, whether Knox was correct in hypothesising that the sex ratio of anencephalics varies with their incidence in relation to the dizygotic twinning rate. The

W H James

1979-01-01

99

Misconceptions about the Golden Ratio.  

ERIC Educational Resources Information Center

Typically, the mathematical properties concerning the golden ratio are stated correctly, but much of what is presented with respect to the golden ratio in art, architecture, literature, and aesthetics is false or seriously misleading. Discussed here are some of the most commonly repeated misconceptions promulgated, particularly within mathematics…

Markowsky, George

1992-01-01

100

Progressive Ratio Schedules of Reinforcement  

PubMed Central

Pigeons’ pecks produced grain under progressive ratio (PR) schedules, whose response requirements increased systematically within sessions. Experiment 1 compared arithmetic (AP) and geometric (GP) progressions. Response rates increased as a function of the component ratio requirement, then decreased linearly (AP) or asymptotically (GP). Experiment 2 found the linear decrease in AP rates to be relatively independent of step size. Experiment 3 showed pausing to be controlled by the prior component length, which predicted the differences between PR and regressive ratio schedules found in Experiment 4. When the longest component ratios were signaled by different key colors, rates at moderate ratios increased, demonstrating control by forthcoming context. Models for response rate and pause duration described performance on AP schedules; GP schedules required an additional parameter representing the contextual reinforcement.

Killeen, Peter R.; Posadas-Sanchez, Diana; Johansen, Espen Borga; Thrailkill, Eric A.

2009-01-01

101

Multiple trait model combining random regressions for daily feed intake with single measured performance traits of growing pigs  

Microsoft Academic Search

A random regression model for daily feed intake and a conventional multiple trait animal model for the four traits average daily gain on test (ADG), feed conversion ratio (FCR), carcass lean content and meat quality index were combined to analyse data from 1 449 castrated male Large White pigs performance tested in two French central testing stations in 1997. Group

Urs Schnyder; Andreas Hofer; Florence Labroue; Niklaus Künzi

2002-01-01

102

High ratio recirculating gas compressor  

SciTech Connect

A high ratio positive displacement recirculating rotary compressor is disclosed. The compressor includes an integral heat exchanger and recirculation conduits for returning cooled, high pressure discharge gas to the compressor housing to reducing heating of the compressor and enable higher pressure ratios to be sustained. The compressor features a recirculation system which results in continuous and uninterrupted flow of recirculation gas to the compressor with no direct leakage to either the discharge port or the intake port of the compressor, resulting in a capability of higher sustained pressure ratios without overheating of the compressor.

Weinbrecht, John F. (601 Oakwood Pl., NE., Albuquerque, NM 87123)

1989-01-01

103

Pressure Ratio to Thermal Environments  

NASA Technical Reports Server (NTRS)

A pressure ratio to thermal environments (PRatTlE.pl) program is a Perl language code that estimates heating at requested body point locations by scaling the heating at a reference location times a pressure ratio factor. The pressure ratio factor is the ratio of the local pressure at the reference point and the requested point from CFD (computational fluid dynamics) solutions. This innovation provides pressure ratio-based thermal environments in an automated and traceable method. Previously, the pressure ratio methodology was implemented via a Microsoft Excel spreadsheet and macro scripts. PRatTlE is able to calculate heating environments for 150 body points in less than two minutes. PRatTlE is coded in Perl programming language, is command-line-driven, and has been successfully executed on both the HP and Linux platforms. It supports multiple concurrent runs. PRatTlE contains error trapping and input file format verification, which allows clear visibility into the input data structure and intermediate calculations.

Lopez, Pedro; Wang, Winston

2012-01-01

104

Arcjet Nozzle Area Ratio Effects  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted to determine the effect of nozzle area ratio on the operating characteristics and performance of a low power dc arcjet thruster. Conical thoriated tungsten nozzle inserts were tested in a modular laboratory arcjet thruster run on hydrogen/nitrogen mixtures simulating the decomposition products of hydrazine. The converging and diverging sides of the inserts had half angles of 30 and 20 degrees, respectively, similar to a flight type unit currently under development. The length of the diverging side was varied to change the area ratio. The nozzle inserts were run over a wide range of specific power. Current, voltage, mass flow rate, and thrust were monitored to provide accurate comparisons between tests. While small differences in performance were observed between the two nozzle inserts, it was determined that for each nozzle insert, arcjet performance improved with increasing nozzle area ratio to the highest area ratio tested and that the losses become very pronounced for area ratios below 50. These trends are somewhat different than those obtained in previous experimental and analytical studies of low Re number nozzles. It appears that arcjet performance can be enhanced via area ratio optimization.

Curran, Francis M.; Sarmiento, Charles J.; Birkner, Bjorn W.; Kwasny, James

1990-01-01

105

Arcjet nozzle area ratio effects  

NASA Technical Reports Server (NTRS)

An experimental investigation was conducted to determine the effect of nozzle area ratio on the operating characteristics and performance of a low power dc arcjet thruster. Conical thoriated tungsten nozzle inserts were tested in a modular laboratory arcjet thruster run on hydrogen/nitrogen mixtures simulating the decomposition products of hydrazine. The converging and diverging sides of the inserts had half angles of 30 and 20 degrees, respectively, similar to a flight type unit currently under development. The length of the diverging side was varied to change the area ratio. The nozzle inserts were run over a wide range of specific power. Current, voltage, mass flow rate, and thrust were monitored to provide accurate comparisons between tests. While small differences in performance were observed between the two nozzle inserts, it was determined that for each nozzle insert, arcjet performance improved with increasing nozzle area ratio to the highest area ratio tested and that the losses become very pronounced for area ratios below 50. These trends are somewhat different than those obtained in previous experimental and analytical studies of low Re number nozzles. It appears that arcjet performance can be enhanced via area ratio optimization.

Curran, Francis M.; Sarmiento, Charles J.; Birkner, Bjorn W.; Kwasny, James

1990-01-01

106

Central Limit Theorem  

NSDL National Science Digital Library

This site from David Lane features a description of the central limit theorem used in statistics. Examples of frequency distributions are shown, and there is also a link to an interactive demonstration of the central limit theorem.

Lane, David M.

107

Central line infections - hospitals  

MedlinePLUS

... and increase how long you are in the hospital. Your central line needs special care to prevent ... The hospital staff will use aseptic technique when a central line is put in your chest or arm. Aseptic ...

108

Martian Central Pit Craters.  

National Technical Information Service (NTIS)

Impact craters containing central pits are rare on the terrestrial planets but common on icy bodies. Mars is the exception among the terrestrial planets, where central pits are seen on crater floors ('floor pits') as well as on top of central peaks ('summ...

E. Hillman N. G. Barlow

2005-01-01

109

Centrality of Cognitive Attributes.  

ERIC Educational Resources Information Center

Develops measures of individual differences in attribute centrality, investigates convergent validity, and explores differences in central and noncentral attribute functions within same person. University students in three countries completed questionnaires. Four relative centrality measures correlated with information required to make decisions…

Scott, William A.; And Others

1980-01-01

110

Point Estimation: Odds Ratios, Hazard Ratios, Risk Differences, Precision  

NSDL National Science Digital Library

This site provides a PowerPoint presentation, created by Dr. Elizabeth Garrett-Mayer of Johns Hopkins University, of a lesson and examples of point estimation, odds ratios, hazard ratios, risk differences and precision. The presentations is quite thorough. The author attempts to define, provide examples of, and then show the application of almost every concept. The presentation follows a easily followed and logical order. Mathematical formulas are intertwined within the slides. If further research is necessary, the author has provided a list of references and cites them during the presentation.

Garrett-Mayer, Elizabeth

2009-02-11

111

Quantifying asymmetry: Ratios and alternatives.  

PubMed

Traditionally, the study of metric skeletal asymmetry has relied largely on univariate analyses, utilizing ratio transformations when the goal is comparing asymmetries in skeletal elements or populations of dissimilar dimensions. Under this approach, raw asymmetries are divided by a size marker, such as a bilateral average, in an attempt to produce size-free asymmetry indices. Henceforth, this will be referred to as "controlling for size" (see Smith: Curr Anthropol 46 (2005) 249-273). Ratios obtained in this manner often require further transformations to interpret the meaning and sources of asymmetry. This model frequently ignores the fundamental assumption of ratios: the relationship between the variables entered in the ratio must be isometric. Violations of this assumption can obscure existing asymmetries and render spurious results. In this study, we examined the performance of the classic indices in detecting and portraying the asymmetry patterns in four human appendicular bones and explored potential methodological alternatives. Examination of the ratio model revealed that it does not fulfill its intended goals in the bones examined, as the numerator and denominator are independent in all cases. The ratios also introduced strong biases in the comparisons between different elements and variables, generating spurious asymmetry patterns. Multivariate analyses strongly suggest that any transformation to control for overall size or variable range must be conducted before, rather than after, calculating the asymmetries. A combination of exploratory multivariate techniques, such as Principal Components Analysis, and confirmatory linear methods, such as regression and analysis of covariance, appear as a promising and powerful alternative to the use of ratios. Am J Phys Anthropol 154:498-511, 2014. © 2014 Wiley Periodicals, Inc. PMID:24842694

Franks, Erin M; Cabo, Luis L

2014-08-01

112

Low aspect ratio tokamak experiment in University of Tokyo  

SciTech Connect

A low aspect ratio tokamak device has been designed and constructed in University of Tokyo. A cylindrical vacuum vessel is employed. The vessel is divided toroidally into two parts insulated each other. In the vessel, central core composed of ohmic coils and a part of toroidal coils is installed. The aluminum shell is installed to keep the vertical and horizontal equilibrium of the plasma. As the result of several efforts to lower the aspect ratio, the predicted minimum value of the aspect ratio reaches less than 1.2. The predicted advantage of low aspect ratio tokamaks is verified by simulation. The analysis of MHD activities and fluctuations will be carried out, after the assembly is completed. 4 refs., 7 figs.

Hanada, K.; Oikawa, T.; Nozawa, K.; Totsuka, H.; Shinohara, K.; Ishiyama, E.; Shinoda, N.; Yamagishi, K.; Toyama, H. [Univ. of Tokyo (Japan)

1995-04-01

113

Discovering Phi: The Golden Ratio  

NSDL National Science Digital Library

Students discover the mathematical constant phi, the golden ratio, through hands-on activities. They measure dimensions of "natural objects"âa star, a nautilus shell and human hand bonesâand calculate ratios of the measured values, which are close to phi. Then students learn a basic definition of a mathematical sequence, specifically the Fibonacci sequence. By taking ratios of successive terms of the sequence, they find numbers close to phi. They solve a squares puzzle that creates an approximate Fibonacci spiral. Finally, the instructor demonstrates the rule of the Fibonacci sequence via a LEGO® MINDSTORMS® NXT robot equipped with a pen. The robot (already created as part of the companion activity, The Fibonacci Sequence & Robots) draws a Fibonacci spiral that is similar to the nautilus shape.

AMPS GK-12 Program,

114

Martian Central Pit Craters  

NASA Technical Reports Server (NTRS)

Impact craters containing central pits are rare on the terrestrial planets but common on icy bodies. Mars is the exception among the terrestrial planets, where central pits are seen on crater floors ( floor pits ) as well as on top of central peaks ( summit pits ). Wood et al. [1] proposed that degassing of subsurface volatiles during crater formation produced central pits. Croft [2] argued instead that central pits might form during the impact of volatile-rich comets. Although central pits are seen in impact craters on icy moons such as Ganymede, they do show some significant differences from their martian counterparts: (a) only floor pits are seen on Ganymede, and (b) central pits begin to occur at crater diameters where the peak ring interior morphology begins to appear in terrestrial planet craters [3]. A study of craters containing central pits was conducted by Barlow and Bradley [4] using Viking imagery. They found that 28% of craters displaying an interior morphology on Mars contain central pits. Diameters of craters containing central pits ranged from 16 to 64 km. Barlow and Bradley noted that summit pit craters tended to be smaller than craters containing floor pits. They also noted a correlation of central pit craters with the proposed rings of large impact basins. They argued that basin ring formation fractured the martian crust and allowed subsurface volatiles to concentrate in these locations. They favored the model that degassing of the substrate during crater formation was responsible for central pit formation due to the preferential location of central pit craters along these basin rings.

Hillman, E.; Barlow, N. G.

2005-01-01

115

Envera Variable Compression Ratio Engine  

Microsoft Academic Search

Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy

Charles Mendler

2011-01-01

116

Optimal gear ratios of drives  

Microsoft Academic Search

One of the most complex problems in the design of practically any mechanism or machine is to select the gear ratio of an electric drive, on the basis of scientific, engineering, and economic principles. There is an extensive literature on this subject, dating mainly to the period from the 1940s to the 1960s. In current economic conditions, however, this problem

B. N. Polyakov

2007-01-01

117

Surface Area to Volume Ratio  

NSDL National Science Digital Library

This page contains two documents explaining surface area to volume ratio. The topic is covered at an advanced level in relation to nanotechnology and requires background knowledge in geometry, algebra, and linear and non-linear unit conversions. A powerpoint with illustrations and instructor guide (available as both a Microsoft Word Document and PDF) containing activities are included to aid in teaching this subject.

2012-10-16

118

Farey Sums and Understanding Ratios  

ERIC Educational Resources Information Center

Mathematical problems when solved with different approaches deepen the understanding of topics learned. It is reported that weighted average is commonly used in applications and the relationship between all the ratios involved in the problem emphasized could be learned from Farey sum of two fractions.

Mihail, Ioana

2004-01-01

119

Declustering Using Golden Ratio Sequences  

Microsoft Academic Search

In this paper we propose a new data declustering scheme for range queries. Our schemeis based on Golden Ratio Sequences (GRS), which have found applications in broadcast disks,hashing, packet routing, etc. We show by analysis and simulation that GRS is nearly the bestpossible scheme for 2-dimensional range queries. Specifically, it is the best possible scheme whenthe number of disks (M

Randeep Bhatia; Rakesh K. Sinha; Chung-min Chen

2000-01-01

120

Empirical Likelihood Ratio Confidence Regions  

Microsoft Academic Search

An empirical likelihood ratio function is defined and used to obtain confidence regions for vector valued statistical functionals. The result is a nonparametric version of Wilks' theorem and a multivariate generalization of work by Owen. Cornish-Fisher expansions show that the empirical likelihood intervals for a one dimensional mean are less adversely affected by skewness than are those based on Student's

Art Owen

1990-01-01

121

Air/fuel ratio regulator  

SciTech Connect

A description is given of an air/fuel ratio regulator for use with the fuel injection control system of an internal combustion engine of the spark ignition type having an air and exhaust gas (gas) induction passage open at one end to air at ambient pressure level and connected at its other end to the engine combustion chamber to be subject to manifold vacuum changes therein, a throttle valve rotatably mounted for movement across the passage to control the gas flow therethrough, exhaust gas recirculation (egr) passage means connecting engine exhaust gases to the induction passage above the closed position of the throttle valve, an egr flow control valve mounted in the egr passage means for movement between open and closed postions to control the volume of egr gas flow, an engine speed responsive positive displacement type fuel injection pump having a fuel flow output to the engine that varies in direct proportion to changes in engines speed to match fuel flow and mass airflow through the induction system of the engine over the entire speed and load range of the engine to maintain the intake mixture ratio of air to fuel constant, the pump having a fuel flow control lever movable to vary the fuel rate of flow, the regulator being characterized by engine manifold vacuum responsive first servo means operably connected to the fuel control lever for maintaining a constant air/fuel (A/F) ratio by changing fuel output as a function of changing manifold vacuum and air flow upon opening of the throttle valve, a fuel enrichment control lever operably connected to the pump control lever and movable to modify the position of the pump lever dictated by the first servo means to change the A/F ratio, and further means responsive to engine operating conditions for moving the fuel enrichment control lever to provide the changed A/F ratio.

Simko, A.

1980-07-22

122

Circumstellar molecular radio line intensity ratios  

NASA Astrophysics Data System (ADS)

We have observed a sample of 61 AGB--stars (39 M--stars and 22 C--stars) in circumstellar CO, CS, HCN, SiO, SiS, and SO radio line emission. The main results presented are based on the use of line intensity ratios, a well defined observational quantity that can be used to infer important conclusions as well as to provide constraints on models. Taken together the data are fully consistent with the facts that for this sample the circumstellar envelopes have the same basic chemistry (i.e., C/O<1 or >1) as the central stars, and that the mass loss rates have not changed drastically over periods between 10(2) --10(3) years. The HCN({\\jtra10})/SiO({\\jtra21}) intensity ratio discriminates unambiguously between {``}normal{''} circumstellar envelopes with C/O<1 (O--CSEs) and >1 (C--CSEs), while the CS({\\jtra21}), HCN({\\jtra10}), SiO({\\jtra21}), and SiS({\\jtra54}) intensity ratios with respect to CO({\\jtra10}) are not perfect for this purpose, and neither is the SiS({\\jtra54})/SiO({\\jtra21}) intensity ratio. The data further shows that SO and the C-bearing molecule HCN are ubiquitously present in O--CSEs, and that their line intensities in O--CSEs are qualitatively consistent with the fact that the molecules are formed in a photo--induced circumstellar chemistry in a quantity that depends on the mass loss rate. Hence, both species can in principle be used to estimate the mass loss rate, and the tight relation between the SO(J_K= 3_2->2_1) and CO({\\jtra10}) intensities in O--CSEs shows that SO line emission may even be a good mass loss rate estimator. On the contrary, the SiO({\\jtra21}) luminosity appears to be essentially independent of the mass loss rate in O--CSEs, possibly due to a larger influence from molecular adhesion onto grains. These results explain why the HCN({\\jtra10})/SiO({\\jtra21}) intensity ratio increases with the mass loss rate in O--CSEs, and there is no need to invoke e.g. a spread in C/O--ratios for the M--stars to explain the large range of this ratio. Maser emission is very likely present in the HCN({\\jtra10}) line in C--CSEs, and it seems to be sensitively dependent on the mass loss rate, i.e., it appears only for dot M la 5x 10(-7) M_sunpyr. Based on time monitoring of this emission towards the C--stars W Ori and X TrA, we suggest that the strongest maser features are due to radial amplification in the {\\ftra21} transition. The predominance of redshifted maser emission could be caused by an additional amplification in the {\\ftra11} transition. We find no evidence for a similar maser in O--CSEs.

Olofsson, H.; Lindqvist, M.; Nyman, L.-A.; Winnberg, A.

1998-01-01

123

Modelling vinasse\\/cotton waste ratio incubation for optimum composting  

Microsoft Academic Search

A central composite experimental design was used to investigate the influence of incubation conditions (vinasse added and operation time) for vinasse\\/cotton waste mixtures on the properties of products obtained (pH, electrical conductivity, organic matter, Kjeldahl-N, C\\/N ratio, biodegradability, Kjeldahl-N losses and germination index) in order to determine the best in-vessel composting conditions. The range of the independent variable measured was

M. J. D??az; M. E. Eugenio; L. Jiménez; E. Madejón; F. Cabrera

2003-01-01

124

Isotopic ratios of lead in contemporary environmental material from Scotland  

Microsoft Academic Search

Lead emitted into the environment, primarily from the combustion of leaded petrol and industrial activities, retains the isotopic\\u000a signature of the ore(s) from which it is derived. Leaded petrol, atmospheric particulates and street dust sampled in central\\u000a Edinburgh between February 1989 and December 1991 had mean206Pb\\/207Pb ratios of 1.082 ± 0.024, 1.092 ± 0.011 and 1.109 ± 0.016 respectively. These

C. L. Sugden; J. G. Farmer; A. B. MacKenzie

1993-01-01

125

Two-stage treatment reduces water/oil ratio  

SciTech Connect

This paper reports how a treatment of amphoteric polymer followed by chrome-complexed anionic polyacrylamide has successfully decreased the water/oil (WOR) ratio of wells producing from the Arbuckle dolomite formation in central Kansas. This technique, the fractured-matrix, water-control (FMWC) treatment, is designed to alter both primary and secondary permeability to water production. In 10 treated wells, the average WOR was reduced by a factor of five.

Wood, F.; Dairymple, D. (Halliburton Services, Duncan, OK (US)); McKown, K.; Matthews, B. (Halliburton Services, KS (US))

1990-09-10

126

Off-center ratios for three-dimensional dose calculations.  

PubMed

A new method is proposed for computing the off-center ratios (OCR's) in three-dimensional dose calculations. For an open field, the OCR at a point is computed as the product of the primary OCR (POCR) and the boundary factors (BF's). The POCR describes the beam profile for an infinite field, that is, without the effect of the collimators. It is defined as the ratio of the dose at a point off the central ray to the dose at the point on the central ray at the same depth for an infinite field. The POCR is a function of radial distance from the beam central ray and depth. The BF describes the shape of the beam in the neighborhood of the field boundary defined by the collimators. It is defined as the ratio of the OCR at a point for a finite field to the OCR at the same point for an infinite field. The BF is a function of distance from the field boundary, depth, and field size. For a wedged field, we assume that the boundary factors remain the same as for open fields but the POCR's are altered. The changes in beam profiles are described by a factor called the wedge profile factor (WPF), defined as the ratio of the dose at a point for the largest wedged field to the dose at the same point for an open field of the same field size. The WPF is a function of lateral distance from the beam central plane and depth. Calculated OCR's using this new method are in agreement with the measured data along both the transverse and the diagonal directions of the field. PMID:3088413

Chui, C S; Mohan, R

1986-01-01

127

Off-center ratios for three-dimensional dose calculations  

SciTech Connect

A new method is proposed for computing the off-center ratios (OCR's) in three-dimensional dose calculations. For an open field, the OCR at a point is computed as the product of the primary OCR (POCR) and the boundary factors (BF's). The POCR describes the beam profile for an infinite field, that is, without the effect of the collimators. It is defined as the ratio of the dose at a point off the central ray to the dose at the point on the central ray at the same depth for an infinite field. The POCR is a function of radial distance from the beam central ray and depth. The BF describes the shape of the beam in the neighborhood of the field boundary defined by the collimators. It is defined as the ratio of the OCR at a point for a finite field to the OCR at the same point for an infinite field. The BF is a function of distance from the field boundary, depth, and field size. For a wedged field, we assume that the boundary factors remain the same as for open fields but the POCR's are altered. The changes in beam profiles are described by a factor called the wedge profile factor (WPF), defined as the ratio of the dose at a point for the largest wedged field to the dose at the same point for an open field of the same field size. The WPF is a function of lateral distance from the beam central plane and depth. Calculated OCR's using this new method are in agreement with the measured data along both the transverse and the diagonal directions of the field.

Chui, C.S.; Mohan, R.

1986-05-01

128

Strange Baryon to Meson Ratio  

NASA Astrophysics Data System (ADS)

We present a model to compute baryon and meson transverse momentum distributions, and their ratios, in relativistic heavy-ion collisions. The model allows to compute the probability to form colorless bound states of either two or three quarks as functions of the evolving density during the collision. The qualitative differences of the baryon to meson ratio for different collision energies and for different particle species can be associated to the different density dependent probabilities and to the combinatorial factors which in turn depend on whether the quarks forming the bound states are heavy or light. We compare to experimental data and show that we obtain a good description up to intermediate values of pt.

Cuautle, Eleazar; Ayala, Alejandro

2014-05-01

129

Rates, Ratios, Percents, and Proportions  

NSDL National Science Digital Library

Each of these sites will help you get better with percentages, rates, ratios, and solving proportions by cross-multiplying. 1. Begin by comparing fractions to decimals and to percentages. These two sites are similar. Pick one and practice it for a few minutes. Fraction-Decimal-Percent Chart or Percents-Fractions-Decimals (2) 2. Next, try to solve these percentage word problems. To find the problems, scroll down to the bottom of the page to the "Exercises." ...

Hbinggeli

2010-10-22

130

Sex ratios in bumble bees  

PubMed Central

The median proportion of investment in females among 11 populations of seven bumble bee (Bombus) species was 0.32 (range 0.07 to 0.64). By contrast, two species of workerless social parasites in the related genus Psithyrus had female-biased sex allocation, the reasons for which remain unclear. Male-biased sex allocation in Bombus contradicts the predictions of Trivers and Hare's sex ratio model for the social Hymenoptera, which are that the population sex investment ratio should be 0.5 (1:1) under queen control and 0.75 (3:1 females:males) under worker control (assuming single, once-mated, outbred queens and non-reproductive workers). Male bias in Bombus does not appear to be either an artefact, or purely the result of symbiotic sex ratio distorters. According to modifications of the Trivers–Hare model, the level of worker male-production in Bombus is insufficient to account for observed levels of male bias. There is also no evidence that male bias arises from either local resource competition (related females compete for resources) or local mate enhancement (related males cooperate in securing mates). Bulmer presented models predicting sexual selection for protandry (males are produced before females) in annual social Hymenoptera and, as a consequence (given some parameter values), male-biased sex allocation. Bumble bees fit the assumptions of Bulmer's models and are protandrous. These models therefore represent the best current explanation for the bees' male-biased sex investment ratios. This conclusion suggests that the relative timing of the production of the sexes strongly influences sex allocation in the social Hymenoptera.

Bourke, A. F. G.

1997-01-01

131

The midbrain to pons ratio  

PubMed Central

Objectives: MRI-based measurements used to diagnose progressive supranuclear palsy (PSP) typically lack pathologic verification and are not easy to use routinely. We aimed to develop in histologically proven disease a simple measure of the midbrain and pons on sagittal MRI to identify PSP. Methods: Measurements of the midbrain and pontine base on midsagittal T1-weighted MRI were performed in confirmed PSP (n = 12), Parkinson disease (n = 2), and multiple system atrophy (MSA) (n = 7), and in controls (n = 8). Using receiver operating characteristic curve analysis, cutoff values were applied to a clinically diagnosed cohort of 62 subjects that included PSP (n = 21), Parkinson disease (n = 10), MSA (n = 10), and controls (n = 21). Results: The mean midbrain measurement of 8.1 mm was reduced in PSP (p < 0.001) with reduction in the midbrain to pons ratio (PSP smaller than MSA; p < 0.001). In controls, the mean midbrain ratio was approximately two-thirds of the pontine base, in PSP it was <52%, and in MSA the ratio was greater than two-thirds. A midbrain measurement of <9.35 mm and ratio of 0.52 had 100% specificity for PSP. In the clinically defined group, 19 of 21 PSP cases (90.5%) had a midbrain measurement of <9.35 mm. Conclusions: We have developed a simple and reliable measurement in pathologically confirmed disease based on the topography of atrophy in PSP with high sensitivity and specificity that may be a useful tool in the clinic.

Massey, Luke A.; Jager, Hans R.; Paviour, Dominic C.; O'Sullivan, Sean S.; Ling, Helen; Williams, David R.; Kallis, Constantinos; Holton, Janice; Revesz, Tamas; Burn, David J.; Yousry, Tarek; Lees, Andrew J.; Fox, Nick C.; Micallef, Caroline

2013-01-01

132

Stable Isotope Ratios: Hurricane Olivia  

Microsoft Academic Search

The oxygen and hydrogen isotopic compositions of rains from HurricaneOlivia (1994) in the eastern Pacific were measured. The rains werecollected on 24 and 25 September during airplane flights conducted at anelevation of 3 km. Hurricane Olivia peaked in intensity to a category-4storm between the two dates. Isotope ratios of rains from HurricaneOlivia were markedly lower (d 18O = –13.9‰to –28.8‰)

James R. Lawrence; Stanley David Gedzelman; John Gamache; Michael Black

2002-01-01

133

Extreme Low Aspect Ratio Stellarators  

NASA Astrophysics Data System (ADS)

Recently proposed Spherical Stellarator (SS) concept [1] includes the devices with stellarator features and low aspect ratio, A <= 3.5, which is very unusual for stellarators (typical stellarators have A ? 7-10 or above). Strong bootstrap current and high-? equilibria are two distinguished elements of the SS concept leading to compact, steady-state, and efficient fusion reactor. Different coil configurations advantageous for the SS have been identified and analyzed [1-6]. In this report, we will present results on novel stellarator configurations which are unusual even for the SS approach. These are the extreme-low-aspect-ratio-stellarators (ELARS), with the aspect ratio A ? 1. We succeeded in finding ELARS configurations with extremely compact, modular, and simple design compatible with significant rotational transform (? ? 0.1 - 0.15), large plasma volume, and good particle transport characteristics. [1] P.E. Moroz, Phys. Rev. Lett. 77, 651 (1996); [2] P.E. Moroz, Phys. Plasmas 3, 3055 (1996); [3] P.E. Moroz, D.B. Batchelor et al., Fusion Tech. 30, 1347 (1996); [4] P.E. Moroz, Stellarator News 48, 2 (1996); [5] P.E. Moroz, Plasma Phys. Reports 23, 502 (1997); [6] P.E. Moroz, Nucl. Fusion 37, No. 8 (1997). *Supported by DOE Grant No. DE-FG02-97ER54395.

Moroz, Paul

1997-11-01

134

Using Ratio Analysis to Evaluate Financial Performance.  

ERIC Educational Resources Information Center

The ways in which ratio analysis can help in long-range planning, budgeting, and asset management to strengthen financial performance and help avoid financial difficulties are explained. Types of ratios considered include balance sheet ratios, net operating ratios, and contribution and demand ratios. (MSE)

Minter, John; And Others

1982-01-01

135

Wetlands of Central America  

Microsoft Academic Search

The wetlands of seven Central American countries – Belize, Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, and Panamá – are reviewed. The region's wetlands are classified into five systems: marine, estuarine, riverine, lacustrine, and palustrine. At a minimum, wetlands cover ˜40,000 km2 (˜8%) of the land area of Central America. These wetlands support high levels of biological diversity, especially of

Aaron M. Ellison

2004-01-01

136

Are Central Banks necessary?  

Microsoft Academic Search

Two recent studies use history and theory to examine the likely consequences of eliminating government intervention in the provision of money. Such proposals would end the central bank monopoly over note issue and replace it with note issues by competing banks. Supervisory functions of central banks would be dispensed with. Accordingly, the proposals would free banks from all regulations on

Anna J. Schwartz

1993-01-01

137

Back to central tolerance.  

PubMed

The establishment and maintenance of immunological tolerance entails both central and peripheral mechanisms. The latter have been highlighted in the past several years, mostly because of great interest in the activities of regulatory T cells. However, an important role for central tolerance mechanisms has been reemphasized by recent results on human autoimmune diseases, including APECED and type 1 diabetes. PMID:15142520

Mathis, Diane; Benoist, Christophe

2004-05-01

138

Central Pontine Myelinolysis  

Microsoft Academic Search

Central pontine myelinolysis (CPM) is a demyelinating disease of the pons often associated with demyelination of other areas of the central nervous system (CNS). The term ‘osmotic demyelinization syndrome’ is used for pontine and extrapontine myelinolysis. In this paper, we are concerned with CPM although the extrapontine one is based on the same pathogenesis. Both share the diagnostic methods, and

Christian Lampl; Kambiz Yazdi

2002-01-01

139

Central centrifugal cicatricial alopecia  

PubMed Central

Central centrifugal cicatricial alopecia is a common cause of progressive permanent apical alopecia. This unique form of alopecia includes entities previously know as “hot comb alopecia,” “follicular degeneration syndrome,” “pseudopelade” in African Americans and “central elliptical pseudopelade” in Caucasians. The etiology appears to be multifactorial and the condition occurs in all races.

Blattner, Collin; Polley, Dennis C.; Ferritto, Frank; Elston, Dirk M.

2013-01-01

140

Central American update  

Microsoft Academic Search

The Central American Energy Resources Project is designed to help the countries of Honduras, Costa Rica, El Salvador, Guatemala, and Panama develop their geothermal resources. Auxiliary project goals are to increase economic development and employment in Central America; to provide a scientific basis for the private sector to develop natural resources; and to provide scientific training to in-country scientists, engineers,

1987-01-01

141

Preservation of near-solar neon isotopic ratios in Icelandic basalts  

Microsoft Academic Search

Neon isotopic ratios measured in olivine and basaltic glass from Iceland are the most primitive observed so far in terrestrial mantle-derived samples. Ratios were measured in gas released from olivine and basaltic glass from a total of 10 samples from the Reykjanes Peninsula, Iceland, and one sample from central Iceland. The neon isotopic ratios include solar-like, mid-ocean ridge basalt (MORB)-like

Eleanor T. Dixon; Masahiko Honda; Ian McDougall; Ian H. Campbell; Ingvar Sigurdsson

2000-01-01

142

Central Banking Resource Center  

NSDL National Science Digital Library

Central Banks of the World is a pointers page to central banks and central bank information for over 45 countries, as well as multilateral financial institutions, research and training establishments, and conference information. To show how little is generally known about the history of central banking in the United States, this site includes an email message sent to the webmaster of the First Bank of the United States, promoting a certain software company's web interactivity applications. Of course, since the First Bank of the United States was closed in 1811, its web site is primarily historical. The Central Banks site lists over 30 Internet directories and pointers pages that list the First Bank of the United States as a functioning financial institution. To help remedy this situation, the site includes a pointer to a brief history of banking in the US.

1996-01-01

143

Central diffraction at ALICE  

NASA Astrophysics Data System (ADS)

The ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment of the central system allows detailed QCD studies and searches for exotic meson states, such as glueballs, hybrids and new charmonium-like states. It would also provide a good testing ground for detailed studies of heavy quarkonia. Due to its central barrel performance, ALICE can accurately measure the low-mass central systems with good purity. The efficiency of the Forward Multiplicity Detector (FMD) and the Forward Shower Counter (FSC) system for detecting rapidity gaps is shown to be adequate for the proposed studies. With this detector arrangement, valuable new data can be obtained by tagging central diffractive processes.

Lämsä, J. W.; Orava, R.

2011-02-01

144

Envera Variable Compression Ratio Engine  

SciTech Connect

Aggressive engine downsizing, variable compression ratio and use of the Atkinson cycle are being combined to improve fuel economy by up to 40 percent relative to port fuel injected gasoline engines, while maintaining full engine power. Approach Engine downsizing is viewed by US and foreign automobile manufacturers as one of the best options for improving fuel economy. While this strategy has already demonstrated a degree of success, downsizing and fuel economy gains are currently limited. With new variable compression ratio technology however, the degree of engine downsizing and fuel economy improvement can be greatly increased. A small variable compression ratio (VCR) engine has the potential to return significantly higher vehicle fuel economy while also providing high power. Affordability and potential for near term commercialization are key attributes of the Envera VCR engine. VCR Technology To meet torque and power requirements, a smaller engine needs to do more work per stroke. This is typically accomplished by boosting the incoming charge with either a turbo or supercharger so that more energy is present in the cylinder per stroke to do the work. With current production engines the degree of engine boosting (which correlates to downsizing) is limited by detonation (combustion knock) at high boost levels. Additionally, the turbo or supercharger needs to be responsive and efficient while providing the needed boost. VCR technology eliminates the limitation of engine knock at high load levels by reducing compression ratio to {approx}9:1 (or whatever level is appropriate) when high boost pressures are needed. By reducing the compression ratio during high load demand periods there is increased volume in the cylinder at top dead center (TDC) which allows more charge (or energy) to be present in the cylinder without increasing the peak pressure. Cylinder pressure is thus kept below the level at which the engine would begin to knock. When loads on the engine are low the compression ratio can be raised (to as much as 18:1) providing high engine efficiency. It is important to recognize that for a well designed VCR engine cylinder pressure does not need to be higher than found in current production turbocharged engines. As such, there is no need for a stronger crankcase, bearings and other load bearing parts within the VCR engine. The Envera VCR mechanism uses an eccentric carrier approach to adjust engine compression ratio. The crankshaft main bearings are mounted in this eccentric carrier or 'crankshaft cradle' and pivoting the eccentric carrier 30 degrees adjusts compression ratio from 9:1 to 18:1. The eccentric carrier is made up of a casting that provides rigid support for the main bearings, and removable upper bearing caps. Oil feed to the main bearings transits through the bearing cap fastener sockets. The eccentric carrier design was chosen for its low cost and rigid support of the main bearings. A control shaft and connecting links are used to pivot the eccentric carrier. The control shaft mechanism features compression ratio lock-up at minimum and maximum compression ratio settings. The control shaft method of pivoting the eccentric carrier was selected due to its lock-up capability. The control shaft can be rotated by a hydraulic actuator or an electric motor. The engine shown in Figures 3 and 4 has a hydraulic actuator that was developed under the current program. In-line 4-cylinder engines are significantly less expensive than V engines because an entire cylinder head can be eliminated. The cost savings from eliminating cylinders and an entire cylinder head will notably offset the added cost of the VCR and supercharging. Replacing V6 and V8 engines with in-line VCR 4-cylinder engines will provide high fuel economy at low cost. Numerous enabling technologies exist which have the potential to increase engine efficiency. The greatest efficiency gains are realized when the right combination of advanced and new technologies are packaged together to provide the greatest gains at the least cost. Aggressive engine downsiz

Charles Mendler

2011-03-15

145

Low-aspect ratio ignimbrites  

NASA Astrophysics Data System (ADS)

Conventionally1, three important characteristics of ignimbrites are that they show a very pronounced tendency to pond in topographic depressions, possess a flat, horizontal or gently sloping upper depositional surface, and have a thickness generally between 10 and 1,000 m. The youngest major ignimbrite, that of 1912 in the Valley of Ten Thousand Smokes (Alaska)2-4 shows these characteristics well, being ponded in a valley 25 km long with a flat upper surface sloping down-valley at an average of 1.3°, and having an estimated thickness exceeding 100 m in places. AU three characteristics are commonly used as field criteria to distinguish ignimbrites from other pyroclastic rock bodies. Here we look at certain ignimbrites which depart significantly from this conventional form in that a major part of them occurs as a thin layer mantling the landscape, resting on slopes as steep as 30°, and with an upper surface sensibly parallel with the underlying surface. We have studied two examples, the 1,800-yr-old5 Taupo ignimbrite (New Zealand), and the 1,400-yr-old Rabual ignimbrite (New Britain)6,7. We also cite several others. These ignimbrites have a remarkably low aspect ratio. This ratio, previously applied to lava extrusions8,9, provides a useful means of quantifying the overall geometry of rock bodies. The ratio is that of average thickness to lateral spread; conveniently the latter is taken as the diameter of the circle which covers the same area as the rock body.

Walker, G. P. L.; Heming, R. F.; Wilson, C. J. N.

1980-01-01

146

Low aspect ratio wing experiment  

NASA Technical Reports Server (NTRS)

This test was initiated to provide validation data on low aspect ratio wings at transonic speeds. The test was conducted so that the data obtained would be useful in the validation of codes, and all boundary condition data required would be measured as part of the test. During the conduct of the test, the measured quantities were checked for repeatability, and when the data would not repeat, the cause was tracked down and either eliminated or included in the measurement uncertainty. The accuracy of the data was in the end limited by wall imperfections of the wind tunnel in which the test was run.

Olsen, Mike; Seegmiller, H. Lee

1994-01-01

147

44Sc Isomeric Yield Ratios  

Microsoft Academic Search

44Sc isomeric yield ratios have been measured for the three reactions 45Sc(gamma,n)44Sc, 46Ti(gamma,np)44Sc, and 45Sc(n,2n)44Sc. Scandium oxide and titanium samples were irradiated with 48-MeV bremsstrahlung to obtain the photo-induced reactions. For the (n,2n) reaction 14-MeV neutrons were used. The yields of 44Sc in the ground and isomeric states were determined by the measurement of the residual gamma activity. A statistical-model

J. R. Tatarczuk; H. A. Medicus

1966-01-01

148

34 CFR 668.172 - Financial ratios.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Financial ratios. 668.172 Section 668.172 Education...STUDENT ASSISTANCE GENERAL PROVISIONS Financial Responsibility § 668.172 Financial ratios. (a) Appendices A and B, ratio...

2010-07-01

149

34 CFR 668.172 - Financial ratios.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Financial ratios. 668.172 Section 668.172 Education...STUDENT ASSISTANCE GENERAL PROVISIONS Financial Responsibility § 668.172 Financial ratios. (a) Appendices A and B, ratio...

2009-07-01

150

Pluto/charon Light Ratio  

NASA Astrophysics Data System (ADS)

Predicting the occultations of the stars P126 and P131.1 by Pluto on 2002 July 20 (UT) and August 21 (UT) respectively (Clancy et al. 2002 BAAS 34 1212) involved astrometric data sets spanning more than three months acquired on several telescopes. Pluto's position in these frames was determined relative to a UCAC astrometric reference network (Zacharias et al. 2000 AJ 120 2131) using a dual-source PSF model fit to the blended Pluto-Charon image. Although the final predictions were quite accurate (see http://occult.mit.edu/research/ occultations/Candidates/Predictions/P126.html and http:// occult.mit.edu/research/occultations/Candidates/Predictions/ P131.1.html) empirical corrections were made to the offset of Pluto from its ephemeris. These were based on the residuals of Pluto's measured position from its ephemeris which were sinusoidal. The consistency of the fitted residual phase and amplitude between all prediction data sets implies either an incorrect Charon to Pluto mass ratio was used in the ephemeris or that we used incorrect Pluto-Charon light ratios in this reduction. Anticipated resolved photometry of Pluto- Charon taken at Magellan should reveal the cause of these residuals. This work was funded in part by NASA grant NAG5-10444 and NSF grant AST-007 3447

Clancy, K. B.; Elliot, J. L.; Person, Mit J.

151

Central Force JS Model  

NSDL National Science Digital Library

The Central Force JavaScript Model computes the trajectory of a particle acted on by a central force.  The model reads uses a JavaScript mathematical expression parser to read the force and a adaptive step Runge-Kutta 5(4) algorithm to compute the trajectory.  This model is designed to test the speed of the JS parser and the accuracy of the EJS JavaScript ODE solver. The Central Force JS Model was developed using the Easy Java Simulations (EJS) version 5. It is distributed as a ready-to-run html page and requires only a browser with JavaScript support.

Christian, Wolfgang

2013-09-01

152

MoneyCentral  

NSDL National Science Digital Library

MoneyCentral is a new personal finance site by Microsoft now in public beta test. An expanded and more user-friendly form of MSN's Money Insider (discussed in the October 23, 1997 Scout Report for Business & Economics), MoneyCentral encompasses a wide variety of guides and tools on everything from Family Financing to Real Estate, Taxes and Investing. Visitors may view the full range of MoneyCentral topics from a clearly-arranged and clickable site map among other helpful links.

1999-01-01

153

Electroretinography in central retinal vein occlusion  

Microsoft Academic Search

In 149 eyes with central retinal vein occlusion (CRVO), we prospectively investigated the role of routine, clinical electroretinography (ERG) in differentiating ischemic (60 eyes) from nonischemic CRVO (89 eyes). Single-flash photopic and scotopic ERGs were recorded. Data for the amplitudes and implicit times of a- and b-waves and for the b-\\/a-wave amplitude ratio were analyzed in detail. The study revealed

Sohan Singh Hayreh; Marie R. Klugman; Patricia Podhajsky; Hansjoerg E. Kolder

1989-01-01

154

Detailed Distribution of the Helium Isotope Ratios in Northeastern Japan  

NASA Astrophysics Data System (ADS)

The geographical distribution of helium isotope ratios (3He/4He ratios) is characterized by high values of 4 to 8RA (where RA is the atmospheric 3He/4He ratio of 1.39×10-6) along the volcanic front and in the back-arc region at Tohoku district, northeastern Japan. In contrast forearc region shows low values less than 1RA. On the other hand, there is no clear contrast of the 3He/4He ratios except at the central region (e.g., Sano and Wakita, 1985). We perform the helium isotope ratio analysis in northeastern Japan, and around the source region of the Niigataken Chuetsu-oki Earthquake in 2007 (M6.8) where 3He/4He ratios data were reported. We have collected 41 samples of gases from hot springs, mineral springs, and deep wells, distributing mainly in the forearc region at Tohoku district. In addition, we also collected 19 samples of gases from hot springs, volcanoes and natural gas fields around the source region of the Niigataken Chuetsu-oki Earthquake in 2007. We measured 3He/4He ratios by noble gas mass spectrometers (Helix and VG5400) of Ocean Research Institute (ORI), the University of Tokyo. The 4He/20Ne were measured by a quadruple mass spectrometer to evaluate air contamination in the samples. ?13C (CO2) values were measured by using a mass spectrometer (DELTA plus XP) of ORI. Main features of our results for Tohoku region are as follows: 1) The 3He/4He ratios in the forearc region are less than 1RA. 2) The 3He/4He ratios vary along the volcanic front. In Miyagi prefecture [38-39N], the ratios range from 2 to 5 RA. On the other hand, the ratios are less than 1RA in and around the southern boundary of Iwate and Akita prefectures [39-39.5N]. The distribution of 3He/4He ratios in Niigata plans to be discussed by comparing with the well-studied seismotectonics and the structure of the crust and upper mantle.

Horiguchi, K.; Ueki, S.; Sano, Y.; Takahata, N.; Hasegawa, A.

2007-12-01

155

Reconstructing bulk isotope ratios from compound-specific isotope ratios.  

PubMed

Carbon isotope analysis by bulk elemental analysis coupled with isotope ratio mass spectrometry has been the mainstay of delta(13)C analyses both at natural abundance and in tracer studies. More recently, compound-specific isotope analysis (CSIA) has become established, whereby organic constituents are separated online by gas or liquid chromatography before oxidation and analysis of CO(2) for constituent delta(13)C. Theoretically, there should be concordance between bulk delta(13)C measurements and carbon-weighted delta(13)C measurements of carbon-containing constituents. To test the concordance between the bulk and CSIA, fish oil was chosen because the majority of carbon in fish oil is in the triacylglycerol form and approximately 95% of this carbon is amenable to CSIA in the form of fatty acids. Bulk isotope analysis was carried out on aliquots of oil extracted from 55 fish samples and delta(13)C values were obtained. Free fatty acids (FFAs) were produced from the oil samples by saponification and derivatised to fatty acid methyl esters (FAMEs) for CSIA by gas chromatography/combustion/isotope ratio mass spectrometry. A known amount of an internal standard (C15:0 FAME) was added to allow analyte quantitation. This internal standard was also isotopically calibrated in both its FFA (delta(13)C = -34.30 per thousand) and FAME (delta(13)C = -34.94 per thousand) form. This allowed reporting of FFA delta(13)C from measured FAME delta(13)C values. The bulk delta(13)C was reconstructed from CSIA data based on each FFA delta(13)C and the relative amount of CO(2) produced by each analyte. The measured bulk mean delta(13)C (SD) was -23.75 per thousand (1.57 per thousand) compared with the reconstructed bulk mean delta(13)C of -23.76 (1.44 per thousand) from CSIA and was not significantly different. Further analysis of the data by the Bland-Altman method did not show particular bias in the data relative to the magnitude of the measurement. Good agreement between the methods was observed with the mean difference between methods (range) of 0.01 per thousand (-1.50 to 1.30). PMID:20499325

Morrison, Douglas J; Cooper, Karen; Preston, Tom

2010-06-30

156

Is Central Bank Transparency Desirable?  

Microsoft Academic Search

I analyse central bank transparency when the central bank's objective function is its private information. Non-transparency exists when the public does not observe the action of the central bank and an unobservable component of the inflation-control error keeps the public from using its observation of inflation to infer perfectly the central bank's action, and hence, the central bank's objective. The

Anne C. Sibert

2006-01-01

157

Central ballast tanker design  

SciTech Connect

The purpose of this paper is to present the CENTRAL BALLAST TANKER Design. This design is intended to reduce the volume of oil spilled from tankers by giving the crew a tanker properly designed and equipped to allow large quantities of oil from ruptured tank(s) to flow safely to a fully-inerted central ballast tank. In addition to reducing the volume of oil spilled, the design also addresses many of the shortcomings of the DOUBLE HULL DESIGN which are increasingly becoming a concern. The following is a brief review of the development of the CENTRAL BALLAST TANKER. The simple operational features, stability, low cost and ease of maintenance of the single hull tanker were important and can be retained with the CENTRAL BALLAST DESIGN.

NONE

1997-01-01

158

Central American Resource Studies.  

National Technical Information Service (NTIS)

Los Alamos National Laboratory has been working with five Central American countries to assist in the development of their energy and mineral resources. Since 1985, mineral resources in Costa Rica, peat resources in Costa Rica and Panama, geothermal energ...

E. Van Eeckhout A. W. Laughlin

1989-01-01

159

Central Pontine Myelinolysis  

MedlinePLUS

... Central Pontine Myelinolysis Information Page Synonym(s): Extrapontine Myelinolysis Table of Contents (click to jump to sections) What ... intellectual impairment or movement disorders like parkinsonism or tremor. Anyone, including adults and children, who undergoes a ...

160

Exploring Central Tendency  

NSDL National Science Digital Library

This lesson is designed for 6th grade students. Student will work in small groups to apply central tendency to a real world scenario to finally answer the age old question of "when will I ever use this."

Friske, Monica

2012-08-14

161

Advanced high area ratio nozzles  

NASA Technical Reports Server (NTRS)

The objective is to develop computational techniques for the design of high-area-ratio nozzles and to validate these models by comparison with experiments and computations using other codes. Progress was made in two areas during the past year. First, performance computations were added to the PARC2D code and the performance of the SSME nozzle was computed for inviscid, laminar and turbulent flow assuming a perfect gas with gamma = 1.2. Second, the PARC2D code was modified in a non-CASP project to compute equilibrium flow about hypersonic blunt bodies. Progress has been made toward modifying this code to compute equilibrium H2/O2 flow through the SSME and related nozzles.

Raiszadeh, Farhad; Collins, Frank G.; Orr, Joseph L., Jr.; Myruski, Brian

1995-01-01

162

Advanced high area ratio nozzles  

NASA Technical Reports Server (NTRS)

The objective is to develop computational techniques for the design of high-area-ratio nozzles and to validate these models by comparison with experiments and computations using other codes. Performance computations were added to the PARC2D code and the performance of the space shuttle main engine (SSME) nozzle was computed for inviscid, laminar and turbulent flow assuming a perfect gas with gamma = 1.2. The PARC2D code was modified in a non-CASP (Center for Advanced Space Propulsion) project to compute equilibrium flow about hypersonic blunt bodies. Progress has been made toward modifying this code to compute equilibrium H2/O2 flow through the SSME and related nozzles.

Raiszadeh, Farhad; Collins, Frank G.; Orr, Joseph L., Jr.; Myruski, Brian

1989-01-01

163

Beaded Braids: Investigating Patterns & Ratios  

NSDL National Science Digital Library

In this activity learners create patterns of hair beads. Simone and Brianna like different mixes of beads in their braids, so learners must figure out how to distribute 40 beads to satisfy both characters. Images of the two girls are provided in the PDF. Either 20 each of two types of real beads can be used, or the learner can cut out paper beads (20 round and 20 heart-shaped), though the pattern is missing from the PDF. Included questions help learners explore ratio through addition, multiplication, and division. Learners can color the pictures and beads, and make braids with yarn for fun. This activity could also be adapted in terms of decorating lanyard and would connect very well with afterschool or home craft activities.

Science, Lawrence H.

2003-01-01

164

Central fatigue: the serotonin hypothesis and beyond.  

PubMed

The original central fatigue hypothesis suggested that an exercise-induced increase in extracellular serotonin concentrations in several brain regions contributed to the development of fatigue during prolonged exercise. Serotonin has been linked to fatigue because of its well known effects on sleep, lethargy and drowsiness and loss of motivation. Several nutritional and pharmacological studies have attempted to manipulate central serotonergic activity during exercise, but this work has yet to provide robust evidence for a significant role of serotonin in the fatigue process. However, it is important to note that brain function is not determined by a single neurotransmitter system and the interaction between brain serotonin and dopamine during prolonged exercise has also been explored as having a regulative role in the development of fatigue. This revised central fatigue hypothesis suggests that an increase in central ratio of serotonin to dopamine is associated with feelings of tiredness and lethargy, accelerating the onset of fatigue, whereas a low ratio favours improved performance through the maintenance of motivation and arousal. Convincing evidence for a role of dopamine in the development of fatigue comes from work investigating the physiological responses to amphetamine use, but other strategies to manipulate central catecholamines have yet to influence exercise capacity during exercise in temperate conditions. Recent findings have, however, provided support for a significant role of dopamine and noradrenaline (norepinephrine) in performance during exercise in the heat. As serotonergic and catecholaminergic projections innervate areas of the hypothalamus, the thermoregulatory centre, a change in the activity of these neurons may be expected to contribute to the control of body temperature whilst at rest and during exercise. Fatigue during prolonged exercise clearly is influenced by a complex interaction between peripheral and central factors. PMID:17004850

Meeusen, Romain; Watson, Philip; Hasegawa, Hiroshi; Roelands, Bart; Piacentini, Maria F

2006-01-01

165

Weather-Corrected Performance Ratio  

SciTech Connect

Photovoltaic (PV) system performance depends on both the quality of the system and the weather. One simple way to communicate the system performance is to use the performance ratio (PR): the ratio of the electricity generated to the electricity that would have been generated if the plant consistently converted sunlight to electricity at the level expected from the DC nameplate rating. The annual system yield for flat-plate PV systems is estimated by the product of the annual insolation in the plane of the array, the nameplate rating of the system, and the PR, which provides an attractive way to estimate expected annual system yield. Unfortunately, the PR is, again, a function of both the PV system efficiency and the weather. If the PR is measured during the winter or during the summer, substantially different values may be obtained, making this metric insufficient to use as the basis for a performance guarantee when precise confidence intervals are required. This technical report defines a way to modify the PR calculation to neutralize biases that may be introduced by variations in the weather, while still reporting a PR that reflects the annual PR at that site given the project design and the project weather file. This resulting weather-corrected PR gives more consistent results throughout the year, enabling its use as a metric for performance guarantees while still retaining the familiarity this metric brings to the industry and the value of its use in predicting actual annual system yield. A testing protocol is also presented to illustrate the use of this new metric with the intent of providing a reference starting point for contractual content.

Dierauf, T.; Growitz, A.; Kurtz, S.; Cruz, J. L. B.; Riley, E.; Hansen, C.

2013-04-01

166

Central Diffraction in ALICE  

SciTech Connect

The ALICE experiment consists of a central barrel in the pseudorapidity range -0.9<{eta}<0.9 and of additional detectors covering about 3 units of pseudorapidity on either side of the central barrel. Such a geometry allows the tagging of single and double gap events. The status of the analysis of such diffractive events in proton-proton collisions at {radical}(s) = 7 TeV is presented.

Schicker, R. [Phys. Inst., Philosophenweg 12, 69120 Heidelberg (Germany)

2011-07-15

167

Competitor-to-resource ratio, a general formulation of operational sex ratio, as a predictor of competitive aggression in Japanese medaka (Pisces: Oryziidae)  

Microsoft Academic Search

Operational sex ratio (OSR), the number of potentially mating males divided by the number of fertilizable females, plays a central role in the theory of mating systems by predicting the intensity of intra-sexual competition and sexual selection. We introduce a general version of OSR, competitor-to-resource ratio (CRR, the number of potential competitors divided by the number of resource units), as

James W. A. Grant; Chantal L. Gaboury; Howard L. Levitt

2000-01-01

168

Diabetes Insipidus, Central (For Parents)  

MedlinePLUS

... Tips: Baseball Pregnant? Your Baby's Growth A to Z: Diabetes Insipidus, Central KidsHealth > Parents > A to Z > ... More to Know Keep in Mind A to Z: Diabetes Insipidus, Central In central diabetes insipidus, the ...

169

Nitrogen to argon ratio in volcanic gases  

Microsoft Academic Search

A study is made of N2\\/Ar ratios in volcanic gases in order to evaluate the factors influencing such ratios. Particular attention is given to N2 derived from sedimentary material as it influences the N2\\/Ar ratio of volcanic gases. Gases derived from the deeper mantle of the earth are also examined for N2\\/Ar ratios. The N2\\/Ar ratios of volcanic gases show

S. Matsuo; M. Suzuki; Y. Mizutani

1978-01-01

170

CENTRAL PLATEAU REMEDIATION  

SciTech Connect

A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress.

ROMINE, L.D.

2006-02-01

171

The Central Limit Theorem  

NSDL National Science Digital Library

The applets in this section of Statistical Java allow you to see how the Central Limit Theorem works. The main page gives the characteristics of five non-normal distributions (Bernoulli, Poisson, Exponential, U-shaped, and Uniform). Users then select one of the distributions and change the sample size to see how the distribution of the sample mean approaches normality. Users can also change the number of samples. To select between the different applets you can click on Statistical Theory, the Central Limit Theorem and then the Main Page. At the bottom of this page you can make your applet selection.

Anderson-Cook, C.; Dorai-Raj, S.; Robinson, T.

2009-12-15

172

Centralized Mouse Repositories  

PubMed Central

Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

Donahue, Leah Rae; de Angelis, Martin Hrabe; Hagn, Michael; Franklin, Craig; Lloyd, K. C. Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Horlein, Andreas; Davisson, Muriel T.

2013-01-01

173

Central American update  

SciTech Connect

The Central American Energy Resources Project is designed to help the countries of Honduras, Costa Rica, El Salvador, Guatemala, and Panama develop their geothermal resources. Auxiliary project goals are to increase economic development and employment in Central America; to provide a scientific basis for the private sector to develop natural resources; and to provide scientific training to in-country scientists, engineers, and technicians. The energy resources project began in March 1985. The progress being made in El Salvador (production well logging and geophysical operations), Panama (site selection for the first temperature-gradient well), and Honduras (well drilling of temperature-gradient wells) is summarized.

Hodgson, S.F.

1987-07-01

174

ChildrensCentralCali  

Cancer.gov

Children’s Hospital Central California is excited to announce a new clinical opportunity due to the expansion of our Pediatric Psychology department. Children’s Hospital Central California is a 354 bed not-for-profit, state-of-the-art free standing Children’s Hospital. As a vital member of our Pediatric Psychology team the primary focus of this position will be on providing consultation-liaison services to our various medical inpatient units. There will also be opportunities for providing assessment and therapy services for our subspecialty clinics.

175

Occultation determination of Neptune's oblateness and stratospheric methane mixing ratio  

NASA Technical Reports Server (NTRS)

The occultation of a star by Neptune on August 20, 1985 was observed at 2.2 micron wavelength with telescopes at the European Southern Observatory (ESO) and the Cerro Tololo Inter-American Observatory (CTIO). The detection of a 'central flash' midway between immersion and emersion has allowed the determination of Neptune's oblateness and the atmospheric extinction at 2.2 microns, which is related to the stratospheric methane mixing ratio. An oblateness of (2.08 +0.19 or -0.18) x 10 to the 2nd is found and, assuming a stratospheric temperature of 120 K, a value of 0.6 percent is inferred (with an uncertainty of a factor of 10) for the methane mixing ratio (CH4/H2) at 0.3 mbar. The latter value may indicate supersaturation of methane in Neptune's stratosphere.

Lellouch, E.; Hubbard, W. B.; Sicardy, B.; Vilas, F.; Bouchet, P.

1986-01-01

176

The Evolution of Central Banking  

Microsoft Academic Search

November 1995What have we learned about central banks? The principal factors affecting central bank autonomy in the past two centuries have been prevailing political conditions, a laissez faire environment, and the exchange rate regime (whether fixed or floating).Institutions we know as central banks emerged or were established as commercial banks or government banks. Their evolution into central banks came with

Forrest Capie

1999-01-01

177

A Librarian's Primer on Financial Ratios.  

ERIC Educational Resources Information Center

Explains in simple terms the nature and function of a number of basic types of business and industrial financial ratios. An annotated list of five basic sources for ratios is included and a reference list and bibliography are attached. (JL)

Kerbel, Sandra Sandor

1982-01-01

178

Likelihood Ratio Derivative Estimators for Stochastic Systems.  

National Technical Information Service (NTIS)

This paper discusses the likelihood ratio derivative estimation techniques for stochastic systems. After a brief review of the basic concepts, likelihood ratio derivative estimators are presented for the following classes of stochastic processes: time hom...

P. W. Glynn

1989-01-01

179

CENTRALIZATION OF CAMPUS CONTROLS.  

ERIC Educational Resources Information Center

A COLLEGE CAMPUS HAVING A LARGE NUMBER OF SEPARATE BUILDINGS WITH ONE BASIC HEATING AND COOLING SYSTEM IS AN IDEAL SITUATION FOR REALIZING GREAT BENEFITS FROM CENTRALIZED BUILDING CONTROL SYSTEMS. TYPICAL REQUIREMENTS AND ADVANTAGES OF SUCH SYSTEMS ARE DISCUSSED BRIEFLY AND DESCRIPTIONS OF THE SYSTEM AT FOUR MAJOR UNIVERSITIES ARE GIVEN. THIS…

1967

180

Central nervous system tuberculosis.  

PubMed

Tuberculosis (TB) has shown a resurgence in nonendemic populations in recent years and accounts for 8 million deaths annually in the world. Central nervous system involvement is one of the most serious forms of this infection, acting as a prominent cause of morbidity and mortality in developing countries. The rising number of cases in developed countries is mostly attributed to factors such as the pandemic of acquired immunodeficiency syndrome and increased migration in a globalized world. Mycobacterium TB is responsible for almost all cases of tubercular infection in the central nervous system. It can manifest in a variety of forms as tuberculous meningitis, tuberculoma, and tubercular abscess. Spinal infection may result in spondylitis, arachnoiditis, and/or focal intramedullary tuberculomas. Timely diagnosis of central nervous system TB is paramount for the early institution of appropriate therapy, because delayed treatment is associated with severe morbidity and mortality. It is therefore important that physicians and radiologists understand the characteristic patterns, distribution, and imaging manifestations of TB in the central nervous system. Magnetic resonance imaging is considered the imaging modality of choice for the study of patients with suspected TB. Advanced imaging techniques including magnetic resonance perfusion and diffusion tensor imaging may be of value in the objective assessment of therapy and to guide the physician in the modulation of therapy in these patients. PMID:24887691

Torres, Carlos; Riascos, Roy; Figueroa, Ramon; Gupta, Rakesh K

2014-06-01

181

Physics Central: Fiddle Physics  

NSDL National Science Digital Library

This PhysicsCentral article describes the physics behind violins. The article discusses the mechanics of violin construction and how violinists produce sound. It includes labeled pictures of violin parts, animations of how the violin bow works, and other helpful images.

Popkin, Gabriel

2009-11-16

182

Central College Perspectives.  

ERIC Educational Resources Information Center

Institutional data are presented which reflect five-year trends in the characteristics of Central College, a two-year institution established by members of the Free Methodist Church of North America in 1884. Data tables present a profile of the faculty with figures for 1972 through 1977 for the following: number and characteristics of full- and…

Knapp, Wesley L.; Hawkins, Calvin H.

183

Channeling the central dogma.  

PubMed

How do neurons and networks achieve their characteristic electrical activity, regulate this activity homeostatically, and yet show population variability in expression? In this issue of Neuron, O'Leary et al. (2014) address some of these thorny questions in this theoretical analysis that starts with the Central Dogma. PMID:24853932

Calabrese, Ronald L

2014-05-21

184

Education in Central America.  

ERIC Educational Resources Information Center

The first chapter of this book describes the physical and cultural environment of Central America and includes analytical comments showing the complexity of the problems confronting the region. Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, and Panama are then treated in separate chapters including: 1) political, economic, social and…

Waggoner, George R.; Waggoner, Barbara Ashton

185

Central City Business.  

ERIC Educational Resources Information Center

Business owners and managers from 10 large cities were surveyed regarding (1) perceptions of their cities' business climate; (2) plans for increasing/decreasing their work force; and (3) whether they had considered moving/closing their businesses. Results suggest that for central city business to thrive, improvement must occur in urban quality of…

Matz, Deborah

1981-01-01

186

Loess of Central Asia  

Microsoft Academic Search

Loess deposits are widespread within the piedmont and intramontane depressions of Central Asia. They cover piedmont plains, river terraces, ridge slopes and watersheds. Loess is a significant component in the piedmonts of Tien Shan, eastern Fergana depression, the Afgan-Tajik depression, piedmonts of Kopetdag, Badchyz and Karabil Hills north of Parapamiz, in the Kashmir valley, on the Potwar Plateau and in

A. E. Dodonov

1991-01-01

187

Central Kitchen Controversy.  

ERIC Educational Resources Information Center

In a properly designed and implemented central kitchen and commissary, nutrition is retained, student acceptability is high, and cost-effectiveness for the school district is attained. Employee productivity can be increased three or four times the average production rate. (MLF)

Bender, Betty

1986-01-01

188

The Central Intelligence Agency's \\  

Microsoft Academic Search

Congress and the media recently have claimed that various activities of the Central Intelligence Agency (CIA)-from rendition operations, to the destruction of videotapes, to the maintenance of secret detention facilities overseas--are illegal. Critics levied similar charges against the CIA thirty-five years ago, with regard to activities contained in the \\

Daniel L Pines

2009-01-01

189

Central venous catheter use  

Microsoft Academic Search

Central venous catheters (CVCs) are used with increasing frequency in the intensive care unit and in general medical wards. Catheter infection, the most frequent complication of CVC use, is associated with increased morbidity, mortality, and duration of hospital stay. Risk factors in the development of catheter colonisation and bloodstream infection include patient factors (increased risk associated with malignancy, neutropenia, and

K. H. Polderman; A. R. J. Girbes

2002-01-01

190

Multicultural Central Asia.  

ERIC Educational Resources Information Center

This article addresses the multicultural aspect of Central Asia in response to the discussion on diversity in U.S. classrooms. Many areas of the world are more diverse than the U.S., and these areas experience successes and failures with many of the same issues the U.S. is currently struggling with. Comparing the U.S. diversity debate with similar…

Boyle, Eric D.

191

Central American resource studies  

Microsoft Academic Search

Los Alamos National Laboratory has been working with five Central American countries to assist in the development of their energy and mineral resources. Since 1985, mineral resources in Costa Rica, peat resources in Costa Rica and Panama, geothermal energy resources in Honduras and Guatemala, and geothermal field development in El Salvador and Costa Rica have been topics of study. This

E. Van Eeckhout; A. W. Laughlin

1989-01-01

192

Biventricular Central Neurocytoma  

PubMed Central

A case of biventricular neurocytoma is reported. A 36 year old Malay lady presented with headache of 8 months duration. Physical examination revealed signs of increase intracranial pressure. CT-scan and MRI showed tumour in both lateral ventricles. Patient underwent tumour debulking followed by adjuvant radiotherapy. The radiological appearances of central neurocytoma are discussed.

Ariff, A R; Muda, AS; Abdullah, JM; Gurjeet, K; Biswal, B M

2000-01-01

193

Biventricular central neurocytoma.  

PubMed

A case of biventricular neurocytoma is reported. A 36 year old Malay lady presented with headache of 8 months duration. Physical examination revealed signs of increase intracranial pressure. CT-scan and MRI showed tumour in both lateral ventricles. Patient underwent tumour debulking followed by adjuvant radiotherapy. The radiological appearances of central neurocytoma are discussed. PMID:22977388

Ariff, A R; Muda, A; Abdullah, J; Gurjeet, K; Biswal, B M

2000-07-01

194

Learning About Ratios: A Sandwich Study  

NSDL National Science Digital Library

This lesson introduces students to the concept of ratio through a hands-on, delicious experiment. After an introductory activity where students identify the ratio of girls to boys in a group of 10 selected students, they create six different peanut butter and jelly sandwiches with different ingredient ratios to find which is the tastiest. Students then plan their own similar experiment using other concoctions which can be expressed in ratios.

Weinberg, Sheryl

1999-01-16

195

Polymer squeeze cuts water\\/oil ratios  

Microsoft Academic Search

Polymer squeeze techniques have reduced water\\/oil ratios by 60 to 90% in the Bemis Shutts field of Ellis County, Kans. More than 100 wells have been treated and the success ratio has been extremely high. Not only have W\\/O ratios been drastically reduced, but a high percentage of the wells has shown a significant increase in oil production. The Bemis

Wieland

1973-01-01

196

Bidding ratios to predict highway project costs  

Microsoft Academic Search

Purpose – Ratios were constructed using bidding data for highway construction projects in Texas to study whether there are useful patterns in project bids that are indicators of the project completion cost. The use of the ratios to improve predictions of completed project cost was studied. Design\\/methodology\\/approach – Ratios were calculated relating the second lowest bid, mean bid, and maximum

Trefor P. Williams

2005-01-01

197

Spray Gun With Constant Mixing Ratio  

NASA Technical Reports Server (NTRS)

Conceptual mechanism mounted in handle of spray gun maintains constant ratio between volumetric flow rates in two channels leading to spray head. With mechanism, possible to keep flow ratio near 1:1 (or another desired ratio) over range of temperatures, orifice or channel sizes, or clogging conditions.

Simpson, William G.

1987-01-01

198

Management Ratios 1. For Colleges & Universities.  

ERIC Educational Resources Information Center

Ratios that enable colleges and universities to select other institutions for comparison are presented. The ratios and underlying data also enable colleges to rank order institutions and to calculate means, quartiles, and ranges for these groups. The data are based on FY 1983 U.S. Department of Education Statistics. The ratios summarize the…

Minter, John, Ed.

199

Large Deviation Rate and Central Limit Theorem for Horton Ratios. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

Although originating in hydrology, the classical Horton analysis is based on a geometric progression that is widely used in the empirical analysis of branching patterns found in biology, atmospheric science, plant pathology, etc., and more recently in tre...

S. X. Wang E. C. Waymire

1991-01-01

200

Spectral line ratios as Teff indicators in solar-like stars  

Microsoft Academic Search

The ratios of spectral line depths are often used as indicators of the stellar effective temperature T_eff. In particular, Gray & Livingston (\\\\cite{grayliv97a}) calibrated the temperature sensitivity of the ratios between the central depths of the line C I 538.032 nm and either the Fe I 537.958 or the Ti II 538.103, making use of observed spectra of several solar-like

B. Caccin; V. Penza; M. T. Gomez

2002-01-01

201

Central island tongue flap.  

PubMed

Pedicled tongue flaps have proved to be an effective method of repairing defects due to tissue loss in the oral cavity. Their central position, mobility, and excellent blood supply make their use feasible in a variety of sites. This paper describes the use and applications of central island tongue flaps to reconstruct defects of anterior floor of the mouth. This procedure was conducted at the Department of Oral and Maxillofacial Surgery, Medical University Hanover, introducing an improved surgical method and presenting the actual operation performed in our department. This method is considered superior for resurfacing the anterior floor of mouth defects because it is easy to perform and results in recovery of function and cosmetics. PMID:9927907

Shibahara, T; Noma, H; Fujikawa, M; Miyao, T; Ishikawa, M; Takasaki, Y

1998-08-01

202

Central Limit Theorem  

NSDL National Science Digital Library

This website, created by Richard Lowry of Vassar College, illustrates the central limit theorem by allowing the user to increase the number of samples in increments of 100, 1,000, or 10,000. The sample size can be changed and these changes will then be reflected in the distribution. Overall, this is a great interactive resource for students wanting to engage more in their study of statistics.

Lowry, Richard

2009-11-04

203

FNAL central email systems  

SciTech Connect

The FNAL Email System is the primary point of entry for email destined for an employee or user at Fermilab. This centrally supported system is designed for reliability and availability. It uses multiple layers of protection to help ensure that: (1) SPAM messages are tagged properly; (2) All mail is inspected for viruses; and (3) Valid mail gets delivered. This system employs numerous redundant subsystems to accomplish these tasks.

Schmidt, Jack; Lilianstrom, Al; Pasetes, Ray; Hill, Kevin; /Fermilab

2004-10-01

204

Investment Club Central  

NSDL National Science Digital Library

Investment Club Central was developed by invest-o-rama! to promote investment clubs. At the site, visitors will find many useful articles on how to start an investment club, as well as a collection of investment club news stories. Other resources at the site include a list of online data sources, links to stock research, tutorials on selecting stocks for the club and a directory of investment clubs online.

Gerlach, Douglas.

1998-01-01

205

The Central Pacific Megatrend  

Microsoft Academic Search

The WNW-ESE-trending Central Pacific Megatrend is a transbasinal feature comprising several types of geornorphic features—ridges, linear seamount chains, and fractures. First appearing on the satellite altimetry data set, an updated bathymetry effort is presented to verify the existence of such a feature. The route is traced from the Banda Sea in the Indonesian region to South America, a distance of

N. Christian Smoot; Bruce A. Leybourne

2001-01-01

206

[Centralization versus decentralization. Hematology].  

PubMed

Clinical haematology is the result of teamwork among dedicated specialists in pathology, molecular diagnostics, imaging, radiotherapy and the haematologist, who in turn can focus on only a limited fraction of the various and highly complex diseases that together constitute clinical haematology. The treatment of patients should be centralized in departments large enough to permit internal subspecialization and to provide expert service focused on haematology. No more than three such hematology centers are needed in Denmark. PMID:16640979

Borregaard, Niels

2006-04-10

207

Lesson Plan Central  

NSDL National Science Digital Library

Lesson Plan Central -- a free lesson plans, WebQuests, worksheets, student link and clipart Web site -- has a great collection of science specific links. Categorized by subject and grade level, the listed sites are are briefly described, and any new site is labeled as such. Links to just the new, cool, and clipart sites are also provided. This collection is a great way for kids and educators to find new teaching and learning aids.

2008-09-16

208

Central Nervous System Emergencies  

Microsoft Academic Search

Emergency management of central nervous system malignancies is an unfortunate reality facing the oncologist. Although expeditious\\u000a treatment is certainly the cornerstone of management, the astute clinician should carefully weigh a combination of multidisciplinary\\u000a therapeutic options to ensure optimal outcome for the patient, with an eye toward both treatment sequelae and anticipation\\u000a of future need for further treatment.

Kevin P. McMullen; Edward G. Shaw; Volker W. Stieber

209

PubMed Central  

NSDL National Science Digital Library

After almost a year of sometimes contentious debate, the National Institutes of Health has officially opened PubMed Central, a free online archive of full-text, peer-reviewed research papers in the life sciences. While the majority of the major scientific publishers have declined to participate, a number of respected journals will be featured at the site. The first of these are Molecular Biology of the Cell and Proceedings of the National Academy of Sciences of the United States of America. At the time of writing, only the November 1, 1999 issue of Molecular Biology of the Cell was available. Users can view abstracts or the full text of over 30 articles in HTML or .pdf format. The full texts of issues for both journals from 1999 and 1998 are in preparation. Forthcoming journals include Biochemical Journal, Canadian Medical Association Journal, Frontiers in Bioscience, and five journals from BioMed Central. Background and participation information are available at the site. While current offerings at the site are modest, PubMed Central promises to become a major resource for scholars and professionals in the life sciences.

210

Central Florida Memory  

NSDL National Science Digital Library

The Central Florida Memory project was started in 2002 by The University of Central Florida Library, The Orange County Regional History Center, and The Orange County Library System. The intent of the project is "to provide an online platform and focal point for gathering, preserving, and disseminating the documents, artifacts, and stories of the history of Central Florida." Over the past few years, the project has been awarded with additional funding grants from the Institute of Museum and Library Services. Currently, the project site contains over 80,000 images, along with maps, plans, and other documents. Visitors to the homepage will find three primary sections of note: "Collection", "Share", and "Learn". In the "Collection" area, visitors can make their way through postcards, maps, and the "most recent" additions to the site. For people looking for a more organized experience, there's the "Learn" area. Here they can find thematic collections like "Dreams and Schemes", "Roads, Rivers and Rails", and "Critters, Crackers and Cottages". For those looking for a sample search, words like "Deland", "Stetson University", "Orlando", and "pineapple" will return a host of compelling items.

211

Central respiratory chemoreception  

PubMed Central

Summary By definition central respiratory chemoreceptors (CRCs) are cells that are sensitive to changes in brain PCO2 or pH and contribute to the stimulation of breathing elicited by hypercapnia or metabolic acidosis. CO2 most likely works by lowering pH. The pertinent proton receptors have not been identified and may be ion channels. CRCs are probably neurons but may also include acid-sensitive glia and vascular cells that communicate with neurons via paracrine mechanisms. Retrotrapezoid nucleus (RTN) neurons are the most completely characterized CRCs. Their high sensitivity to CO2 in vivo presumably relies on their intrinsic acid-sensitivity, excitatory inputs from the carotid bodies and brain regions such as raphe and hypothalamus, and facilitating influences from neighboring astrocytes. RTN neurons are necessary for the respiratory network to respond to CO2 during the perinatal period and under anesthesia. In conscious adults, RTN neurons contribute to an unknown degree to the pH-dependent regulation of breathing rate, inspiratory and expiratory activity. The abnormal prenatal development of RTN neurons probably contributes to the congenital central hypoventilation syndrome. Other CRCs presumably exist but the supportive evidence is less complete. The proposed locations of these CRCs are the medullary raphe, the nucleus tractus solitarius, the ventrolateral medulla, the fastigial nucleus and the hypothalamus. Several wake-promoting systems (serotonergic and catecholaminergic neurons, orexinergic neurons) are also putative CRCs. Their contribution to central respiratory chemoreception may be behavior-dependent or vary according to the state of vigilance.

Guyenet, Patrice G.; Stornetta, Ruth L.; Bayliss, Douglas A.

2010-01-01

212

33. CENTRAL HEIGHT OF CENTRAL PAVILION IN EAST FACADEINCLINED, FRONTAL ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. CENTRAL HEIGHT OF CENTRAL PAVILION IN EAST FACADE--INCLINED, FRONTAL Copy photograph of photogrammetric plate LC-HABS-FS13-B-1974-832L. - St. Mary's Seminary, 600 North Paca Street, Baltimore, Independent City, MD

213

Central African Republic.  

PubMed

Focus in this discussion of the Central African Republic is on: geography; the people; history and political conditions; government; the economy; foreign relations; and relations with the US. The population of the Central African Republic totaled 2.7 million in 1985 with an annual growth rate of 2.8%. The infant mortality rate is 134/1000 with life expectancy at 49 years. The Central African Republic is at almost the precise center of Africa, about 640 km from the nearest ocean. More than 70% of the population live in rural areas. There are more than 80 ethnic groups, each with its own language. The precolonial history of the area was marked by successive waves of migration, of which little is known. These migrations are responsible for the complex ethnic and linguistic patterns today. United with Chad in 1906, it formed the Oubangui-Chari-Chad colony. In 1910, it became 1 of the 4 territories of the Federation of French Equatorial Africa, along with Chad, Congo, and Gabon. After World War II, the French Constitution of 1946 inaugurated the first of a series of reforms that led eventually to complete independence for all French territories in western and equatorial Africa. The nation became an autonomous republic within the newly established French Community on December 1, 1958, and acceded to complete independence as the Central Africa Republic on August 13, 1960. The government is made up of the executive and the judicial branches. The constitution and legislature remain suspended. All executive and legislative powers, as well as judicial oversight, are vested in the chief of state. The Central African Republic is 1 of the world's least developed countries, with an annual per capita income of $310. 85% of the population is engaged in subsistence farming. Diamonds account for nearly 1/3 of export earnings; the industrial sector is limited. The US terminated bilateral assistance programs in 1979, due to the human rights violations of the Bokassa regime, but modest development assistance was resumed in 1982. PMID:12178132

1986-02-01

214

The effect of satellite galaxies on gravitational lensing flux ratios  

NASA Astrophysics Data System (ADS)

Gravitational lenses with anomalous flux ratios are often cited as possible evidence for dark matter satellites predicted by simulations of hierarchical merging in cold dark matter cosmogonies. We show that the fraction of quads with anomalous flux ratios depends primarily on the total mass and spatial extent of the satellites, and the characteristic length-scale d1/2 of their distribution. If d1/2 ~ 100kpc, then for a moderately elliptical galaxy with a line-of-sight velocity dispersion of ~ 250kms-1, a mass of ~3 × 109Msolar in highly concentrated (Plummer model) satellites is needed for 20 per cent of quadruplets to show anomalous flux ratios, rising to ~1.25 × 1010Msolar for 50 per cent. Several times these masses are required if the satellites have more extended Hernquist profiles. Compared to a typical elliptical, the flux ratios of quads formed by typical edge-on disc galaxies with maximum discs are significantly less susceptible to changes through substructure - three times the mass in satellite galaxies is needed to affect 50 per cent of the systems. In many of the lens systems with anomalous flux ratios, there is evidence for visible satellites (e.g. B2045+265 or MG0414+0534). We show that if the anomaly is produced by substructure with properties similar to the simulations, then optically identified substructure should not be preponderant among lens systems with anomalies. There seem to be two possible resolutions of this difficulty. First, in some cases, visible substructure may be projected within or close to the Einstein radius and wrongly ascribed as the culprit, whereas dark matter substructure is causing the flux anomaly. Secondly, bright satellites, in which baryon cooling and condensation have taken place, may have higher central densities than dark satellites, rendering them more efficient at causing flux anomalies.

Shin, E. M.; Evans, N. W.

2008-04-01

215

Theoretical Analysis of Density Ratio Estimation  

NASA Astrophysics Data System (ADS)

Density ratio estimation has gathered a great deal of attention recently since it can be used for various data processing tasks. In this paper, we consider three methods of density ratio estimation: (A) the numerator and denominator densities are separately estimated and then the ratio of the estimated densities is computed, (B) a logistic regression classifier discriminating denominator samples from numerator samples is learned and then the ratio of the posterior probabilities is computed, and (C) the density ratio function is directly modeled and learned by minimizing the empirical Kullback-Leibler divergence. We first prove that when the numerator and denominator densities are known to be members of the exponential family, (A) is better than (B) and (B) is better than (C). Then we show that once the model assumption is violated, (C) is better than (A) and (B). Thus in practical situations where no exact model is available, (C) would be the most promising approach to density ratio estimation.

Kanamori, Takafumi; Suzuki, Taiji; Sugiyama, Masashi

216

Eccentric crank variable compression ratio mechanism  

DOEpatents

A variable compression ratio mechanism for an internal combustion engine that has an engine block and a crankshaft is disclosed. The variable compression ratio mechanism has a plurality of eccentric disks configured to support the crankshaft. Each of the plurality of eccentric disks has at least one cylindrical portion annularly surrounded by the engine block. The variable compression ratio mechanism also has at least one actuator configured to rotate the plurality of eccentric disks.

Lawrence, Keith Edward (Kobe, JP); Moser, William Elliott (Peoria, IL); Roozenboom, Stephan Donald (Washington, IL); Knox, Kevin Jay (Peoria, IL)

2008-05-13

217

High aspect-ratio holographic photoresist gratings.  

PubMed

Holographic gratings with periods as small as 700 nm, rectangular profiles with linewidths of <120 nm, and depths of 1.2 microm (aspect ratio of 10) have been formed using positive photoresist on Si substrates and visible laser exposure (488 nm). Similar aspect ratios have been achieved at a 400-nm period using 334-nm exposing radiation. A simple exposure and development model, which accounts for the large aspect ratios and predicts the grating fabrication limits, is presented. PMID:20531876

Zaidi, S H; Brueck, S R

1988-07-15

218

Sex ratios in sexually dimorphic umbelliferae  

Microsoft Academic Search

Sex ratios in 35 inflorescence and plant counts of perennial, sexually dimorphic Umbelliferae vary from 0·96 to 87·33 times as many males as females. The ranges of ratios are similar in dioecious and gynodioecious populations.In 10 populations in which both the inflorescences and plants were counted, the male\\/female ratios are approximately one in populations in which the plants produce only

David G Lloyd

1973-01-01

219

Measurements of the Proton Elastic-Form-Factor Ratio mupGEp\\/GMp at Low Momentum Transfer  

Microsoft Academic Search

High-precision measurements of the proton elastic form-factor ratio, mupGEp\\/GMp, have been made at four-momentum transfer, Q2, values between 0.2 and 0.5GeV2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement,

G. Ron; J. Glister; B. Lee; K. Allada; W. Armstrong; J. Arrington; A. Beck; F. Benmokhtar; B. L. Berman; W. Boeglin; E. Brash; A. Camsonne; J. Calarco; J. P. Chen; Seonho Choi; E. Chudakov; L. Coman; B. Craver; F. Cusanno; J. Dumas; C. Dutta; R. Feuerbach; A. Freyberger; S. Frullani; F. Garibaldi; R. Gilman; O. Hansen; D. W. Higinbotham; T. Holmstrom; C. E. Hyde; H. Ibrahim; Y. Ilieva; C. W. de Jager; X. Jiang; M. K. Jones; H. Kang; A. Kelleher; E. Khrosinkova; E. Kuchina; G. Kumbartzki; J. J. Lerose; R. Lindgren; P. Markowitz; S. May-Tal Beck; E. McCullough; D. Meekins; M. Meziane; Z.-E. Meziani; R. Michaels; B. Moffit; B. E. Norum; Y. Oh; M. Olson; M. Paolone; K. Paschke; C. F. Perdrisat; E. Piasetzky; M. Potokar; R. Pomatsalyuk; I. Pomerantz; A. Puckett; V. Punjabi; X. Qian; Y. Qiang; R. Ransome; M. Reyhan; J. Roche; Y. Rousseau; A. Saha; A. J. Sarty; B. Sawatzky; E. Schulte; M. Shabestari; A. Shahinyan; R. Shneor; S. Sirca; K. Slifer; P. Solvignon; J. Song; R. Sparks; R. Subedi; S. Strauch; G. M. Urciuoli; K. Wang; B. Wojtsekhowski; X. Yan; H. Yao; X. Zhan; X. Zhu

2007-01-01

220

Optimal dispersion and central places  

NASA Astrophysics Data System (ADS)

This paper presents research into optimal dispersion models as applied to central places. The literature regarding location optimization and central places is reviewed and the motivation for employing dispersion models is identified. Models that employ the objective of maximal dispersion in the context of central places are formulated and solved in the context of both single- and multiple-good systems. Two methods for generating multiple-good systems are presented: a multiple-type dispersion model and a K-value constraint set formulation. Sequential solutions to dispersion models demonstrate how a system of central places could develop over time. The solutions to these models generate the patterns of central places expected under the organizing principles of central place theory. The objective of maximal dispersion is posited as both a motivating factor in central place location decisions, and as the optimal outcome of a mature system of central places.

Curtin, Kevin M.; Church, Richard L.

2007-06-01

221

Central African Industrial Coordination Survey.  

National Technical Information Service (NTIS)

The report presents the findings and conclusions of an Industrial Coordination Survey of the Central African sub-region of Cameroun, Central African Republic, Chad, Congo, Democratic Republic of the Congo (Zaire), and Gabon. The principle objective of the...

R. Manly

1965-01-01

222

Crustal structure along the southern Central American volcanic front  

Microsoft Academic Search

Subduction alters continents several ways, including accretion, magmatic addition, mantle wedge serpentinization, and crustal differentiation. These changes affect seismic velocities, so characterizing upper plate crust establishes a baseline for composition and continental growth. Teleseismic P and PP arrivals from a temporary deployment of broadband seismometers in Central America have been used to estimate crustal thickness and Vp\\/Vs ratio from receiver

Laura MacKenzie; Geoffrey A. Abers; Karen M. Fischer; Ellen M. Syracuse; J. Marino Protti; Victor Gonzalez; Wilfried Strauch

2008-01-01

223

Large-scale use of solar energy with central receivers  

Microsoft Academic Search

The working principles of solar central receiver power plants are outlined and applications are discussed. Heliostat arrays direct sunlight into a receiver cavity mounted on a tower, heating the working fluid in the tower to temperatures exceeding 500 C. The formulation for the image plane and the geometric concentration ratio for a heliostat field are provided, noting that commercial electric

F. Kreith; R. T. Meyer

1983-01-01

224

Central ignition scenarios for TFTR  

SciTech Connect

The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs.

Zweben, S.J.; Redi, M.H.; Bateman, G.

1986-03-01

225

Constraint on the Pair-Density Ratio (Z+) in an Electron-Positron Pair Wind.  

National Technical Information Service (NTIS)

We derive a constraint on the pair density ratio, z(sub +) = n(sub +)/n(sub p), in an electron-positron pair wind flowing away from the central region of an accretion disk around a compact object under the assumption of a coupling between electrons, posit...

M. D. Moscoso J. C. Wheeler

1994-01-01

226

Modeling of fresh egg pasta characteristics for egg content and albumen to yolk ratio  

Microsoft Academic Search

The high compositional variability of commercial fresh egg pasta radically affects its mechanical and cooking properties. The aim of the work was to model the effects of total egg content (E) and albumen to yolk ratio (A\\/Y) on fresh egg pasta compositional and structural characteristics, by the application of a central composite design using response surface methodology. The analysis of

Cristina Alamprese; Ernestina Casiraghi; Margherita Rossi

2009-01-01

227

Using a Market Ratio Factor in Faculty Salary Equity Studies. Professional File Number 103, Spring 2007  

ERIC Educational Resources Information Center

This study used two multiple regression analyses to develop an explanatory model to determine which model might best explain faculty salaries. The central purpose of the study was to determine if using a single market ratio variable was a stronger predictor for faculty salaries than the use of dummy variables representing various disciplines.…

Luna, Andrew L.

2007-01-01

228

Separated Response Function Ratios in Exclusive, Forward ?^{±} Electroproduction.  

PubMed

The study of exclusive ?^{±} electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio R_{L}=?_{L}^{?^{-}}/?_{L}^{?^{+}} is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of R_{T}=?_{T}^{?^{-}}/?_{T}^{?^{+}} from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive ?^{±} electroproduction on the deuteron at central Q^{2} values of 0.6, 1.0, 1.6??GeV^{2} at W=1.95??GeV, and Q^{2}=2.45??GeV^{2} at W=2.22??GeV. Here, we present the L and T cross sections, with emphasis on R_{L} and R_{T}, and compare them with theoretical calculations. Results for the separated ratio R_{L} indicate dominance of the pion-pole diagram at low -t, while results for R_{T} are consistent with a transition between pion knockout and quark knockout mechanisms. PMID:24856691

Huber, G M; Blok, H P; Butuceanu, C; Gaskell, D; Horn, T; Mack, D J; Abbott, D; Aniol, K; Anklin, H; Armstrong, C; Arrington, J; Assamagan, K; Avery, S; Baker, O K; Barrett, B; Beise, E J; Bochna, C; Boeglin, W; Brash, E J; Breuer, H; Chang, C C; Chant, N; Christy, M E; Dunne, J; Eden, T; Ent, R; Fenker, H; Gibson, E F; Gilman, R; Gustafsson, K; Hinton, W; Holt, R J; Jackson, H; Jin, S; Jones, M K; Keppel, C E; Kim, P H; Kim, W; King, P M; Klein, A; Koltenuk, D; Kovaltchouk, V; Liang, M; Liu, J; Lolos, G J; Lung, A; Margaziotis, D J; Markowitz, P; Matsumura, A; McKee, D; Meekins, D; Mitchell, J; Miyoshi, T; Mkrtchyan, H; Mueller, B; Niculescu, G; Niculescu, I; Okayasu, Y; Pentchev, L; Perdrisat, C; Pitz, D; Potterveld, D; Punjabi, V; Qin, L M; Reimer, P E; Reinhold, J; Roche, J; Roos, P G; Sarty, A; Shin, I K; Smith, G R; Stepanyan, S; Tang, L G; Tadevosyan, V; Tvaskis, V; van der Meer, R L J; Vansyoc, K; Van Westrum, D; Vidakovic, S; Volmer, J; Vulcan, W; Warren, G; Wood, S A; Xu, C; Yan, C; Zhao, W-X; Zheng, X; Zihlmann, B

2014-05-01

229

Separated Response Function Ratios in Exclusive, Forward ?± Electroproduction  

NASA Astrophysics Data System (ADS)

The study of exclusive ?± electroproduction on the nucleon, including separation of the various structure functions, is of interest for a number of reasons. The ratio RL=?L?-/?L?+ is sensitive to isoscalar contamination to the dominant isovector pion exchange amplitude, which is the basis for the determination of the charged pion form factor from electroproduction data. A change in the value of RT=?T?-/?T?+ from unity at small -t, to 1/4 at large -t, would suggest a transition from coupling to a (virtual) pion to coupling to individual quarks. Furthermore, the mentioned ratios may show an earlier approach to perturbative QCD than the individual cross sections. We have performed the first complete separation of the four unpolarized electromagnetic structure functions above the dominant resonances in forward, exclusive ?± electroproduction on the deuteron at central Q2 values of 0.6, 1.0, 1.6 GeV2 at W =1.95 GeV, and Q2=2.45 GeV2 at W =2.22 GeV. Here, we present the L and T cross sections, with emphasis on RL and RT, and compare them with theoretical calculations. Results for the separated ratio RL indicate dominance of the pion-pole diagram at low -t, while results for RT are consistent with a transition between pion knockout and quark knockout mechanisms.

Huber, G. M.; Blok, H. P.; Butuceanu, C.; Gaskell, D.; Horn, T.; Mack, D. J.; Abbott, D.; Aniol, K.; Anklin, H.; Armstrong, C.; Arrington, J.; Assamagan, K.; Avery, S.; Baker, O. K.; Barrett, B.; Beise, E. J.; Bochna, C.; Boeglin, W.; Brash, E. J.; Breuer, H.; Chang, C. C.; Chant, N.; Christy, M. E.; Dunne, J.; Eden, T.; Ent, R.; Fenker, H.; Gibson, E. F.; Gilman, R.; Gustafsson, K.; Hinton, W.; Holt, R. J.; Jackson, H.; Jin, S.; Jones, M. K.; Keppel, C. E.; Kim, P. H.; Kim, W.; King, P. M.; Klein, A.; Koltenuk, D.; Kovaltchouk, V.; Liang, M.; Liu, J.; Lolos, G. J.; Lung, A.; Margaziotis, D. J.; Markowitz, P.; Matsumura, A.; McKee, D.; Meekins, D.; Mitchell, J.; Miyoshi, T.; Mkrtchyan, H.; Mueller, B.; Niculescu, G.; Niculescu, I.; Okayasu, Y.; Pentchev, L.; Perdrisat, C.; Pitz, D.; Potterveld, D.; Punjabi, V.; Qin, L. M.; Reimer, P. E.; Reinhold, J.; Roche, J.; Roos, P. G.; Sarty, A.; Shin, I. K.; Smith, G. R.; Stepanyan, S.; Tang, L. G.; Tadevosyan, V.; Tvaskis, V.; van der Meer, R. L. J.; Vansyoc, K.; Van Westrum, D.; Vidakovic, S.; Volmer, J.; Vulcan, W.; Warren, G.; Wood, S. A.; Xu, C.; Yan, C.; Zhao, W.-X.; Zheng, X.; Zihlmann, B.; Jefferson Lab F? Collaboration

2014-05-01

230

Spectral Atlas Central  

NSDL National Science Digital Library

From the National Optical Astronomy Observatories and the Kitt Peak National Observatory, comes the Spectral Atlas Central Web site. Users can plot wavelengths covering the spectra of 3005ÃÂ thru 10598ÃÂ, 3000ÃÂ thru 10900ÃÂ, and 3300ÃÂ thru 11100ÃÂ by inputting a start and end wavelength and specifying the number of lines. The resulting plots can then be viewed or downloaded as a FITS file, Postscript file, or a line list. The specificity of subject contained on the site will certainly exclude those unfamiliar with the topic, but should be helpful for those whose work or research is similar in nature.

2001-01-01

231

Fires in Central Africa  

NASA Technical Reports Server (NTRS)

Hundreds of fires are set every year during the dry season in Central Africa. This true color image from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) shows dozens of smoke plumes in the Democratic Republic of the Congo on June 29, 2000. Residents burn away scrub and brush annually in the woody savanna to clear land for farming and grazing. For more information, visit the SeaWiFS Home Page, Global Fire Monitoring Fact Sheet, and 4km2 Fire Data Image Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

2002-01-01

232

Floods in Central China  

NASA Technical Reports Server (NTRS)

This pair of true- and false-color images from the Moderate resolution Imaging Spectroradiometer (MODIS) shows flooding in central China on July 4, 2002. In the false-color image vegetation appears orange and water appears dark blue to black. Because of the cloud cover and the fact that some of the water is filled with sediment, the false-color image provides a clearer picture of where rivers have exceeded their banks and lakes have risen. The river in this image is the Yangtze River, and the large lake is the Poyang Hu. Credits: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

2002-01-01

233

Central receiver technology  

SciTech Connect

The research and development described in this document was conducted within the US Department of Energy's (DOE) Solar Thermal Technology Program. The goal of this program is to advance the engineering and scientific understanding of solar thermal technology and to establish the technology base from which private industry can develop solar thermal power production options for introduction into the competitive energy market. This report describes central receiver technology: its accomplishments to date, its current technology status, and the efforts still necessary to fully exploit it.

Holl, R.L. (HGH Entperises, Inc. (USA))

1989-09-01

234

Central American electrical interconnection  

SciTech Connect

A technical cooperation grant of $2.25 million, designed to strengthen the capacity of Central American countries to operate their regional interconnected electrical system, was announced by the Inter-American Development Bank (IDB). The grant, extended from the banks Fund for Special Operations, will help improve the capacity of the regions electric power companies to achieve economical, safe operation of the interconnected electric power systems. The funds will also be used to finance regional studies of the accords, procedures, regulations, and supervisory mechanisms for the system, as well as program development and data bases.

Not Available

1988-12-01

235

Controlling centrality in complex networks  

Microsoft Academic Search

Spectral centrality measures allow to identify influential individuals in social groups, to rank Web pages by their popularity, and even to determine the impact of scientific researches. The centrality score of a node within a network crucially depends on the entire pattern of connections, so that the usual approach is to compute the node centralities once the network structure is

Vincenzo Nicosia; Regino Criado; Miguel Romance; Giovanni Russo; Vito Latora

2011-01-01

236

Central Vision in the Newborn.  

ERIC Educational Resources Information Center

Tests newborns' ability to detect a dot with central vision and compares both the proportion of time the infants fixated centrally and the duration of each central fixation. Subjects were 46 newborns ranging in age from 1 to 7 days. (MP)

Lewis, Terri L.; Maurer, Daphne

1980-01-01

237

The effect of end-cell stability on the confinement of the central-cell plasma in TMX  

Microsoft Academic Search

In the Tandem Mirror Experiment (TMX), the central-cell losses provide the warm unconfined plasma necessary to stabilize the drift-cyclotron loss-cone instability in the end cells. This places a theoretical limit on central-cell confinement, which is expressed as a limit on the end-cell to central-cell density ratio. As this density ratio increases in a TMX experiment, large increases of end-cell ion-cyclotron-frequency

R. P. Drake; T. A. Casper; J. F. Clauser; F. H. Coensgen; D. L. Correll; W. F. Cummins; J. C. Davis; J. H. Foote; A. H. Futch; R. K. Goodman; D. P. Grubb; R. S. Hornady; W. E. Nexsen; T. C. Simonen; B. W. Stallard

1981-01-01

238

Africa Research Central  

NSDL National Science Digital Library

Historically, researchers in Europe and the US have had difficulty finding updated information on primary source African collections. African Research Central, hosted by California State University at San Bernardino, seeks to bridge this information gap by offering centralized and frequently updated information on primary source collections, as well as publicizing the needs of the repositories and suggesting a plan of action for concerned researchers. The site is divided into three sections: The Repositories, For Researchers, and For Repository Professionals. The first section serves as a gateway to the archives, libraries, and museums with important collections of African primary sources. The emphasis is on Africa, but European and North American institutions are also listed. Information for institutions includes contact information, access conditions, publications, references, and a preservation wish list. The second section includes a Researcher's Questionnaire and information on how academics can contribute to the preservation of African sources. The Repository Professionals section invites archivists to update information on repositories or add new ones and publicize their preservation needs and desires. Both of the latter sections also offer related links. Future plans for the site include a searchable database, an expanded repository list, and a section for educators.

239

Financial Ratio Analysis Comes to Nonprofits.  

ERIC Educational Resources Information Center

To evaluate their financial health, a growing number of colleges, universities, and other nonprofit organizations are using financial ratio analysis, a technique used in business. The strengths and weaknesses of ratio analysis are assessed and suggestions are made on how nonprofits can use it most effectively. (Author/MLW)

Chabotar, Kent John

1989-01-01

240

Key financial ratios can foretell hospital closures.  

PubMed

An analysis of various financial ratios sampled from open and closed hospitals shows that certain leverage, liquidity, capital efficiency, and resource availability ratios can predict hospital closure up to two years in advance of the closure with an accuracy of nearly 75 percent. PMID:10145901

Lynn, M L; Wertheim, P

1993-11-01

241

Osmosis and Surface Area to Volume Ratio.  

ERIC Educational Resources Information Center

Describes an experiment designed to help students understand the concepts of osmosis and surface area to volume ratio (SA:VOL). The task for students is to compare water uptake in different sizes of potato cubes and relate differences to their SA:VOL ratios. (JN)

Barrett, D. R. B.

1984-01-01

242

Sustainable sex ratio in lattice populations  

NASA Astrophysics Data System (ADS)

We present a lattice model of mating populations. Simulation is performed by two different methods: local and global interactions. Simulation results account for the reason why the observed sex ratio is nearly one half in many animals. The male-biased sex ratio, such as in human populations, is also explained.

Tainaka, K.; Hayashi, T.; Yoshimura, J.

2006-05-01

243

Axial Ratio of the Projected Polarization Ellipse.  

National Technical Information Service (NTIS)

The axial ratio of the polarization ellipse of a radio wave is often evaluated using a crossed-dipole antenna system placed in a horizontal plane. The axial ratio of the ellipse as deduced from the responses of the two antennas should correspond to the ax...

S. Ramu

1964-01-01

244

Likelihood Ratio Tests for Special Rasch Models  

ERIC Educational Resources Information Center

In this article, a general class of special Rasch models for dichotomous item scores is considered. Although Andersen's likelihood ratio test can be used to test whether a Rasch model fits to the data, the test does not differentiate between special Rasch models. Therefore, in this article, new likelihood ratio tests are proposed for testing…

Hessen, David J.

2010-01-01

245

On ratio-based color indexing  

Microsoft Academic Search

The color ratio approach to indexing has been found to be robust and effective in indexing image and video databases, in different color spaces, and when using transformed color features, such as those from the Karhunen-Loeve transform (KLT) or the discrete cosine transform (DCT). However, the reason for the superior performance of the color ratio model, especially on different color

Donald A. Adjeroh; Moon-chuen Lee

2001-01-01

246

GOLDEN RATIO-HAAR WAVELET BASED STEGANOGRAPHY  

Microsoft Academic Search

In this paper, we have presented the golden ratio-Haar wavelet based multimedia steganography. The key features of the proposed method are: 1. New Haar wavelet structure based on the Fibonacci se- quence, and Golden Ratio. 2. Parametric transform dependency, as decryption key, on the security of the sensitive data. One of the important differences between the existing trans- form based

Sos S. Agaian; Okan Caglayan; Juan Pablo Perez; Hakob Sarukhanyan; Jaakko Astola

247

The Golden Ratio--A Contrary Viewpoint  

ERIC Educational Resources Information Center

Many assertions about the occurrence of the golden ratio phi in art, architecture, and nature have been shown to be false, unsupported, or misleading. For instance, we show that the spirals found in sea shells, in particular the "Nautilus pompilius," are not in the shape of the golden ratio, as is often claimed. Some of the most interesting…

Falbo, Clement

2005-01-01

248

The Divine Ratio and Golden Rectangles.  

ERIC Educational Resources Information Center

The material examines aspects of Fibonacci and Lucas sequences, the generation of the Divine Ratio, and the nature of this ratio in golden rectangles, triangles, and figures made up of golden triangles. It is noted Lucas sequence is formed like Fibonacci but has one and three as the first elements. (Author/MP)

Cooper, Martin

1982-01-01

249

Graphs (networks) with golden spectral ratio  

Microsoft Academic Search

We propose two new spectral measures for graphs and networks which characterize the ratios between the width of the “bulk” part of the spectrum and the spectral gap, as well as the ratio between spectral spread and the width of the “bulk” part of the spectrum. Using these definitions we introduce the concept of golden spectral graphs (GSG), which are

Ernesto Estrada; Edificio CACTUS

2007-01-01

250

HIT RATIO OF DYNAMICALLY PROGRAMMABLE CACHE  

Microsoft Academic Search

Dynamically Programmable Cache is a Reconfigurable Cache designed for General Purpose Microprocessor with multimedia applications. This paper evaluates the performance of DPC as a coprocessor accelerator with FPGA fabric integrated on it. DPC stores its FPGA configurations in the cache, which may affect the hit\\/miss ratio of this cache. This paper shows small effect induced on the miss ratio due

Mouna Nakkar

2004-01-01

251

Line Ratio Imaging of a Gas Discharge  

NASA Technical Reports Server (NTRS)

The intensity ratio of two atomic or ionic spectral lines in a plasma is a function of electron temperature. By imaging two spectral lines, and computing the line ratio, pixel by pixel, an image of the electron temperature is produced. This is demonstrated using a dusty plasma consisting of submicron particles suspended in an argon RF glow discharge.

Samsonov, D.; Goree, J.; Rogers, Rick (Technical Monitor)

1999-01-01

252

Sex ratios in pheasant research and management  

USGS Publications Warehouse

Sex ratios are of primary importance in interpretation of extensive studies of pheasant populations. They are necessary for converting crowing-cock indices to population estimates even where annual trends are to be studied in the same area. Reliability of population estimates from hunting season kill of pheasants suffers primarily from inability to estimate sex ratios accurately. Fall sex ratio is an index to production and where adult sex ratios are divergent can serve as a good check on production per hen. Age ratios of cocks cannot be interpreted directly as an index of productivity, even within the boundaries of one state, unless adult sex ratios are known. The relationship between observed and actual sex ratio varies significantly from season to season and according to the method of observation. In view of their importance in population studies and the lack of reliability of present methods, it is believed that intensive studies on techniques for obtaining sex ratios are a major need in pheasant research.

Dale, F.H.

1952-01-01

253

Contact ratio of rough surfaces with multiple asperities in mixed lubrication at high pressures  

NASA Astrophysics Data System (ADS)

Relative optical intensity interference was used to measure the lubrication film thickness when four kinds of polyalphaolefin (PAO) were used as lubricants confined between a smooth sapphire disc surface and a rough steel ball surface. Maximum Hertz contact pressure up to 3 GPa was applied in the central part of the contact region in mixed lubrication. It was found that the contact ratio (the ratio of real contact region to the whole nominal contact region) is related to the film thickness, the applied pressure, the surface roughness and the rolling speed, and so on. Contact ratio evidently reduces as lubrication film thickness or rolling speed increases. Quantitative relationship between the contact ratio and the influence factors was summarized based on the nonlinear fitting of experimental measurements. A formula was put forward to calculate the contact ratio at high pressure conditions according to the current experimental results.

Xiao, Huaping; Guo, Dan; Liu, Shuhai; Pan, Guoshun; Lu, Xinchun

2012-02-01

254

Duty ratio of cooperative molecular motors  

NASA Astrophysics Data System (ADS)

Molecular motors are found throughout the cells of the human body and have many different and important roles. These micromachines move along filament tracks and have the ability to convert chemical energy into mechanical work that powers cellular motility. Different types of motors are characterized by different duty ratios, which is the fraction of time that a motor is attached to its filament. In the case of myosin II (a nonprocessive molecular machine with a low duty ratio), cooperativity between several motors is essential to induce motion along its actin filament track. In this work we use statistical mechanical tools to calculate the duty ratio of cooperative molecular motors. The model suggests that the effective duty ratio of nonprocessive motors that work in cooperation is lower than the duty ratio of the individual motors. The origin of this effect is the elastic tension that develops in the filament which is relieved when motors detach from the track.

Dharan, Nadiv; Farago, Oded

2012-02-01

255

Poisson's ratio of individual metal nanowires.  

PubMed

The measurement of Poisson's ratio of nanomaterials is extremely challenging. Here we report a lateral atomic force microscope experimental method to electromechanically measure the Poisson's ratio and gauge factor of individual nanowires. Under elastic loading conditions we monitor the four-point resistance of individual metallic nanowires as a function of strain and different levels of electrical stress. We determine the gauge factor of individual wires and directly measure the Poisson's ratio using a model that is independently validated for macroscopic wires. For macroscopic wires and nickel nanowires we find Poisson's ratios that closely correspond to bulk values, whereas for silver nanowires significant deviations from the bulk silver value are observed. Moreover, repeated measurements on individual silver nanowires at different levels of mechanical and electrical stress yield a small spread in Poisson ratio, with a range of mean values for different wires, all of which are distinct from the bulk value. PMID:25000139

McCarthy, Eoin K; Bellew, Allen T; Sader, John E; Boland, John J

2014-01-01

256

Poisson's ratio of individual metal nanowires  

PubMed Central

The measurement of Poisson’s ratio of nanomaterials is extremely challenging. Here we report a lateral atomic force microscope experimental method to electromechanically measure the Poisson’s ratio and gauge factor of individual nanowires. Under elastic loading conditions we monitor the four-point resistance of individual metallic nanowires as a function of strain and different levels of electrical stress. We determine the gauge factor of individual wires and directly measure the Poisson’s ratio using a model that is independently validated for macroscopic wires. For macroscopic wires and nickel nanowires we find Poisson’s ratios that closely correspond to bulk values, whereas for silver nanowires significant deviations from the bulk silver value are observed. Moreover, repeated measurements on individual silver nanowires at different levels of mechanical and electrical stress yield a small spread in Poisson ratio, with a range of mean values for different wires, all of which are distinct from the bulk value.

McCarthy, Eoin K.; Bellew, Allen T.; Sader, John E.; Boland, John J.

2014-01-01

257

HIGHLY VARIABLE HELIUM ISOTOPE RATIOS IN THE VANUATU VOLCANIC ARC  

NASA Astrophysics Data System (ADS)

The Vanuatu (former New Hebrides) island arc results from the eastward subduction of the Australian plate beneath the North Fiji back-arc basin. Whereas its southern part is characterized by a single chain of volcanic islands parallel to a well-defined trench, the structure of its central part is strongly modified by the collision-subduction of the d’Entrecasteaux Zone, lacking a deep trench and consisting of three N-S chains of volcanic islands. In order to get further insight into the source of volcanism in this complex tectonic setting, we have analysed helium isotopes in groundwaters and hot springs (37°-90°C) from both the southern (Tanna and Efate) and central (Ambrym, Ambae and Pentecost) volcanic islands. Additional data were also acquired on bubbling gases and olivine phenocrysts from the islands of Ambrym and Ambae, respectively. Most waters show substantial helium enrichment (between 1.3 and 24.3 times the atmospheric solubility). 3He/4He ratios vary over a wide range, going from low (crustal He-influenced) 4.4 - 4.6 Ra and 4.8 -5.6 Ra in Efate and Pentecost respectively, to 6.3 - 7.0 Ra in Tanna, 6.8 - 8.2 Ra in Ambae, and up to 10.05 Ra in Ambrym (measured in both waters and bubbling gases). This latter value is similar to those measured in the nearby north Fiji basin (9-10 Ra - Ishibashi et al., EPSL, 1994) and approaches those, further north, of Manus basin glasses (12.2±1 Ra - Macpherson et al., Geology, 1998), suggesting a possible plume (or hotspot) influence. In Ambrym, this influence is confined to the north of the central rift zone - coincident with a major volcano-tectonic fault structure, since fluids in the southwest part of the island (a few kilometres apart) display typical arc-type ratios of 7 Ra. Interestingly, the analysis of tremor activity from the two large active cones located at the centre of the island, the Marum and Benbow volcanos, also suggest two distinct magmatic sources beneath Ambrym (Legrand et al., GRL 2005). Clearly, further investigations on yet unsampled islands of the Vanuatu arc are needed to better elucidate the magmatic and geodynamic significance of this high spatial variability of helium isotope ratios highligted by our first results.

Jean-Baptiste, P.; Allard, P.; Bani, P.; Garaebiti, E.; Pelletier, B.; Fourré, E.; Metrich, N.

2009-12-01

258

Future Flight Central  

NASA Technical Reports Server (NTRS)

NASA 'Future Flight Central,' the world's first full-scale virtual airport control tower, opened December 13, 1999 at NASA Ames Research Center, Moffett Field, California. Constructed at a cost of $10 million, the two story facility was jointly funded by NASA and the Federal Aviation Administration (FAA). The facility is designed to test ways to solve potential air and ground traffic problems at commercial airports under realistic airport conditions and configurations. The facility provides an opportunity for airlines and airports to mitigate passenger delays by fine tuning airport hub operations, gate management, ramp movement procedures, and various other airport improvements. Twelve rear projection screens provide a seamless 360 degree high- resolution view of the airport or other screens being depicted. The imaging system, powered by supercomputers, provides a realistic view of weather conditions, enviromental and seasonal effects and the movement of up to 200 active aircraft and ground vehicles.

1999-01-01

259

Central solar energy receiver  

DOEpatents

An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

Drost, M. Kevin (Richland, WA)

1983-01-01

260

Central Michigan University  

NSDL National Science Digital Library

Central Michigan University serves Michigan and the larger community as a doctoral/research intensive public university focused on excellent teaching and student-focused learning. The University is committed to providing a broad range of undergraduate and graduate programs and services to prepare its students for varied roles as responsible citizens and leaders in a democratic and diverse society. Its programs encourage intellectual and moral growth, prepare students for meaningful careers and professions, instill the values of lifelong learning, and encourage civic responsibility, public service and understanding among social groups in a global society. The university emphasizes an undergraduate program that maintains a balance between general education and specialization. In addition to educational depth in at least one academic discipline or professional field, the university provides educational experiences in the arts, humanities, natural and social sciences, global cultures, and issues of race and diversity. The university offers selected high quality graduate programs in traditional disciplines and professional fields. Through its College of Extended Learning, the university provides access to higher education programs and lifelong learning opportunities both nationally and internationally through a variety of innovative instructional methods and schedules designed to meet the demands of adult populations. Central Michigan University encourages research, scholarship and creative activity and promotes the scholarly pursuit and dissemination of new knowledge, artistic production and applied research. Through its support of research, the university enhances the learning opportunities of both its undergraduate and graduate students and promotes economic, cultural and social development. The university�s sense of community is reflected through governance structures that allow broadbased participation, opportunities for close student-faculty interaction, and a rich array of residential and campus-based co-curricular activities. Through its partnerships and outreach efforts, the university promotes learning outsideof the traditional classroom and enhances the general welfare of society.

University, Central M.

261

Prospects for detection of gravitational waves from intermediate-mass-ratio inspirals.  

PubMed

We explore prospects for detecting gravitational waves from stellar-mass compact objects spiraling into intermediate mass black holes (BHs) M approximately 50M to 350M) with ground-based observatories. We estimate a rate for such intermediate-mass-ratio inspirals of central body is not a BH but its metric is stationary, axisymmetric, reflection symmetric and asymptotically flat, then the waves will likely be triperiodic, as for a BH. We suggest that the evolutions of the waves' three fundamental frequencies and of the complex amplitudes of their spectral components encode (in principle) details of the central body's metric, the energy and angular momentum exchange between the central body and the orbit, and the time-evolving orbital elements. We estimate that advanced ground-based detectors can constrain central body deviations from a BH with interesting accuracy. PMID:18233130

Brown, Duncan A; Brink, Jeandrew; Fang, Hua; Gair, Jonathan R; Li, Chao; Lovelace, Geoffrey; Mandel, Ilya; Thorne, Kip S

2007-11-16

262

Optimal sampling ratios in comparative diagnostic trials  

PubMed Central

Summary A subjective sampling ratio between the case and the control groups is not always an efficient choice to maximize the power or to minimize the total required sample size in comparative diagnostic trials.We derive explicit expressions for an optimal sampling ratio based on a common variance structure shared by several existing summary statistics of the receiver operating characteristic curve. We propose a two-stage procedure to estimate adaptively the optimal ratio without pilot data. We investigate the properties of the proposed method through theoretical proofs, extensive simulation studies and a real example in cancer diagnostic studies.

Dong, Ting; Tang, Liansheng Larry; Rosenberger, William F.

2014-01-01

263

Negative Poisson's Ratio Materials via Isotropic Interactions  

NASA Astrophysics Data System (ADS)

We show that under tension a classical many-body system with only isotropic pair interactions in a crystalline state can, counterintuitively, have a negative Poisson’s ratio, or auxetic behavior. We derive the conditions under which the triangular lattice in two dimensions and lattices with cubic symmetry in three dimensions exhibit a negative Poisson’s ratio. In the former case, the simple Lennard-Jones potential can give rise to auxetic behavior. In the latter case, a negative Poisson’s ratio can be exhibited even when the material is constrained to be elastically isotropic.

Rechtsman, Mikael C.; Stillinger, Frank H.; Torquato, Salvatore

2008-08-01

264

Transcription and the aspect ratio of DNA  

NASA Astrophysics Data System (ADS)

Two separate regimes exist for the aspect ratio of DNA. A low aspect regime where DNA will twist further under strain and a high aspect regime where DNA will untwist under strain. The question of the overall geometry, i.e. the aspect ratio, of DNA is revisited from the perspective of a geometrical analysis of transcription. It is shown that under certain reasonable assumptions transcription is only possible if the aspect ratio is in the regime corresponding to further twisting. We find this constraint to be in agreement with long-established crystallographic studies of DNA.

Olsen, Kasper W.; Bohr, Jakob

2013-09-01

265

S V line ratios in the sun  

NASA Technical Reports Server (NTRS)

In the present prediction of level populations and emission line intensity ratios for electron densities and temperatures appropriate to the sun, on the basis of new atomic data for S V, the electron impact collision rates for spin-forbidden transitions, and the intercombination transition spontaneous radiative rate, are noted to be substantially larger than previously ascertained. The S V intensity ratio is shown to be a useful electron density diagnostic for log N(e) greater than 11.5 ratios deduced from observations obtained with a slit spectrograph aboard Skylab generally agree with the theoretical values presented.

Dufton, P. L.; Hibbert, A.; Keenan, F. P.; Kingston, A. E.; Doschek, G. A.

1986-01-01

266

The golden ratio in facial symmetry.  

PubMed

Symmetry is believed to be a hallmark of appealing faces. However, this does not imply that the most aesthetically pleasing proportions are necessary those that arise from the simple division of the face into thirds or fifths. Based on the etymology of the word symmetry, as well as on specific examples and theories of beauty, we conclude that ?-value, a ratio also known as the golden ratio or the divine proportion, can also characterize symmetrical forms. Therefore, we propose the utilization of this ratio in facial aesthetics. PMID:23441307

Prokopakis, E P; Vlastos, I M; Picavet, V A; Nolst Trenite, G; Thomas, R; Cingi, C; Hellings, P W

2013-03-01

267

Estimation of signal-to-noise ratios  

NASA Technical Reports Server (NTRS)

Statistical method estimates signal-to-noise ratios in an observed random voltage, such as the output of a telemetry receiver. Signals from a distant transmitting source, overlaid by noise signals, are monitored continuously.

Couvillon, L. A., Jr.; Gilchriest, C. E.

1969-01-01

268

Science Application of Area and Ratio Concepts  

ERIC Educational Resources Information Center

This article describes using area and ratio concepts to examine why some animals, or people wearing different types of shoes, sink into the surface on which they are standing. Students compute "sinking values" to explain these differences. (Contains 2 figures.)

Horak, Virginia M.

2006-01-01

269

Omniclassical Diffusion in Low Aspect Ratio Tokamaks.  

National Technical Information Service (NTIS)

Recently reported numerical results for axisymmetric devices with low aspect ratio A found radial transport enhanced over the expected neoclassical value by a factor of 2 to 3. In this paper, we provide an explanation for this enhancement. Transport theor...

H. E. Mynick R. B. White D. A. Gaes

2004-01-01

270

Si III line ratios in the sun  

NASA Technical Reports Server (NTRS)

New atomic data for Si III have been used to predict level populations and emission-line intensity ratios for electron densities and temperatures appropriate to the solar transition region. The electron impact collision rates used here are substantially larger than those previously published owing to delineation of the complex resonance structures in the low-energy collision strengths. This together with small changes in the spontaneous radiative rates produces significant changes in the calculated intensity ratios. Generally good agreement is found with observations obtained using the Naval Research Laboratory slit spectrograph aboard Skylab, electron densities from three Si III ratios and from other methods normally agreeing to 0.2 dex or better for a wide variety of solar features. For a fourth ratio, incorporating lines with a wide wavelength separation, the agreement is less satisfactory, possibly owing to uncertainties in the observational data.

Dufton, P. L.; Hibbert, A.; Kingston, A. E.; Doschek, G. A.

1983-01-01

271

Detrended minimum-variance hedge ratio: A new method for hedge ratio at different time scales  

NASA Astrophysics Data System (ADS)

In this paper, based on the detrended fluctuation analysis (DFA) method and the detrended cross-correlation analysis (DCCA) method, we propose an improved method of minimum-variance (MV) hedge ratio, i.e., the detrended minimum-variance (D-MV) hedge ratio, which can measure the hedge ratio at different time scales. The proposed D-MV hedge ratio is defined as the detrended covariance function between spot and futures returns divided by the detrended variance function of futures returns. Through the simulated and empirical analysis, we find that (i) the outcomes of the hedge ratio and the corresponding hedging effectiveness for the D-MV hedge ratio are diverse at different time scales, which can meet needs of various hedging participants with different hedging horizons; (ii) our proposed D-MV hedge ratio has a better hedging performance and a greater potential to determine the hedge ratio because its results of hedging effectiveness at most of time scales are better than those of the traditional MV hedge ratio; and (iii) as for the method of D-MV hedge ratio for different polynomial orders m in the fitting procedure, the D-MV-1 hedge ratio (i.e., the linear polynomial in the fitting procedure) has the best hedging capability for determining the hedge ratio.

Wang, Gang-Jin; Xie, Chi; He, Ling-Yun; Chen, Shou

2014-07-01

272

RNA gels with negative Poisson ratio  

NASA Astrophysics Data System (ADS)

We present a simple model for the elastic properties of very large single-stranded RNA molecules linked by partial complementary pairing, such as a viral RNA genome in solution. It shown that the sign of Poisson's Ratio is determined by the convexity of the force-extension curve of single-stranded RNA. The implications of negative Poisson Ratio's for viral genome encapsidation will be discussed.

Ahsan, Amir

2005-03-01

273

Exact Likelihood Ratio Tests for Penalized Splines  

Microsoft Academic Search

Summary Penalized spline-based additive models allow a simple mixed model representation where the variance components control departures from linear models. The smoothing parameter is the ratio between the random-coe-cient and error variances and tests for linear regression reduce to tests for zero random-coe-cient variances. We propose exact likelihood and restricted likelihood ratio tests, (R)LRTs, for testing polynomial regression versus a

CIPRIAN CRAINICEANU; DAVID RUPPERT; GERDA CLAESKENS; M. P. WAND

2004-01-01

274

Exact likelihood ratio tests for penalised splines  

Microsoft Academic Search

Penalised-spline-based additive models allow a simple mixed model representation where the variance components control departures from linear models. The smoothing parameter is the ratio of the random-coefficient and error variances and tests for linear regression reduce to tests for zero random-coefficient variances. We propose exactlikelihood and restricted likelihood ratio tests for testing polynomial regression versus a general alternative modelled by

Ciprian Crainiceanu; David Ruppert; Gerda Claeskens; M. P. Wand

2005-01-01

275

A sex ratio theory of gregarious parasitoids  

Microsoft Academic Search

Summary  A mathematical model is constructed to explain a density-dependent increase in the progeny sex ratios of gregarious parasitoids.\\u000a In the model we considered non-cooperative game between females concerned with their own inclusive fitness. Equilibrium progeny\\u000a sex ratios of the first and second females ovipositing on the same host are expressed in terms of the probability of double\\u000a parasitism (p), the

Yoshito Suzuki; Yoh Iwasa

1980-01-01

276

Central pulse pressure is an independent determinant of vascular remodeling in the retinal circulation.  

PubMed

Pulse pressure has been recognized as a risk factor for stroke. Moreover, it was shown that central pulse pressure relates more strongly to vascular disease and outcome than (peripheral) brachial pulse pressure. Because vascular remodeling in the retinal circulation mirrors the 1 in the cerebral circulation and represents an easy, noninvasive possibility to assess microvascular changes in humans, we analyzed the impact of central pulse pressure on retinal vascular structure in humans. The study cohort comprised 135 nondiabetic patients across a wide range of blood pressure values. Parameter of retinal arteriolar remodeling (wall-to-lumen ratio) was assessed noninvasively and in vivo by scanning laser Doppler flowmetry. Central pulse pressure and augmentation index normalized to a heart rate of 75 beats per minute were assessed by pulse wave analysis. Central pulse pressure correlated with wall-to-lumen ratio (r=0.302; P<0.001), central augmentation index normalized to a heart rate of 75 beats per minute correlated with wall-to-lumen ratio (r=0.190; P=0.028), and in accordance pulse pressure amplification (peripheral pulse pressure/central pulse pressure) was negatively correlated with wall-to-lumen ratio (r=-0.223; P=0.009). In contrast, central mean arterial pressure was not correlated with wall-to-lumen ratio (r=0.110; P=0.203). Multiple regression analysis revealed an independent relationship between wall-to-lumen ratio and central pulse pressure (?=0.277; P=0.009), but not with other classical cardiovascular risk factors. Thus, central pulse pressure, indicative of changes in large conduit arteries is an independent determinant of vascular remodeling in small retinal arterioles. Such a relationship indicates a coupling and crosstalk between the microvascular and macrovascular changes attributable to hypertension. PMID:23569083

Ott, Christian; Raff, Ulrike; Harazny, Joanna M; Michelson, Georg; Schmieder, Roland E

2013-06-01

277

A note on trader Sharpe Ratios.  

PubMed

Traders in the financial world are assessed by the amount of money they make and, increasingly, by the amount of money they make per unit of risk taken, a measure known as the Sharpe Ratio. Little is known about the average Sharpe Ratio among traders, but the Efficient Market Hypothesis suggests that traders, like asset managers, should not outperform the broad market. Here we report the findings of a study conducted in the City of London which shows that a population of experienced traders attain Sharpe Ratios significantly higher than the broad market. To explain this anomaly we examine a surrogate marker of prenatal androgen exposure, the second-to-fourth finger length ratio (2D:4D), which has previously been identified as predicting a trader's long term profitability. We find that it predicts the amount of risk taken by traders but not their Sharpe Ratios. We do, however, find that the traders' Sharpe Ratios increase markedly with the number of years they have traded, a result suggesting that learning plays a role in increasing the returns of traders. Our findings present anomalous data for the Efficient Markets Hypothesis. PMID:19946367

Coates, John M; Page, Lionel

2009-01-01

278

Spectral variability of the particulate backscattering ratio  

NASA Astrophysics Data System (ADS)

The spectral dependency of the particulate backscattering ratio is relevant in the fields of ocean color inversion, light field modeling, and inferring particle properties from optical measurements. Aside from theoretical predictions for spherical, homogeneous particles, we have very limited knowledge of the actual in situ spectral variability of the particulate backscattering ratio. This work presents results from five research cruises that were conducted over a three-year period. Water column profiles of physical and optical properties were conducted across diverse aquatic environments that offered a wide range of particle populations. The main objective of this research was to examine the behavior of the spectral particulate backscattering ratio in situ, both in terms of its absolute magnitude and its variability across visible wavelengths, using over nine thousand 1-meter binned data points for each of five wavelengths of the spectral particulate backscattering ratio. Our analysis reveals no spectral dependence of the particulate backscattering ratio within our measurement certainty, and a geometric mean value of 0.013 for this dataset. This is lower than the commonly used value of 0.0183 from Petzold’s integrated volume scattering data. Within the first optical depth of the water column, the mean particulate backscattering ratio was 0.010.

Whitmire, A. L.; Boss, E.; Cowles, T. J.; Pegau, W. S.

2007-05-01

279

A Note on Trader Sharpe Ratios  

PubMed Central

Traders in the financial world are assessed by the amount of money they make and, increasingly, by the amount of money they make per unit of risk taken, a measure known as the Sharpe Ratio. Little is known about the average Sharpe Ratio among traders, but the Efficient Market Hypothesis suggests that traders, like asset managers, should not outperform the broad market. Here we report the findings of a study conducted in the City of London which shows that a population of experienced traders attain Sharpe Ratios significantly higher than the broad market. To explain this anomaly we examine a surrogate marker of prenatal androgen exposure, the second-to-fourth finger length ratio (2D?4D), which has previously been identified as predicting a trader's long term profitability. We find that it predicts the amount of risk taken by traders but not their Sharpe Ratios. We do, however, find that the traders' Sharpe Ratios increase markedly with the number of years they have traded, a result suggesting that learning plays a role in increasing the returns of traders. Our findings present anomalous data for the Efficient Markets Hypothesis.

Coates, John M.; Page, Lionel

2009-01-01

280

Optimal power split ratio for autobalanced photodetection.  

PubMed

The noise suppression of the autobalanced photoreceiver devised by Hobbs [Proc. SPIE1376, 216 (1990)] had been determined to depend on the photocurrent ratio of reference beam to signal beam under the condition of constant signal beam photocurrent, and the best noise cancellation was suggested at a ratio close to 2. But in most applications, the available optical power has a limit. Therefore, to optimize the sensitivity of measurements, we should consider how to allocate the beam power in the case of fixed total optical power. In this paper, we measure the air Faraday rotation at different azimuth angles of beam polarization, which correspond to different photocurrent ratios. The signal-to-noise ratio at each photocurrent ratio is determined, and the best sensitivity appears at the photocurrent ratio of 1. This best sensitivity achieved is 3.02×10(-8)??rad?Hz(-1/2), which is about 1.3 times the shot noise limit. Our results are useful for sensitive optical measurements with the autobalanced photoreceiver. PMID:24514118

Chang, Chia-Yu; Shy, Jow-Tsong

2014-01-20

281

Reversal of the /O III/lambda 4363/H sub gamma lambda 4340 ratio in the planetary nebula IC 4997  

NASA Technical Reports Server (NTRS)

Five image-tube spectrograms of the planetary nebula IC 4997 obtained during August 1977 show that the intensity forbidden ratio O III 4363 A/H-gamma 4340 A was equal to unity, but a sixth one obtained in April 1978 showed the ratio to be 0.91. These results represent a significant increase in the intensity ratio, which had been declining from 1895 to 1962 (when it was considerably less than unity), and is interpreted as resulting from a gradual increase in temperature of the nebula's central star accompanied by a transient event which led to a temporarily high value for the ratio in mid-1977.

Feibelman, W. A.; Hobbs, R. W.; Mccracken, C. W.; Brown, L. W.

1979-01-01

282

Physicians' Perceptions of the Need for Primary Care Physicians in West-Central Ohio.  

National Technical Information Service (NTIS)

The West-Central Ohio health systems plan states that 'the arbitrary figure of one primary care physician per 2,000 persons has been selected as the appropriate, and practical ratio...' This ratio has been met with criticism, and in response, the Health S...

1980-01-01

283

Origin of Sr, Nd and Pb isotopic systematics in high-Sr basalts from central Arizona  

Microsoft Academic Search

Alkalic and tholeiitic basalts were erupted in the central Arizona Transition Zone during Miocene-Pliocene time before and after regional faulting. The alkalic lava types differ from the subalkaline lavas in Sr, Nd and Pb isotopic ratios and trace element ratios and, despite close temporal and spatial relationships, the two types appear to be from discrete mantle sources. Pre-faulting lava types

James H. Wittke; Douglas Smith; Joseph L. Wooden

1989-01-01

284

Modelling 12C/13C ratios.  

NASA Astrophysics Data System (ADS)

Measurement of isotopic ratios is a good way to constrain stellar evolution models. In particular, isotopic ratio 12C/13C is well known to be a good signature of process such as dredge up and nucleosynthesis. Furthermore, these two isotopes are abundant enough to be easily observed in AGB envelopes. After a comprehensive study of the CNO abundances performed in 1986 by Lambert et al. from IR spectrocopy of CO and CN vibration-rotation bands, the observations focused on some stars which present remarkably low 12C/13C ratios ~4, i.e. an order of magnitude lower than the average ratio of their sample. In addition, from radio observations of a rotational line of CO, Jura et al. (1988) suggest that ratios could be a factor 2 smaller than previously believed. However, this is based on a simple analysis (assuming negligible line opacities) of a single transition of isotopomers of a single chemical species. IR observations performed recently by Ohnaka and Tsuji (1996) report values of about a factor 2 smaller than those derived by Lambert et al. in a number of stars. This controversy is an additional argument to revise the 12C/13C ratio determination. That's why we have performed with the IRAM 30m telescope and with the James Clerk Maxwell Telescope multi-transitions observations of the isotopomers of CO and CS (respectively J = 1-0, J = 2-1, J = 3-2 and J = 2-1, J = 3-2, J = 5-4) towards the three brightest envelopes of 13C-rich stars (T Lyr, RY Dra and Y CVn). To derive reliable ratios, i.e. to estimate radiative transfer effects, we have modelled all the observed transitions with a single set of envelope parameters. Comparison of the ratios obtained from CO and CS observation provides informations on the chemical fractionation and selective photodissociation effects. Depending on the line (molecule and transition), we derive the following isotopic ratios from integrated intensities: 2.2(+0.2,-0.2) < 12C13C < 4.0 (+1.4, -1.0) for RY Dra and 2.3(+0.2, -0.2) < 12C/13C < 3.7(+0.2, -0.2) for Y CVn. The modelling indicates that (1) ratios derived from CO are under-estimated because the CO lines are optically thicker and (2) no major radiative transfer effects take place because we derived values in good agreement with the measured one.

Dufour, Emmanuel; Kahane, Claudine; Greaves, J. S.

285

HealthCentral  

NSDL National Science Digital Library

HealthCentral (formerly HealthScout), a news service provided by Rx Remedy, Inc., posts fifteen to twenty short, easy-to-understand articles each day on a variety of medical and health topics in the news. Articles are based on interviews with experts and reports from medical journals, and HealthScout cites sources and provides links to related resources for each. HealthScout also summarizes newswire stories and links to the original newspaper or journal article. A Directory section contains an archive of older articles. Registration is not required to use the site; however, visitors can sign up to receive personalized health or medical news reports by filling out a personal survey. Quick registration allows users to select from nearly 350 topics; "7-Minute Checkup" requires extensive personal information, but provides a choice of over 700 topics and a detailed health-risk assessment based on the user's responses. The site contains a privacy statement and recommends that users select "Switch to Secure Server" [which requires a browser that supports Secure Socket Layers (SSL)] before submitting information. Searches of news sources are performed every four hours, and users can opt to receive email notification when HealthScout posts new information on their topic.

1998-01-01

286

Central odontogenic fibroma  

PubMed Central

Central odontogenic fibroma (COF), which has been categorized under the subheading of odontogenic tumors of ectomesenchyme, is such an uncommon neoplasm that much of its nature is left uncharted. COF is a rare tumor that accounts for 0.1% of all odontogenic tumors. Clinically, the lesion grows slowly and leads to cortical expansion. Radiologically, the lesion may be unilocular or multilocular. In some cases, it may be associated with root resorption or displacement. Histopathologically, the lesion is characterized by mature collagen fibers and numerous fibroblasts. A case of COF of the mandible in a male patient aged 49 years is described in this report. The patient showed no symptoms, no history of swelling discomfort or pain, and was unaware of the presence of the lesion. Orthopantomogram (OPG) showed generalized bone loss along with a unilocular radiolucent area, with a clear sclerotic lining and angular bone loss. Surgical enucleation of the lesion along with placement of osseo-graft, which is a bioresorbable demineralized bone matrix (DMBM), and platelet-rich fibrin was carried out in the defect site. Following surgery, patient was recalled for revaluation of the lesion; the surgical site showed good healing and an increase in bone height was seen.

Venugopal, Sanjay; Radhakrishna, Satish; Raj, Akshatha; Sawhney, Anshul

2014-01-01

287

Central nervous system histoplasmosis.  

PubMed

Involvement of the central nervous system (CNS) is recognized clinically in 5% to 10% of patients with progressive disseminated histoplasmosis. The risk of developing CNS histoplasmosis is increased in individuals with impaired cellular immunity, but not all patients with this condition are immunocompromised. Clinical syndromes include chronic meningitis, focal parenchymal lesions of the brain or spinal cord, stroke due to infected emboli, and diffuse encephalitis. CNS histoplasmosis should be considered in any patient with one of these syndromes who has resided in an area endemic for histoplasmosis. A high index of suspicion is necessary when extraneural signs and symptoms are absent. Culture of the causative fungus, Histoplasma capsulatum, from cerebrospinal fluid, brain tissue, or other sites is the gold standard for diagnosis. In culture-negative cases, detection of H. capsulatum antigen in cerebrospinal fluid, urine, or blood is helpful diagnostically. Aggressive and prolonged antifungal therapy is indicated in all cases of CNS histoplasmosis. There are no data from prospective comparative trials upon which to base specific recommendations for treatment. Expert opinion favors an initial course of liposomal amphotericin B, followed by at least 1 year of itraconazole. PMID:18579019

Saccente, Michael

2008-05-01

288

TACS Central Control Facility  

NASA Astrophysics Data System (ADS)

The Terminal Access Control System (TACS) is designed to make efficient usage of 25-kHz-wide satellite transponder channels, such as those available on FLEETSAT, GAPSAT, LEASAT. It does so by applying time division multiple access and automated demand assignment techniques to these channels, allowing a significant increase in both data throughput and supportable user population, as compared to the initial, single network per transponder FLEETSAT operating mode. The Terminal Technology Group of Lincoln Laboratory Division 6 has built prototypes of all of the TACS ground segment equipment, as well as special-purpose test equipment used to demonstrate and quantify the performance of TACS. This report describes the implementation details of components of the TACS Central Control Facility as configured for testing at the Laboratory. The components described are: the Multiple access Controller, the Call Simulator, the System Operator's Console, and the Scenario Generator. All differences in implementation/configuration between the testing environment and a full-scale operational environment are noted in the report.

Storch, S. B.; Taylor, L. E.; Landon, S. N.; Cappello, C. D.

1981-02-01

289

The anomalous C 4 intensity ratio in symbiotic stars  

NASA Technical Reports Server (NTRS)

The C IV lambda lambda 1548.2,1550.8 resonance doublet in a symbiotic stars was shown to exhibit anomalous line intensity ratios in which I (lambda 1548.2)/I(lambda 1550.8) less than 1, or less than the optically-thick limit of unity. The R Aquarii-central HII region and RX Puppis exhibit this phenomena. The I(lambda 1548.2)/I(lambda 1550.8) ratio in RX Puppis is found to vary inversely with the total C IV line intensity, and with the FES-visual light, as the object declined over a 5 yr period following a brightening in UV and optical emission which peaked in 1982. This doublet intensity behavior could be explained by a wind which has a narrow velocity range of 600 approx. less than sup v wind approx. less than 1000 km/sec, or by the pumping of the Fe II (mul. 45.01) transition a sup 4 F sub 9/2 - y sup 4 H(o) sub 11/2 by C IV lambda 1548.2, which effectively scatters C IV photons into the Fe II spectrum in these objects.

Michalitsianos, A. G.; Kafatos, M.; Fahey, R. P.

1988-01-01

290

Synoptic Control of Cross-Barrier Precipitation Ratios  

NASA Astrophysics Data System (ADS)

The substantial precipitation contrasts across mountain barriers, with windward enhancement on one side and leeward reduction on the other, have been the subject of several studies and reviews, both observational and theoretical. A lesser number of papers have examined the temporal variability of the orographic precipitation contrasts, including the origins of such variability. For example, Siler et al. (2013) examined the variability of the rain-shadow effect across the Cascade Mountains of Washington State. They found that the intensity of the winter-mean rain shadow was weaker in El Nino than La Nina years, and suggested that the strongest (weakest) rain shadows occurred for warm-sector (warm-frontal) situations. Dettinger et al. (2004) examined the synoptic controls of varying orographic precipitation ratios across the Sierra Nevada of California, with ratios defined by the difference in precipitation between the Central Valley and the western slopes of the barrier. They found increased ratios when the flow was more normal to the terrain and when vertical stability was less, with higher ratios after cold frontal passage compared to the warm sectors of midlatitude cyclones. The latter result appears to contradict the findings of Siler et al (2013). This presentation explores the temporal variations in the intensity of the precipitation gradient across the Cascade Mountains of Washington State and describes the synoptic conditions associated with periods in which precipitation is heavier on the western side, heavier on the eastern side, or nearly equal across the barrier. The talk will begin by summarizing the temporal variations of precipitation on the windward and leeward sides of the Cascades for a several year period. Segregating the hours when precipitation is substantially greater on the windward side, greater on the leeward side, or roughly equal, provides a series of dates used for synoptic composites for these three situations. It is shown that there are coherent and significant synoptic differences between the three precipitation ratio regimes, and these differences are illustrated for several case studies. For example, windward enhancement is greater after the passage of cold or occluded fronts, when stability is reduced and the flow is more westerly. Finally, the physical connection between synoptic flow and the changing cross-barrier precipitation contrasts are discussed.

Mass, C.; Vargas, R.

2013-12-01

291

Serial binary interval ratios improve rhythm reproduction  

PubMed Central

Musical rhythm perception is a natural human ability that involves complex cognitive processes. Rhythm refers to the organization of events in time, and musical rhythms have an underlying hierarchical metrical structure. The metrical structure induces the feeling of a beat and the extent to which a rhythm induces the feeling of a beat is referred to as its metrical strength. Binary ratios are the most frequent interval ratio in musical rhythms. Rhythms with hierarchical binary ratios are better discriminated and reproduced than rhythms with hierarchical non-binary ratios. However, it remains unclear whether a superiority of serial binary over non-binary ratios in rhythm perception and reproduction exists. In addition, how different types of serial ratios influence the metrical strength of rhythms remains to be elucidated. The present study investigated serial binary vs. non-binary ratios in a reproduction task. Rhythms formed with exclusively binary (1:2:4:8), non-binary integer (1:3:5:6), and non-integer (1:2.3:5.3:6.4) ratios were examined within a constant meter. The results showed that the 1:2:4:8 rhythm type was more accurately reproduced than the 1:3:5:6 and 1:2.3:5.3:6.4 rhythm types, and the 1:2.3:5.3:6.4 rhythm type was more accurately reproduced than the 1:3:5:6 rhythm type. Further analyses showed that reproduction performance was better predicted by the distribution pattern of event occurrences within an inter-beat interval, than by the coincidence of events with beats, or the magnitude and complexity of interval ratios. Whereas rhythm theories and empirical data emphasize the role of the coincidence of events with beats in determining metrical strength and predicting rhythm performance, the present results suggest that rhythm processing may be better understood when the distribution pattern of event occurrences is taken into account. These results provide new insights into the mechanisms underlining musical rhythm perception.

Wu, Xiang; Westanmo, Anders; Zhou, Liang; Pan, Junhao

2013-01-01

292

A new ratio for protocol categorization.  

PubMed

The present review describes and validates a new ratio "S" created for matching predictability and balance between TP and TN. Validity of S was studied in a three-step process as follows: (i) S was applied to the data of a past study predicting cardiac output response to fluid bolus from response to passive leg raise (PLR); (ii) S was comparatively analyzed with traditional ratios by modeling different 2 ? 2 contingency tables in 1000 hypothetical patients; (iii) precision of S was compared with other ratios by computing random fluctuations in the same patients. In comparison to other ratios, S performs better in predicting the cardiac response to fluid bolus and supports more directly the clinical conclusions. When the proportion of false responses is high, S is close to the coefficient correlation (CC). When the proportion of true responses is high, S is the unique ratio that identifies the categorization that balances the proportion of TP and TN. The precision of S is close to that of CC. In conclusion, S should be considered for creating categories from quantitative variables; especially when matching predictability with balance between TP and TN is a concern. PMID:24738007

Squara, Pierre

2014-01-01

293

Leptin to adiponectin ratio in preeclampsia.  

PubMed

The aim of the present study was to assess leptin/adiponectin ratio in preeclamptic patients compared with normal pregnant women. A cross-sectional study was designed. The study population consisted of 30 preeclamptic patients and 30 healthy pregnant women. Serum levels of total leptin and adiponectin were assessed using commercially available enzyme-linked immunosorbent assay methods. The one-way ANOVA and Student's t tests and Pearson's correlation analysis were used for statistical calculations. Levels of leptin and adiponectin were also adjusted for BMI. A p-value < 0.05 was considered statistically significant. The leptin/adiponectin ratio was increased significantly in preeclamptic patients. The leptin/adiponectin ratio was significantly higher in severe preeclamptic patient than in mild preeclampsia. Adjusted leptin/adiponectin ratio was also significantly increased in preeclamptic patients than in normal pregnant women. The findings of the present study suggest that the leptin/adiponectin ratio was increased in preeclamsia and imbalance between the adipocytokines could be involved in the pathogenesis of preeclampsia. PMID:23923407

Khosrowbeygi, A; Ahmadvand, H

2013-04-01

294

A New Ratio for Protocol Categorization  

PubMed Central

The present review describes and validates a new ratio “S” created for matching predictability and balance between TP and TN. Validity of S was studied in a three-step process as follows: (i) S was applied to the data of a past study predicting cardiac output response to fluid bolus from response to passive leg raise (PLR); (ii) S was comparatively analyzed with traditional ratios by modeling different 2 ? 2 contingency tables in 1000 hypothetical patients; (iii) precision of S was compared with other ratios by computing random fluctuations in the same patients. In comparison to other ratios, S performs better in predicting the cardiac response to fluid bolus and supports more directly the clinical conclusions. When the proportion of false responses is high, S is close to the coefficient correlation (CC). When the proportion of true responses is high, S is the unique ratio that identifies the categorization that balances the proportion of TP and TN. The precision of S is close to that of CC. In conclusion, S should be considered for creating categories from quantitative variables; especially when matching predictability with balance between TP and TN is a concern.

Squara, Pierre

2014-01-01

295

Autofluorescence ratio imaging of human colonic adenomas  

NASA Astrophysics Data System (ADS)

Recently autofluorescence imaging (AFI) endoscopy, visualizing tissue fluorescence in combination with reflected light, has been adopted as a technique for detecting neoplasms in the colon and other organs. However, autofluorescence colonoscopy is not infallible, and improvement of the detection method can be expected to enhance the performance. Colonic mucosa contains metabolism-related fluorophores, such as reduced nicotinamide adenine dinucleotide, which may be useful for visualizing neoplasia in autofluorescence endoscopy. We examined sliced cross-sections of endoscopically resected tubular adenomas under a microscope. Fluorescence images acquired at 365-nm excitation (F365ex) and 405-nm excitation (F405ex), and reflectance images acquired at 550 nm (R550) were obtained. Fluorescence ratio (F365ex/F405ex) images and reflectance/fluorescence ratio (R550/F405ex) images were calculated from the acquired images. The fluorescence ratio images could distinguish adenomatous mucosa from normal mucosa more clearly than the reflectance/fluorescence ratio images. The results showed that the autofluorescence ratio imaging is a potential technique for increasing the diagnostic power of autofluorescence endoscopy.

Imaizumi, Katsuichi; Harada, Yoshinori; Wakabayashi, Naoki; Yamaoka, Yoshihisa; Dai, Ping; Tanaka, Hideo; Takamatsu, Tetsuro

2011-02-01

296

Central and southern Africa  

SciTech Connect

Exploration in central and southern Africa continued to expand during 1980. The greatest concentration of activity was in Nigeria. However, there was considerable increase in the level of exploratory work in Cameroon and Congo. Significant new finds have been made in Ivory Coast. Geological and geophysical activity was carried out in 18 of the countries, with those in the western part having the largest share. Seismic work involved 225 party months of operation. Most of this time was spent on land, but marine operations accounted for 73,389 km of new control. Gravity and magnetic data were recorded during the marine surveys, and several large aeromagnetic projects were undertaken to obtain a total of 164,498 line km of data. Exploratory and development drilling accounted for a total of 304 wells and 2,605,044 ft (794,212 m) of hole. The 92 exploratory wells that were drilled resulted in 47 oil and gas discoveries. In development drilling 89% of the 212 wells were successful. At the end of the year, 27 exploratory wells were underway, and 34 development wells were being drilled for a total of 61. Oil production from the countries that this review covers was 918,747,009 bbl in 1980, a drop of about 9% from the previous year. Countries showing a decline in production were Nigeria, Gabon, Cabinda, and Zaire. Increases were recorded in Cameroon, Congo, and Ghana. A new country was added to the list of producers when production from the Belier field in Ivory Coast came on stream. 33 figures, 15 tables.

McGrew, H.J.

1981-10-01

297

Central African Republic.  

PubMed

The Central African Republic contains 242,000 square miles, which rolling terrain almost 2000 feet above sea level. The climate is tropical, and it has a population of 2.8 million people with a 2.5% growth rate. There are more than 80 ethnic groups including Baya 34%, Banda 28%, Sara 10%, Mandja 9%, Mboum 9%, and M'Baka 7%. The religions are traditional African 35%, protestant 25%, Roman Catholic 25%, and Muslim 15%, and the languages are French and Sangho. The infant mortality rate is 143/1000, with expectancy at 49 years and a 40% literacy rate. The work force of 1 million is 70% agricultural, industry 6% and commerce and service 6% and government 3%. The government consists of a president assisted by cabinet ministers and a single party. Natural resources include diamonds, uranium, timber, gold, and oil, and major industries are beverages, textiles, and soap. Agricultural products feature coffee, cotton, peanuts, tobacco, food crops and livestock. Most of the population live in rural areas and most of the 80 ethnic groups have their own language. This is one of the world's least developed countries, with a per capita income of $375/year. The main problems with development are the poor transportation infrastructure, and the weak internal and international marketing systems. The US and various international organizations have aided in agriculture development, health programs, and family planning. US investment is mainly in diamond and gold mining, and although oil drilling has been successful it is not economically feasible at current prices. PMID:12178020

1989-11-01

298

Russia's Place in Central Asia.  

National Technical Information Service (NTIS)

This thesis assesses the need for U.S.-Russian cooperation in Central Asia to create a stronger, more reliable long-term stability in the region. Current United States policy toward Russia in Central Asia is tailored to isolate and minimize Russian influe...

J. M. Edwards

2001-01-01

299

Regional Education Profile: Central America.  

ERIC Educational Resources Information Center

Profiles of the educational systems in the seven Central American countries are presented, along with an introductory essay by Rene Greenwald, "Higher Education in Central America: Trends and Developments: 1985-86." Country profiles are provided for Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama. For each country, an…

Institute of International Education, New York, NY.

300

Algorithms for high aspect ratio oriented triangulations  

NASA Technical Reports Server (NTRS)

Grid generation plays an integral part in the solution of computational fluid dynamics problems for aerodynamics applications. A major difficulty with standard structured grid generation, which produces quadrilateral (or hexahedral) elements with implicit connectivity, has been the requirement for a great deal of human intervention in developing grids around complex configurations. This has led to investigations into unstructured grids with explicit connectivities, which are primarily composed of triangular (or tetrahedral) elements, although other subdivisions of convex cells may be used. The existence of large gradients in the solution of aerodynamic problems may be exploited to reduce the computational effort by using high aspect ratio elements in high gradient regions. However, the heuristic approaches currently in use do not adequately address this need for high aspect ratio unstructured grids. High aspect ratio triangulations very often produce the large angles that are to be avoided. Point generation techniques based on contour or front generation are judged to be the most promising in terms of being able to handle complicated multiple body objects, with this technique lending itself well to adaptivity. The eventual goal encompasses several phases: first, a partitioning phase, in which the Voronoi diagram of a set of points and line segments (the input set) will be generated to partition the input domain; second, a contour generation phase in which body-conforming contours are used to subdivide the partition further as well as introduce the foundation for aspect ratio control, and; third, a Steiner triangulation phase in which points are added to the partition to enable triangulation while controlling angle bounds and aspect ratio. This provides a combination of the advancing front/contour techniques and refinement. By using a front, aspect ratio can be better controlled. By using refinement, bounds on angles can be maintained, while attempting to minimize the number of Steiner points.

Posenau, Mary-Anne K.

1995-01-01

301

Radioactive anomaly discrimination from spectral ratios  

DOEpatents

A method for discriminating a radioactive anomaly from naturally occurring radioactive materials includes detecting a first number of gamma photons having energies in a first range of energy values within a predetermined period of time and detecting a second number of gamma photons having energies in a second range of energy values within the predetermined period of time. The method further includes determining, in a controller, a ratio of the first number of gamma photons having energies in the first range and the second number of gamma photons having energies in the second range, and determining that a radioactive anomaly is present when the ratio exceeds a threshold value.

Maniscalco, James; Sjoden, Glenn; Chapman, Mac Clements

2013-08-20

302

Precambrian Dynamo Reversal Behavior from Polarity Ratios  

NASA Astrophysics Data System (ADS)

Numerous speculations exist regarding the abundance of geomagnetic superchrons through Earth history, as a function of secular cooling and inner core growth; however, data have generally been evaluated only on a regional basis. Global assessments of geomagnetic polarity require robust continental reconstructions, and only recently have these been generated with paleomagnetic compatibility and kinematic viability. Geomagnetic polarity ratio is the average ratio of normal polarity to total polarity in a series of discrete paleopole observations. We compile paleomagnetic polarity ratios from 0-335 Ma and 900-2200 Ma, with the goal to compare geodynamo polarity ratio behavior from the Phanerozoic to the Precambrian and to assess whether Precambrian superchrons can be identified. First, we compute polarity ratio, represented as percent normal (%N), from a 0-335 Ma compilation of paleopoles and identify the best timescale of polarity ratio averaging (tau) for distinguishing the two known superchrons during this record. We find that for tau?20 Myr both the Cretaceous Normal Superchron (CNS) and the Kiaman Reverse Superchron are discernible in the polarity ratio series. Second, we compile paleopole data from the global paleomagnetic database with strict quality criteria and age precision within +/-15 Myr (a nominal superchron duration). We find that the Precambrian %N series using tau=20 Myr does not contain obvious superchrons like the 0-335 Ma record, but there is evidence for low frequency modulation from periods with prolonged low (<30%) to high (>70%) polarity ratio, similar to the 0-335 Ma record. Third, we test whether it is possible for superchrons to be identified in the 0-335 Ma set with the much lower sampling frequency of the Precambrian data set. This is done by subsampling the 0-335 Ma record with a random set of Precambrian sample age spacings. The procedure is then reproduced in a bootstrap, producing an average superchron identification success rate. If the success rate is high then we expect it to be possible to identify superchron-like behavior in the Precambrian, and whether such behavior is quasi-periodic like the ~200 Myr period between the three known Phanerozoic superchrons.

Evans, D. A.; Driscoll, P. E.

2012-12-01

303

On the variability of alligator sex ratios  

USGS Publications Warehouse

Samples of alligators from wild and 'farm' populations exhibited disproportionate sex ratios. Males predominated among young alligators from wild populations, whereas females were much more abundant than males in the farm population, where resources were superabundant. These results and other considerations lead us to hypothesize that environmental factors influence sex determination in alligators. During favorable environmental conditions natural selection is expected to favor a preponderance of the sex whose individuals exhibit the greater environmentally associated variation in relative fitness. We hypothesize that environmentally associated variation in age at sexual maturity of females produces sufficient variation in relative fitness of females to result in selection for low sex ratios during periods of resource abundance.

Nichols, J.D.; Chabreck, R.H.

1980-01-01

304

On central black holes in ultra-compact dwarf galaxies  

NASA Astrophysics Data System (ADS)

Context. The dynamical mass-to-light (M/L) ratios of massive ultra-compact dwarf galaxies (UCDs) are about 50% higher than predicted by stellar population models. Aims: Here we investigate the possibility that these apparently elevated M/L ratios of UCDs are caused by a central black hole (BH) that heats up the internal motion of stars. We focus on a sample of ~50 extragalactic UCDs from the literature for which velocity dispersions and structural parameters have been measured. Methods: To be self-consistent in our BH mass estimates, we first redetermine the dynamical masses and M/L ratios of our sample UCDs, using up-to-date distance moduli and a consistent treatment of aperture and seeing effects. On average, the homogeneously redetermined dynamical mass and M/L ratios agree to within 5% with previous literature results. We calculate the ratio ? = (M/L)dyn/(M/L)pop between the dynamical and the stellar population M/L for an assumed age of 13 Gyr. ? > 1 indicates an elevated dynamical M/L ratio, suggesting dark mass on top of a canonical stellar population of old age. For all UCDs with ? > 1 we estimate the mass of a hypothetical central black hole needed to reproduce the observed integrated velocity dispersion Results: Massive UCDs (M > 107 M?) have an average ? = 1.7 ± 0.2, implying notable amounts of dark mass in them. We find that, on average, central BH masses of 10-15% of the UCD mass can explain these elevated dynamical M/L ratios. The implied BH masses in UCDs range from several 105 M? to several 107 M?. In the MBH-luminosity plane, UCDs are offset by about two orders of magnitude in luminosity from the relation derived for galaxies. Our findings can be interpreted such that massive UCDs originate from progenitor galaxies with masses around ~109 M?, and that those progenitors have SMBH occupation fractions of ~60-100%. The suggested UCD progenitor masses agree with predictions from the tidal stripping scenario. Also, the typical BH mass fractions of nuclear clusters in such ~109 M? galaxy bulges agree with the 10-15% BH fraction estimated for UCDs. Lower-mass UCDs (M < 107 M?) exhibit a bimodal distribution in ?, suggestive of a coexistence of massive globular clusters and tidally stripped galaxies in this mass regime. Conclusions: Central BHs as relict tracers of tidally stripped progenitor galaxies are a plausible explanation for the elevated dynamical M/L ratios of UCDs. Direct observational tests of this scenario are suggested.

Mieske, S.; Frank, M. J.; Baumgardt, H.; Lützgendorf, N.; Neumayer, N.; Hilker, M.

2013-10-01

305

IKONOS Signal-to-Noise Ratio Estimation  

NASA Technical Reports Server (NTRS)

This viewgraph presentation focuses on the differences in Signal-to-Noise Ratio (SNR) between IKONOS imagery with and without Modulation Transfer Function Correction (MTFC). The researchers used a simulated scene to evaluate the effects of MTFC on SNR. They also used four very uniform IKONOS scenes, two of Antarctica, one of Ivanpah, CA, and one of Mali to estimate SNR.

Zanoni, Vicki; Ryan, Robert; Holekamp, Kara; Pagnutti, Mary

2002-01-01

306

Giving More Realistic Definitions of Trigonometric Ratios  

ERIC Educational Resources Information Center

Trigonometry is a well known branch of Mathematics. The study of trigonometry is of great importance in surveying, astronomy, navigation, engineering, and in different branches of science. This paper reports on the discovery of flaws in the traditional definitions of trigonometric ratios of an angle, which (in most cases) make use of the most…

Bhattacharjee, Pramode Ranjan

2012-01-01

307

Atomic Capture Ratios for Muons in Oxides.  

National Technical Information Service (NTIS)

Using the lifetime technique, atomic capture ratios of negative muons have been measured in 41 oxides. The results, though somewhat different from the earlier TRIUMF findings, are consistent with the mesic x-ray measurements. It has been noticed that the ...

S. Stanislaus F. Entezami A. Bagheri D. F. Measday D. Garner

1984-01-01

308

Shale Gouge Ratio — calibration by geohistory  

Microsoft Academic Search

At the 1996 NPF Conference on Hydrocarbon Seals we gave the first presentation of results of a fault-seal study using the Shale Gouge Ratio algorithm, describing a project undertaken in 1994 by Badleys and Norsk Hydro on the Oseberg Syd field. Over subsequent years the methodology has been applied to many tens of data sets in both exploration and production

Graham Yielding

2002-01-01

309

Air-fuel ratio control system  

Microsoft Academic Search

This patent described an air-fuel ratio control system for an internal combustion engine having an intake passage, fuel supply means for supplying fuel to cylinders of the engine through the intake passage in dependency on engine operating conditions, an exhaust passage from the engine. It also includes an Oâ-sensor for detecting the concentration of oxygen in exhaust gases passing through

Kataoka

1986-01-01

310

Compression ratio effect on methane HCCI combustion  

SciTech Connect

The authors have used the HCT (hydrodynamics, chemistry, and transport) chemical kinetics code to simulate HCCI (homogeneous charge compression ignition) combustion of methane-air mixtures. HCT is applied to explore the ignition timing, burn duration, NO{sub X}production, gross indicated efficiency and gross IMEP of a supercharged engine (3 atm. intake pressure) with 14:1, 16:1 and 18:1 compression ratios at 1200 rpm. HCT has been modified to incorporate the effect of heat transfer and to calculate the temperature that results from mixing the recycled exhaust with the fresh mixture. This study uses a single reaction zone that varies as a function of crank angle. The ignition process is controlled by adjusting the intake equivalence ratio and the residual gas trapping (RGT). RGT is internal exhaust gas recirculation, which recycles both thermal energy and combustion product species. Adjustment of equivalence ratio and RGT is accomplished by varying the timing of the exhaust valve closure in either two-stroke or four-stroke engines. Inlet manifold temperature is held constant at 300 K. Results show that, for each compression ratio, there is a range of operational conditions that show promise of achieving the control necessary to vary power output while keeping indicated efficiency above 50 percent and NO{sub X}levels below 100 ppm. HCT results are also compared with a set of recent experimental data for natural gas.

Aceves, S.M.; Smith, J.R.; Westbrook, C.K.; Pitz, W.J. [Lawrence Livermore National Lab., CA (United States)

1999-07-01

311

Compression ratio effect on methane HCCI combustion  

SciTech Connect

We have used the HCT (Hydrodynamics, Chemistry and Transport) chemical kinetics code to simulate HCCI (homogeneous charge compression ignition) combustion of methane-air mixtures. HCT is applied to explore the ignition timing, bum duration, NOx production, gross indicated efficiency and gross IMEP of a supercharged engine (3 atm. Intake pressure) with 14:1, 16:l and 18:1 compression ratios at 1200 rpm. HCT has been modified to incorporate the effect of heat transfer and to calculate the temperature that results from mixing the recycled exhaust with the fresh mixture. This study uses a single control volume reaction zone that varies as a function of crank angle. The ignition process is controlled by adjusting the intake equivalence ratio and the residual gas trapping (RGT). RGT is internal exhaust gas recirculation which recycles both thermal energy and combustion product species. Adjustment of equivalence ratio and RGT is accomplished by varying the timing of the exhaust valve closure in either 2-stroke or 4-stroke engines. Inlet manifold temperature is held constant at 300 K. Results show that, for each compression ratio, there is a range of operational conditions that show promise of achieving the control necessary to vary power output while keeping indicated efficiency above 50% and NOx levels below 100 ppm. HCT results are also compared with a set of recent experimental data for natural gas.

Aceves, S. M.; Pitz, W.; Smith, J. R.; Westbrook, C.

1998-09-29

312

Using likelihood ratios to test imprecise hypotheses  

Microsoft Academic Search

Responds to the suggestion by M. R. Marler that likelihood ratio tests should be based on precise hypotheses rather than on the imprecise hypotheses recommended by G. F. Pitz . Precise hypotheses, however, are usually false and hence are rarely worth testing. In any case, the correct procedure for testing precise hypotheses is not that suggested by Marler, but a

Gordon F. Pitz

1980-01-01

313

Ratio Analysis in Higher Education: Caveat Emptor.  

ERIC Educational Resources Information Center

Ratio analyses are useful, but care must be taken not to overstate their importance or disregard their limitations. Internally designated, nonstandardized recording techniques in interinstitutional comparisons, inflationary distortions in internal analysis, and judgments made on trends can obstruct the manager's efforts to assess a higher…

DiSalvio, Philip

1989-01-01

314

Ratio of Specific Heats of Gases  

NSDL National Science Digital Library

Students bounce a steel ball in a gas-filled tube. The compressed gas provides a restoring force on the ball. By measuring the distance of initial fall or the frequency of oscillation, the ratio of specific heats of several gases, Cp/Cv may be determined.

2009-02-16

315

Sheath voltage ratio for asymmetric rf discharges  

SciTech Connect

Spherical and cylindrical many-particle models are used to simulate rf (radio frequency) discharges in which the rf powered and the grounded electrodes have different areas. This asymmetry determines the magnitude of the average plasma-to-electrode voltage {ital V}{sub {ital a}} (the ion bombarding energy) at the smaller powered electrode, which is a critical process parameter. A collisionless uniform ionization discharge model predicts that the voltage ratio {ital V}{sub {ital a}}/{ital V}{sub {ital b}} scales as the fourth power of the electrode area ratio {ital A}{sub {ital b}}/{ital A}{sub {ital a}}, where {ital V}{sub {ital b}} is the potential drop at the other electrode. However, measurements indicate a much weaker dependence of {ital V}{sub {ital a}}/{ital V}{sub {ital b}} on the area ratio, which is also observed in our simulations. Over a limited range of area ratios it was found that the power dependence was close to one, in agreement with a local ionization discharge model. The simulation codes used are PDC1 (plasma device cylindrical one-dimensional) and PDS1 (plasma device spherical one-dimensional).

Alves, M.V.; Lieberman, M.A.; Vahedi, V.; Birdsall, C.K. (Department of Electrical Engineering and the Electronics Research Laboratory, University of California, Berkeley, California 94720 (USA) Department of Computer Sciences and the Electronics Research Laboratory, University of California, Berkeley, California 94720 (USA))

1991-04-01

316

Student-Faculty Ratios and Unions.  

ERIC Educational Resources Information Center

Student-faculty ratios from 1970-1976 at 34 institutions covered by collective bargaining contracts do not indicate decreases in the number of students per full-time faculty member. Further research is suggested to determine if there is an increase in the use of part-time faculty at these schools and to investigate the lack of nonpecuniary gains…

Brown, William W.; Stone, Courtenay C.

1979-01-01

317

Plutonium to Uranium Fission Ratio Measurements.  

National Technical Information Service (NTIS)

The measurement of the ratio of plutonium to uranium fissions has for some years been used as a method of characterizing the thermal spectrum in reactor lattices. This report describes the method of analysis of this type of measurement which has been deve...

R. H. Waterson

1971-01-01

318

Calculating Confidence Intervals for Rates and Ratios  

Microsoft Academic Search

Since the probability of developing or dying from most neurologic disorders is relatively small, the Poisson distribution is often utilized to establish confidence intervals around rates or ratios for diseases of the nervous system. This report describes a simplified method and provides a table of factors based on the Poisson distribution for calculating confidence intervals around estimates of rates and

Bruce S. Schoenberg

1983-01-01

319

Space Elevator Ribbon Mass and Taper Ratio  

Microsoft Academic Search

Assumptions about tensile strength and density aect the space elevator ribbon taper ratio, and therefore its mass. We examine the technical trade-os between material properties and total mass of a modern space elevator ribbon, and the economic trade-os between ribbon mass, the number of rocket launches required to loft the initial ribbon, and the time required to build the ribbon

Tom Nugent

320

Predicting the Equity Premium with Dividend Ratios  

Microsoft Academic Search

ur paper suggests a simple, recursive residuals (out-of-sample) graphical approach to evaluating the predictive power of popular equity premium and stock market time- series forecasting regressions. When applied, we find that dividend ratios should have been known to have no predictive ability even prior to the 1990s, and that any seeming ability even then was driven by only two years,

Amit Goyal; Ivo Welch

2003-01-01

321

JONAH Algorithms: C-2 the Ratio Option.  

National Technical Information Service (NTIS)

Information concerning input is given first. Then formulas are given for calculation of atoms/millimeter, fissions, kiloton yield, R-value, atoms/fission, fissions/fission, bomb fraction, fissions/atoms, atoms, atoms/atoms, fissions/atoms, atom ratio, tot...

J. Rego

1979-01-01

322

Measurement of the ? topological branching ratios  

Microsoft Academic Search

Using data collected in the DELPHI detector at LEP-1, measurements of the inclusive ? branching ratios for decay modes containing one, three, or five charged particles have been performed: where h is either a charged ? or K meson. The first quoted uncertainties are statistical and the second systematic.

Francisco Matorras; Duncan W. Reid; T Adye; P Adzic; Z Albrecht; T Alderweireld; G D Alekseev; R Alemany; T Allmendinger; P P Allport; S Almehed; Ugo Amaldi; N Amapane; S Amato; E Anashkin; E G Anassontzis; P Andersson; A Andreazza; S Andringa; N Anjos; P Antilogus; W D Apel; Y Arnoud; B Åsman; J E Augustin; A Augustinus; Paul Baillon; A Ballestrero; P Bambade; F Barão; Guido Barbiellini; R Barbier; Dimitri Yuri Bardin; G Barker; A Baroncelli; Marco Battaglia; M Baubillier; K H Becks; M Begalli; A Behrmann; T F Bellunato; Yu A Belokopytov; K S Belous; N C Benekos; Alberto C Benvenuti; C Bérat; M Berggren; L Berntzon; D Bertrand; M Besançon; N Besson; S M Bilenky; D Bloch; H M Blom; J L Bol; M Bonesini; M Boonekamp; P S L Booth; G Borisov; C Bosio; O Botner; E Boudinov; B Bouquet; T J V Bowcock; I Boyko; I Bozovic; M Bozzo; M Bracko; P Branchini; R A Brenner; E Brodet; P Brückman; J M Brunet; L Bugge; P Buschmann; M Caccia; M Calvi; T Camporesi; V Canale; F Carena; L Carroll; Carlo Caso; A Cattai; F R Cavallo; M M Chapkin; P Charpentier; P Checchia; G A Chelkov; R Chierici; P Shlyapnikov; P Chochula; V Chorowicz; J Chudoba; S H Chung; K Cieslik; P Collins; R Contri; G Cosme; F Cossutti; M Costa; H B Crawley; D J Crennell; J Croix; J Cuevas-Maestro; S Czellar; J D'Hondt; J Dalmau; M Davenport; W Da Silva; G Della Ricca; P A Delpierre; N Demaria; A De Angelis; Wim de Boer; C De Clercq; B De Lotto; A De Min; L S De Paula; H Dijkstra; Lucia Di Ciaccio; K Doroba; M Dracos; J Drees; M Dris; G Eigen; T J C Ekelöf; M Ellert; M Elsing; J P Engel; M C Espirito-Santo; G K Fanourakis; D Fassouliotis; Michael Feindt; J Fernández; A Ferrer; E Ferrer-Ribas; F Ferro; A Firestone; U Flagmeyer; H Föth; E Fokitis; F Fontanelli; B J Franek; A G Frodesen; R Frühwirth; F Fulda-Quenzer; J A Fuster; D Gamba; S Gamblin; M Gandelman; C García; C Gaspar; M Gaspar; U Gasparini; P Gavillet; E N Gazis; D Gelé; T Geralis; N Ghodbane; F Glege; R Gokieli; B Golob; G Gómez-Ceballos; P Gonçalves; I González-Caballero; Gian P Gopal; L Gorn; Yu Guz; Valerio Gracco; J Grahl; E Graziani; G Grosdidier; K Grzelak; J Guy; C Haag; F Hahn; S Hahn; S Haider; Z Hajduk; A Hallgren; K Hamacher; J Hansen; F J Harris; S Haug; F Hauler; V Hedberg; S Heising; P Herquet; H Herr; O Hertz; E Higón; Sven Olof Holmgren; P J Holt; S Hoorelbeke; M A Houlden; Josef Hrubec; G J Hughes; K Hultqvist; J N Jackson; R Jacobsson; C Jarlskog; G Jarlskog; P Jarry; B Jean-Marie; D Jeans; E K Johansson; P Jonsson; C Joram; P Juillot; L Jungermann; F Kapusta; K Karafasoulis; S Katsanevas; E C Katsoufis; R Keränen; Borut P Kersevan; B A Khomenko; N N Khovanskii; A P Kiiskinen; B J King; A Kinvig; N J Kjaer; O Klapp; P M Kluit; P Kokkinias; V Kostyukhin; C Kourkoumelis; O Kuznetsov; Manfred Krammer; E Kriznic; Z Krumshtein; P Kubinec; W Kucewicz; M Kucharczyk; J Kurowska; J Lamsa; J P Laugier; Gerhard Leder; F Ledroit; L Leinonen; A Leisos; R Leitner; J Lemonne; Georg Lenzen; V Lepeltier; M Lethuillier; J Libby; W Liebig; D Liko; A Lipniacka; I Lippi; J G Loken; J H Lopes; J M López; R López-Fernandez; D Loukas; P Lutz; L Lyons; J N MacNaughton; J R Mahon; A Maio; A Malek; S Maltezos; V Malychev; F Mandl; J Marco; R Marco; B Maréchal; M Margoni; J C Marin; C Mariotti; A Markou; C Martínez-Rivero; S Martí i García; J Masik; N Mastroyiannopoulos; C Matteuzzi; Giorgio Matthiae; F Mazzucato; M Mazzucato; M L McCubbin; R McKay; R McNulty; E Merle; C Meroni; W T Meyer; A Myagkov; E Migliore; L Mirabito; Winfried A Mitaroff; U Mjörnmark; T Moa; M Moch; K Mönig; M R Monge; J Montenegro; D Moraes; P Morettini; G Morton; U Müller; K Münich; M Mulders; L M Mundim; W J Murray; Gerald Myatt; T Myklebust; M Nassiakou; Francesco Luigi Navarria; K Nawrocki; P Negri; S Némécek; N Neufeld; R Nicolaidou; P Niezurawski; M Nikolenko; V P Nomokonov; A Nygren; A Oblakowska-Mucha; V F Obraztsov; A G Olshevskii; A Onofre; Risto Orava; K Österberg; A Ouraou; A Oyanguren; M Paganoni; S Paiano; R Pain; R Paiva; J Palacios; H Palka; T D Papadopoulou; L Pape; C Parkes; F Parodi; U Parzefall; A Passeri; O Passon; L Peralta; V F Perepelitsa; Manfred Pernicka; A Perrotta; C Petridou; A Petrolini; H T Phillips; F Pierre; M Pimenta; E Piotto; T Podobnik; V Poireau; M E Pol; G Polok; P Poropat; V Pozdnyakov; P Privitera; N Pukhaeva; Antonio Pullia; D Radojicic; S Ragazzi; H Rahmani; P N Ratoff; A L Read; P Rebecchi; N G Redaelli; Meinhard Regler; J Rehn; R Reinhardt; P B Renton; L K Resvanis; F Richard; J Rídky; G Rinaudo; I Ripp-Baudot; A Romero; P Ronchese; E I Rosenberg; P Rosinsky; Patrick Roudeau; T Rovelli; V Ruhlmann-Kleider; A Ruiz; H Saarikko; Yu Sacquin; A Sadovskii; G Sajot; L Salmi; J Salt; D Sampsonidis; M Sannino; Aurore Savoy-Navarro; C Schwanda; P Schwemling; B Schwering; U Schwickerath; F Scuri; P Seager; Yu Sedykh; A M Segar; R L Sekulin; G Sette; R C Shellard

2001-01-01

323

IC test using the energy consumption ratio  

Microsoft Academic Search

Dynamic-current based test techniques can potentially address the drawbacks of traditional and Iddq test methodologies. The qual- ity of dynamic current based test is degraded by process variations in IC manufacture. The energy consumption ratio (ECR) is a new metric that improves the effectiveness of dynamic current test by reducing the impact of process variations by an order of magni-

Wanli Jiang; Bapiraju Vinnakota

1999-01-01

324

MAGNESIUM ISOTOPE RATIOS IN NATURAL SAMPLES  

Microsoft Academic Search

Magnesium isotope ratios of 60 natural samples, including carbonate, evaporite, hydroxide, silicate, oxide, seawater, brine, meteorite, and biological samples, were measured by thermal emission mass spectrometry. Statistical analysis of the data reveals no evidence of variations among the natural samples or between any of the natural samples and a reference sample of magnesium metal. The 95% confidence limits for each

E. J. Catanzaro; T. J. Murphy

1966-01-01

325

Liquid Asset Ratios and Financial Sector Reform  

Microsoft Academic Search

As a monetary, selective credit, and government debt-management instrument, a liquid asset ratio is generally inefficient and may introduce serious distortions. However, it may play a limited role as a prudential instrument, particularly in less sophisticated banking systems or in the context of currency board arrangements. Recent trends in the use of this instrument have been to either abolish it

Anne-Marie Gulde; Jean Claude Nascimento; Lorena Zamalloa

1997-01-01

326

ULTIMA RATIO - A Visual Language for Argumentation  

Microsoft Academic Search

In the third act of Shakespeare's Hamlet, the hero is unsure whether to kill Claudius - the assassin of Hamlet's father - or not. He argues that if he does kill him, Claudius who is praying at that very moment goes to heaven and if he does not kill him Hamlet's father is not revenged. A contradictio n. Ultima Ratio

Michael Schroeder; Daniela Alina Plewe; Andreas Raab

1999-01-01

327

A Blip-Scan Ratio Scoring System.  

National Technical Information Service (NTIS)

A digital recording system for use in determining the blip-scan ratio of search radars was designed and constructed. The system accepts input from as many as seven operators observing one or more radars. Each operator has a choice of three input levels or...

F. D. Queen E. E. Maine

1974-01-01

328

The Prigogine-Defay ratio revisited  

NASA Astrophysics Data System (ADS)

One of the basic characteristics of the glass transition, the Prigogine-Defay ratio, connecting jumps of the thermal expansion coefficient, isothermal compressibility, and isobaric specific heat capacity in vitrification is rederived in the framework of the thermodynamics of irreversible processes employing the order-parameter concept introduced by de Donder and van Rysselberghe [Thermodynamic Theory of Affinity (Stanford University Press, Stanford, 1936)]. In our analysis, glass-forming liquids and glasses are described by only one structural order parameter. However, in contrast to previous approaches to the derivation of this ratio, the process of vitrification is treated not in terms of Simon's simplified model [Z. Anorg. Allg. Chem. 203, 219 (1931)] as a freezing-in process proceeding at some sharp temperature, the glass transition temperature Tg, but in some finite temperature interval accounting appropriately for the nonequilibrium character of vitrifying systems in this temperature range. As the result of the theoretical analysis, we find, in particular, that the Prigogine-Defay ratio generally has to have values larger than 1 for vitrification in cooling processes. Quantitative estimates of the Prigogine-Defay ratio are given utilizing a mean-field lattice-hole model of glass-forming melts. Some further consequences are derived concerning the behavior of thermodynamic coefficients, in particular, of Young's modulus in vitrification. The theoretical results are found to be in good agreement with experimental data.

Schmelzer, Jürn W. P.; Gutzow, Ivan

2006-11-01

329

The Prigogine-Defay ratio revisited.  

PubMed

One of the basic characteristics of the glass transition, the Prigogine-Defay ratio, connecting jumps of the thermal expansion coefficient, isothermal compressibility, and isobaric specific heat capacity in vitrification is rederived in the framework of the thermodynamics of irreversible processes employing the order-parameter concept introduced by de Donder and van Rysselberghe [Thermodynamic Theory of Affinity (Stanford University Press, Stanford, 1936)]. In our analysis, glass-forming liquids and glasses are described by only one structural order parameter. However, in contrast to previous approaches to the derivation of this ratio, the process of vitrification is treated not in terms of Simon's simplified model [Z. Anorg. Allg. Chem. 203, 219 (1931)] as a freezing-in process proceeding at some sharp temperature, the glass transition temperature T(g), but in some finite temperature interval accounting appropriately for the nonequilibrium character of vitrifying systems in this temperature range. As the result of the theoretical analysis, we find, in particular, that the Prigogine-Defay ratio generally has to have values larger than 1 for vitrification in cooling processes. Quantitative estimates of the Prigogine-Defay ratio are given utilizing a mean-field lattice-hole model of glass-forming melts. Some further consequences are derived concerning the behavior of thermodynamic coefficients, in particular, of Young's modulus in vitrification. The theoretical results are found to be in good agreement with experimental data. PMID:17115769

Schmelzer, Jürn W P; Gutzow, Ivan

2006-11-14

330

Do Credit Spreads Reflect Stationary Leverage Ratios?  

Microsoft Academic Search

Most structural models of default preclude the firm from altering its capital structure. In practice, firms adjust outstanding debt levels in response to changes in firm value, thus generating mean-reverting leverage ratios. We propose a structural model of default with stochastic interest rates that captures this mean reversion. Our model generates credit spreads that are larger for low-leverage firms, and

Pierre Collin-Dufresne; Robert S. Goldstein

2001-01-01

331

A Maximum Likelihood Ratio Information Retrieval Model  

Microsoft Academic Search

In this paper we present a novel probabilistic information retrieval model that scores documents based on the relative change in the doc- ument likelihoods, expressed as the ratio of the conditional probabil- ity of the document given the query and the prior probability of the document before the query is specified. The document likelihoods are computed using statistical language modeling

Ng Kenney

1999-01-01

332

Disproportionate sex ratios of wolf pups  

USGS Publications Warehouse

Males comprised 66 percent of wild wolf (Canis lupus) pups from a saturated, high-density wolf range in northeastern Minnesota, possibly reflecting disproportionate conception of males. Packs from areas of lower wolf density in other areas of Minnesota had equal sex ratios of pups or a disproportionate number of female pups. Captive wolves showed a slight preponderance of male pups.

Mech, L.D.

1975-01-01

333

Measuring Isotope Ratios Across the Solar System  

NASA Technical Reports Server (NTRS)

Stable isotope ratios in C, H, N, O and S are powerful indicators of a wide variety of planetary geophysical processes that can identify origin, transport, temperature history, radiation exposure, atmospheric escape, environmental habitability and biology [1]. For the Allan Hills 84001 meteorite, for example, the (sup 1)(sup 3)C/(sup 1)(sup 2)C ratio identifies it as a Mars (SNC) meteorite; the ??K/??Ar ratio tells us the last time the rock cooled to solid, namely 4 Gya; isotope ratios in (sup 3)He, (sup 2)(sup 1)Ne and (sup 3)?Ar show it was in space (cosmic ray exposure) for 10-20 million years; (sup 1)?C dating that it sat in Antarctica for 13,000 years before discovery; and clumped isotope analysis of (sup 1)?O(sup 1)(sup 3)C(sup 1)?O in its carbonate that it was formed at 18+/-4 ?C in a near-surface aqueous environment [2]. Solar System Formation

Webster, Chris R.; Mahaffy, Paul R.

2012-01-01

334

Dynamic Programming creates The Golden Ratio, too  

Microsoft Academic Search

Since ancient times of Greek as the Parthenon at Athens, the Golden Ratio has been keeping to give a profound influence in many various fields. Mathematicians love the number to explain the nature of the universe and of human life. It comes up even with a formula for the human de- cision making process; aesthetics, etc. Also in the typical

Seiichi Iwamoto; Masami Yasuda

335

Generalized golden ratios of ternary alphabets  

Microsoft Academic Search

Expansions in noninteger bases often appear in number theory and probability theory, and they are closely connected to ergodic theory, measure theory and topology. For two-letter alphabets the golden ratio plays a special role: in smaller bases only trivial expansions are unique, whereas in greater bases there exist nontrivial unique expansions. In this paper we determine the corresponding critical bases

Vilmos Komornik; Anna Chiara Lai; Marco Pedicini

2009-01-01

336

Amylase creatinine clearance ratio after biliary surgery  

Microsoft Academic Search

The amylase creatinine clearance ratio (ACCR) is considered to be a more sensitive index of acute pancreatitis than the serum amylase level. Serial ACCR estimations were undertaken in 25 patients undergoing an elective cholecystectomy. Using accepted criteria, 28% of these patients developed, in the postoperative period, biochemical evidence of pancreatic gland damage, although the serum amylase level remained normal. This

L A Donaldson; W McIntosh; S N Joffe

1977-01-01

337

Fission Product Ratios as Treaty Monitoring Discriminants  

SciTech Connect

The International Monitoring System (IMS) of the Comprehensive Test Ban Treaty Organization (CTBTO) is currently under construction. The IMS is intended for monitoring of nuclear explosions. The radionuclide branch of the IMS monitors the atmosphere for short-lived radioisotopes indicative of a nuclear weapon test, and includes field collection and measurement stations, as well as laboratories to provide reanalysis of the most important samples and a quality control function. The Pacific Northwest National Laboratory in Richland, Washington hosts the United States IMS laboratory, with the designation “RL16.” Since acute reactor containment failures and chronic reactor leakage may also produce similar isotopes, it is tempting to compute ratios of detected isotopes to determine the relevance of an event to the treaty or agreement in question. In this paper we will note several shortcomings of simple isotopic ratios: (1) fractionation of different chemical species, (2) difficulty in comparing isotopes within a single element, (3) the effect of unknown decay times. While these shortcomings will be shown in the light of an aerosol sample, several of the problems extend to xenon isotopic ratios. The result of the difficulties listed above is that considerable human expertise will be required to convert a simple mathematical ratio into a criterion which will reliably categorize an event as ‘reactor’ or ‘weapon’.

Miley, Harry S.; Bowyer, Ted W.; Greenwood, Lawrence R.; Arthur, Richard J.

2008-05-15

338

1998 Kemp's Ridley Sex Ratio Project.  

National Technical Information Service (NTIS)

During 1998, a multi-year study was initiated to implement state-of-the-art technology for monitoring hatching sex ratios in the Kemp's ridley recovery program.The Kemp's ridley, like all sea turtles, possesses temperature-dependent sex determination. Thi...

T. Wibbels

1998-01-01

339

Sex ratio evolution when fitness varies  

Microsoft Academic Search

The sex ratio favoured by natural selection is studied in a single-locus model of a random-mating population. The population inhabits a “patchy” (spatially heterogeneous) environment, and offspring reared in different patches have corresponding differences in fitness, depending on their sex. Thus, some patches produce the best males; these or other patches produce the best females. The mating pool is comprised

J J Bull

1981-01-01

340

Female-predominant sex ratios in angiosperms  

Microsoft Academic Search

A model is presented which expresses the seed production of dioecious and gynodioecious animal-pollinated Angiosperms in terms of the relative seed-fecundity of the sexes, the number of pollinator visits to each flower and the sex ratio. The model predicts that the maximum seed set occurs when females predominate, providing the pollinators visit each flower more than once and the seed

David G Lloyd

1974-01-01

341

Facultative sex ratio manipulation in American kestrels  

Microsoft Academic Search

For animals that are sexually dimorphic in size, the larger sex is expected to be more costly to raise to independence. Manipulating offspring sex ratios may thus be one means by which parents can fine-tune their reproductive effort to resource availability. Parents in poor physical condition or during poor food years should produce more of the cheaper (smaller) sex. We

Karen L. Wiebe; Gary R. Bortolotti

1992-01-01

342

Sex Ratio Manipulation and Selection for Attractiveness  

Microsoft Academic Search

Laboratory experiments performed on a monogamous estrildid, the zebra finch (Poephila guttata), indicate that sex ratio of offspring is affected by non-genetic markers (colored plastic leg bands) that vary in attractiveness to birds. Results suggest that natural selection favors individuals that produce offspring of the sex of the more attractive parent within a breeding pair.

Nancy Burley

1981-01-01

343

Centralized versus Decentralized Information Systems  

NASA Astrophysics Data System (ADS)

This paper brings into question whether information systems should be centralized or decentralized in order to provide greater support for different business processes. During the last century companies and organizations have used different approaches for centralization and decentralization; a simple answer to the question does not exist. This paper provides a survey of the evolution of centralized and decentralized approaches, mainly in a Nordic perspective. Based on critical reflections on the situation in the end of the century we can discuss what we can learn from history to achieve alignment between centralized and decentralized systems and the business structure. The conclusion is that theories, management and practice for decisions on centralization or decentralization of information systems must be improved. A conscious management and control of centralization /decentralization of IT support is a vital question in the company or the organization, and this is not a task that can be handled only by IT-specialists. There is a need for business oriented IT management of centralization/decentralization.

Hugoson, Mats-Åke

344

Asymmetric Lévy flight in financial ratios.  

PubMed

Because financial crises are characterized by dangerous rare events that occur more frequently than those predicted by models with finite variances, we investigate the underlying stochastic process generating these events. In the 1960s Mandelbrot [Mandelbrot B (1963) J Bus 36:394-419] and Fama [Fama EF (1965) J Bus 38:34-105] proposed a symmetric Lévy probability distribution function (PDF) to describe the stochastic properties of commodity changes and price changes. We find that an asymmetric Lévy PDF, L, characterized by infinite variance, models several multiple credit ratios used in financial accounting to quantify a firm's financial health, such as the Altman [Altman EI (1968) J Financ 23:589-609] Z score and the Zmijewski [Zmijewski ME (1984) J Accounting Res 22:59-82] score, and models changes of individual financial ratios, ?X(i). We thus find that Lévy PDFs describe both the static and dynamics of credit ratings. We find that for the majority of ratios, ?X(i) scales with the Lévy parameter ? ? 1, even though only a few of the individual ratios are characterized by a PDF with power-law tails X(i)(-1-?) with infinite variance. We also find that ? exhibits a striking stability over time. A key element in estimating credit losses is the distribution of credit rating changes, the functional form of which is unknown for alphabetical ratings. For continuous credit ratings, the Altman Z score, we find that P(?Z) follows a Lévy PDF with power-law exponent ? ? 1, consistent with changes of individual financial ratios. Estimating the conditional P(?Z|Z) versus Z, we demonstrate how this continuous credit rating approach and its dynamics can be used to evaluate credit risk. PMID:22006296

Podobnik, Boris; Valentin?i?, Aljoša; Horvati?, Davor; Stanley, H Eugene

2011-11-01

345

Focal ratio degradation in lightly fused hexabundles  

NASA Astrophysics Data System (ADS)

We are now moving into an era where multi-object wide-field surveys, which traditionally use single fibres to observe many targets simultaneously, can exploit compact integral field units (IFUs) in place of single fibres. Current multi-object integral field instruments such as Sydney-AAO Multi-object Integral field spectrograph have driven the development of new imaging fibre bundles (hexabundles) for multi-object spectrographs. We have characterized the performance of hexabundles with different cladding thicknesses and compared them to that of the same type of bare fibre, across the range of fill fractions and input f-ratios likely in an IFU instrument. Hexabundles with 7-cores and 61-cores were tested for focal ratio degradation (FRD), throughput and cross-talk when fed with inputs from F/3.4 to >F/8. The five 7-core bundles have cladding thickness ranging from 1 to 8 ?m, and the 61-core bundles have 5 ?m cladding. As expected, the FRD improves as the input focal ratio decreases. We find that the FRD and throughput of the cores in the hexabundles match the performance of single fibres of the same material at low input f-ratios. The performance results presented can be used to set a limit on the f-ratio of a system based on the maximum loss allowable for a planned instrument. Our results confirm that hexabundles are a successful alternative for fibre imaging devices for multi-object spectroscopy on wide-field telescopes and have prompted further development of hexabundle designs with hexagonal packing and square cores.

Bryant, J. J.; Bland-Hawthorn, J.; Fogarty, L. M. R.; Lawrence, J. S.; Croom, S. M.

2014-02-01

346

Combined central and peripheral demyelination.  

PubMed

Acquired central and peripheral demyelination in the same patient is a very rare feature. We report a 52-year-male patient with the chronic autoimmune hepatitis (CAH) presenting with pure motor areflexic quadriparesis from 4 months and recent onset of drowsiness of 4 days duration. Studies of imaging and electrophysiology suggested central pontine myelinolysis and chronic inflammatory demyelinating polyradiculoneuropathy. Patient was effectively treated with high dose steroids. To the best of our knowledge, this is the first case of central and peripheral demyelination in a patient with CAH. PMID:24741261

Menon, Bindu; Bedi, Saranjeet Singh; Rao, G Uma Maheshwar

2014-01-01

347

CASWW Central Asia Experts Directory  

NSDL National Science Digital Library

Provided by the Harvard Forum for Central Asian Studies, this site will prove useful to graduate students and scholars of Central Asia. The site was created to facilitate access for policy-makers, the press, and others to scholars with the appropriate expertise in Central Asian Studies. The Directory features those who have indicated their willingness to be contacted for expert consultations, and their listing will include a brief description of their qualifications. It organizes experts by name, topic, location, and under several headings: Politics and International Relations, Economy, Social Issues, and Cultural and Historical Background. The site is still soliciting experts for inclusion, and a link to the questionnaire is provided.

348

Prevalence of Low Birth Weight and Obesity in Central Iran  

ERIC Educational Resources Information Center

To estimate the prevalence of low birth weight (LBW) and to document distribution of body mass index (BMI) at birth in Arak (central Iran) neonates of the 10,241 live neonates (5241 boys, 5000 girls, sex ratio 105) born in 2004 in Arak. A birth weight of less than 2500 g was classified as LBW. BMI based on the original supine length and weight…

Rafiei, M.; Ayatollahi, S. M. T.

2008-01-01

349

The proton elastic form factor ratio µpG p E\\/G p M at low momentum transfer  

Microsoft Academic Search

High-precision measurements of the proton elastic form factor ratio, µpG p E\\/G p M , have been made at four-momentum transfer, Q2, values between 0.2 and 0.5 GeV2. The new data, while consistent with previous results, clearly show a ratio less than unity and si gnificant differences from the central values of several recent phenomenological fits. By combining the ne

G. Ron; J. Glister; B. Lee; K. Allada; W. Armstrong; J. Arrington; A. Beck; F. Benmokhtar; B. L. Berman; W. Boeglin; E. Brash; A. Camsonne; J. Calarco; Seonho Choi; E. Chudakov; L. Coman; B. Craver; F. Cusanno; J. Dumas; C. Dutta; R. Feuerbach; A. Freyberger; S. Frullani; F. Garibaldi; R. Gilman; D. W. Higinbotham; T. Holmstrom; C. E. Hyde; H. Ibrahim; Y. Ilieva; C. W. de Jager; H. Kang; A. Kelleher; E. Kuchina; G. Kumbartzki; J. J. LeRose; R. Lindgren; P. Markowitz; S. May-Tal Beck; E. McCullough; D. Meekins; M. Meziane; E. Meziani; R. Michaels; B. Moffit; B. E. Norum; M. Olson; M. Paolone; K. Paschke; C. F. Perdrisat; E. Piasetzky; M. Potokar; R. Pomatsalyuk; I. Pomerantz; A. Puckett; V. Punjabi; Y. Qiang; R. Ransome; M. Reyhan; J. Roche; Y. Rousseau; A. J. Sarty; B. Sawatzky; E. Schulte; M. Shabestari; A. Shahinyan; R. Shneor; K. Slifer; P. Solvignon; J. Song; R. Sparks; R. Subedi; S. Strauch; G. M. Urciuoli; K. Wang; B. Wojtsekhowski; X. Yan; H. Yao; X. Zhan; X. Zhu

350

Glycosaminoglycans of the porcine central nervous system†  

PubMed Central

Glycosaminoglycans (GAG) are known to participate in central nervous system processes such as development, cell migration, and neurite outgrowth. In this paper, we report an initial glycomics study on GAGs from porcine central nervous system. GAGs of the porcine central nervous system, brain and spinal cord, were isolated and purified by defating, proteolysis, anion-exchange chromatography and methanol precipitation. The isolated GAG content in brain was 5-times higher than in spinal cord (0.35 mg/g, compared to 0.07 mg/g dry sample). In both tissues, chondroitin sulfate (CS) and heparan sulfate (HS) were the major and the minor GAG. The average molecular weight of CS from brain and spinal cord was 35.5 and 47.1 kDa, respectively, and HS from brain and spinal cord was 56.9 and 34 kDa, respectively. The disaccharide analysis showed that the composition of CS from brain and spinal cords are similar with uronic acid (1?3) 4-O-sulfo-N-acetylgalactosamine residue corresponding to the major disaccharide unit (CS type-A) along with five minor disaccharide units. The major disaccharides of both brain and spinal cord HS were uronic acid (1?4) N-acetylglucosamine and uronic acid (1?4) 6-O-sulfo-N-sulfoglucosamine but their composition of minor disaccharides differed. Analysis by 1H- and two-dimensional-NMR spectroscopy confirmed these disaccharide analyses and provided the glucuronic/iduronic acid ratio. Finally, both purified CS and HS were biotinylated and immobilized on BIAcore SA biochips. Interactions between these GAGs and fibroblast growth factors (FGF1 and FGF2) and sonic hedgehog (Shh) were investigated by surface plasmon resonance.

Liu, Zhenling; Masuko, Sayaka; Solakyildirim, Kemal; Pu, Dennis; Linhardt, Robert J.; Zhang, Fuming

2010-01-01

351

Experimental Investigation of Lubrication Failure of Polyalphaolefin Oil Film at High Slide\\/Roll Ratios  

Microsoft Academic Search

Lubrication failure of polyalphaolefin (PAO) oil film at high slide\\/roll ratios of more than 1.9 has been experimentally investigated\\u000a based on a ball-on-disc configuration. The central film thickness and the oil pool shape in the contact were determined by\\u000a optical interferometry and fluorescence microscopy, respectively, and the traction coefficient and surface profiles of the\\u000a tribopairs were measured using a tension-compression

Shanhua Qian; Dan Guo; Shuhai Liu; Xinchun Lu

352

Study on Corporate Hereditary Central Dogma  

Microsoft Academic Search

Based on analyzing the central dogma of biology, this paper raises hypothesis, using the analogism method to set up the corporate hereditary central dogma. It analyzes the differences between the Corporate hereditary central dogma and the central dogma of biology, which explains the significance of research on Corporate hereditary central dogma; it discusses the meanings of all factors of Corporate

Li Xianbai

2010-01-01

353

Super Kitchen Centralizes Food Service  

ERIC Educational Resources Information Center

To centralize food service within the entire Pittsburgh school district, a 90,000-square-foot food service preparation building contains cranes and monorails to move 500-pound capacity vats throughout the kitchen. (Author/MLF)

Modern Schools, 1975

1975-01-01

354

Top Officials in Central Asia.  

National Technical Information Service (NTIS)

The primer on leaders in the Central Asian region (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan) provides biographic snapshots of key figures in each country. In addition, a directory of cabinet ministers, other leading officials, and ...

1992-01-01

355

Central Dogma of Molecular Biology  

Microsoft Academic Search

The central dogma of molecular biology deals with the detailed residue-by-residue transfer of sequential information. It states that such information cannot be transferred from protein to either protein or nucleic acid.

Francis Crick

1970-01-01

356

How Much Centralization is Enough?  

ERIC Educational Resources Information Center

A system for the statewide coordination of higher education that emphasizes centralized accountability and decentralized management should ensure that the concept of institutional autonomy is preserved. (Editor/PG)

Ketter, Robert L.

1975-01-01

357

Rainfall in West Central Africa.  

National Technical Information Service (NTIS)

An estimation of the relative importance of various factors to the rainfall in West Central Africa has been attempted. The factors considered were tropical waves, monsoon depressions, the position of the intertropical discontinuity (ITD) and the tropical ...

S. Mbele-Mbong

1974-01-01

358

Residential Abandonment in Central Cities.  

National Technical Information Service (NTIS)

The abandonment of residential properties in central cities is considered in this information bulletin prepared by the Urban Coalition. The coalition is a consortium of 34 urban governments working together with Federal officials and private industry to e...

1977-01-01

359

Central Valley Water Resource Study.  

National Technical Information Service (NTIS)

There is growing concern over water quality in the Central Valley of California, particularly in the Sacramento-San Joaquin Delta. Federal actions on both water quality standards and water project development are of major significance in future water mana...

1970-01-01

360

Central-Office Real Estate.  

ERIC Educational Resources Information Center

Describes how to upgrade a school district's central-office facilities without incurring taxpayer enmity. Includes case studies from Harford County, Maryland; Orange and Broward Counties, Florida; South Milwaukee, Wisconsin; Mt. Baker, Washington; Chicago, Illinois; and Rochester, New Hampshire. (PKP)

Pardini, Priscilla

2003-01-01

361

Geothermal Activities in Central America.  

National Technical Information Service (NTIS)

The Agency for International Development is funding a new program in energy and minerals for Central America. Geothermal energy is an important component. A country-wide geothermal assessment has started in Honduras, and other assessment activities are in...

J. T. Whetten R. J. Hanold

1985-01-01

362

Trinity Division: Central Valley Project.  

National Technical Information Service (NTIS)

The Central Valley Project (CVP) continued expanding in California after completion of the Project's initial features. The Trinity River Division was part of this expansion. California picked up on the idea for the Division from a Federal Power Commission...

E. A. Stene

1996-01-01

363

Solar Central Receiver Test Facility.  

National Technical Information Service (NTIS)

The world's largest high intensity solar experimental facility became fully operational October 1978. The Central Receiver Test Facility is capable of delivering 5 million watts of thermal power to experimental equipment. The primary CRTF testing programs...

G. E. Brandvold J. T. Holmes

1979-01-01

364

Tourism in East Central Florida.  

National Technical Information Service (NTIS)

This report summarizes a research effort to project tourism as an industry in East Central Florida and present such key planning factors as employment, population supported, retail sales, motel and restaurant data and total investment. The approach used i...

1969-01-01

365

Centrality Metric for Dynamic Networks  

Microsoft Academic Search

Centrality is an important notion in network analysis and is used to measure\\u000athe degree to which network structure contributes to the importance of a node\\u000ain a network. While many different centrality measures exist, most of them\\u000aapply to static networks. Most networks, on the other hand, are dynamic in\\u000anature, evolving over time through the addition or deletion

Kristina Lerman; Rumi Ghosh; Jeon Hyung Kang

2010-01-01

366

Central schemes and contact discontinuities  

Microsoft Academic Search

We introducé a family of new second-orcier Godunov-type central schemes for one-dimensio- nal Systems of conservation laws. They are a less dissipative generalization of the central-upwind schemes, proposed in (A. Kurganov et aL: submitted to SIAM J. Sci. Comput), whose construction is based on the maximal one-sided local speeds of propagation. We also present a recipe, which helps to improve

Alexander Kurganov; Guergana Petrova

2000-01-01

367

Leibniz superalgebras and central extensions  

Microsoft Academic Search

Dialgebras are generalizations of associative algebras which give rise to\\u000aLeibniz algebras instead of Lie algebras. In this paper we study super\\u000adialgebras and Leibniz superalgebras, which are $\\\\z_2$-graded dialgebras and\\u000aLeibniz algebras. We also study universal central extesions of Leibniz\\u000asuperalgebras and obtain some results as in the case of Lie superalgebras. We\\u000adetermine universal central extensions of basic

Dong Liu; Naihong Hu

2005-01-01

368

Non-stationary (13)C-metabolic flux ratio analysis.  

PubMed

(13)C-metabolic flux analysis ((13)C-MFA) has become a key method for metabolic engineering and systems biology. In the most common methodology, fluxes are calculated by global isotopomer balancing and iterative fitting to stationary (13)C-labeling data. This approach requires a closed carbon balance, long-lasting metabolic steady state, and the detection of (13)C-patterns in a large number of metabolites. These restrictions mostly reduced the application of (13)C-MFA to the central carbon metabolism of well-studied model organisms grown in minimal media with a single carbon source. Here we introduce non-stationary (13)C-metabolic flux ratio analysis as a novel method for (13)C-MFA to allow estimating local, relative fluxes from ultra-short (13)C-labeling experiments and without the need for global isotopomer balancing. The approach relies on the acquisition of non-stationary (13)C-labeling data exclusively for metabolites in the proximity of a node of converging fluxes and a local parameter estimation with a system of ordinary differential equations. We developed a generalized workflow that takes into account reaction types and the availability of mass spectrometric data on molecular ions or fragments for data processing, modeling, parameter and error estimation. We demonstrated the approach by analyzing three key nodes of converging fluxes in central metabolism of Bacillus subtilis. We obtained flux estimates that are in agreement with published results obtained from steady state experiments, but reduced the duration of the necessary (13)C-labeling experiment to less than a minute. These results show that our strategy enables to formally estimate relative pathway fluxes on extremely short time scale, neglecting cellular carbon balancing. Hence this approach paves the road to targeted (13)C-MFA in dynamic systems with multiple carbon sources and towards rich media. PMID:23860906

Hörl, Manuel; Schnidder, Julian; Sauer, Uwe; Zamboni, Nicola

2013-12-01

369

Low fineness ratio kinetic energy penetrators  

SciTech Connect

We have modeled the penetration process of a low fineness ratio, heavy metal kinetic energy projectile impacting a semi-infinite steel target at and above typical ordnance speeds using the Lawrence Livermore National Laboratory (LLNL) two-dimensional, finite difference code, GLO. We have also performed ballistic experiments using an LLNL two-stage light gas gun to gather data over a range of impact speeds from 2.0 to 7.5 km/s. On this basis, we have constructed relationships between penetration efficiency (total penetration/projectile length), projectile fineness ratio (projectile length/profile diameter), and projectile impact speed. Furthermore, we have constructed a three-dimensional surface of penetration efficiency for tungsten alloy projectiles impacting semi-infinite steel. From these constructions, it is straightforward to determine minimum kinetic energy requirements at a target for a prespecified level of penetration. 12 refs., 16 figs., 3 tabs.

Cline, C.F.; Gogolewski, R.P.; Reaugh, J.E.

1989-02-01

370

Econometric models for predicting confusion crop ratios  

NASA Technical Reports Server (NTRS)

Results for both the United States and Canada show that econometric models can provide estimates of confusion crop ratios that are more accurate than historical ratios. Whether these models can support the LACIE 90/90 accuracy criterion is uncertain. In the United States, experimenting with additional model formulations could provide improved methods models in some CRD's, particularly in winter wheat. Improved models may also be possible for the Canadian CD's. The more aggressive province/state models outperformed individual CD/CRD models. This result was expected partly because acreage statistics are based on sampling procedures, and the sampling precision declines from the province/state to the CD/CRD level. Declining sampling precision and the need to substitute province/state data for the CD/CRD data introduced measurement error into the CD/CRD models.

Umberger, D. E.; Proctor, M. H.; Clark, J. E.; Eisgruber, L. M.; Braschler, C. B. (principal investigators)

1979-01-01

371

The HNC/HCN ratio in comets.  

PubMed

The abundance ratio of the isomers HCN and HNC has been investigated in comet Hale-Bopp (C/1995 O1) through observations of the J = 4-3 rotational transitions of both species for heliocentric distances 0.93 < r < 3 AU, both pre- and post-perihelion. After correcting for the optical depth of the stronger HCN line, we find that the column density ratio of HNC/HCN in our telescope beam increases significantly as the comet approaches the Sun. We compare this behavior to that predicted from an ion-molecule chemical model and conclude that the HNC is produced in significant measure by chemical processes in the coma; i.e., for comet Hale-Bopp, HNC is not a parent molecule sublimating from the nucleus. PMID:11543322

Irvine, W M; Dickens, J E; Lovell, A J; Schloerb, F P; Senay, M; Bergin, E A; Jewitt, D; Matthews, H E

1997-01-01

372

First Order Ratio for Mid Symmetry Scale  

NASA Astrophysics Data System (ADS)

To see a way it is in far greater symmetry overall we key a toy Omega =1 universe to the maximum integral submultiple least integer ratio where onehalf the maximum (delta rho )/(rho ) wavelength has the value slantfrac {1}{8} asymmetry at onehalf R_s system radius. A tacit transpose scaling basis: X(3) _{1- SCALE 1 to 0} = Y_{1- SYMMETRY 1 to 0} wherein symmetry degenerates exponentially proportional and asymptotic to linear lower scale rectifies the above and another point. It is where the value of symmetry crosses onehalf : 1-(3) surd onehalf R_s. A harmonic expansion is tuned to allow the state to occur and refer on in forming a (Doroshkevich 1970) collapse redshift probability distribution function. The function, in a sense, may act as an age ordinal field where the ratio above can trace through the dimension of trans relativistic perspective in phase-space, discrete time series.

von Gronefeld, P.

1996-12-01

373

Measuring Abundance Ratios from Integrated Light  

NASA Astrophysics Data System (ADS)

Age, overall abundance, and detailed, element-by-element abundances can be extracted from the integrated light of distant galaxies. The method, at its most basic, is merely the comparison of observed spectra with appropriate models. The relative ratios of elements C, N, O, Na, Mg, Ca, Sc, Ti, Cr, Mn, Fe, Co, Ni, Sr, and Ba can be determined to scientifically useful precision. Cases of interest that are borderline because they suffer internal degeneracies (although plenty of signal is present) are Al and the trio C, N, and O. The elements S, K, Cu, Eu, and the noble gases are too difficult to measure, and V is borderline. Changing the relative abundance ratios, even at fixed heavy-element content, changes the temperatures, luminosities, and number densities of the underlying stellar evolution, as well as more direct changes in the spectra of the stars present. The latter effects dominate the spectral shape, while the former effects render age estimation quite difficult.

Worthey, G.

2010-06-01

374

Mixing Ratios or Parts per Million, Billion  

NSDL National Science Digital Library

In this activity, students will gain experience with very small amounts, known as mixing ratios, using the technique of serial dilution. Measurements such as parts per million can be expressed in terms of volume or mass. With gases in the atmosphere, we usually think in terms of volume and may express this as parts per million by volume (ppmv). One can also use the units parts per billion by volume (ppbv), and parts per trillion by volume (pptv). Measurements such as ppmv, ppbv, and pptv are called mixing ratios. The student guide has an overall description of the activity, a list of materials, the procedure, and observations and questions. The teacher's guide contains detailed background material, learning goals, alignment to national standards, grade level/time, details on materials and preparation, procedure, assessment ideas, and modifications for alternative learners.

375

Measurements of crustal thickness and Poisson's ratio in southeastern Tibet from receiver functions  

NASA Astrophysics Data System (ADS)

In this study we present new measurements of crustal thickness and Poisson's ratios for southeastern Tibet extending east from Lhasa across the eastern syntaxis. The syntaxis is characterized by the end of Himalayan orogen and the start of `escape' tectonics, as material is extruded from the central plateau and rotates around the corner of the Indian plate indentor. Depth to Moho and determination of Poisson's ratio were made by measuring the travel times of direct and multiple P to S converted phases from the Moho and solving jointly for depth and Poisson's ratio assuming a crustal average Vp of 6.4 km/s. The depth to Moho ranged in value from 55 to 75 km below sea level. These depth measurements can be divided into two regions, a moderately uniform, deep Moho, extending from the central plateau toward the eastern margin and a higher relief, shallower Moho within the core of the syntaxis. Poisson's ratio ranged from 0.21 to 0.29. These measurements can be divided into three regions, fairly homogenous low to intermediate values within the central plateau, predominantly low to intermediate values but localized high values (0.29) within the eastern margin, and a wide range of values (0.21-0.29) over short scale lengths within the central syntaxis. No correlation is seen between Poisson's ratio and depth to Moho. The predominantly low to intermediate Poisson's ratios are indicative of a crust that is relatively felsic in composition compared to "average" continental crust. The lack of consistent high Poisson's ratio means there is no evidence for widespread partial melt within the crust, but does not rule out the presence of at least localized pockets of melt. To see if the depth of the Moho correlates with the surface topography correlation analysis was preformed with the surface topography smoothed over a range of 20-400 km. The best correlation occurs (r=0.75) when the surface topography is smoothed to 180km. This correlation can not however be explained by simple Airy Isostasy alone, it requires at least in part another mechanism controlling the thickness of the crust in this region. Such mechanisms could be variations in density or rheology within the lithosphere or for the region to be out of isostatic equilibrium.

Zurek, B. D.; Meltzer, A.; Sol, S.; Zhang, X.; Zhang, J.

2005-12-01

376

The quantity and duration of FcR signals determine mast cell degranulation and survival  

Microsoft Academic Search

Immunoglobulin E (IgE) bound to multiva- lent antigen (Ag) elicits mast cell degranu- lation but not survival; on the contrary, IgE in the absence of Ag (IgE(-Ag)) in- duces survival only but not degranula- tion. Although these distinct responses are mediated through the same receptor, FcRI, the molecular mechanism generat- ing the divergence is largely unknown. We recently showed that

Sho Yamasaki; Eri Ishikawa; Masayuki Kohno; Takashi Saito

2004-01-01

377

Nucleoprotein-specific nonneutralizing antibodies speed up LCMV elimination independently of complement and Fc?R.  

PubMed

CD8(+) T cells have an essential role in controlling lymphocytic choriomeningitis virus (LCMV) infection in mice. Here, we examined the contribution of humoral immunity, including nonneutralizing antibodies (Abs), in this infection induced by low virus inoculation doses. Mice with impaired humoral immunity readily terminated infection with the slowly replicating LCMV strain Armstrong but showed delayed virus elimination after inoculation with the faster replicating LCMV strain WE and failed to clear the rapidly replicating LCMV strain Docile, which is in contrast to the results obtained with wild-type mice. Thus, the requirement for adaptive humoral immunity to control the infection was dependent on the replication speed of the LCMV strains used. Ab transfers further showed that LCMV-specific IgG Abs isolated from LCMV immune serum accelerated virus elimination. These Abs were mainly directed against the viral nucleoprotein (NP) and completely lacked virus neutralizing activity. Moreover, mAbs specific for the LCMV NP were also able to decrease viral titers after transfer into infected hosts. Intriguingly, neither C3 nor Fc? receptors were required for the antiviral activity of the transferred Abs. In conclusion, our study suggests that rapidly generated nonneutralizing Abs specific for the viral NP speed up virus elimination and thereby may counteract T-cell exhaustion. PMID:23749409

Straub, Tobias; Schweier, Oliver; Bruns, Michael; Nimmerjahn, Falk; Waisman, Ari; Pircher, Hanspeter

2013-09-01

378

Compression ratio control in reciprocating piston engines  

Microsoft Academic Search

The patent describes compression ratio control for reciprocating piston engines. It comprises: a reciprocating engine crankcase; a plurality of compression\\/expansion cylinders rigidly attached to the crankcase; each of the cylinders including a curved surface and a cylinder head; a fuel mixture in-taken in the cylinders; a piston reciprocating along each cylinder's curved surface for providing compression\\/expansion to the fuel mixture;

Doundoulakis

1989-01-01

379

Factors affecting the aldosterone/renin ratio.  

PubMed

Although the aldosterone/renin ratio (ARR) is the most reliable screening test for primary aldo-steronism, false positives and negatives occur. Dietary salt restriction, concomitant malignant or renovascular hypertension, pregnancy and treatment with diuretics (including spironolactone), dihydropyridine calcium blockers, angiotensin converting enzyme inhibitors, and angiotensin receptor antagonists can produce false negatives by stimulating renin. We recently reported selective serotonin reuptake inhibitors lower the ratio. Because potassium regulates aldosterone, uncorrected hypokalemia can lead to false negatives. Beta-blockers, alpha-methyldopa, clonidine, and nonsteroidal anti-inflammatory drugs suppress renin, raising the ARR with potential for false positives. False positives may occur in patients with renal dysfunction or advancing age. We recently showed that (1) females have higher ratios than males, and (2) false positive ratios can occur during the luteal menstrual phase and while taking an oral ethynylestradiol/drospirenone (but not implanted subdermal etonogestrel) contraceptive, but only if calculated using direct renin concentration and not plasma renin activity. Where feasible, diuretics should be ceased at least 6 weeks and other interfering medications at least 2 before ARR measurement, substituting noninterfering agents (e. g., verapamil slow-release±hydralazine and prazosin or doxazosin) were required. Hypokalemia should be corrected and a liberal salt diet encouraged. Collecting blood midmorning from seated patients following 2-4 h upright posture improves sensitivity. The ARR is a screening test only and should be repeated once or more before deciding whether to proceed to confirmatory suppression testing. Liquid chromatography-tandem mass spectrometry aldosterone assays represent a major advance towards addressing inaccuracies inherent in other available methods. PMID:22147655

Stowasser, M; Ahmed, A H; Pimenta, E; Taylor, P J; Gordon, R D

2012-03-01

380

Compression ratio effect on methane HCCI combustion  

Microsoft Academic Search

The authors have used the HCT (hydrodynamics, chemistry, and transport) chemical kinetics code to simulate HCCI (homogeneous charge compression ignition) combustion of methane-air mixtures. HCT is applied to explore the ignition timing, burn duration, NO{sub X}production, gross indicated efficiency and gross IMEP of a supercharged engine (3 atm. intake pressure) with 14:1, 16:1 and 18:1 compression ratios at 1200 rpm.

S. M. Aceves; J. R. Smith; C. K. Westbrook; W. J. Pitz

1999-01-01

381

Compression ratio effect on methane HCCI combustion  

Microsoft Academic Search

We have used the HCT (Hydrodynamics, Chemistry and Transport) chemical kinetics code to simulate HCCI (homogeneous charge compression ignition) combustion of methane-air mixtures. HCT is applied to explore the ignition timing, bum duration, NOx<\\/sub> production, gross indicated efficiency and gross IMEP of a supercharged engine (3 atm. Intake pressure) with 14:1, 16:l and 18:1 compression ratios at 1200 rpm. HCT

S. M. Aceves; W. Pitz; J. R. Smith; C. Westbrook

1998-01-01

382

Low fineness ratio kinetic energy penetrators  

Microsoft Academic Search

We have modeled the penetration process of a low fineness ratio, heavy metal kinetic energy projectile impacting a semi-infinite steel target at and above typical ordnance speeds using the Lawrence Livermore National Laboratory (LLNL) two-dimensional, finite difference code, GLO. We have also performed ballistic experiments using an LLNL two-stage light gas gun to gather data over a range of impact

C. F. Cline; R. P. Gogolewski; J. E. Reaugh

1989-01-01

383

Golden ratio prediction for solar neutrino mixing  

Microsoft Academic Search

We present a simple texture that predicts the cotangent of the solar neutrino mixing angle to be equal to the golden ratio. This prediction is 1.4sigma below the present best-fit value and final SNO and KamLAND data could discriminate it from tri-bimaximal mixing. The neutrino mass matrix is invariant under a Z2?Z2' symmetry: that geometrically is a reflection along the

Yuji Kajiyama; Martti Raidal; Alessandro Strumia

2007-01-01

384

The golden ratio in special relativity  

Microsoft Academic Search

In this note we show that Euclid’s construction of the golden rectangle can be used to derive both the dilation of time intervals and the Lorentz contraction of lengths as predicted by Einstein’s theory of special relativity. In this simple exercise, the Lorentz factor arises as a direct consequence of the Pythagorean theorem, while the golden ratio, ?=1+5\\/2, is found

Leonardo Di G. Sigalotti; Antonio Mejias

2006-01-01

385

Directed Percolation and the Golden Ratio  

Microsoft Academic Search

Applying the theory of Yang-Lee zeros to nonequilibrium critical phenomena,\\u000awe investigate the properties of a directed bond percolation process for a\\u000acomplex percolation parameter p. It is shown that for the Golden Ratio\\u000ap=(1(+\\/-)sqrt(5))\\/2 and for p=2 the survival probability of a cluster can be\\u000acomputed exactly.

Stephan M Dammer; Silvio R Dahmen; Haye Hinrichsenk

2001-01-01

386

Golden ratio prediction for solar neutrino mixing  

Microsoft Academic Search

It has recently been speculated that the solar neutrino mixing angle is connected to the golden ratio phiv. Two such proposals have been made, cot theta12=phiv and cos theta12=phiv\\/2. We compare these ansätze and discuss a model leading to cos theta12=phiv\\/2 based on the dihedral group D10. This symmetry is a natural candidate because the angle in the expression cos

Adisorn Adulpravitchai; Alexander Blum; Werner Rodejohann

2009-01-01

387

Omniclassical Diffusion in Low Aspect Ratio Tokamaks  

SciTech Connect

Recently reported numerical results for axisymmetric devices with low aspect ratio A found radial transport enhanced over the expected neoclassical value by a factor of 2 to 3. In this paper, we provide an explanation for this enhancement. Transport theory in toroidal devices usually assumes large A, and that the ratio B{sub p}/B{sub t} of the poloidal to the toroidal magnetic field is small. These assumptions result in transport which, in the low collision limit, is dominated by banana orbits, giving the largest collisionless excursion of a particle from an initial flux surface. However in a small aspect ratio device one may have B{sub p}/B{sub t} {approx} 1, and the gyroradius may be larger than the banana excursion. Here, we develop an approximate analytic transport theory valid for devices with arbitrary A. For low A, we find that the enhanced transport, referred to as omniclassical, is a combination of neoclassical and properly generalized classical effects, which become dominant in the low-A, B{sub p}/B{sub t} {approx} 1 regime. Good agreement of the analytic theory with numerical simulations is obtained.

H.E. Mynick; R.B. White; D.A. Gates

2004-03-19

388

Carbon Isotope Abundance Ratios in Comets  

NASA Astrophysics Data System (ADS)

High resolution (lambda /Delta lambda ~ 10(5) ) spectra of the CN B-X (0-0) band at 3883 Angstroms have been obtained of four comets using the Mt. Stromlo 1.8-m telescope echelle spectrograph. The resolution and the S/N ratios of the spectra are of sufficient quality that (13) C(14) N lines have been identified in two of the comets. A fluorescence equilibrium model has been developed to compute the rotational line populations in the four lowest vibrational levels of the ground electronic state of the CN B-X (0-0) band. Line fluorescence efficiencies and rotational line intensities for all isotopic combinations of (12) C, (13) C, (14) N and (15) N have been computed for a range in heliocentric velocites. The computed CN spectra generated at the observed resolution are compared with the observations, and (12) C/(13) C ratios are derived. We show for the first time that collisions in the inner coma significantly affect the rotational line populations in the lowest vibrational levels of the ground electronic state. We find that the carbon isotope ratios are consistent with terrestrial values in all four comets.

Kleine, M.; Wyckoff, S.; Wehinger, P. A.; Peterson, B.

1992-12-01

389

Isotopic abundance ratios in interstellar carbon monosulfide  

SciTech Connect

A survey of the relative abundances of the isotopic species, /sup 12/C/sup 32/S, /sup 12/C/sup 34/S, and /sup 13/C/sup 32/S has been made in 14 dense molecular clouds through observations of the J=3-1 rotational transitions at 3 mm. The abundance ratio, (/sup 13/C/sup 32/S)/(/sup 12/C/sup 34/S), is found to be 1.9 times greater in the galactic center sources than in the galactic disk sources. The average ratio for the galactic disk sources is 0.35 +- 0.10 where the quoted error is the rms of the source-to-source fluctuations. The average disk value for (/sup 13/C)/(/sup 12/C) is 0.015, if (/sup 32/S)/(/sup 34/S) is terrestrial. No evidence is found for a systematic variation of the ratio within the disk itself. Terrestrial sulfur abundances would imply that either the observations in CS are spatially unresolved or the kinetic temperature for CS is lower than that for CO. Beam dilution factors are derived for the sources studied. In addition, values for the molecular hydrogen densities and CS fractional abundances are obtained for these sources.

Frerking, M.A.; Wilson, R.W.; Linke, R.A.; Wannier, P.G.

1980-08-15

390

Activity ratios of thorium daughters in vivo  

SciTech Connect

A computerized method of least squares has been used to analyze the /sup 228/Ac and /sup 212/Pb-/sup 212/Bi and daughter ..gamma..-ray spectra obtained in vivo from 133 former workers at a thorium refinery. In addition, the exhalation rate of /sup 220/Rn was determined for each subject and expressed as pCi of emanating /sup 224/Ra. This value was added to the /sup 212/Pb value determined from the ..gamma..-ray measurements to obtain the total /sup 224/Ra present, and the ratio of /sup 224/Ra to /sup 228/Ac was calculated. Values of the ratio ranged from 0.52 +- 0.32 to 2.1 +- 1.7, with a weighted mean of 0.92 +- 0.17. However, it appears that the ratio observed in a given case is characteristic for that case alone; the computed mean value may not be meaningful. The least squares fitting procedure and the overall calibration of the counting system were validated by measurements of /sup 224/Ra in the lungs of one subject postmortem, compared with results obtained from the same subject in vivo. 6 references, 5 figures.

Toohey, R.E.; Rundo, J.; Sha, J.Y.; Essling, M.A.; Pedersen, J.C.; Slane, J.M.

1984-01-01

391

Noise of Embedded High Aspect Ratio Nozzles  

NASA Technical Reports Server (NTRS)

A family of high aspect ratio nozzles were designed to provide a parametric database of canonical embedded propulsion concepts. Nozzle throat geometries with aspect ratios of 2:1, 4:1, and 8:1 were chosen, all with convergent nozzle areas. The transition from the typical round duct to the rectangular nozzle was designed very carefully to produce a flow at the nozzle exit that was uniform and free from swirl. Once the basic rectangular nozzles were designed, external features common to embedded propulsion systems were added: extended lower lip (a.k.a. bevel, aft deck), differing sidewalls, and chevrons. For the latter detailed Reynolds-averaged Navier-Stokes (RANS) computational fluid dynamics (CFD) simulations were made to predict the thrust performance and to optimize parameters such as bevel length, and chevron penetration and azimuthal curvature. Seventeen of these nozzles were fabricated at a scale providing a 2.13 inch diameter equivalent area throat." ! The seventeen nozzles were tested for far-field noise and a few data were presented here on the effect of aspect ratio, bevel length, and chevron count and penetration. The sound field of the 2:1 aspect ratio rectangular jet was very nearly axisymmetric, but the 4:1 and 8:1 were not, the noise on their minor axes being louder than the major axes. Adding bevel length increased the noise of these nozzles, especially on their minor axes, both toward the long and short sides of the beveled nozzle. Chevrons were only added to the 2:1 rectangular jet. Adding 4 chevrons per wide side produced some decrease at aft angles, but increased the high frequency noise at right angles to the jet flow. This trend increased with increasing chevron penetration. Doubling the number of chevrons while maintaining their penetration decreased these effects. Empirical models of the parametric effect of these nozzles were constructed and quantify the trends stated above." Because it is the objective of the Supersonics Project that future design work be done more by physics-based computations and less by experiments, several codes under development were evaluated against these test cases. Preliminary results show that the RANS-based code JeNo predicts the spectral directivity of the low aspect ratio jets well, but has no capability to predict the non-axisymmetry. An effort to address this limitations, used in the RANS-based code of Leib and Goldstein, overpredicted the impact of aspect ratio. The broadband shock noise code RISN, also limited to axisymmetric assumptions, did a good job of predicting the spectral directivity of underexpanded 2:1 cold jet case but was not as successful on high aspect ratio jets, particularly when they are hot. All results are preliminary because the underlying CFD has not been validated yet. An effort using a Large Eddy Simulation code by Stanford University predicted noise that agreed with experiments to within a few dB.

Bridges, James E.

2011-01-01

392

Variation of equivalence ratio and element ratios in low-pressure premixed flames of aliphatic fuels  

SciTech Connect

In previously published work it was found that the element ratios (such as C/O, H/O, H/C) and the equivalence ratio all varied in the flame zone of a low-pressure premixed fuel-rich benzene/oxygen/argon laminar flat flame. These variations were seen from analyses of both the data and detailed kinetic modeling. In the present work, seven additional flames were analyzed in the same manner, including five flames with a single hydrocarbon fuel (methane, acetylene, ethylene, allene, and propene) and two flames with a mixture of fuels (acetylene/allene, hydrogen/allene). All the flames had argon as the diluent, with pressures between 20 and 37.5 Torr, equivalence ratios between 1.6 and 2.5, cold gas velocities between 42 and 126 cm/sec. All of these flames showed variations in the element ratios and equivalence ratios. Furthermore, these variations changed in a consistent pattern with respect to the molecular weight of the fuel. In the flame zone, the percent change in the H/O, C/O and equivalence ratios increased with increasing molecular weight of the fuel, except for the hydrogen/allene flame in which the C/O ratio first increases, then decreases in the flame zone. Also, unlike all the other hydrocarbon flames, the C/O ratio decreases below its inlet value for the methane flame. The H/O and equivalence ratios decrease below their inlet values for the hydrogen/allene flame. These results are explained in terms of differential diffusion effects between the products and the reactants, which increase as the fuel becomes increasingly heavier than the major carbon- and hydrogen-containing products.

C. J. Pope; J. A. Miller

2000-03-14

393

Genetics Home Reference: Central core disease  

MedlinePLUS

... Recent literature OMIM Genetic disorder catalog Conditions > Central core disease On this page: Description Genetic changes Inheritance ... Glossary definitions Reviewed October 2007 What is central core disease? Central core disease is a disorder that ...

394

The Proton Elastic Form Factor Ratio mu(p) G**p(E)/G**p(M) at Low Momentum Transfer  

SciTech Connect

High precision measurements of the proton elastic form factor ratio have been made at four-momentum transfers, Q^2, between 0.2 and 0.5 GeV^2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q^2 range the deviation from unity is primarily due to GEp being smaller than the dipole parameterization.

G. Ron; J. Glister; B. Lee; K. Allada; W. Armstrong; J. Arrington; A. Beck; F. Benmokhtar; B.L. Berman; W. Boeglin; E. Brash; A. Camsonne; J. Calarco; J. P. Chen; Seonho Choi; E. Chudakov; L. Coman; B. Craver; F. Cusanno; J. Dumas; C. Dutta; R. Feuerbach; A. Freyberger; S. Frullani; F. Garibaldi; R. Gilman; O. Hansen; D. W. Higinbotham; T. Holmstrom; C.E. Hyde; H. Ibrahim; Y. Ilieva; C. W. de Jager; X. Jiang; M. K. Jones; A. Kelleher; E. Khrosinkova; E. Kuchina; G. Kumbartzki; J. J. LeRose; R. Lindgren; P. Markowitz; S. May-Tal Beck; E. McCullough; D. Meekins; M. Meziane; Z.-E. Meziani; R. Michaels; B. Moffit; B.E. Norum; Y. Oh; M. Olson; M. Paolone; K. Paschke; C. F. Perdrisat; E. Piasetzky; M. Potokar; R. Pomatsalyuk; I. Pomerantz; A. Puckett; V. Punjabi; X. Qian; Y. Qiang; R. Ransome; M. Reyhan; J. Roche; Y. Rousseau; A. Saha; A.J. Sarty; B. Sawatzky; E. Schulte; M. Shabestari; A. Shahinyan; R. Shneor; S. ? Sirca; K. Slifer; P. Solvignon; J. Song; R. Sparks; R. Subedi; S. Strauch; G. M. Urciuoli; K. Wang; B. Wojtsekhowski; X. Yan; H. Yao; X. Zhan; X. Zhu

2007-11-01

395

Near infrared hydrogen emission line ratios as diagnostics of the broad emission line region  

NASA Astrophysics Data System (ADS)

Broad emission line flux ratios are a powerful diagnostic of the physical conditions of the broad-line region gas in Active Galactic Nuclei. With recent advances in infrared spectroscopy, previously unstudied emission lines provide a new means to investigate the physical nature of the BELR gas. The hydrogen emission lines are particularly sensitive to the upper limits of both the radius from the central ionising source and the number density of the gas. Using an existing subset of near-infrared quasar spectra from the Glikman et al. (2006) sample [1] together with Cloudy photoionization simulations, we confirm the Locally Optimally emitting Cloud (LOC) model's ability to reproduce observed emission line flux ratios. The model is then used to constrain physical conditions for individual sources. The photoionization models show that high number density, low incident flux gas is required to reproduce observed near-infrared hydrogen emission line ratios. We also find that comparison to individual sources, rather than composites, is vital.

Ruff, Andrea J.; Floyd, David J. E.; Korista, Kirk T.; Webster, Rachel L.; Porter, Ryan L.; Ferland, Gary J.

2012-07-01

396

Co-composting of green waste and food waste at low C/N ratio  

SciTech Connect

In this study, co-composting of food waste and green waste at low initial carbon to nitrogen (C/N) ratios was investigated using an in-vessel lab-scale composting reactor. The central composite design (CCD) and response surface method (RSM) were applied to obtain the optimal operating conditions over a range of preselected moisture contents (45-75%) and C/N ratios (13.9-19.6). The results indicate that the optimal moisture content for co-composting of food waste and green waste is 60%, and the substrate at a C/N ratio of 19.6 can be decomposed effectively to reduce 33% of total volatile solids (TVS) in 12 days. The TVS reduction can be modeled by using a second-order equation with a good fit. In addition, the compost passes the standard germination index of white radish seed indicating that it can be used as soil amendment.

Kumar, Mathava; Ou, Y.-L. [Institute of Environmental Engineering, National Chiao Tung University, 1001, University Road, Hsinchu City 30010, Taiwan (China); Lin, J.-G., E-mail: jglin@mail.nctu.edu.t [Institute of Environmental Engineering, National Chiao Tung University, 1001, University Road, Hsinchu City 30010, Taiwan (China)

2010-04-15

397

Centralization or decentralization of facial structures in Korean young adults.  

PubMed

It is well known that facial beauty is dictated by facial type, and harmony between the eyes, nose, and mouth. Furthermore, facial impression is judged according to the overall facial contour and the relationship between the facial structures. The aims of the present study were to determine the optimal criteria for the assessment of gathering or separation of the facial structures and to define standardized ratios for centralization or decentralization of the facial structures.Four different lengths were measured, and 2 indexes were calculated from standardized photographs of 551 volunteers. Centralization and decentralization were assessed using the width index (interpupillary distance / facial width) and height index (eyes-mouth distance / facial height). The mean ranges of the width index and height index were 42.0 to 45.0 and 36.0 to 39.0, respectively. The width index did not differ with sex, but males had more decentralized faces, and females had more centralized faces, vertically. The incidence rate of decentralized faces among the men was 30.3%, and that of centralized faces among the women was 25.2%.The mean ranges in width and height indexes have been determined in a Korean population. Faces with width and height index scores under and over the median ranges are determined to be "centralized" and "decentralized," respectively. PMID:23714934

Yoo, Ja-Young; Kim, Jeong-Nam; Shin, Kang-Jae; Kim, Soon-Heum; Choi, Hyun-Gon; Jeon, Hyun-Soo; Koh, Ki-Seok; Song, Wu-Chul

2013-05-01

398

On auroral electron precipitation and colour ratios  

NASA Astrophysics Data System (ADS)

Auroral electron precipitation spectra can be retrieved from several complementary techniques, either ground-based or satellite. They include for example inversions of electron density profiles (measured for instance by incoherent scatter radars, IS), inversions of volume emission rate profiles (optical instruments), and the use of multi-spectral imaging in combination with ionospheric modelling (optical emission ratios). This study investigates several well-known colour ratios in discrete aurorae at Earth, such as N2+ 391.4 nm / 427.8 nm or O2+ 5620 / OI 777.4 nm, in order to determine the uncertainties of these inversion techniques. Their theoretical dependence to parameters such as the neutral atmosphere, the electron precipitation distribution and the cross section is presented. In a second step, comparison of these simulations with real data is proposed. The multi-spectral multi-station Auroral Large Imaging System (ALIS) was operated in March 2008 in Northern Scandinavia during a joint campaign with the EISCAT UHF radar in Tromso. Colour ratios, such as OI 844.6 nm / N2+ 427.8 nm and OI 630.0 nm / N2+ 427.8 nm, observed nearly simultaneously, are extracted and give access to the characteristic energy of the precipitation. They are shown to be consistent with electron spectra retrieved by IS radar. Perspectives are given for planetary studies, for which a global view of electron precipitation mechanisms and their impact on the atmosphere is needed to complement the limited number of observations and instruments aboard planetary space missions.

Simon Wedlund, C.; Gronoff, G.; Mertens, C. J.; Lamy, H.; Gustavsson, B.

2012-12-01

399

Network Centrality of Metro Systems  

PubMed Central

Whilst being hailed as the remedy to the world’s ills, cities will need to adapt in the 21st century. In particular, the role of public transport is likely to increase significantly, and new methods and technics to better plan transit systems are in dire need. This paper examines one fundamental aspect of transit: network centrality. By applying the notion of betweenness centrality to 28 worldwide metro systems, the main goal of this paper is to study the emergence of global trends in the evolution of centrality with network size and examine several individual systems in more detail. Betweenness was notably found to consistently become more evenly distributed with size (i.e. no “winner takes all”) unlike other complex network properties. Two distinct regimes were also observed that are representative of their structure. Moreover, the share of betweenness was found to decrease in a power law with size (with exponent 1 for the average node), but the share of most central nodes decreases much slower than least central nodes (0.87 vs. 2.48). Finally the betweenness of individual stations in several systems were examined, which can be useful to locate stations where passengers can be redistributed to relieve pressure from overcrowded stations. Overall, this study offers significant insights that can help planners in their task to design the systems of tomorrow, and similar undertakings can easily be imagined to other urban infrastructure systems (e.g., electricity grid, water/wastewater system, etc.) to develop more sustainable cities.

Derrible, Sybil

2012-01-01

400

Network centrality of metro systems.  

PubMed

Whilst being hailed as the remedy to the world's ills, cities will need to adapt in the 21(st) century. In particular, the role of public transport is likely to increase significantly, and new methods and technics to better plan transit systems are in dire need. This paper examines one fundamental aspect of transit: network centrality. By applying the notion of betweenness centrality to 28 worldwide metro systems, the main goal of this paper is to study the emergence of global trends in the evolution of centrality with network size and examine several individual systems in more detail. Betweenness was notably found to consistently become more evenly distributed with size (i.e. no "winner takes all") unlike other complex network properties. Two distinct regimes were also observed that are representative of their structure. Moreover, the share of betweenness was found to decrease in a power law with size (with exponent 1 for the average node), but the share of most central nodes decreases much slower than least central nodes (0.87 vs. 2.48). Finally the betweenness of individual stations in several systems were examined, which can be useful to locate stations where passengers can be redistributed to relieve pressure from overcrowded stations. Overall, this study offers significant insights that can help planners in their task to design the systems of tomorrow, and similar undertakings can easily be imagined to other urban infrastructure systems (e.g., electricity grid, water/wastewater system, etc.) to develop more sustainable cities. PMID:22792373

Derrible, Sybil

2012-01-01

401

Sex Ratios at Birth and Environmental Temperatures  

NASA Astrophysics Data System (ADS)

The relationship between average monthly air temperature and sex ratios at birth (SRB) was analyzed for children born in Germany during the period 1946-1995. Both the absolute temperature and - more markedly - the monthly temperature deviations from the overall mean were significantly positively correlated with the SRB (P<0.01) when temperatures were time-lagged against the SRB data by -10 or -11months. It is concluded that the sex of the offspring is partially determined by environmental temperatures prior to conception.

Lerchl, Alexander

402

Implications of Fast Reactor Transuranic Conversion Ratio  

SciTech Connect

Theoretically, the transuranic conversion ratio (CR), i.e. the transuranic production divided by transuranic destruction, in a fast reactor can range from near zero to about 1.9, which is the average neutron yield from Pu239 minus 1. In practice, the possible range will be somewhat less. We have studied the implications of transuranic conversion ratio of 0.0 to 1.7 using the fresh and discharge fuel compositions calculated elsewhere. The corresponding fissile breeding ratio ranges from 0.2 to 1.6. The cases below CR=1 (“burners”) do not have blankets; the cases above CR=1 (“breeders”) have breeding blankets. The burnup was allowed to float while holding the maximum fluence to the cladding constant. We graph the fuel burnup and composition change. As a function of transuranic conversion ratio, we calculate and graph the heat, gamma, and neutron emission of fresh fuel; whether the material is “attractive” for direct weapon use using published criteria; the uranium utilization and rate of consumption of natural uranium; and the long-term radiotoxicity after fuel discharge. For context, other cases and analyses are included, primarily once-through light water reactor (LWR) uranium oxide fuel at 51 MWth-day/kg-iHM burnup (UOX-51). For CR<1, the heat, gamma, and neutron emission increase as material is recycled. The uranium utilization is at or below 1%, just as it is in thermal reactors as both types of reactors require continuing fissile support. For CR>1, heat, gamma, and neutron emission decrease with recycling. The uranium utilization exceeds 1%, especially as all the transuranic elements are recycled. exceeds 1%, especially as all the transuranic elements are recycled. At the system equilibrium, heat and gamma vary by somewhat over an order of magnitude as a function of CR. Isotopes that dominate heat and gamma emission are scattered throughout the actinide chain, so the modest impact of CR is unsurprising. Neutron emitters are preferentially found among the higher actinides, so the neutron emission varies much stronger with CR, about three orders of magnitude.

Steven J. Piet; Edward A. Hoffman; Samuel E. Bays

2010-11-01

403

Analysis of volume dependence of Grüneisen ratio  

NASA Astrophysics Data System (ADS)

Various models on volume dependence of the Grüneisen ratio have been analyzed in the present study. The Sharma model [Mod. Phys. Lett. B 22/31 (2008) 3113] is found to be similar to that used by Nie [Phys. Stat. Sol. (b) 219 (2004) 241] on the basis of approximation made by Jeanloz [J. Geophys. Res. 94 (1989) 5929]. The Nie expression is amended in a manner so that the resulted expression follows the constraint of high pressure thermodynamics in the limit of infinite pressure. The newly developed relationship is applied successfully on materials for which experimental data are accessible such as epsilon-iron, NaCl, Li, Na, and K.

Srivastava, S. K.; Sinha, Pallavi

2009-11-01

404

High aspect ratio, remote controlled pumping assembly  

DOEpatents

A miniature dual syringe-type pump assembly which has a high aspect ratio and which is remotely controlled, for use such as in a small diameter penetrometer cone or well packer used in water contamination applications. The pump assembly may be used to supply and remove a reagent to a water contamination sensor, for example, and includes a motor, gearhead and motor encoder assembly for turning a drive screw for an actuator which provides pushing on one syringe and pulling on the other syringe for injecting new reagent and withdrawing used reagent from an associated sensor.

Brown, Steve B. (Livermore, CA); Milanovich, Fred P. (Lafayette, CA)

1995-01-01

405

The fog influence on bit error ratio  

NASA Astrophysics Data System (ADS)

The free space optic links are used in places, where it is very difficult to use optical fiber links. The advantages of free space optic link are a great bit rate, easy and fast installation, unlicensed frequency band. The greatest disadvantage is transmission medium, which it uses in case of FSO link, the atmosphere. The worst influence on FSO link is caused by atmospherical effect called fog. This article deals with the study of fog influence on FSO link and its bit error ratio. The real measurement of BER with artificial generated fog and FSO link was performed. The measurement was done in laboratory conditions. The results are presented in this article.

Vitasek, Jan; Látal, Jan; Vašinek, Vladimir; Hejduk, Stanislav; Liner, Andrej; Papes, Martin; Koudelka, Petr; Ganiyev, Artem

2012-01-01

406

Poisson's ratio measurements of martensitic steels  

SciTech Connect

The objective of this effort is to provide property data on candidate alloys for use in concept evaluation, design, safety analysis and performance/verification studies of various fusion energy systems. Poisson's ratio measurements using an ultrasonic technique over the temperature range room temperature to 600/degree/C are reported for HT-9. As much as a 0.1 variation is found as a result of specimen orientation. However, based on comparisons from the literature, it is concluded that such variations are common and are not due to orientation effects. Further measurements will be needed before a design equation for the MHFES can be generated. 6 refs., 1 fig., 3 tabs.

Gelles, D.S.

1984-12-01

407

Tilt and drainage ratio in sedimentary basins  

SciTech Connect

The effect of trap tilt on its drainage ratio (defined as the area of drainage for the trap divided by the corresponding area of closure) can by quantified using a one-parameter spherical approximation for hydrocarbon trap shape. We use our results to calculate the tilt angles for a number of traps in the Toolachee and Patchawarra formations of the Cooper basin, South Australia, and demonstrate that the results are consistent with the superposition of a local relief roughness on the regional tilt. 9 refs., 12 figs.

Radlinski, A.P. (Australian Geological Survey Organization, Canberra (Australia)); Cadman, S.J. (Bureau of Mineral Resources, Canberra (Australia))

1993-01-01

408

Diagnostic tests using gene expression ratios  

US Patent & Trademark Office Database

The invention provides methods for diagnosing biological states or conditions based on ratios of gene expression data from cell or tissue samples, such as cancer cell or tissue samples. The invention also provides sets of genes that are expressed differentially in normal and cancer lung cells and tissues. These sets of genes can be used to discriminate between normal and malignant cells or tissues, and between classes of malignant cells or tissues. Accordingly, diagnostic assays for classification of tumors, prediction of tumor outcome, selecting and monitoring treatment regimens and monitoring tumor progression/regression also are provided.

2013-05-28

409

Infrared analysis of lecithin/sphingomyelin ratios.  

PubMed

A clinical evaluation of a quantitative infrared method for lecithin and sphingomyelin is described. The method incorporates techniques of computer-assisted infrared spectroscopy for both control of the microprocessor-based infrared spectrophotometer and for evaluation of the data. An advanced software package for quantitative infrared analysis, which can operate on a microcomputer, provides the possibility of complete automation of the analysis. Results of the analyses of amniotic fluids from 20 patients are presented. In general, the results of the analysis of the lecithin/sphingomyelin ratio by the infrared method correspond closely to those obtained by two-dimensional thin-layer chromatography on the same respective samples. PMID:6488696

Lehmann, C A; McClure, G L; Danielson, L A

1984-01-01

410

6.RP Ratio of boys to girls  

NSDL National Science Digital Library

This is a task from the Illustrative Mathematics website that is one part of a complete illustration of the standard to which it is aligned. Each task has at least one solution and some commentary that addresses important asects of the task and its potential use. Here are the first few lines of the commentary for this task: The ratio of the number of boys to the number of girls at school is 4:5. What fraction of the students are boys? If there are 120 boys, how many studen...

411

Amylase creatinine clearance ratio after biliary surgery.  

PubMed

The amylase creatinine clearance ratio (ACCR) is considered to be a more sensitive index of acute pancreatitis than the serum amylase level. Serial ACCR estimations were undertaken in 25 patients undergoing an elective cholecystectomy. Using accepted criteria, 28% of these patients developed, in the postoperative period, biochemical evidence of pancreatic gland damage, although the serum amylase level remained normal. This raised ACCR was particularly noted in patients who had undergone an exploration of the common bile duct. The ACCR would appear to be a more sensitive index of pancreatic gland disruption secondary to biliary surgery than the serum amylase level. PMID:402305

Donaldson, L A; McIntosh, W; Joffe, S N

1977-01-01

412

Energy Balance Bowen Ratio Station (EBBR) Handbook  

SciTech Connect

The energy balance Bowen ratio (EBBR) system produces 30-minute estimates of the vertical fluxes of sensible and latent heat at the local surface. Flux estimates are calculated from observations of net radiation, soil surface heat flux, and the vertical gradients of temperature and relative humidity (RH). Meteorological data collected by the EBBR are used to calculate bulk aerodynamic fluxes, which are used in the Bulk Aerodynamic Technique (BA) EBBR value-added product (VAP) to replace sunrise and sunset spikes in the flux data. A unique aspect of the system is the automatic exchange mechanism (AEM), which helps to reduce errors from instrument offset drift.

Cook, DR

2011-02-23

413

12 CFR 3.6 - Minimum capital ratios.  

Code of Federal Regulations, 2010 CFR

... (b) Total assets leverage ratio. All national banks must... (c) Additional leverage ratio requirement. An institution...composite 1 under the Uniform Financial Institutions Rating System...the minimum Tier 1 leverage ratio is 4 percent. In all...

2010-01-01

414

12 CFR 3.6 - Minimum capital ratios.  

Code of Federal Regulations, 2010 CFR

... (b) Total assets leverage ratio. All national banks must... (c) Additional leverage ratio requirement. An institution...composite 1 under the Uniform Financial Institutions Rating System...the minimum Tier 1 leverage ratio is 4 percent. In all...

2009-01-01

415

42 CFR 403.256 - Loss ratio supporting data.  

Code of Federal Regulations, 2010 CFR

...earned premiums in the loss ratio calculation period. (8...incurred claims in the loss ratio calculation period. (9...used in calculating the loss ratio. (i) Morbidity. (ii...Expected distribution, by age and sex, of persons who will...

2010-10-01

416

42 CFR 403.256 - Loss ratio supporting data.  

Code of Federal Regulations, 2010 CFR

...earned premiums in the loss ratio calculation period. (8...incurred claims in the loss ratio calculation period. (9...used in calculating the loss ratio. (i) Morbidity. (ii...Expected distribution, by age and sex, of persons who will...

2009-10-01

417

42 CFR 403.256 - Loss ratio supporting data.  

Code of Federal Regulations, 2013 CFR

...earned premiums in the loss ratio calculation period. (8...incurred claims in the loss ratio calculation period. (9...used in calculating the loss ratio. (i) Morbidity. (ii...Expected distribution, by age and sex, of persons who will...

2013-10-01

418

Induced attack during multiple fixed-ratio, variable-ratio schedules of reinforcement.  

PubMed

TWO PIGEONS WERE EXPOSED TO A MULTIPLE SCHEDULE OF REINFORCEMENT: in the presence of one discriminative stimulus, key pecks produced grain according to a fixed-ratio schedule; in the presence of a second discriminative stimulus, key pecks produced grain according to a variable-ratio schedule. The key-peck requirements in the two components were increased in successive stages from 50 to 125 responses. Live target pigeons were restrained at the rear of the chamber. Attacks against the targets were automatically recorded, and a variety of measures of attack behavior were taken. Attacks, when they occurred, always followed grain presentation. All measures revealed higher levels of attack during the fixed-ratio component at all parameter values. All measures generally increased with increases in fixed-ratio values with both birds, and with increases in variable-ratio values with one bird. With the other bird, only the per cent of reinforcements followed by attack increased with increases in variable-ratio value; all other measures first increased and then decreased. Both increasing and bitonic functions relating induced attack to schedule parameters have been reported in experiments usually employing a single measure of attack. The measures have varied widely among these experiments. It is suggested that further studies of induced attack examine a wider range of schedule parameters and that relationships among measures be studied. PMID:16811777

Webbe, F M; Deweese, J; Malagodi, E F

1974-07-01

419

Complications with using ratios for environmental data: Comparing enantiomeric ratios (ERs) and enantiomer fractions (EFs)  

USGS Publications Warehouse

Complications arise when ratios are used to present environmental data because ratios are an unbounded, multiplicative scale that can lead to asymmetrical (skewed) data distributions. Enantiomeric ratios (ERs), historically used in discussions of chiral signatures, often are published as mean ER??single-value standard deviation. Application of statistical summaries, such as the widely used sample mean and standard deviation, to skewed ratio data is misleading and often inappropriate. Comparison of statistically summarized ER and enantiomer fraction (EF) data (which are based on a bounded, additive scale) for a range of hypothetical values reveals substantial discrepancies when conversion between ER and EF formats is used. These discrepancies are largest when the ratio data are greater than one and have large variability, because the data are more skewed. In many cases, the use of fractions instead of ratios can help to minimize misrepresentation of environmental data, including chiral data. The use of nonparametric statistical summaries, e.g., median and percentiles, provides a more robust indicator of the typical value and spread for both ER and EF data. ?? 2003 Elsevier Ltd. All rights reserved.

Ulrich, E. M.; Helsel, D. R.; Foreman, W. T.

2003-01-01

420

The Central Asia Caucacus Analyst  

NSDL National Science Digital Library

This biweekly journal is the product of the Central Asia-Caucacus Institute (CACI), an independent think tank, affiliated with the Paul H. Nitze School of Advanced International Studies at The Johns Hopkins University. The journal, which CACI has been publishing for about a year, aims to "link the business, governmental, journalistic and scholarly communities," and each issue has four or five short articles, field reports (short pieces focused on communities' assessments of a particular news event), and news bites (paragraph summaries of relevant news items). The current issue contains four articles, S. Frederick Starr's "A Federated Afghanistan?" Maria Sultan's "Avoiding Escalation in Central Asia's Southern Borderland," "Turkey's New Challenges in the Caucacus and Central Asia" by Kemal Kaya, and Miriam Lanskoy's "The Cost of the Chechen War." The journal is available online, or users can download each issue in .pdf format. Note: When we visited, the material available in .pdf format was more current than that in HTML.

2001-01-01

421

Finger length ratios in serbian transsexuals.  

PubMed

Atypical prenatal hormone exposure could be a factor in the development of transsexualism. There is evidence that the 2nd and 4th digit ratio (2D?:?4D) associates negatively with prenatal testosterone and positively with estrogens. The aim was to assess the difference in 2D?:?4D between female to male transsexuals (FMT) and male to female transsexuals (MFT) and controls. We examined 42?MFT, 38?FMT, and 45 control males and 48 control females. Precise measurements were made by X-rays at the ventral surface of both hands from the basal crease of the digit to the tip using vernier calliper. Control male and female patients had larger 2D?:?4D of the right hand when compared to the left hand. Control male's left hand ratio was lower than in control female's left hand. There was no difference in 2D?:?4D between MFT and control males. MFT showed similar 2D?:?4D of the right hand with control women indicating possible influencing factor in embryogenesis and consequently finger length changes. FMT showed the lowest 2D?:?4D of the left hand when compared to the control males and females. Results of our study go in favour of the biological aetiology of transsexualism. PMID:24982993

Vujovi?, Svetlana; Popovi?, Srdjan; Mrvoševi? Marojevi?, Ljiljana; Ivovi?, Miomira; Tan?i?-Gaji?, Milina; Stojanovi?, Miloš; Marina, Ljiljana V; Bara?, Marija; Bara?, Branko; Kova?evi?, Milena; Duišin, Dragana; Bariši?, Jasmina; Djordjevi?, Miroslav L; Mici?, Dragan

2014-01-01

422

[Sex ratio in myelocele and anencephaly].  

PubMed

The secondary sex ratio in 254 probands with anencephaly and spina bifida, their 138 sibs and 2492 relatives (sibs of mothers and fathers, sibs of grandmothers and grandfathers) was studied. In anencephaly, girls prevail (males - 29%, p less than 0.001), and in sibs of anencephalic male probands there is a predominance of males (males - 71%, p less than 0.05). The change in the sex ratio of the probands with spina bifida and their sibs is not significant. In anencephaly, a significant decrease of a male part is also found in the sibs of the probands' mothers (males - 42%, p less than 0.01), in the sibs of the probands' grandmothers and grandfaterhs by the maternal line (males - 45%, p less than 0.025 and males - 42%, p less than 0.01), and also in the sibs of the probands' grandmothers by the paternal line (males - 40%, p less than 0.01). A significant increase in the incidence of the spina bifida occulta is noted among the probands' fathers. The data obtained are in accordance with the hypothesis suggested by Timpson, on the three loci (linked with the X-chromosome by two loci) heredity of the neural tube defects. PMID:6889552

Gushchina, L A; Golovachev, G D

1982-07-01

423

Finger Length Ratios in Serbian Transsexuals  

PubMed Central

Atypical prenatal hormone exposure could be a factor in the development of transsexualism. There is evidence that the 2nd and 4th digit ratio (2D?:?4D) associates negatively with prenatal testosterone and positively with estrogens. The aim was to assess the difference in 2D?:?4D between female to male transsexuals (FMT) and male to female transsexuals (MFT) and controls. We examined 42?MFT, 38?FMT, and 45 control males and 48 control females. Precise measurements were made by X-rays at the ventral surface of both hands from the basal crease of the digit to the tip using vernier calliper. Control male and female patients had larger 2D?:?4D of the right hand when compared to the left hand. Control male's left hand ratio was lower than in control female's left hand. There was no difference in 2D?:?4D between MFT and control males. MFT showed similar 2D?:?4D of the right hand with control women indicating possible influencing factor in embryogenesis and consequently finger length changes. FMT showed the lowest 2D?:?4D of the left hand when compared to the control males and females. Results of our study go in favour of the biological aetiology of transsexualism.

Vujovic, Svetlana; Popovic, Srdjan; Mrvosevic Marojevic, Ljiljana; Ivovic, Miomira; Tancic-Gajic, Milina; Stojanovic, Milos; Marina, Ljiljana V.; Barac, Marija; Barac, Branko; Kovacevic, Milena; Duisin, Dragana; Barisic, Jasmina; Djordjevic, Miroslav L.; Micic, Dragan

2014-01-01

424

Ultra-high bypass ratio jet noise  

NASA Astrophysics Data System (ADS)

The jet noise from a 1/15 scale model of a Pratt and Whitney Advanced Ducted Propulsor (ADP) was measured in the United Technology Research Center anechoic research tunnel (ART) under a range of operating conditions. Conditions were chosen to match engine operating conditions. Data were obtained at static conditions and at wind tunnel Mach numbers of 0.2, 0.27, and 0.35 to simulate inflight effects on jet noise. Due to a temperature dependence of the secondary nozzle area, the model nozzle secondary to primary area ratio varied from 7.12 at 100 percent thrust to 7.39 at 30 percent thrust. The bypass ratio varied from 10.2 to 11.8 respectively. Comparison of the data with predictions using the current Society of Automotive Engineers (SAE) Jet Noise Prediction Method showed that the current prediction method overpredicted the ADP jet noise by 6 decibels. The data suggest that a simple method of subtracting 6 decibels from the SAE Coaxial Jet Noise Prediction for the merged and secondary flow source components would result in good agreement between predicted and measured levels. The simulated jet noise flight effects with wind tunnel Mach numbers up to 0.35 produced jet noise inflight noise reductions up to 12 decibels. The reductions in jet noise levels were across the entire jet noise spectra, suggesting that the inflight effects affected all source noise components.

Low, John K. C.

1994-10-01

425

Hydraulic system for a ratio change transmission  

DOEpatents

Disclosed is a drive assembly (10) for an electrically powered vehicle (12). The assembly includes a transaxle (16) having a two-speed transmission (40) and a drive axle differential (46) disposed in a unitary housing assembly (38), an oil-cooled prime mover or electric motor (14) for driving the transmission input shaft (42), an adapter assembly (24) for supporting the prime mover on the transaxle housing assembly, and a hydraulic system (172) providing pressurized oil flow for cooling and lubricating the electric motor and transaxle and for operating a clutch (84) and a brake (86) in the transmission to shift between the two-speed ratios of the transmission. The adapter assembly allows the prime mover to be supported in several positions on the transaxle housing. The brake is spring-applied and locks the transmission in its low-speed ratio should the hydraulic system fail. The hydraulic system pump is driven by an electric motor (212) independent of the prime mover and transaxle.

Kalns, Ilmars (Northville, MI)

1981-01-01

426

Parasite Stress Predicts Offspring Sex Ratio  

PubMed Central

In this study, I predict that the global variation of offspring sex ratio might be influenced in part by the level of parasite stress. From an energetic standpoint, higher gestational costs of producing a male offspring could decrease male births in a population with limited resources. This implies that, any factor that limits the parental resources could be expected to favor female offspring production. Human sex ratio at birth (SRB) is believed to be influenced by numerous socioeconomic, biological, and environmental factors. Here, I test a prediction that parasite stress, by virtue of its effects on the general health condition, may limit the parental investment ability and therefore could influence the SRB at the population level. The statistical analysis supports this prediction, and show that the level of parasite stress has a significant inverse relation with population SRB across the world. Further, this relation is many-folds stronger than the association of SRB with other factors, like; polygyny, fertility, latitude, and son-preference. Hence, I propose that condition affecting ability of parasites (but not adaptive significance) could be a likely causal basis for the striking variation of SRB across populations.

Dama, Madhukar Shivajirao

2012-01-01

427

Flexible Conversion Ratio Fast Reactor Systems Evaluation  

SciTech Connect

Conceptual designs of lead-cooled and liquid salt-cooled fast flexible conversion ratio reactors were developed. Both concepts have cores reated at 2400 MWt placed in a large-pool-type vessel with dual-free level, which also contains four intermediate heat exchanges coupling a primary coolant to a compact and efficient supercritical CO2 Brayton cycle power conversion system. Decay heat is removed passively using an enhanced Reactor Vessel Auxiliary Cooling System and a Passive Secondary Auxiliary Cooling System. The most important findings were that (1) it is feasible to design the lead-cooled and salt-cooled reactor with the flexible conversion ratio (CR) in the range of CR=0 and CR=1 n a manner that achieves inherent reactor shutdown in unprotected accidents, (2) the salt-cooled reactor requires Lithium thermal Expansion Modules to overcme the inherent salt coolant's large positive coolant temperature reactivity coefficient, (3) the preferable salt for fast spectrum high power density cores is NaCl-Kcl-MgCl2 as opposed to fluoride salts due to its better themal-hydraulic and neutronic characteristics, and (4) both reactor, but attain power density 3 times smaller than that of the sodium-cooled reactor.

Neil Todreas; Pavel Hejzlar

2008-06-30

428

Multi-factorial influences on sex ratio: a spatio-temporal investigation of endocrine disruptor pollution and neighborhood stress.  

PubMed

Background: It is suggested the declining male birth proportion in some industrialized countries is linked to ubiquitous endocrine disruptor exposure. Stress and advanced parental age are determinants which frequently present positive findings. Multi-factorial influences on population sex ratio are rarely explored or tested in research. Objectives: To test the hypothesis that dual factors of pollution and population stress affects sex proportion at birth through geographical analysis of Central Scotland. Methods: The study incorporates the use of Geographical Information Systems (GIS) tools to overlay modeled point source endocrine disruptor air emissions with "small-area" data on multiple deprivation (a proxy measurement of stress) and birth sex. Historical review of regional sex ratio trends presents additional data on sex ratio in Scotland to consider. Results: There was no overall concentration in Central Scotland of low sex ratio neighborhoods with areas where endocrine disruptor air pollution and deprivation or economic stress were high. Historical regional trends in Scotland (from 1973), however, do show significantly lower sex ratio values for populations where industrial air pollution is highest (i.e. Eastern Central Scotland). Conclusions: Use of small area data sets and pollution inventories is a potential new method of inquiry for reproductive environmental and health protection monitoring and has produced interesting findings. PMID:25000111

McDonald, Ewan; Watterson, Andrew; Tyler, Andrew N; McArthur, John; Scott, E Marion

2014-07-01

429

Association between obesity and calcium:phosphorus ratio in the habitual diets of adults in a city of Northeastern Brazil: an epidemiological study  

PubMed Central

Background Low calcium:phosphorus ratios (Ca:P ratio) in habitual diet have been observed worldwide, and it has been shown to be harmful to the bone health of the population. However, no study associating this ratio with obesity was found. Thus, considering that the intake of calcium and phosphorus will generate a ratio between them, which may be associated with obesity, this research seeks at evaluating the relation between obesity and the Ca:P ratio in the habitual diet of adults. Methods Cross-sectional population-based epidemiological study with stratified and systematic sampling. The sample was composed of 506 adults, aged between 18 and 60 years, of both genders. Information on socioeconomic and demographic conditions was obtained through questionnaires completed during home visits, where anthropometric and dietary evaluations were also conducted. Results In the habitual diet consumed by the study subjects, a Ca:P ratio above the median of 0.57 reduced the risk of central obesity based on waist-to-height ratio (WHtR) (OR: 0.61; 95% CI: 0.41 – 0.92). Habitual dietary intake of calcium (OR: 0.65; 95% CI: 0.43 – 0.97) and dairy products (OR: 0.56; 95% CI: 0.37 – 0.84) above the median value (485.4 mg and 0.9 servings, respectively) was found to be a protective factor related to central obesity based on WHtR. Conclusions Values above the median for the Ca:P ratio found in the habitual diet were negatively associated with central obesity based on WHtR. In addition, calcium and dairy consumption were negatively associated with central obesity based on WHtR. Therefore, higher Ca:P ratios contributed to a lower prevalence of central obesity.

2013-01-01

430

Estimation of Se(VI)/Se(IV) ratio in water by the ratio recorded in barite  

NASA Astrophysics Data System (ADS)

It is possible that the distribution behaviors of redox-sensitive elements such as selenium (Se) between authigenic minerals and water can provide information on the oxidation state of the element in the coexistent water during mineral deposition. Considering the similar chemical characteristics of Se(IV) and Se(VI) oxyanions, we propose that the Se(VI)/Se(IV) ratio in a particular precipitate, such as barite, may enable us to estimate the Se(VI)/Se(IV) ratio in the coexistent water. The coprecipitation experiments of Se with barite coupled with the determination of the oxidation state of Se both in the aqueous phase and in barite were conducted by Se K-edge X-ray absorption near-edge structure and high-performance liquid chromatography connected to inductively coupled plasma-mass spectrometry, respectively, to investigate the influence of the oxidation state of Se on its immobilization into barite at pH 4.0 and 8.0. The results showed that the Se(VI)/Se(IV) ratio in barite was correlated with the Se(VI)/Se(IV) ratio in water, which in turn can provide physicochemical and biogeochemical information related to the Se(VI)/Se(IV) ratio in water in the environment where barite precipitated.

Tokunaga, Kohei; Yokoyama, Yuka; Takahashi, Yoshio

2013-11-01

431

Winglets on low aspect ratio wings  

NASA Technical Reports Server (NTRS)

The drag reduction potentially available from the use of winglets at the tips of low aspect ratio (1.75-2.67) wings with pronounced (45-60 deg) leading edge sweep is assessed numerically for the case of a cruise design point at Mach of 0.8 and a lift coefficient of 0.3. Both wing-winglet and wing-alone design geometries are derived from a linear-theory, minimum induced drag design methodology. Relative performance is evaluated with a nonlinear extended small disturbance potential flow analysis code. Predicted lift coefficient/pressure drag coefficient increases at equal lift for the wing-winglet configurations over the wing-alone planform are of the order of 14.6-15.8, when boundary layer interaction is included.

Kuhlman, John M.; Liaw, Paul

1987-01-01

432

Horizon ratio bound for inflationary fluctuations.  

PubMed

We demonstrate that the gravity wave background amplitude implies a robust upper bound on the wavelength-to-horizon ratio at the end of inflation: lambda/H(-1) less than or approximately equal e(60), as long as the cosmic energy density does not drop faster than radiation subsequent to inflation. This limit implies that N, the number of e-folds between horizon exit and the end of inflation for wave modes of interest, is less, similar 60 plus a model-dependent factor-for vast classes of slow-roll models, N less than or approximately equal 67. As an example, this bound solidifies the tension between observations of the cosmic microwave background anisotropies and chaotic inflation with a phi(4) potential by closing the escape hatch of large N (<62). PMID:14525296

Dodelson, Scott; Hui, Lam

2003-09-26

433

Likelihood ratio-based biometric score fusion.  

PubMed

Multibiometric systems fuse information from different sources to compensate for the limitations in performance of individual matchers. We propose a framework for optimal combination of match scores that is based on the likelihood ratio test. The distributions of genuine and impostor match scores are modeled as finite Gaussian mixture model. The proposed fusion approach is general in its ability to handle (i) discrete values in biometric match score distributions, (ii) arbitrary scales and distributions of match scores, (iii) correlation between the scores of multiple matchers and (iv) sample quality of multiple biometric sources. Experiments on three multibiometric databases indicate that the proposed fusion framework achieves consistently high performance compared to commonly used score fusion techniques based on score transformation and classification. PMID:18084063

Nandakumar, Karthik; Chen, Yi; Dass, Sarat C; Jain, Anil K

2008-02-01

434

Measurement of the K+??+??¯ branching ratio  

NASA Astrophysics Data System (ADS)

Experiment E949 at Brookhaven National Laboratory studied the rare decay K+??+??¯ and other processes with an exposure of 1.77×1012 K+’s. The data were analyzed using a blind analysis technique yielding one candidate event with an estimated background of 0.30±0.03 events. Combining this result with the observation of two candidate events by the predecessor experiment E787 gave the branching ratio B(K+??+??¯)=(1.47-0.89+1.30)×10-10, consistent with the standard model prediction of (0.74±0.20)×10-10. This is a more detailed report of results previously published [V. V. Anisimovsky , Phys. Rev. Lett.PRLTAO0031-9007 93, 031801 (2004)10.1103/PhysRevLett.93.031801].

Adler, S.; Anisimovsky, V. V.; Aoki, M.; Ardebili, M.; Artamonov, A. V.; Atiya, M.; Bassalleck, B.; Bazarko, A. O.; Bhuyan, B.; Blackmore, E. W.; Bryman, D. A.; Chen, S.; Chiang, I.-H.; Christidi, I.-A.; Convery, M. R.; Cooper, P. S.; Diwan, M. V.; Frank, J. S.; Fujiwara, T.; Haggerty, J.; Hu, J.; Inagaki, T.; Ito, M. M.; Ivashkin, A. P.; Jaffe, D. E.; Kabe, S.; Kazumori, M.; Kuno, Y.; Kuriki, M.; Kettell, S. H.; Khabibullin, M. M.; Khotjantsev, A. N.; Kitching, P.; Kobayashi, M.; Komatsubara, T. K.; Konaka, A.; Kozhevnikov, A. P.; Kudenko, Yu. G.; Kushnirenko, A.; Landsberg, L. G.; Lewis, B.; Li, K. K.; Littenberg, L. S.; MacDonald, J. A.; Marlow, D. R.; McPherson, R. A.; Meyers, P. D.; Mildenberger, J.; Mineev, O. V.; Miyajima, M.; Mizouchi, K.; Mukhin, V. A.; Muramatsu, N.; Nakano, T.; Nomachi, M.; Nomura, T.; Numao, T.; Obraztsov, V. F.; Omata, K.; Patalakha, D. I.; Petrenko, S. V.; Poutissou, R.; Ramberg, E. J.; Redlinger, G.; Sato, T.; Sekiguchi, T.; Shinkawa, T.; Shoemaker, F. C.; Smith, A. J. S.; Stone, J. R.; Strand, R. C.; Sugimoto, S.; Tamagawa, Y.; Tschirhart, R.; Tsunemi, T.; Vavilov, D. V.; Viren, B.; Yershov, N. V.; Yoshimura, Y.; Yoshioka, T.

2008-03-01

435

Golden Ratio Controlled Chaos in Supersymmetric Dynamics  

NASA Astrophysics Data System (ADS)

We construct supersymmetric Lagrangians for the recently constructed off-shell worldline N = 3 supermultiplet YI/(iD_I{X}) for I = 1, 2, 3, where YI and X are standard, Salam-Strathdee superfields: YI fermionic and X bosonic. Already the Lagrangian bilinear in component fields exhibits a total of thirteen free parameters, seven of which specify Zeeman-like coupling to external (magnetic) fluxes. All but special subsets of this parameter space describe aperiodic oscillatory response, some of which are controlled by the "golden ratio," ??1.61803. We also show that all of these Lagrangians admit an N = 3 ?4 supersymmetry extension, while a subset admits two inequivalent such extensions.

Hübsch, Tristan; Katona, Gregory A.

2013-12-01

436

Branching ratios for CO+ electronic transitions  

NASA Astrophysics Data System (ADS)

In the present work a study of the electronic spectrum of CO+ produced by electron impact on CO has been carried out. From the measured emission intensities the branching ratios of the A2?? X2?+andB2?+? X2?+ transitions have been obtained. The dependence of the electronic transition moment on the internuclear separation for the “comet tail” and first negative band systems has been studied. For the first negative system the electronic transition moment decreases by a factor of about 1.15 in the r-centroid range 1.10-1.25 Å. For the “comet tail” system no dependence on the r-centroid in the range 1.07-1.21 Å has been found.

Arqueros, F.; Campos, J.

1982-01-01

437

Natrolite: A zeolite with negative Poisson's ratios  

NASA Astrophysics Data System (ADS)

The recently published experimental elastic constants [C. Sanchez-Valle, S. V. Sinogeikin, Z. A. Lethbridge, R. I. Walton, C. W. Smith, K. E. Evans, and J. D. Bass, J. Appl. Phys. 98, 053508 (2005)] for single crystals of the orthorhombic aluminosilicate zeolite NAT (natrolite, Na2(Al2Si3O10)2H2O, Fdd2) throw valuable light on the potential of NAT as a material which exhibits single crystalline negative Poisson's ratios (auxetic). On performing an off-axis analysis of these elastic constants we confirm that the zeolite natrolite exhibits auxetic behavior in the (001) plane. This supports our preliminary report that NAT-type zeolites exhibit auxetic behavior through a mechanism involving microscopic rotation of semi-rigid structural units.

Grima, Joseph N.; Gatt, Ruben; Zammit, Victor; Williams, Jennifer J.; Evans, Kenneth E.; Alderson, Andrew; Walton, Richard I.

2007-04-01

438

Interstellar C-12/C-13 ratio revisited  

NASA Astrophysics Data System (ADS)

Recent 107-in telescope observations of the molecular ion CH(+) at 4232 A in the direction of Zeta Oph are reported. One-dimensional spectra were extracted from the frames using procedures in IRAF. A Gaussian line profile was fitted to the data at random points well separated from the CH(+) features. The resulting distribution of equivalent widths is presented. Results for the individual spectra are summarized as well as the errors assigned to the individual results. Histograms of the equivalent widths for the CH-12(+) and CH-13(+) lines are shown and compared to the data from Stahl at al. (1989), and good agreement is found. It is concluded that the C-12/C-13 ratio toward Zeta Oph is closer to 70 than to 45, as argued by Hawkins et al. (1985).

Crane, Philippe; Hegyi, Dennis J.; Lambert, David L.

1991-09-01

439

Ultrahigh-Aspect-Ratio Contact Hole Etching  

NASA Astrophysics Data System (ADS)

An ultrasmall, 60nm-diameter, 2um-deep contact hole pattern of BPSG film was successfully fabricated using a poly-Si mask and a magnetically enhanced reactive-ion-etching system. Significantly weaker dependence of etch rate on aspect ratio(AR) was obtained up to AR=30, showing that the energetic ions (and/or neutralized molecules) with a sufficient flux for etching reaction are supplied onto the hole bottom even in such a extremely fine feature. On the other hand, neutral supply of polymer precursors onto the hole bottom (Si substrate) is not sufficient for polymerization in holes with aspect ratios greater than 10, where several energetic particles reach the hole bottoms and contribute to the etching reaction with Si substrates. For features with dimensions below 100nm, processing of vertical profiles is extremely difficult, and problems in the form of bowing at the sidewalls of the holes can occur. The shape of the etched feature and the occurrence of etch stops were shown to be in a trade-off relationship. However, vertical profiles were successfully obtained with diameters greater than 100nm without etch stops. It is possible that ion flux is significantly influenced (reduced) when ions pass through the poly-Si mask, rather than through the BPSG hole. The bowing is associated with bending of the incident ion trajectories, where the first stage of the trajectory change occurs at the mask, and subsequent multiple scattering of ions at the sidewall of the hole can occur. Other factors include sidewall protection by redeposited Si that was sputtered from the poly-Si mask and/or the deposited fluorocarbon polymers, and the effects of ion flux and energy bombarding these deposited materials. In the future, it will be necessary to clarify the details of the mechanisms of these phenomena and to establish technologies to control them. note number.

Ikegami, Naokatsu

1997-10-01

440

Volcanoes of the Central Andes.  

National Technical Information Service (NTIS)

The Central Volcanic Zone of the Andes is located between latitudes 14 deg and 28 deg S of the Andean cordillera. An elevated region, much of it over 4000 m in altitude, constituting the altiplano of Bolivia and puna of northern Chile and Argentina, domin...

S. L. de Silva P. W. Francis

1990-01-01

441

Central America: A Regional Study.  

ERIC Educational Resources Information Center

This lesson is a series of activities and multi-media presentations designed to enable students to understand the historic and geographic roots of some of the problems that Central American nations have faced. Geography, history, writing, and storytelling are used as ways of understanding a multicultural world. Creative thinking and participation…

Mowry, George; Lacy, Ann

442

Central Bureau Status and Perspective  

NASA Technical Reports Server (NTRS)

The Central Bureau continues to promote the IGS organization, data and data products as setting the world standard for GPS/GNSS geodetic applications as outlined in the IGS Strategic Plan. The Central Bureau was responsible for the organization of the strategic planning process, preparation of all documents, and the editing and publication of the plan. This was a major activity and the Board s consensus on the plan is a significant milestone in the evolution of the IGS. The Central Bureau is responsible for the day-to-day management of the Service. With 200 organizations in over 80 countries and a ground network of approx. 350 stations, this requires daily interfaces on many different levels globally. The separate summary of the IGS Network Coordinator is included in this annual report and demonstrates the vital technical tasks of the Central Bureau. The CB is also responsible to arrange and organize all Board activities and is involved in the supporting the planning and logistics of all IGS workshops and meetings.

Neilan, Ruth

2004-01-01

443

Music Libraries: Centralization versus Decentralization.  

ERIC Educational Resources Information Center

Considers the decision that branch libraries, music libraries in particular, have struggled with concerning a centralized location in the main library versus a decentralized collection. Reports on a study of the Association of Research Libraries that investigated the location of music libraries, motivation for the location, degrees offered,…

Kuyper-Rushing, Lois

2002-01-01

444

Central 5HT 4 receptors  

Microsoft Academic Search

Activation of the 5-HT4 receptor mediates widespread effects in central and peripheral nervous systems. Recent developments, such as the identification of novel, selective agonists and antagonists, as well the cloning of the receptor, have provided insights into the physiological role of the receptor. In this article, Richard Eglen and colleagues assess the emerging evidence relating to the function of the

Aline Dumuis; Joël Bockaert

1995-01-01

445

Central banks and financial crises  

Microsoft Academic Search

The paper draws lessons from the experience of the past year for the conduct of central banks in the pursuit of macroeconomic and financial stability. Macroeconomic stability is defined as either price stability or as price stability and sustainable output or employment growth. Financial stability refers to (1) the absence of asset price bubbles, (2) the prevention or mitigation of

Willem Buiter

2008-01-01

446

Central Corneal Thickness in Children  

PubMed Central

Objective To report the central corneal thickness (CCT) in healthy white, African-American, and Hispanic children from birth to 17 years of age. Design Prospective observational multicenter study. Central corneal thickness was measured with a hand-held contact pachymeter. Results Two thousand seventy-nine children were included in the study, with ages ranging from day of birth to 17 years. Included were 807 white, 494 Hispanic, and 474 African-American individuals, in addition to Asian, unknown and mixed race individuals. African-American children had thinner corneas on average than that of both white (p< .001) and Hispanic children (p< .001) by approximately 20 micrometers. Thicker median CCT was observed with each successive year of age from age 1 to 11 years, with year-to-year differences steadily decreasing and reaching a plateau after age 11 at 573 micrometers in white and Hispanic children and 551 micrometers in African-American children. For every 100 micrometers of thicker CCT measured, the intraocular pressure was 1.5 mmHg higher on average (p< 0.001). For every diopter of increased myopic refractive error (p< 0.001) CCT was 1 micrometer thinner on average. Conclusions Median CCT increases with age from 1 to 11 years with the greatest increase present in the youngest age groups. African-American children on average have thinner central corneas than white and Hispanic children, while white and Hispanic children demonstrate similar central corneal thickness.

2011-01-01

447

Central Libraries in Uncertain Times.  

ERIC Educational Resources Information Center

Discusses security and safety issues for public libraries, especially high-profile central facilities, in light of the September 11 terrorist attacks. Highlights include inspecting bags as patrons enter as well as exit; the need for security guidelines for any type of disaster or emergency; building design; and the importance of communication.…

Kenney, Brian J.

2001-01-01

448

Central mechanisms of pathological pain  

Microsoft Academic Search

Chronic pain is a major challenge to clinical practice and basic science. The peripheral and central neural networks that mediate nociception show extensive plasticity in pathological disease states. Disease-induced plasticity can occur at both structural and functional levels and is manifest as changes in individual molecules, synapses, cellular function and network activity. Recent work has yielded a better understanding of

Rohini Kuner

2010-01-01

449

Geothermal activities in Central America  

Microsoft Academic Search

The Agency for International Development is funding a new program in energy and minerals for Central America. Geothermal energy is an important component. A country-wide geothermal assessment has started in Honduras, and other assessment activities are in progress or planned for Costa Rica, El Salvador, Guatemala, and Panama. Instrumentation for well logging has been provided to Costa Rica, and a

J. T. Whetten; R. J. Hanold

1985-01-01

450

Geothermal initiatives in Central America  

Microsoft Academic Search

The US Agency for International Development is supporting a new project in energy and resources exploitation for Central America. One of the largest components of the project involves exploration and reservoir development investigations directed at enhancing the production of electricity from the region's geothermal resources. An assessment of the geothermal resources of Honduras is in progress, and interesting geothermal regions

R. J. Hanold; V. W. Loose; A. W. Laughlin; P. E. Wade

1986-01-01

451

Central Neuroplasticity and Pathological Pain  

Microsoft Academic Search

The traditional specificity theory of pain perception holds that pain involves a direct transmission system from somatic receptors to the brain. The amount of pain perceived, moreover, is assumed to be directly proportional to the extent of injury. Recent research, however, indicates far more complex mechanisms. Clinical and experimental evidence shows that noxious stimuli may sensitize central neural structures involved

Ronald Melzack; Terence J. Coderre; Joel Katz; Anthony L. Vaccarino

2006-01-01

452

The CMS central hadron calorimeter  

SciTech Connect

The CMS central hadron calorimeter is a copper absorber/ scintillator sampling structure. We describe design choices that led us to this concept, details of the mechanical and optical structure, and test beam results. We discuss calibration techniques, and finally the anticipated construction schedule.

Freeman, J.; E892 Collaboration

1996-12-31

453

GLOBUS-M Central Solenoid.  

National Technical Information Service (NTIS)

The central solenoid (CS) is identified as a critical component of GLOBUS-M spherical tokamak. The CS coil is located between the 108 mm diameter toroidal field coil inner legs bundle and the 218 mm diameter bore of the vacuum vessel. A space restriction ...

A. A. Kavin A. G. Panin K. A. Podushnikova N. V. Sakharov S. A. Grigor'ev V. A. Bykov V. A. Divavin V. A. Korotkov V. F. Soikin V. I. Nikolaev V. K. Gusev V. V. Shpeizman Y. K. M. Peng

2012-01-01

454

Geology of offshore central California  

Microsoft Academic Search

The offshore central California margin records Mesozoic and Cenozoic events attributable to continental and oceanic plate interactions. Terranes, some carried thousands of kilometers northward on the Kula and\\/or Farallon plates, were accreted to North America by late Eocene. Following accretion to North America, terranes along the margin were silvered and redistributed by strike-slip motion along the San Andreas and related

D. S. McCulloch; S. D. Lewis

1988-01-01

455

Today's central receiver power plant  

NASA Astrophysics Data System (ADS)

For 15 years, the United States Department of Energy has worked with industry, both utilities and manufacturers, to develop the technology of solar central receiver power plants. In this type of plant, sunlight is concentrated by a field of sun-tracking mirrors, called heliostats, onto a centrally located receiver. The solar energy is collected in the form of a heated fluid, which is used to generate steam to power a conventional turbine generator. For a number of reasons, molten nitrate salt is now the preferred heat transfer fluid. Commercial plants will be sized between 100 and 200 MW. The impetus for developing central receivers comes from their unique advantages: (1) they produce clean, reliable, low-cost electricity; (2) they have practical energy storage that provides a high degree of dispatchability (annually up to 60 percent) - without fossil fuels; and (3) they are environmentally benign. Development efforts around the world have brought the technology to the brink of commercialization: The technical feasibility has been proven, and cost, performance, and reliability can be confidently predicted. Plans are currently being developed for the final steps toward commercial central receiver power plants.

Alpert, D. J.; Kolb, G. J.; Chavez, J. M.

1991-04-01

456

An IP Central Office Architecture  

Microsoft Academic Search

The primary goal of this work is to design an IP based voice, video, and data communication infrastructure that will eventually replace, and far surpass, the a bilities of the existing TDM based local switching infrastructure; that i s, local, and PBX switches. The ce ntral point of this new infrastructure is an IP technology based central office (IPCO) that

Michael S. Borella; Ikhlaq Sidhu; Guido M. Schuster; David Grabelsky; Jerry Mahler; Jacek Grabiec; Thomas J. Kostas

457

Measures of Central Tendency Rap  

NSDL National Science Digital Library

This video on basic statistics provides a short rap to help students remember the meaning of range, and the measures of central tendency, namely, mean, median, and mode. Each word is given in a short rhyme that includes how to calculate the value.

Devoto, Paul

2010-11-20

458

Central New York's New Workforce  

ERIC Educational Resources Information Center

Conducted in late 2008 in partnership with the Greater Syracuse Chamber of Commerce and the Mohawk Valley Chamber of Commerce, this is the largest survey ever taken of Central New York businesses regarding the English language skills of the area workforce. The online survey was emailed to several hundred local businesses; 126 responses were…

Center for an Urban Future, 2009

2009-01-01

459

Central lactate metabolism regulates food intake.  

PubMed

The central nervous system regulates food intake (FI) and body weight (BW), but the associated mechanisms remain to be elucidated. Here we report that central injections of lactate reduced FI and BW in rodents. Inhibition of central lactate metabolism to pyruvate with the lactate dehydrogenase inhibitor oxamate abolished the central effects of lactate on FI and BW. Conversely, central injections of pyruvate recapitulated the effects of lactate. Finally, inhibition of central lactate metabolism prevented the ability of circulating lactate to lower FI and BW. Together, the data indicate that activation of central lactate metabolism lowers FI and BW. PMID:18577696

Lam, Carol K L; Chari, Madhu; Wang, Penny Y T; Lam, Tony K T

2008-08-01

460

Miocene paleotopography of the Central Alps  

NASA Astrophysics Data System (ADS)

Reconstructing surface elevation, surface uplift, and relief histories is fundamental to understanding the growth of mountain ranges, to explore their topographic limits, and relate these to the interplay between geodynamic and Earth surface processes. Here, we aim to quantify Miocene paleoelevation of the Central European Alps through stable isotope paleoaltimetry. The novelty of our approach, which renders our analysis less sensitive to past climate change, is that stable isotope proxies of identical age are analyzed from both the high internal parts of the Alpine orogen and the adjacent foreland basin. Whereas the foreland basin was at or near sea level and traces the combined effects of upstream changes in rainfall amount and composition, the high Alpine site additionally records the effect of elevation on stable isotopes in precipitation. We compare hydrogen isotopic ratios (?D) in mica and chlorite that interacted with meteoric water along the Simplon detachment, a major normal fault that developed at high elevations, with meteoric water compositions deduced from carbonate-bearing paleosols of the North-Alpine foreland basin. ?D values of muscovite (-126‰) and chlorite (-135‰) from the brittle hanging wall and of recrystallized muscovite (-108‰) and biotite (-140‰) from adjacent footwall mylonites provide unequivocal evidence for localized syntectonic meteoric water interaction along the Simplon detachment. Detailed 40Ar/39Ar and fission track geochronology constrains the timing of isotopic exchange to ca. 14.5 Ma, when the footwall mylonites passed through the ductile to brittle transition. Age-equivalent oxygen isotope ratios (?18O) measured within pedogenic carbonate from North-Alpine foreland paleosols that developed near Miocene sea level serve as our low-elevation point of reference. ?18O values in these paleosols, dated with ca. 100 ka precision, vary between +19 and +25‰ (SMOW) with average values of +20‰ at ca. 14.5 Ma. Using the relative differences between meteoric water compositions in the foreland basin and the high Alpine Simplon detachment, our isotope data are consistent with a mid-Miocene minimum average elevation difference of 2350 (+700/-500) m for the Simplon region. Our results indicate that Miocene Alpine elevations were at least comparable to those of today and are likely to have acted as an important barrier to Atlantic-derived moisture transport into central Europe and Eurasia since that time.

Campani, M.; Mulch, A.; Kempf, O.; Schlunegger, F.; Mancktelow, N.

2012-07-01