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Formant Centralization Ratio: A Proposal for a New Acoustic Measure of Dysarthric Speech  

ERIC Educational Resources Information Center

Purpose: The vowel space area (VSA) has been used as an acoustic metric of dysarthric speech, but with varying degrees of success. In this study, the authors aimed to test an alternative metric to the VSA--the "formant centralization ratio" (FCR), which is hypothesized to more effectively differentiate dysarthric from healthy speech and register…

Sapir, Shimon; Ramig, Lorraine O.; Spielman, Jennifer L.; Fox, Cynthia



Formant Centralization Ratio: A Proposal for a New Acoustic Measure of Dysarthric Speech  

E-print Network

Purpose: The vowel space area (VSA) has been used as an acoustic metric of dysarthric speech, but with varying degrees of success. In this study, the authors aimed to test an alternative metric to the VSA-the formant centralization ratio (FCR), which is hypothesized to more effectively differentiate dysarthric from healthy speech and register treatment effects. Method: Speech recordings of 38 individuals with idiopathic Parkinson's disease and dysarthria (19 of whom received 1 month of intensive speech therapy [Lee Silverman Voice Treatment; LSVT LOUD]) and 14 healthy control participants were acoustically analyzed. Vowels were extracted from short phrases. The same vowelformant

Shimon Sapir; Lorraine Ramig; Jennifer L. Spielman; Cynthia Fox


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

PubMed Central

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 (TM) of the CH2 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 TM of the CH2 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



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. PMID:24892930

Zhang, Qiu; Tian, Honggang; Li, Hongmei



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



Phenology, sex ratios, and population trends of Selasphorus hummingbirds in central coastal California  

Microsoft Academic Search

From 1980 to 2000, we mist-netted 2412 Allen's Hummingbirds (Selasphorus sasin) and 203 Rufous Hummingbirds (S. rufus) at a site in central coastal California. Adult Allen's occurred from late January to early August and juveniles from early April to early September. Overall ratios of female to male Allen's were 2.5:1 for adults, 1:1.1 for juveniles. The breeding season female-to-male ratio

Steve N. G. Howell; Thomas Gardali




NSDL National Science Digital Library

This set of instructional materials and problems helps students understand ratios and proportions, starting with a simple review and progressing into the more advanced territory of similar triangles. The first three pages introduce ratios, proportions, and checking proportionality and the last four pages present mathematical and real-world problems for students to solve given their understanding of ratios and proportions.

Stapel, Elizabeth



The evaluation of pollen quality, and a further appraisal of the fluorochromatic (FCR) test procedure.  


Methods currently available for evaluating pollen quality in vitro include, (a) tests of germinability; (b) tests of the stainability of the vegetative cell contents; (c) tests for enzyme activity, and (d) the fluorochromatic procedure (FCR), which tests principally the integrity of the plasmalemma of the vegetative cell. Using germinability in vitro as a standard, a comparison has been made between histochemical methods of classes (b), (c) and (d) in application to various pollens, immature, mature, and treated in ways known to affect viability and membrane state. Predictably, the lowest correlation was obtained with tests of stainability. The highest was given by the FCR, which generally provided an excellent guide to potential germinability. The FCR procedure is subject to various limitations, however, (a) A high correlation between FCR and germinability can only be expected when mature, ripe pollen is used; with immature pollen, the FCR will predict excessively high potential germinability. (b) The FCR may also predict a higher potential level of pollen function than in vitro germinability when the germination medium is sub-optimal. In this situation, however, it will generally give a better guide to fertilising capacity, (c) The FCR is not a test of pollen viability. Like germinability in vitro, it can yield a negative score with pollen which is nevertheless capable of functioning. For example, false negatives will be obtained with some species if the pollen is not properly pre-conditioned by rehydration before testing, an important point in monitoring stored pollen. The paper includes a brief discussion of the rationale of pollen testing. PMID:24258660

Heslop-Harrison, J; Heslop-Harrison, Y; Shivanna, K R



Observations of the Magnitude Dependence of Pn/Lg Ratios from Underground Explosions in Central Asia  

NASA Astrophysics Data System (ADS)

Xie and Patton (1999, JGR) developed scaling relationships for seismic moment M0 and corner frequency fc determined from Pn and Lg spectra for many explosions and earthquakes located in central Asia. Scaling relationships were found to depend on the phase and the source type. Pn/Lg ratios ratios are predicted to increase significantly in a frequency range determined by Lg fc (lower limit) and Pn fc (upper limit). The increase slows down or stops outside this frequency range, and the range shifts to higher frequency with decreasing event magnitude. As a result, ratios from smaller events reach maxima at higher frequencies than do larger events. This predicted magnitude-dependent frequency shift of Pn/Lg ratios has been marked by controversy over whether direct observations support it or not. Here we summarize results from direct observations of Pn/Lg spectral ratios for Semipalatinsk and Lop Nor explosions. These observations include (1) ratios from Lop Nor explosions between 1992-1996 recorded on multiple broad-band stations, (2) ratios from Semipalatinsk explosions between 1987-1989 recorded on the Chinese station WMQ, (3) ratios from chemical explosions at Semipalatinsk between 1997-1999 recorded on broad-band Kazakhstan network stations, and (4) ratios from Semipalatinsk explosions between 1987-1989 from the Borovoye Digital Seismogram Archive (Kim et al., 2001). Pn/Lg ratios are stacked in three event populations with mb values of ~ 6.0, 5.0 and 4.0, respectively. Additionally, Pn/Lg ratios are available from multiple stations from a mb=6.6 explosion. The stacked ratios are compared with one another for near-repeated paths or for paths for which corrections are known based on path Q-inversions. All of the stacked Pn/Lg ratios show magnitude-dependence and statistically support the predicted magnitude-dependent frequency shift. The observations also indicate more complexity in Pn/Lg ratios from the mb ~ 4 population, which is largely made up of recent chemical explosions.

Xie, J.; Patton, H. J.; Kim, W.



Role of FcR? and factor XIIIA in coated platelet formation  

PubMed Central

Platelet activation in response to dual stimulation with collagen and thrombin results in the formation of a subpopulation of activated platelets known as coated platelets. Coated platelets are characterized by high surface levels of ?-granule proteins and phosphatidylserine, which support the assembly of procoagulant protein complexes. Using murine models, we tested the hypothesis that the collagen receptor-associated molecule FcR? and the transglutaminase factor XIIIA are required for the formation of coated platelets. Following dual stimulation with the collagen receptor agonist convulxin and thrombin, 68% of platelets from C57BL/6 mice acquired the coated platelet phenotype, defined by high surface levels of fibrinogen and von Willebrand factor and decreased binding of the ?IIb?3 activation-dependent antibody PE-JON/A. In FcR?-/- mice, only 10% of platelets became “coated” after dual stimulation with convulxin plus thrombin (P < .05 vs C57BL/6 platelets). Decreased coated platelet formation in FcR?-/- platelets was accompanied by decreased annexin V binding (P < .01) and decreased platelet procoagulant activity (P < .05). Platelets from FXIIIA-/- mice did not differ from control platelets in coated platelet formation or annexin V binding. We conclude that FcR?, but not factor XIIIA, is essential for formation of highly procoagulant coated platelets following dual stimulation with collagen and thrombin. PMID:16105983

Jobe, Shawn M.; Leo, Lorie; Eastvold, Joshua S.; Dickneite, Gerhard; Ratliff, Timothy L.; Lentz, Steven R.; Di Paola, Jorge



The evaluation of pollen quality, and a further appraisal of the fluorochromatic (FCR) test procedure  

Microsoft Academic Search

Methods currently available for evaluating pollen quality in vitro include, (a) tests of germinability; (b) tests of the stainability of the vegetative cell contents; (c) tests for enzyme activity, and (d) the fluorochromatic procedure (FCR), which tests principally the integrity of the plasmalemma of the vegetative cell. Using germinability in vitro as a standard, a comparison has been made between

J. Heslop-Harrison; Y. Heslop-Harrison; K. R. Shivanna



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.


Long-term results of first salvage treatment in CLL patients treated initially with FCR (fludarabine, cyclophosphamide, rituximab).  


Although fludarabine, cyclophosphamide, and rituximab (FCR) together are established as a standard first-line treatment of younger patients with chronic lymphocytic leukemia (CLL), there is little information to guide the management of patients with CLL refractory to, or who have relapsed after, receiving frontline FCR treatment. To define optimal salvage strategy and identify patients unsuitable for retreatment with FCR, we examined the survival and treatment outcome of 300 patients enrolled in a phase 2 study of FCR. After a median 142 months of follow-up, 156 patients developed progressive CLL, with a median survival of 51 months after disease progression. The duration of first remission (REM1) was a key determinant of survival after disease progression and first salvage. Patients with a short REM1 (<3 years) had a short survival period, irrespective of salvage therapy received; these patients have high unmet medical needs and are good candidates for investigation of novel therapies. In patients with a long REM1 (?3 years), salvage treatment with either repeat FCR or lenalidomide-based therapy results in subsequent median survival exceeding 5 years; for these patients, FCR rechallenge represents a reasonable standard of care. PMID:25281606

Tam, Constantine S; O'Brien, Susan; Plunkett, William; Wierda, William; Ferrajoli, Alessandra; Wang, Xuemei; Do, Kim-Anh; Cortes, Jorge; Khouri, Issa; Kantarjian, Hagop; Lerner, Susan; Keating, Michael J



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. PMID:17050574

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



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

PubMed Central

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 Ca2+ 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



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


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



Waist circumference, waist/height ratio, and neck circumference as parameters of central obesity assessment in children?  

PubMed Central

Objective: To analyze studies that assessed the anthropometric parameters waist circumference (WC), waist-to-height ratio (WHR) and neck circumference (NC) as indicators of central obesity in children. Data sources: We searched PubMed and SciELO databases using the combined descriptors: "Waist circumference", "Waist-to-height ratio", "Neck circumference", "Children" and "Abdominal fat" in Portuguese, English and Spanish. Inclusion criteria were original articles with information about the WC, WHR and NC in the assessment of central obesity in children. We excluded review articles, short communications, letters and editorials. Data synthesis: 1,525 abstracts were obtained in the search, and 68 articles were selected for analysis. Of these, 49 articles were included in the review. The WC was the parameter more used in studies, followed by the WHR. Regarding NC, there are few studies in children. The predictive ability of WC and WHR to indicate central adiposity in children was controversial. The cutoff points suggested for the parameters varied among studies, and some differences may be related to ethnicity and lack of standardization of anatomical site used for measurement. Conclusions: More studies are needed to evaluate these parameters for determination of central obesity children. Scientific literature about NC is especially scarce, mainly in the pediatric population. There is a need to standardize site measures and establish comparable cutoff points between different populations.

Magalhães, Elma Izze da Silva; Sant'Ana, Luciana Ferreira da Rocha; Priore, Silvia Eloiza; Franceschini, Sylvia do Carmo Castro



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




EPA Science Inventory

The report is the first in a series of four, documenting research performed under EPA's Fundamental Combustion Research (FCR) program. It is divided in two: Part A is a program overview and an introduction to the series; and Part B documents research performed in the gas-phase ch...


Altered Ig levels and antibody responses in mice deficient for the Fc receptor for IgM (Fc?R)  

PubMed Central

Cell surface Fc receptor for IgM antibody (Fc?R) is the most recently identified member among FcRs. We determined the cellular distribution of mouse Fc?R and the functional consequences of Fcmr disruption. Surface Fc?R expression was restricted to B-lineage cells, from immature B to plasma cells, except for a transient down-modulation during germinal center reactions. Fcmr ablation had no significant effect on overall B- and T-cell development, but led to a reduction of marginal zone B cells and an increase in splenic B1 B cells. Preimmune serum IgM in mutant mice was significantly elevated as were natural autoantibodies. When immunized with live attenuated pneumococci, mutant mice mounted robust antibody responses against phosphorylcholine, but not protein, determinants compared with wild-type mice. By contrast, upon immunization with a hapten-carrier conjugate, nitrophenyl-coupled chicken ?-globulin (NP-CGG), the mutant mice had a diminished primary IgG1 response to both NP and CGG. These findings suggest that Fc?R has an important role in IgM homeostasis and regulation of humoral immune responses. PMID:22984178

Honjo, Kazuhito; Kubagawa, Yoshiki; Jones, Dewitt M.; Dizon, Brian; Zhu, Zilu; Ohno, Hiroshi; Izui, Shozo; Kearney, John F.; Kubagawa, Hiromi



The flicker electroretinogram interocular amplitude ratio is a strong prognostic indicator of neovascularization in patients with central retinal vein occlusion  

Microsoft Academic Search

Background  To evaluate the prognostic value of interocular amplitude ratio of flicker electroretinogram (ERG) in determining the development\\u000a of neovascularization in patients with central retinal vein occlusion (CRVO).\\u000a \\u000a \\u000a \\u000a Methods  We retrospectively reviewed the data obtained from flicker ERG in 51 CRVO patients. Of these, 22 eyes which had enough follow-up\\u000a to differentiate ischemic CRVO from nonischemic CRVO were included for data analysis.

Hsi-Kung Kuo; Ming-Tse Kuo; Yung-Jen Chen; Pei-Chang Wu; Chih-Hsin Chen; Yi-Hao Chen



Is radio jet power linearly proportional to the product of central black hole mass and Eddington ratio in AGN?  

E-print Network

A model for the relation between radio jet power and the product of central black hole (BH) mass and Eddington ratio of AGN is proposed, and the model is examined with data from the literature. We find that radio jet power positively correlates but not linearly with the product of BH mass ($m$ in solar mass) and Eddington ratio ($\\lambda$), and the power law indices ($\\mu$) are significantly less than unity for relatively low accretion ($\\lambdapower assuming that the spin induced jet is gradually suppressed as the accretion rate increases. Whereas, for the high-z quasars which often show the slope $\\mu\\geq1$, a positive correlation between the radio loudness and disc luminosity is pr...

Liu, Xiang



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)



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


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



Cutting edge: antibody-dependent memory-like NK cells distinguished by FcR? deficiency.  


Because NK cells lack gene-recombination machinery and are thought to be relatively short-lived, it is unclear whether NK cells can mount long-term effective recall responses to reinfections by diverse pathogens. In this article, we report that FcR?-deficient NK cells, which we recently identified and termed g(-)NK cells, possess distinct memory features directed by FcR-mediated Ab-dependent target recognition. The presence of g(-)NK cells was associated with prior human CMV (HMCV) infection, yet g(-)NK cell responses were not restricted to HCMV-infected target cells. In the presence of virus-specific Abs, g(-)NK cells had greatly enhanced functional capabilities, superior to conventional NK cells, and were highly responsive to cells infected with either HCMV or HSV-1. Remarkably, the g(-)NK cell subset persisted long-term at nearly constant levels in healthy individuals. Therefore, FcR? deficiency distinguishes an Ab-dependent memory-like NK cell subset with enhanced potential for broad antiviral responses. PMID:23345329

Zhang, Tianxiang; Scott, Jeannine M; Hwang, Ilwoong; Kim, Sungjin



Using the nutrient ratio NO/PO as a tracer of continental shelf waters in the central Arctic Ocean  

SciTech Connect

Historical nitrate, phosphate, and dissolved oxygen data from the central Arctic Ocean are examined with particular emphasis on the conservative parameters NO (9 * NO{sub 3} + O{sub 2}) and PO (135 * PO{sub 4} + O{sub 2}). The NO/PO ratio is shown to increase with depth in the Canada Basin, being {approximately}0.78 in Surface and Upper Halocline Waters and {approximately}1.0 in the Atlantic Layer and Deep Waters. Lower Halocline Water is marked by NO and PO minima and intermediate NO/PO. NO/PO ratios from the Arctic shelf seas are examined to determine possible source regions for the various water masses. The NO/PO ration of Canada Basin Deep Water implies an upper bound of {approximately}11% shelf water contribution to this water mass. A slight oxygen maximum core in the Lower Halocline Water is identified at a salinity of S{double bond}34.5 in the vicinity of the Alpha Ridge. This core appears to be diminished by diapycnal mixing and does not extend into the Beaufort Gyre.

Wilson, C.; Wallace, D.W.R. (Brookhaven National Lab., Upton, NY (USA))



U-shaped association between central body fat and the urinary albumin-to-creatinine ratio and microalbuminuria  

PubMed Central

Background The prevalence of obese and overweight patients has increased dramatically worldwide. Both are common risk factors for chronic kidney disease (CKD) as indicated by a diminished estimated glomerular filtration rate (eGFR) or microalbuminuria. This study aimed to investigate whether anthropometric parameters [waist circumference (WC), waist-to-height ratio (WHtR) and body mass index (BMI)] are associated with renal function in a population-based study of Caucasian subjects. Methods Data from 3749 subjects (1825 women) aged 20 to 81 years from the Study of Health in Pomerania (SHIP) were analysed. Renal indices, including the urinary albumin-to-creatinine ratio (uACR), microalbuminuria, eGFR and CKD, were studied. Parameters of anthropometry (WC, WHtR and BMI) were categorised into sex-specific quintiles. Results Analysis of variance (ANOVA) models, adjusting for age, sex, type 2 diabetes mellitus and hypertension, revealed that a high and low WC or WHtR and low BMI were independently related to a higher uACR. Logistic regression models confirmed these results with respect to uACR and showed that subjects with a high or low WC or a high WHtR had increased odds of microalbuminuria. The ANOVA models revealed no relations of the investigated anthropometric parameters with eGFR. However, subjects with high values for these parameters had increased odds of CKD. Conclusions Our results demonstrate U-shaped associations between markers of central fat distribution and uACR or microalbuminuria in the general population, suggesting that both obese and very thin subjects have a higher risk of renal impairment. PMID:23594567



?2?1 Integrin, GPVI Receptor, and Common FcR? Chain on Mouse Platelets Mediate Distinct Responses to Collagen in Models of Thrombosis  

PubMed Central

Objective Platelets express the ?2?1 integrin and the glycoprotein VI (GPVI)/FcR? complex, both collagen receptors. Understanding platelet-collagen receptor function has been enhanced through use of genetically modified mouse models. Previous studies of GPVI/FcR?-mediated collagen-induced platelet activation were perfomed with mice in which the FcR? subunit was genetically deleted (FcR??/?) or the complex was depleted. The development of ?2?1?/? and GPVI?/? mice permits side-by-side comparison to address contributions of these collagen receptors in vivo and in vitro. Approach and Results To understand the different roles played by the ?2?1 integrin, the GPVI receptor or FcR? subunit in collagen-stimulated hemostasis and thrombosis, we compared ?2?1?/?, FcR??/?, and GPVI?/? mice in models of endothelial injury and intravascular thrombosis in vivo and their platelets in collagen-stimulated activation in vitro. We demonstrate that both the ?2?1 integrin and the GPVI receptor, but not the FcR? subunit influence carotid artery occlusion in vivo. In contrast, the GPVI receptor and the FcR? chain, but not the ?2?1 integrin, play similar roles in intravascular thrombosis in response to soluble Type I collagen. FcR??/? platelets showed less attenuation of tyrosine phosphorylation of several proteins including RhoGDI when compared to GPVI?/? and wild type platelets. The difference between FcR??/? and GPVI?/? platelet phosphotyrosine levels correlated with the in vivo thrombosis findings. Conclusion Our data demonstrate that genetic deletion of GPVI receptor, FcR? chain, or the ?2?1 integrin changes the thrombotic potentials of these platelets to collagen dependent on the stimulus mechanism. The data suggest that the FcR? chain may provide a dominant negative effect through modulating signaling pathways in platelets involving several tyrosine phosphorylated proteins such as RhoGDI. In addition, these findings suggest a more complex signaling network downstream of the platelet collagen receptors than previously appreciated. PMID:25415203

Marjoram, Robin J.; Li, Zhengzhi; He, Li; Tollefsen, Douglas M.; Kunicki, Thomas J.; Dickeson, S. Kent; Santoro, Samuel A.; Zutter, Mary M.




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. PMID:23369486

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



Centrality dependence of charged antiparticle to particle ratios near midrapidity in d+Au collisions at ?(sNN )=200 GeV  

NASA Astrophysics Data System (ADS)

The ratios of the yields of charged antiparticles to particles have been obtained for pions, kaons, and protons near midrapidity for d+Au collisions at ?(sNN )=200 GeV as a function of centrality. The reported values represent the ratio of the yields averaged over the rapidity range of 0.1< y? <1.3 and 0< yK,p <0.8 , where positive rapidity is in the deuteron direction, and for transverse momenta 0.1< p?,K T <1 GeV/c and 0.3< ppT <1 GeV/c . Within the uncertainties, a lack of centrality dependence is observed in all three ratios. The data are compared to results from other systems and model calculations.

Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Becker, B.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Harrington, A. S.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Ho?y?ski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Khan, N.; Kulinich, P.; Kuo, C. M.; Lee, J. W.; Lin, W. T.; Manly, S.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Roland, C.; Roland, G.; Sagerer, J.; Sarin, P.; Sedykh, I.; Skulski, W.; Smith, C. E.; Steinberg, P.; Stephans, G. S.; Sukhanov, A.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Veres, G. I.; Wolfs, F. L.; Wosiek, B.; Wo?niak, K.; Wys?ouch, B.; Zhang, J.



Experiment investigations on the performance of a centrally fuel rich swirl coal combustion burner: Influence of primary air ratio - article no. A39  

SciTech Connect

A three-component particle-dynamics anemometer is used to measure, in the near-burner region, the influence of the primary air ratio on the gas/particle two phase characteristics for a centrally fuel rich swirl coal combustion burner, on a gas/particle two phase test facility. Velocities, particle volume flux profiles and particle relative number concentrations were obtained. With a low primary air ratio, the axial velocities for gas and particles on the chamber axis are always small and easily reach the negative, and the central recirculation zone is easily formed and much closer to the outlet of the burner. In each cross-section, in the radius range from Rratio is higher than that with a low primary air ratio. The influence of gas/particle flow characteristics with a different primary air ratio on combustion has been analyzed.

Chen, Z.C.; Li, Z.Q.; Jing, J.P.; Wei, H.D.; Chen, L.Z.; Wu, S.H.; Yao, Y. [Harbin Institute of Technology, Harbin (China)



Fast CollisionResolution (FCR) MAC Algorithm for Wireless Local Area Networks YounggooKwon, YugyangFang, and Haniph Latch"  

E-print Network

Fast CollisionResolution (FCR) MAC Algorithm for Wireless Local Area Networks YounggooKwon, Yugyang 32611-6130 Absmzc-Dwelopmrat of rffidcot medlum ~ C C D I Ieootml (MAC) pro- tomb lr a fnadmentnlCoUkion Awidiarr(CSMA/CA). We `propow an efficient dWbotrd mitention-hmed MAC pmtoeol for wiml`ss 1-1 *rea

Latchman, Haniph A.


Student-to-faculty ratios, teaching loads, and salaries in associate degree nursing programs in the central United States  

Microsoft Academic Search

While much can be found in the literature about what constitutes quality teaching and learning, little published research addresses how to structure faculty workloads to maximize faculty productivity without jeopardizing program quality. This descriptive study provides an initial look at issues of program structure (student-to-faculty ratios in class and in clinical settings, teaching loads for the director and the faculty,

Donna Jones; Barbara Caton; Joyce DeWitt; Nancy Stubbs; Esther Conner



Extreme high field strength element (HFSE) depletion and near-chondritic Nb/Ta ratios in Central Andean adakite-like lavas (~ 28°S, ~ 68°W)  

NASA Astrophysics Data System (ADS)

The eruption of andesites with steep REE patterns and high Sr concentrations (adakite-like) in the northernmost Chilean flatslab region of the Central Andes spatially and temporally corresponds with the appearance of a marked HFSE (high field strength element) depletion in these lavas (La/Ta up to 95). Known as the Dos Hermanos and Pircas Negras andesites, these lavas erupted at the beginning (˜ 8 Ma), during (7-3 Ma), and immediately following (3-2 Ma) a period of tectonic instability characterized by eastward migration of the frontal volcanic arc. ICP-MS analyses of the HFSE reveal a range of chondritic (20-18) to subchondritic (18-11) Nb/Ta ratios in these lavas. Evident temporal trace element trends support a change from a rutile-bearing to an amphibole-bearing eclogitic residual assemblage in equilibrium with the mafic precursor magmas of these andesites. This change in residual mineralogy is contemporaneous with the onset of frontal arc migration in the region. Potential eclogitic sources for the Dos Hermanos and Pircas Negras adakitic andesites include mafic Andean lower crust and an additional flux of forearc crust transported to the sub-arc mantle via subduction erosion during the height of arc migration and Pircas Negras magmatism. Batch melting models of rutile- or amphibole-bearing eclogitic arc basalt in tandem with magma mixing calculations generate the observed adakitic signatures and near-chondritic Nb/Ta ratios of these Central Andean andesites.

Goss, A. R.; Kay, S. M.



Deciphering petrogenic processes using Pb isotope ratios from time-series samples at Bezymianny and Klyuchevskoy volcanoes, Central Kamchatka Depression  

NASA Astrophysics Data System (ADS)

The Klyuchevskoy group of volcanoes in the Kamchatka arc erupts compositionally diverse magmas (high-Mg basalts to dacites) over small spatial scales. New high-precision Pb isotope data from modern juvenile (1956-present) erupted products and hosted enclaves and xenoliths from Bezymianny volcano reveal that Bezymianny and Klyuchevskoy volcanoes, separated by only 9 km, undergo varying degrees of crustal processing through independent crustal columns. Lead isotope compositions of Klyuchevskoy basalts-basaltic andesites are more radiogenic than Bezymianny andesites (208Pb/204Pb = 37.850-37.903, 207Pb/204Pb = 15.468-15.480, and 206Pb/204Pb = 18.249-18.278 at Bezymianny; 208Pb/204Pb = 37.907-37.949, 207Pb/204Pb = 15.478-15.487, and 206Pb/204Pb = 18.289-18.305 at Klyuchevskoy). A mid-crustal xenolith with a crystallization pressure of 5.2 ± 0.6 kbars inferred from two-pyroxene geobarometry and basaltic andesite enclaves from Bezymianny record less radiogenic Pb isotope compositions than their host magmas. Hence, assimilation of such lithologies in the middle or lower crust can explain the Pb isotope data in Bezymianny andesites, although a component of magma mixing with less radiogenic mafic recharge magmas and possible mantle heterogeneity cannot be excluded. Lead isotope compositions for the Klyuchevskoy Group are less radiogenic than other arc segments (Karymsky—Eastern Volcanic Zone; Shiveluch—Northern Central Kamchatka Depression), which indicate increased lower-crustal assimilation beneath the Klyuchevskoy Group. Decadal timescale Pb isotope variations at Klyuchevskoy demonstrate rapid changes in the magnitude of assimilation at a volcanic center. Lead isotope data coupled with trace element data reflect the influence of crustal processes on magma compositions even in thin mafic volcanic arcs.

Kayzar, Theresa M.; Nelson, Bruce K.; Bachmann, Olivier; Bauer, Ann M.; Izbekov, Pavel E.



Origin of lead in eight Central European peat bogs determined from isotope ratios, strengths, and operation times of regional pollution sources.  


Lead originating from coal burning, gasoline burning, and ore smelting was identified in 210Pb-dated profiles through eight peat bogs distributed over an area of 60,000 km2. The Sphagnum-dominated bogs were located mainly in mountainous regions of the Czech Republic bordering with Germany, Austria, and Poland. Basal peat 14C-dated at 11,000 years BP had a relatively high 206Pb/207Pb ratio (1.193). Peat deposited around 1800 AD had a lower 206Pb/207Pb ratio of 1.168-1.178, indicating that environmental lead in Central Europe had been largely affected by human activity (smelting) even before the beginning of the Industrial Revolution. Five of the sites exhibited a nearly constant 206Pb/207Pb ratio (1.175) throughout the 19th century, resembling the "anthropogenic baseline" described in Northern Europe (1.17). At all sites, the 206Pb/207Pb ratio of peat decreased at least until 1980; at four sites, a reversal to more radiogenic values (higher 206Pb/207Pb), typical of easing pollution, was observed in the following decade (1980-1990). A time series of annual outputs for 14 different mining districts dispersing lead into the environment has been constructed for the past 200 years. The production of Ag-Pb, coal, and leaded gasoline peaked in 1900, 1980, and 1980, respectively. In contrast to other European countries, no peak in annual Pb accumulation rates was found in 1900, the year of maximum ore smelting. The highest annual Pb accumulation rates in peat were consistent with the highest Pb emission rates from coal-fired power plants and traffic (1980). Although maximum coal and gasoline production coincided in time, their isotope ratios were unique. The mean measured 206Pb/207Pb ratios of local coal, ores, and gasoline were 1.19, 1.16, and 1.11, respectively. A considerable proportion of coal emissions, relative to gasoline emisions, was responsible for the higher 206Pb/207Pb ratios in the recent atmosphere (1.15) compared to Western Europe (1.10). As in West European countries, the gasoline sold in the Czech Republic during the Communist era (1948-1989) contained an admixture of low-radiogenic Precambrian lead from Australia. PMID:12630456

Novák, Martin; Emmanuel, Simon; Vile, Melanie A; Erel, Yigal; Véron, Alain; Paces, Tomás; Wieder, R Kelman; Vanecek, Mirko; Stepánová, Markéta; Brízová, Eva; Hovorka, Jan



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. PMID:24155889

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



Changes in weight, total fat, percent body fat, and central-to-peripheral fat ratio associated with injectable and oral contraceptive use  

PubMed Central

Objective To determine changes in body weight and composition resulting from hormonal contraception. Study design Dual-energy X-ray absorptiometry was performed at baseline and every 6 months for 3 years on 703 women (200 Black, 247 White, 256 Hispanic) initiating use of oral contraception (OC, n = 245), depot medroxyprogesterone acetate (DMPA, n = 240), or nonhormonal contraception (NH, n = 218). DMPA discontinuers were followed for up to 2 years to examine the reversibility of observed changes. Results Over 36 months, DMPA users increased their weight (+5.1 kg), body fat (+4.1 kg), percent body fat (+3.4%), and central-to-peripheral fat ratio (+0.1) more than OC and NH users (P<.01). OC use did not cause weight gain. After DMPA discontinuation, NH users lost 0.42 kg/6 months while OC users gained 0.43 kg/6 months. Conclusions Body weight and fat significantly increase while using DMPA. After discontinuation, some decrease occurs when NH is used. PMID:19254592

BERENSON, Abbey B.; RAHMAN, Mahbubur



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.



Neutrophils in autoantibody-mediated arthritis: critical producers of FcR? , the receptor for C5a, and LFA-1  

PubMed Central

Objective Neutrophils represent a prominent component of inflammatory joint effusions and are required for synovial inflammation in mouse models, but mechanisms are poorly understood. We developed a system to test the importance of production of specific factors by neutrophils in a mouse model of arthritis. Methods Neutrophil-deficient Gfi-1?/? mice were sub-lethally irradiated, then engrafted with donor bone-marrow cells (BMC), which resulted in production of mature neutrophils within two weeks. By reconstituting with BMC from mice lacking selected pro-inflammatory factors, mice specifically lacking these factors on neutrophils were generated. Arthritis was initiated by transfer of K/BxN serum to identify the role of defined neutrophil factors on arthritis incidence and severity. Results Neutrophils lacking the signaling chain of stimulatory Fc receptors (FcR? ?/?) were unable to elicit arthritis, but neutrophils lacking Fc? RIII still did so. Neutrophils lacking the chemotactic or adhesion receptors C5aR or CD11a/LFA-1 also failed to initiate arthritis but could enter joints in which inflammation had been initiated by wild-type neutrophils. Neutrophils unable to produce interleukin-1 ? and ? (IL-1?? ?/?) or leukotrienes (5-LO?/?) produced arthritis of intermediate severity. Inability of neutrophils to make tumor necrosis factor (TNF), or to express receptors for TNF or IL-1, had no effect on arthritis. Conclusion A novel transfer system was developed to identify neutrophil production of FcR? , C5aR, and CD11a/LFA-1 as critical components of autoantibody-mediated arthritis. Neutrophil production of IL-1 and leukotriene B4 likely contributes to inflammation but is not essential. Molecular requirements for neutrophil influx into joints become more permissive after inflammation is initiated. PMID:20191628

Monach, Paul A; Nigrovic, Peter A; Chen, Mei; Hock, Hanno; Lee, David M; Benoist, Christophe; Mathis, Diane



Utility of waist-to-height ratio in assessing the status of central obesity and related cardiometabolic risk profile among normal weight and overweight\\/obese children: The Bogalusa Heart Study  

Microsoft Academic Search

BACKGROUND: Body Mass Index (BMI) is widely used to assess the impact of obesity on cardiometabolic risk in children but it does not always relate to central obesity and varies with growth and maturation. Waist-to-Height Ratio (WHtR) is a relatively constant anthropometric index of abdominal obesity across different age, sex or racial groups. However, information is scant on the utility

Jasmeet S Mokha; Sathanur R Srinivasan; Pronabesh DasMahapatra; Camilo Fernandez; Wei Chen; Jihua Xu; Gerald S Berenson



Nitrous oxide emissions from yellow brown soil as affected by incorporation of crop residues with different carbon-to-nitrogen ratios: a case study in central China.  


To investigate the influence of crop residues decomposition on nitrous oxide (N2O) emission, a field study was performed with application of crop residues with different C:N ratios in a bare yellow brown soil at the experimental station of Zhangjiachong at Zigui, China. We set up six experimental treatments: no crop residue (CK), rapeseed cake (RC), potato stalk (PS), rice straw (RS), wheat straw (WS), and corn straw (CS). The carbon (C) to nitrogen (N) ratios of these crop residues were 7.5, 32.9, 40.4, 65.7, and 90.9, respectively. Nitrous oxide fluxes were measured using a static closed chamber method. N2O emissions were significantly enhanced by incorporation of crop residues. Cumulative N2O emissions negatively correlated with C:N ratio (R (2) = 0.9821) of the crop residue, but they were positively correlated with average concentrations of dissolved organic carbon and microbial biomass carbon. Nitrogen emission fraction, calculated as N2O-N emissions originated from the crop residues N, positively correlated with C:N ratio of the residues (P < 0.05). Soil temperature did, whereas soil moisture did not, control the residue's induced N2O emissions because a significant correlation (P < 0.01) existed between soil temperature and N2O emissions in all treatments except the control. In contrast, a significant relationship between soil moisture and N2O emissions was found in the control only. Furthermore, N2O emission significantly correlated (P < 0.05) with NO3 (-)-N, and NH4 (+)-N contents from all residue treatments. These results indicate that (1) crop residues with distinct carbon and nitrogen contents can significantly alter soil N2O flux rates; and (2) soil biotic as well as abiotic variables are critical in determining soil-atmospheric N2O emissions after crop residue incorporation into soil. PMID:23609028

Lin, Shan; Iqbal, Javed; Hu, Ronggui; Shaaban, Muhammad; Cai, Jianbo; Chen, Xi



First measurement of the ratio of central-electron to forward-electron W partial cross sections in pp[over] collisions at (square root)s =1.96 TeV.  


We present a measurement of sigma(pp[over] --> W) x B(W --> e nu) at (square root)s = 1.96 TeV, using electrons identified in the forward region (1.2 < |eta| < 2.8) of the CDF II detector, in 223 pb(-1) of data. We measure sigma x B = 2796 +/- 13(stat)(-90)(+95)(syst) +/- 162(lum) pb. Combining this result with a previous CDF measurement obtained using electrons in the central region (|eta| approximately < 1), we present the first measurement of the ratio of central-electron to forward-electron W partial cross sections R(exp) = 0.925 +/- 0.006(stat) +/- 0.032(syst), consistent with theoretical predictions using Coordinated Theoretical-Experimental Project on QCD (CTEQ) and Martin-Roberts-Stirling-Thorne (MRST) parton distribution functions. PMID:17678012

Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Almenar, C Cuenca; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Giovanni, G P Di; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Fernandez, P Movilla; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J



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


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



Rumpshaker-like proteolipid protein (PLP) ratio in a mouse model with unperturbed structural and functional integrity of the myelin sheath and axons in the central nervous system.  


The gene plp on the X chromosome encodes the isoforms proteolipid protein (PLP) and DM(20), two dominant integral membrane proteins of central nervous system (CNS) myelin. DM(20) results from the activation of the cryptic splice site in exon III of the PLP gene. We inserted a sense-orientated loxP flanked neomycin-gene into intron III of the plp sequence, using homologous recombination in embryonic stem cells and generated the homozygous neoS mouse line. Unlike the previously described complete PLP/DM(20) ablation (plp(-/-)), which has been obtained by introducing a neo-gene in antisense-orientation in the same position of intron III, the plp expression surprisingly revealed reduced mRNA levels. The PLP isoform was reduced to 50%, but DM(20) expression was unaffected. This protein pattern resembles the expression profile of the PLP isoforms in the natural occurring rumpshaker mutant. Electron microscopic examination revealed a normal compaction of CNS-myelin and maintenance of axon integrity. PLP expression levels of the wt control were recovered by Cre excision of the neo-selection gene after intercrossing neoS mice and oligodendrocyte-specific Cre-mice. These data strongly hint at different functions of intron III in PLP/DM(20)-specific splicing and mRNA stability. Furthermore evidence is provided for functionally affected translation products of the PLP gene in the rumpshaker mutant, whereas no PLP-isoform occur in plp(-/-) mice generated by introducing a selectable marker into intron III in antisense orientation. PMID:11424193

Uschkureit, T; Spörkel, O; Büssow, H; Stoffel, W



Rod Ratios  

NSDL National Science Digital Library

This activity builds student knowledge of ratios by using Cuisenaire rods to determine proportion and form equivalent ratios. Students may use the Cuisenaire rod environment embedded in this resource or they may use actual Cuisenaire rods depending on preference/ability/accessibility. This resource includes teacher notes, solution, and suggestions for questioning.

Team, Nrich



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.


Reconstructing C3 and C4 vegetation cover using n-alkane carbon isotope ratios in recent lake sediments from Cameroon, Western Central Africa  

NASA Astrophysics Data System (ADS)

Trees and shrubs in tropical Africa use the C3 cycle as a carbon fixation pathway during photosynthesis, while grasses and sedges mostly use the C4 cycle. Leaf-wax lipids from sedimentary archives such as the long-chain n-alkanes (e.g., n-C27 to n-C33) inherit carbon isotope ratios that are representative of the carbon fixation pathway. Therefore, n-alkane ?13C values are often used to reconstruct past C3/C4 composition of vegetation, assuming that the relative proportions of C3 and C4 leaf waxes reflect the relative proportions of C3 and C4 plants. We have compared the ?13C values of n-alkanes from modern C3 and C4 plants with previously published values from recent lake sediments and provide a framework for estimating the fractional contribution (areal-based) of C3 vegetation cover (fC3) represented by these sedimentary archives. Samples were collected in Cameroon, across a latitudinal transect that accommodates a wide range of climate zones and vegetation types, as reflected in the progressive northward replacement of C3-dominated rain forest by C4-dominated savanna. The C3 plants analysed were characterised by substantially higher abundances of n-C29 alkanes and by substantially lower abundances of n-C33 alkanes than the C4 plants. Furthermore, the sedimentary ?13C values of n-C29 and n-C31 alkanes from recent lake sediments in Cameroon (-37.4‰ to -26.5‰) were generally within the range of ?13C values for C3 plants, even when from sites where C4 plants dominated the catchment vegetation. In such cases simple linear mixing models fail to accurately reconstruct the relative proportions of C3 and C4 vegetation cover when using the ?13C values of sedimentary n-alkanes, overestimating the proportion of C3 vegetation, likely as a consequence of the differences in plant wax production, preservation, transport, and/or deposition between C3 and C4 plants. We therefore tested a set of non-linear binary mixing models using ?13C values from both C3 and C4 vegetation as end-members. The non-linear models included a sigmoid function (sine-squared) that describes small variations in the fC3 values as the minimum and maximum ?13C values are approached, and a hyperbolic function that takes into account the differences between C3 and C4 plants discussed above. Model fitting and the estimation of uncertainties were completed using the Monte Carlo algorithm and can be improved by future data addition. Models that provided the best fit with the observed ?13C values of sedimentary n-alkanes were either hyperbolic functions or a combination of hyperbolic and sine-squared functions. Such non-linear models may be used to convert ?13C measurements on sedimentary n-alkanes directly into reconstructions of C3 vegetation cover.

Garcin, Yannick; Schefuß, Enno; Schwab, Valérie F.; Garreta, Vincent; Gleixner, Gerd; Vincens, Annie; Todou, Gilbert; Séné, Olivier; Onana, Jean-Michel; Achoundong, Gaston; Sachse, Dirk



Energy dependence of kaon-to-proton ratio fluctuations in central Pb+Pb collisions from $\\sqrt{s_{NN}}$ = 6.3 to 17.3 GeV  

E-print Network

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 $(\\mathrm{K}^+ + \\mathrm{K}^-)/(\\mathrm{p}+\\bar{\\mathrm{p}})$ and $\\mathrm{K}^+/\\mathrm{p}$ ratios have been measured for the first time by NA49 in central Pb+Pb collisions at 5 SPS energies between $\\sqrt{s_{NN}}$= 6.3 GeV and 17.3 GeV. Both ratios exhibit a change of sign in $\\sigma_{\\mathrm{dyn}}$, a measure of non-statistical fluctuations, around $\\sqrt{s_{NN}}$ = 8 GeV. Below this energy, $\\sigma_{\\mathrm{dyn}}$ is positive, indicating higher fluctuation compared to a mixed event background sample, while for higher energies, $\\sigma_{\\mathrm{dyn}}$ is negative, indicating correlated emission of kaons and protons. The results are compared to UrQMD calculations which which give a good description at the higher SPS energies, but fail to reproduce the transition to positive values.

T. Anticic; B. Baatar; D. Barna; J. Bartke; H. Beck; L. Betev; H. Bia?kowska; C. Blume; M. Bogusz; B. Boimska; J. Book; M. Botje; P. Bun?i?; T. Cetner; P. Christakoglou; P. Chung; O. Chvala; J. G. Cramer; V. Eckardt; Z. Fodor; P. Foka; V. Friese; M. Ga?dzicki; K. Grebieszkow; C. Höhne; K. Kadija; A. Karev; V. I. Kolesnikov; T. Kollegger; M. Kowalski; D. Kresan; A. Laszlo; R. Lacey; M. van Leeuwen; M. Mackowiak; M. Makariev; A. I. Malakhov; M. Mateev; G. L. Melkumov; M. Mitrovski; St. Mrówczy?ski; V. Nicolic; G. Pálla; A. D. Panagiotou; W. Peryt; J. Pluta; D. Prindle; F. Pühlhofer; R. Renfordt; C. Roland; G. Roland; M. Rybczy?ski; A. Rybicki; A. Sandoval; N. Schmitz; T. Schuster; P. Seyboth; F. Siklér; E. Skrzypczak; M. Slodkowski; G. Stefanek; R. Stock; H. Ströbele; T. Susa; M. Szuba; M. Utvi?; D. Varga; M. Vassiliou; G. I. Veres; G. Vesztergombi; D. Vrani?; Z. W?odarczyk; A. Wojtaszek-Szwarc



The Mycobacterium tuberculosis 19-Kilodalton Lipoprotein Inhibits Gamma Interferon-Regulated HLA-DR and Fc R1 on Human Macrophages through Toll-Like Receptor 2  

Microsoft Academic Search

Mycobacterium tuberculosis survives in macrophages in the face of acquired CD4 T-cell immunity, which controls but does not eliminate the organism. Gamma interferon (IFN-) has a central role in host defenses against M. tuberculosis by activating macrophages and regulating major histocompatibility complex class II (MHC-II) antigen (Ag) processing. M. tuberculosis interferes with IFN- receptor (IFN-R) signaling in macrophages, but the

Adam J. Gehring; Roxana E. Rojas; David H. Canaday; David L. Lakey; Clifford V. Harding; W. Henry Boom



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.



Ratios For All Occasions  

NSDL National Science Digital Library

This resource guide from the Middle School Portal 2 project, written specifically for teachers, provides links to exemplary resources including background information, lessons, career information, and related national science education standards.A central theme in the middle school mathematics curriculum, proportional reasoning is based on making sense of ratios in a variety of contexts. The resources chosen for this unit provide practice in solving problems, often informally, in the format of games, hands-on modeling, mapmaking, and questions selected for their interest for students. As students work through the activities, they will exercise reasoning about basic proportions as ell as further develop their knowledge of the relationship between fractions and percents.The section titled Background Resources for Teachers contains links to workshop sessions, developed for teachers, on the mathematical content of the unit. Ratios in Childrens Books identifies three picture books that entertain while they explore scale and proportion. In the final section, we look at the coverage of proportionality at the iddle level in the NCTM Principles and Standards for School Mathematics.

Herrera, Terese




E-print Network

Mexican food. Mon.­Fri., 7 am­6 pm Sat., 8 am­2 pm; Sun., 9 am­2 pm 9 Home Run Pizza 1627 Central Avenue-7591 Breakfast burritos, hamburgers, and New Mexican food. Tues.­Fri., 6 am­1 pm Sat., 7 am­noon Closed Sunday salads and sandwiches. Daily, 6 am­12 am NOT SHOWN ON MAP 22 De Colores at the Gate 2470 East Road 662



E-print Network

am­3 pm Sat.­Sun., 7 am­3 pm 8 El Parasol 1903 Central Avenue 661-0303 Native New Mexican food. Mon, hamburgers, and New Mexican food. Tues.­Fri., 6 am­1 pm Sat., 7 am­noon Closed Sunday & Monday 11 Sonic Drive NOT SHOWN ON MAP 22 De Colores at the Gate 2470 East Road 662-6285 Native New Mexican cuisine, grilled


Ratios and Proportions  

NSDL National Science Digital Library

In this learning object from Wisc-Online, students will examine ratios and proportions. The unit's activities include defining ratios and proportions, simplifying ratios, solving problems using proportions and answering practice questions.

Blohowiak, Chad; Jensen, Douglas; Reed, Allen



Studies on the phosphorus requirement and proper calcium/phosphorus ratio in the diet of the black sea bream ( Sparus macrocephalus)  

NASA Astrophysics Data System (ADS)

An expriment on the phosphorus requirement and the proper Ca/P ratio in the diet of the black sea bream using the phosphorus gradient method (with casein as basic diet, sodium dihydrogen phosphate as source of phosphorus, and calcium lactate as source of calcium) showed that growth was greatly affected by the diet's phosphorus content and Ca/P ratio. Inadequate phosphorus in the diet resulted in slow growth and poor food conversion ratio (FCR). Analyses of the fish body showed it contained a high level of lipid but a low level of moisture, ash, calcium and phosphorus. The optimal values of phosphorus and Ca/P ratio in the black sea bream diet are 0.68% and 1?2 respectively. Phosphorus in excess of this optimum value resulted in slow growth or even death. The results of this experiment clearly indicated that phosphorus is the principal mineral additive affecting black sea bream growth.

Liu, Jingke; Li, Maotang; Wang, Keling; Wang, Xincheng; Liu, Jianking



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.  


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



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



Steiner Ratio for Manifolds  

E-print Network

The Steiner ratio characterizes the greatest possible deviation of the length of a minimal spanning tree from the length of the minimal Steiner tree. In this paper, estimates of the Steiner ratio on Riemannian manifolds are obtained. As a corollary, the Steiner ratio for flat tori, flat Klein bottles, and projective plane of constant positive curvature are computed. Steiner ratio - Steiner problem - Gilbert--Pollack conjecture - surfaces of constant curvature

Cieslik, D; Tuzhilin, A A; 10.1023/A:1026106802540



Zernike representation and Strehl ratio of scaled pupil functions  

E-print Network

Zernike representation and Strehl ratio of scaled pupil functions A.J.E.M. Janssen Philips Research derivatives as a function of the scaling factor 1, and we apply this to the Strehl ratio and its derivatives in the focal region under high-NA conditions. Keywords: NA-scaling, Zernike coefficients, Strehl ratio, central


The Strehl Ratio in Adaptive Optics Images: Statistics and Estimation  

E-print Network

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 using a non-central Gamma distribution.

Soummer, Rémi



The Strehl Ratio in Adaptive Optics Images: Statistics and Estimation  

E-print Network

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 using a non-central Gamma distribution.

Rémi Soummer; André Ferrari



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



Optimal content and ratio of lysine to arginine in the diet of Pacific white shrimp, Litopenaeus vannamei  

NASA Astrophysics Data System (ADS)

The optimal quantity of dietary lysine (Lys) and arginine (Arg), and the optimal ratio of dietary Lys to Arg for Pacific white shrimp Litopenaeus vannamei were investigated. Coated Lys and Arg were added to a basal diet (37.99% crude protein and 7.28% crude lipid) to provide graded levels of Lys and Arg. The experimental diets contained three Lys levels (2.51%, 2.11%, and 1.70% of total diet), and three Arg levels (1.41%, 1.80%, and 2.21% of total diet) and all combinations of these levels were tested. Pacific white shrimp, with a mean weight of 3.62±0.1 g, were randomly distributed in 36 fiberglass tanks with 30 shrimp per tank and reared on the experimental diets for 50 days. After the feeding trial, the growth performance, survival, feed conversion rate (FCR), body composition and protease and lipase activities in the hepatopancreases of the experimental shrimps were determined. The results show that weight gain (WG), specific growth rate (SGR), FCR, body protein, body Lys and Arg content were significantly affected by dietary Lys and Arg ( P <0.05) and improved when dietary Lys and Arg levels were 2.11% ˜ 2.51% and 1.80%˜2.21%, respectively. Protease and lipase activities in the hepatopancreases of the shrimps appeared higher when dietary Lys and Arg quantities were 2.11% ˜2.51% and 1.80%˜2.21%, although the difference was not statistically significant ( P >0.05). Therefore, according to our results, the optimal Lys and Arg quantities in the diet of Pacific white shrimp, L. vannamei, were considered to be 2.11%-2.51% and 1.80%-2.21%, respectively, and the optimal ratio to be 1:0.88-1:1.05.

Feng, Zhengfu; Dong, Chaohua; Wang, Linlin; Hu, Yanjiang; Zhu, Wei



On savings ratio  

Microsoft Academic Search

This paper explores the factors that affect saving and consumption behaviours, in a context where some believe that the high savings ratio of the East Asia and oil-producing countries is one major cause for the global imbalances and the crisis. The paper elaborates on the factors behind the high savings ratios in East Asia and oil producing countries and low

Z. Xiaochuan



Baseball Lab (Ratios)  

NSDL National Science Digital Library

Using batting averages, students will create ratios and convert them to rounded decimals (3 places). In addition, they will take decimals and determine several possible equivalent ratios. Then using the relationship that batting average = hits/at bats, the students can use proportions or equations to find either the number of hits or the number of at bats for a given situations.



Transformer ratio enhancement experiment  

Microsoft Academic Search

Recently, a multibunch scheme for efficient acceleration based on dielectric wakefield accelerator technology was outlined in ref.[1]. In this paper we present an experimental program for the design, development and demonstration of an Enhanced Transformer Ratio Dielectric Wakefield Accelerator (ETR-DWA). The principal goal is to increase the transformer ratio R, the parameter that characterizes the energy transfer efficiency from the

A. Kanareykin; Wei Gai; J. G. Power; E. Nenasheva; A. Altmark



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



Common ratio using delay  

Microsoft Academic Search

We present an experiment in which we add a common delay in a choice between two risky prospects. The results show that delay\\u000a produces the same change in preferences as in the well-documented common ratio effect in risky lotteries. The added common\\u000a delay acts as if the probabilities were divided by some common ratio. Moreover, we show that there is

Manel Baucells; Franz H. Heukamp



Isotope Ratio Mass Spectrometry.  


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



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.



The Likelihood Ratio Test  

NSDL National Science Digital Library

This module, created by Don Johnson of Rice University, provides an explanation and an example of the likelihood ratio test. Topics include: decision regions, Bayes' decision criterion, Bayes' cost, and likelihood function. The site is enhanced by Johnson's use of graphic and numerical demonstrations to better explain his points. Additionally, a PDF attachment providing an in-depth explanation is also featured.

Johnson, Don



Sex ratio bias, male aggression, and population collapse in lizards  

E-print Network

20, 2005) The adult sex ratio (ASR) is a key parameter of the demography of human and other animal population extinction sexual coercion The adult sex ratio (ASR) is a central concept of population demography of understanding the popu- lation consequences of ASR variation has attracted much atten- tion from human

Alvarez, Nadir


Digit ratio in birds.  


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



@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.


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.



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



Helium isotope ratios in Ethiopian Rift basalts  

NASA Astrophysics Data System (ADS)

Helium isotope ratios were measured in olivine and pyroxene phenocrysts from basalts of the Ethiopian Rift Valley and Afar Depression between 6° and 15°N and 37° and 43°E. 3He/ 4He ratios range from 6 to 17 times the atmospheric value (R A = 1.4 × 10 -6), that is, from ratios less than typical MORB (depleted mantle) helium (R/R A= 8 ± 1) to ratios similar to high- 3He hotspots and to the Yellowstone hotspot (R/R A= 16.5). The high 3He/ 4He ratios occur all along the Ethiopian Rift and well up into the Afar Depression, with a maximum value of 17.0 R A at 8°N in the Rift Axis and a high value of 14.2 R A in the central Tat'Ali sector of the Afar Depression. The ratios decrease to MORB-like values near the edge of the Red Sea, and to sub-MORB ratios (5-6 R A) at the northern end of the Rift (Zula Peninsula) and at the southern end, at lakes Abaya and Chamo. The Ethiopian Rift provides the only continental hotspot terrain in which helium isotope ratios can be compared in detail between volcanic lavas and associated geothermal and volcanic gases, a primary motivation for this work. Comparison with our previously measured ratios in fluids and gases (range 2-15 R A) shows excellent agreement in the areas sampled for both lavas and fluids, and indicates that high-temperature volcanic fluids can be used for establishing helium isotope signatures in such terrains. The high- 3He values in both fluids and basalts show that a Primitive Mantle (PM) component is required and that a Lower Mantle High- 3He plume is strongly involved as a driving force in the rifting process of the East African Rift System.

Scarsi, P.; Craig, H.



10 CFR 429.16 - Central air conditioners and heat pumps.  

...central air conditioning heat pumps: The seasonal energy efficiency ratio...central air conditioning heat pumps whose seasonal energy efficiency ratio and...duct, high velocity heat pumps: The seasonal energy efficiency...



10 CFR 429.16 - Central air conditioners and heat pumps.  

Code of Federal Regulations, 2013 CFR

...central air conditioning heat pumps: The seasonal energy efficiency ratio...central air conditioning heat pumps whose seasonal energy efficiency ratio and...duct, high velocity heat pumps: The seasonal energy efficiency...



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.



Ratios and Proportions  

NSDL National Science Digital Library

This interactive slideshow explains the notion of ratios and proportions, how to write the, and how to find them. There are practice problems which walk visitors through each step of the process, including reducing answers to simplest terms, in which students are asked to calculate the rate of grass seed coverage per square foot and find the miles per gallon fuel use of a car. The lesson continues on to introduce proportion and work through practice problems in the same fashion.

Jensen, Douglas; Reed, Allen



Measurement of ? branching ratios  

NASA Astrophysics Data System (ADS)

We have measured the branching ratios for several ? decay modes. We use e+e--->?+?- events accumulated with the TPC/Two-Gamma facility at the SLAC e+e- storage ring PEP. The data correspond to an integrated luminosity of 77 pb-1 at a center-of-mass energy of 29 GeV. The one- and three-charged-particle inclusive branching ratios of the ? decay are measured to be B1=(84.7+/-1.0)% and B3=(15.1+/-1.0)%, where B1+B3 is constrained to be 99.85%. The branching ratios of the two leptonic decay modes are B(?--->e- ?¯e??)=(18.4+/-1.6)% and B(?--->?- ?¯???)=(17.7+/-1.4)%. If we then assume lepton universality, we obtain B(?--->e- ?¯e??)=(18.3+/-0.9)% and B(?--->?- ?¯???)=(17.8+/-0.9)%. We measure the Cabibbo-allowed semihadronic decay mode B(?--->?-+neutral particles)=(47.0+/-1.5)%, and the Cabibbo-suppressed ? decay mode B(?--->K-+neutral particles)=(1.6+/-0.4)%. By looking for associated photons, we find B(?--->K-?0+neutral particles) to be (1.2+/-0.6)%. Using the channel K*--->KOS?+?-, we find B(?--->K*-(892)+neutral particles)=(1.4+/-0.9)%. The quoted errors are the combined statistical and systematic errors.

Aihara, H.; Alston-Garnjost, M.; Avery, R. E.; Bakken, J. A.; Barbaro-Galtieri, A.; Barker, A. R.; Barnes, A. V.; Barnett, B. A.; Barnett, B. A.; Bauer, D. A.; Bengtsson, H.-U.; Bintinger, D. L.; Bobbink, G. J.; Bolognese, T. S.; Bross, A. D.; Buchanan, C. D.; Buijs, A.; Caldwell, D. O.; Chien, C.-Y.; Clark, A. R.; Cowan, G. D.; Crane, D. A.; Dahl, O. I.; Derby, K. A.; Eastman, J. J.; Edberg, T. K.; Eberhard, P. H.; Eisner, A. M.; Enomoto, R.; Erné, F. C.; Fujii, T.; Gary, J. W.; Gorn, W.; Hauptman, J. M.; Hofmann, W.; Huth, J. E.; Hylen, J.; Kamae, T.; Kaye, H. S.; Kees, K. H.; Kenney, R. W.; Kerth, L. T.; Ko, Winston; Koda, R. I.; Kofler, R. R.; Kwong, K. K.; Lander, R. L.; Langeveld, W. G.; Layter, J. G.; Linde, F. L.; Lindsey, C. S.; Loken, S. C.; Lu, A.; Lu, X.-Q.; Lynch, G. R.; Madansky, L.; Madaras, R. J.; Maeshima, K.; Magnuson, B. D.; Marx, J. N.; Masek, G. E.; Mathis, L. G.; Matthews, J. A.; Maxfield, S. J.; Melnikoff, S. O.; Miller, E. S.; Moses, W.; McNeil, R. R.; Nemethy, P.; Nygren, D. R.; Oddone, P. J.; Paar, H. P.; Park, D. A.; Park, S. K.; Pellett, D. E.; Pevsner, A.; Pripstein, M.; Ronan, M. T.; Ross, R. R.; Rouse, F. R.; Schwitkis, K. A.; Sens, J. C.; Shapiro, G.; Shapiro, M. D.; Shen, B. C.; Slater, W. E.; Smith, J. R.; Steinman, J. S.; Stevenson, M. L.; Stork, D. H.; Strauss, M. G.; Sullivan, M. K.; Takahashi, T.; Thompson, J. R.; Toge, N.; Toutounchi, S.; van Tyen, R.; van Uitert, B.; Vandalen, G. J.; van Daalen Wetters, R. F.; Vernon, W.; Wagner, W.; Wang, E. M.; Wang, Y. X.; Wayne, M. R.; Wenzel, W. A.; White, J. T.; Williams, M. C.; Wolf, Z. R.; Yamamoto, H.; Yellin, S. J.; Zeitlin, C.; Zhang, W.-M.



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. PMID:18958244

Uchida, Naoshige; Mainen, Zachary F.



Central Venous Catheter (Central Line)  


... of central line Collarbone ATS PATIENT INFORMATION SERIES Infection— ? ? Any tube (catheter) entering the body can make it easier for ... catheter. 4 If you have any sign of infection or other catheter problem, call your health care provider immediately. Doctor’s ...


Central Park  

NSDL National Science Digital Library

As one of the worldâÂÂs greatest urban green spaces, Central Park is loved by dyed-in-the wool New Yorkers as well as visitors to the city. This reverential website provides detailed information about this fine public space and the activities that take place within its confines. On this site, visitors can look over maps of the park, learn about the parkâÂÂs many attractions, and browse a selection of photographs of this fine urban paradise. The homepage contains much of this material, along with a âÂÂCentral Park Newsâ feature, which provides news updates about goings on throughout Central Park. For those planning a visit to the park, the Events area will be most useful, as it provides information about such pastimes as rock climbing, ice skating lessons, and yoga.



Garlic Central  

NSDL National Science Digital Library

Can garlic help repel mosquitoes? Find out the answer to this question and more at Garlic Central, an all-about-garlic website created by aficionado Trevor Mendham. The site contains an introductory section--titled Garlic 101--and sections that address culinary uses, medicinal benefits, and cultivation. The site's Cooking section includes a collection of recipes; and information about storing, freezing, and crushing garlic. The site also features a brief how-to guide for planting, growing, and harvesting garlic. Garlic Central even hosts a virtual shopping mall that connects site visitors to a wide range of garlic-related websites peddling foodstuffs, kitchen implements, posters, books, and garden supplies. This site is also reviewed in the September 17, 2004 _NSDL Life Sciences Report_.


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.



IPO Central  

NSDL National Science Digital Library

IPO (Initial Public Offerings) Central, provided by The Reference Press, contains a wealth of information on IPOs. It features a complete list of companies that "filed for an initial public offering of common stock on or after May 6, 1996, the first day that all US companies were required to file electronically," along with EDGAR Online SEC filings. This directory can be accessed alphabetically or by date, and the latest filings are available under a separate menu item. IPO Central also highlights one featured IPO per week, with a free link to a Hoover Online profile on that company. "The Insider" offers short analytical columns on IPOs, and the "Beginner's Guide" has links to basic IPO information to help the novice. The site also offers links to other IPO-related sites. IPO Central does not at this time offer a searchable interface to its directory, but the providers promise improved search features soon. Note that listings are removed from the directory after six months and that EDGAR Online is in no way related to SEC (Securities and Exchange Commission) EDGAR.


Ratios, Proportions, Similarity  

NSDL National Science Digital Library

This is a set of four, one-page problems about the size of planets compared to earth. Learners may use ratios to compare planets within our solar system or those outside of our solar system with the earth. Options are presented so that students may learn about the MESSENGER mission to Mercury through a NASA press release or by viewing a NASA eClips video [6 min.]. This activity is part of the Space Math multi-media modules that integrate NASA press releases, NASA archival video, and mathematics problems targeted at specific math standards commonly encountered in middle school.


Central pain.  


ABSTRACT Questions from patients about pain conditions and analgesic pharmacotherapy and responses from authors are presented to help educate patients and make them more effective self-advocates. The topic addressed in this issue is central pain, a neuropathic pain syndrome caused by a lesion in the brain or spinal cord that sensitizes one's perception of pain. It is a debilitating condition caused by various diseases such as multiple sclerosis, strokes, spinal cord injuries, or brain tumors. Varied symptoms and the use of pharmacological medicines and nonpharmacological therapies will be addressed. PMID:25295639

Singh, Supreet



Neuropsychology Central  

NSDL National Science Digital Library

Neuropsychology Central is devoted to the subject of - "Neuropsychology, a new branch of science with the specific and unique aim of investigating the role of individual brain systems in complex forms of mental activity." - A.R. Luria "The Working Brain" The page aims to describe the importance of neuropsychology as a science of brain and behavior, and to act as a resource for the professional and layperson alike. See links to current technology for brain imaging, and sections covering different aspects of this ever growing field such as cognitive, developmental, and geriatric Neuropsychology. In addition, a reader survey is included to facilitate the expansion of the site.

Browndyke, J. N.



Peak power ratio generator  


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)



Trace ratio problem revisited.  


Dimensionality reduction is an important issue in many machine learning and pattern recognition applications, and the trace ratio (TR) problem is an optimization problem involved in many dimensionality reduction algorithms. Conventionally, the solution is approximated via generalized eigenvalue decomposition due to the difficulty of the original problem. However, prior works have indicated that it is more reasonable to solve it directly than via the conventional way. In this brief, we propose a theoretical overview of the global optimum solution to the TR problem via the equivalent trace difference problem. Eigenvalue perturbation theory is introduced to derive an efficient algorithm based on the Newton-Raphson method. Theoretical issues on the convergence and efficiency of our algorithm compared with prior literature are proposed, and are further supported by extensive empirical results. PMID:19304481

Jia, Yangqing; Nie, Feiping; Zhang, Changshui



Ratio and Proportion  

NSDL National Science Digital Library

This interactive Flash applet helps students explore concepts of ratio and proportion. It displays two containers, each with its own tap that can be set to deliver different-colored liquids in units of 1 to 10. A main tap can be set to deliver multiples of the amounts on the left- and right-hand taps. Proportion can be modelled using the drain container, which receives whatever is in the left- and right-hand containers. Users can choose the capacity of the containers, whether to hide or show the scales, and the size and visibility of the drain container. Clicking on the info button allows users to mouse over items to learn about them. This applet lends itself well for use with an interactive white board. A pdf guide to this collection of teaching applets is cataloged separately.



Nuclear temperature measurement for central collisions  

Microsoft Academic Search

Nuclear temperatures from double isotope yield ratios and excited state populations were measured for central ^86Kr + ^93Nb collision at 35 70 100 and 120 AMeV. Temperatures based on ^3He\\/^4He isotope ratio increase with beam energy while temperatures from excited state populations remain nearly constant around 4-5 MeV. Temperatures from the double isotope yield based on ^11C\\/^12C ratio are consistent

H. Xi; G. J. Kunde; R. Shomin; O. Bjarki; S. Fritze; C. K. Gelbke; C. Gross; J. Imme; R. C. Lemmon; W. G. Lynch; A. Nadason; C. Nociforo; V. Maddalena; D. Magestro; T. Odeh; R. Popescu; G. Raciti; G. Riccobene; P. Romano; A. Saija; C. Schwarz; C. Sfienti; M. B. Tsang; A. M. Vandermolen; G. D. Westfall; L. W. Weathers



Note on the Odds Ratio and the Probability Ratio  

Microsoft Academic Search

This note compares the odds ratio with the probability ratio (relative risk). These quantities arise, for example, in the analysis of educational and social science data by means of logistic regression.

Michael P. Cohen



Dietary L-arginine supplement alleviates hepatic heat stress and improves feed conversion ratio of Pekin ducks exposed to high environmental temperature.  


The current intensive indoor production system of commercial Pekin ducks never allows adequate water for swimming or wetting. Therefore, heat stress is a key factor affecting health and growth of ducks in the hot regions and season. Experiment 1 was conducted to study whether heat stress was deleterious to certain organs of ducks. Forty-one-day-old mixed-sex Pekin ducks were randomly allocated to four electrically heated battery brooders comprised of 10 ducks each. Ducks were suddenly exposed to 37 °C ambient temperature for 3 h and then slaughtered, in one brooder at 21 days and in another brooder at 49 days of age. The results showed that body weight and weight of immune organs, particularly liver markedly decreased in acute heat stress ducks compared with the control. Experiment 2 was carried out to investigate the influences of dietary L-arginine (Arg) supplement on weight and compositions of certain lymphoid organs, and growth performance in Pekin ducks, under daily cyclic hot temperature environment. A total of 151-day-old mixed-sex Pekin ducks were randomly divided into one negative control and two treatment groups, fed experimental diets supplemented with 0, 5, and 10 g L-Arginine (L-Arg)/kg to the basal diet respectively. Ducks were exposed to cyclic high temperature simulating natural summer season. The results showed that the addition of L-Arg improves feed conversion ratio (FCR) during a period of 7-week trial, as well as increases hepatic weight relative to body weight at 21 days, while decreases the hepatic water content at 49 days of age. This study indicated that the liver was more sensitive to acute heat stress, and the hepatic relative weight and chemical composition could be regulated by dietary L-Arg supplementation in Pekin ducks being reared at high ambient temperature. These beneficial effects of Arg on liver might be a cause of improved FCR. PMID:24773570

Zhu, W; Jiang, W; Wu, L Y



Video Resources Central Asia  

E-print Network

Video Resources Central Asia � Central Asia Country Overviews: phase of political and economic change, what new partnership opportunities will emerge?

Qian, Ning


Central Pain Syndrome  


NINDS Central Pain Syndrome Information Page Table of Contents (click to jump to sections) What is Central Pain Syndrome? Is there ... being done? Clinical Trials Organizations What is Central Pain Syndrome? Central pain syndrome is a neurological condition ...


Strehl ratio and aberration balancing  

Microsoft Academic Search

The relation between the Strehl ratio and the wave-front variance is analyzed from the point of view of aberration balancing. For some given set of aberrations the Strehl ratio is calculated along two different parametric paths in the aberration space: one corresponding to the minimum wave-front variance and the other to the maximum Strehl ratio. The case of the combination

Geiser Martial



Debate Central  

NSDL National Science Digital Library

Courtesy of the National Center for Policy Analysis (NCPA), 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."



Spetroscopic Line-Depth Ratios and Solar Variability  

Microsoft Academic Search

The ratios of the central depths of selected spectral lines has proved to be a sensitive index of a star's temperature. Line-depth ratios have been successfully applied to main sequence stars (Gray 1994 P.A.S.P. 106, 1248) as well as giants (Gray &Brown 2001 P.A.S.P., 113, 723). A stellar calibration and subsequent application to solar data over a magnetic cycle gave

D. Gray



Sex ratio dependent dispersal when sex ratios vary between patches.  


Female biased sex ratios reduce competition between brothers when mating takes place within local patches. Male dispersal prior to mating is another strategy that reduces competition between brothers. One may thus expect these two traits to co-evolve and this is partially met in that sex ratios becomes less female biased as dispersal increases. However, the evolutionary stable degree of dispersal is unaffected by the sex ratio. The analytical models developed to reach these conclusions ignored variance in sex ratios, since this increases the structural complexity of models. For similar reasons finite clutch sizes are also routinely ignored. To overcome these shortfalls, we developed individual based simulations that allowed us to incorporate realistic clutch sizes and binomial variance in sex ratios between patches. We show that under variable sex ratios, males evolve to more readily disperse away from patches with higher sex ratios than lower sex ratios. We show that, while the dispersal rate is insensitive to the sex ratio when sex ratios are precise, it is affected by the number of males with dispersal decreasing as the number of males decreases. PMID:21893071

Nelson, Ronald M; Greeff, Jaco M



Enhanced photosynthetic assimilation ratios in Antarctic Polar Front (convergence) diatoms  

Microsoft Academic Search

Diatom populations from the Antarctic Polar Front (convergence) in the Drake Passage area exhibited relatively high photosynthesis : chlorophyll a ratios at light saturation. The permanent water column instability and the adverse meteorological conditions observed in the central Drake Passage area seem to product a light-color stress on the physiology of convergence diatoms that are restricted to a blue-green light




Overview Chromosomal Recombination Extensions on the Likelihood Ratio  

E-print Network

Overview Chromosomal Recombination Topic 19 Extensions on the Likelihood Ratio Chi-square Tests 1 / 10 #12;Overview Chromosomal Recombination Outline Overview Chromosomal Recombination 2 / 10 #12;Overview Chromosomal Recombination Overview For the two-sided sample proportion test, we used the central

Watkins, Joseph C.


Statistical moments of the Strehl ratio  

NASA Astrophysics Data System (ADS)

Knowledge of the statistical characteristics of the Strehl ratio is essential for the performance assessment of the existing and future adaptive optics systems. For full assessment not only the mean value of the Strehl ratio but also higher statistical moments are important. Variance is related to the stability of an image and skewness reflects the chance to have in a set of short exposure images more or less images with the quality exceeding the mean. Skewness is a central parameter in the domain of lucky imaging. We present a rigorous theory for the calculation of the mean value, the variance and the skewness of the Strehl ratio. In our approach we represent the residual wavefront as being formed by independent cells. The level of the adaptive optics correction defines the number of the cells and the variance of the cells, which are the two main parameters of our theory. The deliverables are the values of the three moments as the functions of the correction level. We make no further assumptions except for the statistical independence of the cells.

Yaitskova, Natalia; Esselborn, Michael; Gladysz, Szymon



Photovoltaic central-station power conditioner subsystems  

NASA Technical Reports Server (NTRS)

The potential of applying new advanced circuit topologies and semiconductors with improved switching characteristics to the design and development of central-station power conditioning subsystems is assessed. State-of-the-art large power conditioners suitable for photovoltaic central-station application are reviewed. Advanced topology power conditioning subsystems, when compared to available production hardware, promise improved performance, significant cost reduction, and lower cost-to-efficiency ratios.

Krauthamer, S.; Das, R.; Bahrami, K.; Bulawka, A.



Original article Multivariate restricted  

E-print Network

in slaughtered animals, a fixed sex effect and a covariable (weight at the beginning or at the end of the test of 7 traits measured in central test stations - average daily gain (ADG1), feed conversion ratio (FCR restricted maximum likelihood (DF-REML) procedure applied to a multiple trait individual animal model

Paris-Sud XI, Université de


High ratio recirculating gas compressor  


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)



High ratio recirculating gas compressor  


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. 10 figs.

Weinbrecht, J.F.



North America Europe Central &  

E-print Network

1 North America Western Europe Central & Eastern Europe Latin America & Caribbean Middle East & Central Asia Asia Pacific Africa Population (100 millions) 0 5 10 15 20 25 30 35 North America Western Europe Central & Eastern Europe Latin America & Caribbean Middle East & Central Asia Asia Pacific Africa

Johnson, Matthew


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



FcR Activation Regulates Inflammation-Associated Squamous Carcinogenesis  

E-print Network

, chronic inflammatory diseases, including several autoimmune disorders, are associated with increased risk about the function of CICs in tumor development, the role of CICs in inflammatory and autoimmune

Dalang, Robert C.


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



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



Pressure Ratio to Thermal Environments  

NASA Technical Reports Server (NTRS)

A pressure ratio to thermal environments ( 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



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



Isotopic ratios in planetary atmospheres.  


Recent progress on measurements of isotopic ratios in planetary or satellite atmospheres include measurements of the D/H ratio in the methane of Uranus, Neptune and Titan and in the water of Mars and Venus. Implications of these measurements on our understanding of the formation and evolution of the planets and satellite are discussed. Our current knowledge of the carbon, nitrogen and oxygen isotopic ratios in the atmospheres of these planets, as well as on Jupiter and Saturn, is also reviewed. We finally show what progress can be expected in the very near future due to some new ground-based instrumentation particularly well suited to such studies, and to forthcoming space missions. PMID:11539257

de Bergh, C



Ultra-high extinction ratio micropolarizers using plasmonic lenses.  


The design of a new type of plasmonic ultra-high extinction ratio micropolarizing transmission filter is presented along with an experimental demonstration. A pair of dielectric coated metal gratings couple incident TM polarized light into surface plasmons, which are fed into a central metal-insulator-metal (MIM) waveguide, followed by transmission through a sub-wavelength aperture. Extinction ratios exceeding 10¹¹ are predicted by finite element simulation. Good absolute agreement for both the spectral and polarization response is obtained between measurement and simulations using measured geometric parameters. The filters can be easily fabricated and sized to match the pixel pitch of current focal plane arrays. PMID:21935173

Peltzer, J J; Flammer, P D; Furtak, T E; Collins, R T; Hollingsworth, R E



Surface to Volume Ratio Activity  

NSDL National Science Digital Library

By the National Nanotechnology Infrastructure Network, this two-part laboratory activity was designed to complement any chemistry unit on catalysts to "help students understand how nanoparticles may be more effective catalysts by investigating how the surface area-to-volume ratio of a substance is affected as its shape changes." On this site, educators can find both the teacher and student instructions for preparing and presenting the laboratory with objectives, time periods, materials, procedures, example answers, and much more. It is a ready-to-use lesson to help students understand catalysts and surface to volume ratio at molecular and atomic levels.



Central line infections - hospitals  


... 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 ...


Centralize Printing, and Save.  

ERIC Educational Resources Information Center

Describes the operations of a centralized printing office in a California school district. Centralization greatly increased the efficiency and lowered the cost of generating publications, information services, newsletters, and press releases throughout the school year. (TE)

McCormick, Kathleen



Central Tendency and Variability  

NSDL National Science Digital Library

This chapter presents two important interrelated topics in statistics: central tendency and variability. Measures of central tendency show how similar the data points in a set of data are, while measures of variability show how much the

Christmann, Edwin P.; Badgett, John L.



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.



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



Central and peripheral demyelination  

PubMed Central

Several conditions cause damage to the inherently normal myelin of central nervous system, perepheral nervous system or both central and perepheral nervous system and hence termed as central demyelinating diseases, perepheral demyelinating diseases and combined central and perepheral demyelinating diseases respectively. Here we analysed and foccused on the etiology, prevalance, incidence and age of these demyelinating disorders. Clinical attention and various diagnostic tests are needed to adequately assess all these possibilities. PMID:24741263

Mehndiratta, Man Mohan; Gulati, Natasha Singh



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))



Origin of Lead in Eight Central European Peat Bogs Determined  

E-print Network

Research Origin of Lead in Eight Central European Peat Bogs Determined from Isotope Ratios. The Sphagnum-dominated bogs were located mainly in mountainous regions of the Czech Republic bordering that environmental lead in Central Europe had been largely affected by human activity (smelting) even before

Wieder, R. Kelman



E-print Network

1 OPERATOR INTERACTION WITH CENTRALIZED VERSUS DECENTRALIZED UAV ARCHITECTURES Affiliation M research activity attempting to streamline Unmanned Aerial Vehicle (UAV) operations and reduce staffing in order to invert the current many-to-one ratio of operators to vehicles. Centralized multiple UAV

Cummings, Mary "Missy"


Magnetic Field and Critical Current of a BSCCO HTS Magnet at Various Aspect Ratios  

Microsoft Academic Search

When the length of wire used to make an HTS magnet is fixed, the magnetic properties of the HTS magnet including the central magnetic field and stored energy mostly depend on the as- pect ratio of the HTS magnet. This paper presents calculations of the magnetic properties of a BSCCO HTS magnet at various as- pect ratios. The HTS magnet

Myunghun Kang; Youngmin Kim; Heejoon Lee; Gueesoo Cha; Kyungwoo Ryu



System and rapidity dependence of baryon to meson ratios at RHIC  

E-print Network

The rapidity and centrality dependence of baryon to meson ratios in Au$+$Au, Cu$+$Cu and p$+$p collisions at $\\sqrt{s_{NN}}$ = 200 GeV at RHIC is presented. The $\\bar{p}/\\pi^{-}$ ratios are founded to be independent of collision system at a fixed $$ at mid- and forward rapidities.

Eun-Joo Kim



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.



Global Carbon Reservoir Oxidative Ratios  

NASA Astrophysics Data System (ADS)

Photosynthesis and respiration move carbon and oxygen between the atmosphere and the biosphere at a ratio that is characteristic of the biogeochemical processes involved. This ratio is called the oxidative ratio (OR) of photosynthesis and respiration, and is defined as the ratio of moles of O2 per moles of CO2. This O2/CO2 ratio is a characteristic of biosphere-atmosphere gas fluxes, much like the 13C signature of CO2 transferred between the biosphere and the atmosphere has a characteristic signature. OR values vary on a scale of 0 (CO2) to 2 (CH4), with most ecosystem values clustered between 0.9 and 1.2. Just as 13C can be measured for both carbon fluxes and carbon pools, OR can also be measured for fluxes and pools and can provide information about the processes involved in carbon and oxygen cycling. OR values also provide information about reservoir organic geochemistry because pool OR values are proportional to the oxidation state of carbon (Cox) in the reservoir. OR may prove to be a particularly valuable biogeochemical tracer because of its ability to couple information about ecosystem gas fluxes with ecosystem organic geochemistry. We have developed 3 methods to measure the OR of ecosystem carbon reservoirs and intercalibrated them to assure that they yield accurate, intercomparable data. Using these tools we have built a large enough database of biomass and soil OR values that it is now possible to consider the implications of global patterns in ecosystem OR values. Here we present a map of the natural range in ecosystem OR values and begin to consider its implications. One striking pattern is an apparent offset between soil and biospheric OR values: soil OR values are frequently higher than that of their source biomass. We discuss this trend in the context of soil organic geochemistry and gas fluxes.

Masiello, C. A.; Gallagher, M. E.; Hockaday, W. C.



GUT Scale Fermion Mass Ratios  

NASA Astrophysics Data System (ADS)

We present a series of recent works related to group theoretical factors from GUT symmetry breaking which lead to predictions for the ratios of quark and lepton Yukawa couplings at the unification scale. New predictions for the GUT scale ratios y?/ys, y?/yb and yt/yb in particular are shown and compared to experimental data. For this comparison it is important to include possibly large supersymmetric threshold corrections. Due to this reason the structure of the fermion masses at the GUT scale depends on TeV scale physics and makes GUT scale physics testable at the LHC. We also discuss how this new predictions might lead to predictions for mixing angles by discussing the example of the recently measured last missing leptonic mixing angle ?13 making this new class of GUT models also testable in neutrino experiments.

Spinrath, Martin



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. PMID:23616165

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



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



The golden ratio autocorrelation function  

E-print Network

On the base of the recurrence relation formalism an autocorrelation function is obtained, the continued fraction form of which corresponds to the golden ratio ones. It turns out that this GR autocorrelation is known in science and obeys all necessary conditions, in contrast to the exponential autocorrelation function. Using the Kubo approach it is shown how exponential correlations appear in the linear response theory as a result on non-Hermitian relaxation of the system.

R. Tsekov



Oxygen isotope ratio studies in the Galactic center region  

NASA Astrophysics Data System (ADS)

Using the Delingha 13.7 m telescope with a 9-beam SIS superconducting receiver installed, we carried out mapping of C18O and C17O J = (1 - 0) toward molecular clouds in the central molecular zone (CMZ) and in the halo of our galaxy. From the integrated intensity ratio of C18O to C17O, the isotope ratio 18O/17O ratio can be estimated, which is considered to be one of the most useful tracers of nuclear processing and metal enrichment. Here preliminary results are presented toward Sgr A, Sgr B2, Sgr C, Sgr D, and the 1.°3 complex in the CMZ and M+5.3-0.3 in the halo.

Zhang, JiangShui; Sun, Lulu; Qiu, Jianjie; Lu, Dengrong; Wang, Min



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



Is bank supervision central to central banking?  

Microsoft Academic Search

Recently, several central banks have lost their bank supervisory responsibilities, in part because it has not been shown that supervisory authority improves the conduct of monetary policy. This paper finds that confidential bank supervisory information could help the Board staff more accurately forecast important macroeconomic variables and is used by FOMC members to guide monetary policy. These findings suggest that

Joe Peek; Eric S. Rosengren; Geoffrey M. B. Tootell



Variable ratio regenerative braking device  


Disclosed is a regenerative braking device (10) for an automotive vehicle. The device includes an energy storage assembly (12) having a plurality of rubber rollers (26, 28) mounted for rotation between an input shaft (36) and an output shaft (42), clutches (38, 46) and brakes (40, 48) associated with each shaft, and a continuously variable transmission (22) connectable to a vehicle drivetrain and to the input and output shafts by the respective clutches. The rubber rollers are torsionally stressed to accumulate energy from the vehicle when the input shaft is clutched to the transmission while the brake on the output shaft is applied, and are torsionally relaxed to deliver energy to the vehicle when the output shaft is clutched to the transmission while the brake on the input shaft is applied. The transmission ratio is varied to control the rate of energy accumulation and delivery for a given rotational speed of the vehicle drivetrain.

Hoppie, Lyle O. (Birmingham, MI)



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.



CDF Central Outer Tracker  

Microsoft Academic Search

The Central Outer Tracker is a large cylindrical drift chamber constructed to replace Collider Detector at Fermilab's original central drift chamber for the higher luminosity expected for Run 2 at the Fermilab Tevatron. The chamber's drift properties are described in the context of meeting the operating requirements for Run 2. The design and construction of the chamber, the front-end readout

T. Affolder; D. Allspach; D. Ambrose; J. Bialek; W. Bokhari; M. Brozovic; M. Binkley; K. Burkett; A. Byon-Wagner; F. Cogswell; N. Dressnandt; Z. Feng; M. Franklin; L. Galtieri; D. W Gerdes; J. Greenwood; V. Guarino; J Guimaraes da Costa; R. Haggerty; C. Hall; J. Heinrich; A. Holloway; T. Jacobi; K. Kephart; D. Khazins; Y. K Kim; M. Kirby; W. Kononenko; A. V. Kotwal; J. Kraus; T. M Liss; N. Lockyer; R. Madrak; T. Miao; A. Mukherjee; C. Neu; M. Newcomer; J. M Niczyporuk; L. Nodulman; W. Orejudous; T. J Phillips; K. T Pitts; W. Reigler; R. Richards; C. Rivetta; W. J Robertson; R. Roser; L. Sadler; R. Sandberg; S. Sansone; R. Schmitt; K. Schultz; D. Shuman; R. Silva; P. Singh; R. Snihur; P. Tamburello; J. Taylor; R. Thurman-Keup; D. Tousignant; F. Ukegawa; R Van Berg; G. Veramendi; T. Vickey; J. Wacker; R. L Wagner; R. Weidenbach; W. C Wester; H. H. Williams; P. Wilson; P. Wittich; A. Yagil; I. Yu; S. Yu; J. C Yun



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,



Back to Central Tolerance  

Microsoft Academic Search

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.

Diane Mathis; Christophe Benoist



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



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.



System-size dependence of particle-ratio fluctuations in Pb + Pb collisions at 158A GeV  

NASA Astrophysics Data System (ADS)

New measurements by the NA49 experiment of the centrality dependence of event-by-event fluctuations of the particle yield ratios (K++K-)/(?++?-), (p+p¯)/(?++?-), and (K++K-)/(p+p¯) are presented for Pb+Pb collisions at 158A GeV. The absolute values of the dynamical fluctuations of these ratios, quantified by the measure ?dyn, increase by about a factor of two from central to semiperipheral collisions. Multiplicity scaling scenarios are tested and found to apply for both the centrality and the previously published energy dependence of the (K++K-)/(?++?-) and (p+p¯)/(?++?-) ratio fluctuations. A description of the centrality and energy dependence of (K++K-)/(p+p¯) ratio fluctuations by a common scaling prescription is not possible since there is a sign change in the energy dependence.

Anticic, T.; Baatar, B.; Barna, D.; Bartke, J.; Beck, H.; Betev, L.; Bia?kowska, H.; Blume, C.; Bogusz, M.; Boimska, B.; Book, J.; Botje, M.; Bun?i?, P.; Cetner, T.; Christakoglou, P.; Chung, P.; Chvála, O.; Cramer, J. G.; Eckardt, V.; Fodor, Z.; Foka, P.; Friese, V.; Ga?dzicki, M.; Grebieszkow, K.; Höhne, C.; Kadija, K.; Karev, A.; Kolesnikov, V. I.; Kollegger, T.; Kowalski, M.; Kresan, D.; László, A.; Lacey, R.; van Leeuwen, M.; Ma?kowiak-Paw?owska, M.; Makariev, M.; Malakhov, A. I.; Mateev, M.; Melkumov, G. L.; Mitrovski, M.; Mrówczy?ski, St.; Nicolic, V.; Pálla, G.; Panagiotou, A. D.; Peryt, W.; Pluta, J.; Prindle, D.; Pühlhofer, F.; Renfordt, R.; Roland, C.; Roland, G.; Rybczy?ski, M.; Rybicki, A.; Sandoval, A.; Schmitz, N.; Schuster, T.; Seyboth, P.; Siklér, F.; Skrzypczak, E.; S?odkowski, M.; Stefanek, G.; Stock, R.; Ströbele, H.; Susa, T.; Szuba, M.; Utvi?, M.; Varga, D.; Vassiliou, M.; Veres, G. I.; Vesztergombi, G.; Vrani?, D.; W?odarczyk, Z.; Wojtaszek-Szwarc, A.



Variable expansion ratio reaction engine  

SciTech Connect

A variable expansion ratio reaction rocket engine for producing a mainstream of hot combustion gases is described comprising: a reaction chamber including a thrust nozzle portion formed by converging and diverging wall portions in which the diverging portion terminates in a gas discharge and through which the combustion gases pass; a nozzle throat section at the juncture of the convergent-divergent wall portions; rows of circumferentially and axially spaced injection ports formed within the wall portions and communicating therethrough and into the reaction chamber; fluid conduit means in communication with the injection ports; at least one high pressure pump in communication with the fluid conduit means; a fluid containing storage tank including a conduit in communication with the high pressure pump; and means for selectively controlling a flow of fluid out of the tank, through the pump and to the fluid conduit means and the injection ports for controlling a cross-sectional area of the mainstream combustion gases passing through the thrust nozzle.

Wagner, W.R.




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.



NUCLEAR PHYSICS: Impact Parameter Dependence of the Double Neutron/Proton Ratio of Nucleon Emissions in Isotopic Reaction Systems  

NASA Astrophysics Data System (ADS)

Within the transport model IBUU04, we investigate the double neutron/proton ratio of free nucleons taken from two reaction systems using two Sn isotopes at a beam energy of 50 MeV/nucleon and with impact parameters 2 fm, 4 fm and 8 fm, respectively. It is found that the double neutron/proton ratio from peripheral collisions is more sensitive to the density dependence of the symmetry energy than those from mid-central and central collisions.

Zhang, Xun-Chao; Li, Bao-An; Chen, Lie-Wen; Yong, Gao-Chan



Correlation between psoriasis' severity and waist-to-height ratio*  

PubMed Central

In the absence of ideal biomarkers, the research for clinical markers correlated to the severity of psoriasis and/or its comorbidities becomes crucial. Recently, studies have shown positive correlation between body mass index and prevalence and severity of psoriasis. Abdominal circumference showed stronger correlation with disease severity than body mass index. We evaluated the waist-to-height ratio in a sample of 297 adult patients with psoriasis and observed that it has a significant correlation with body mass index and PASI, and together with body mass index allows the identification of central obesity, reducing its subdiagnosis. PMID:25184937

Duarte, Gleison Vieira; da Silva, Larissa Porto



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



Central serous choroidopathy  


... studies found that people with aggressive, "type A" personalities who are under a lot of stress may be more likely to develop central serous retinopathy. The condition can also occur as a complication of steroid drug use.


Central core disease  

Microsoft Academic Search

Central core disease (CCD) is an inherited neuromuscular disorder characterised by central cores on muscle biopsy and clinical\\u000a features of a congenital myopathy. Prevalence is unknown but the condition is probably more common than other congenital myopathies.\\u000a CCD typically presents in infancy with hypotonia and motor developmental delay and is characterized by predominantly proximal\\u000a weakness pronounced in the hip girdle;

Heinz Jungbluth



CDF Central Outer Tracker  

NASA Astrophysics Data System (ADS)

The Central Outer Tracker is a large cylindrical drift chamber constructed to replace Collider Detector at Fermilab's original central drift chamber for the higher luminosity expected for Run 2 at the Fermilab Tevatron. The chamber's drift properties are described in the context of meeting the operating requirements for Run 2. The design and construction of the chamber, the front-end readout electronics, and the high-voltage system are described in detail. Wire aging considerations are also discussed.

Affolder, T.; Allspach, D.; Ambrose, D.; Bialek, J.; Bokhari, W.; Brozovic, M.; Binkley, M.; Burkett, K.; Byon-Wagner, A.; Cogswell, F.; Dressnandt, N.; Feng, Z.; Franklin, M.; Galtieri, L.; Gerdes, D. W.; Greenwood, J.; Guarino, V.; Guimaraes da Costa, J.; Haggerty, R.; Hall, C.; Heinrich, J.; Holloway, A.; Jacobi, T.; Kephart, K.; Khazins, D.; Kim, Y. K.; Kirby, M.; Kononenko, W.; Kotwal, A. V.; Kraus, J.; Liss, T. M.; Lockyer, N.; Madrak, R.; Miao, T.; Mukherjee, A.; Neu, C.; Newcomer, M.; Niczyporuk, J. M.; Nodulman, L.; Orejudous, W.; Phillips, T. J.; Pitts, K. T.; Reigler, W.; Richards, R.; Rivetta, C.; Robertson, W. J.; Roser, R.; Sadler, L.; Sandberg, R.; Sansone, S.; Schmitt, R.; Schultz, K.; Shuman, D.; Silva, R.; Singh, P.; Snihur, R.; Tamburello, P.; Taylor, J.; Thurman-Keup, R.; Tousignant, D.; Ukegawa, F.; Van Berg, R.; Veramendi, G.; Vickey, T.; Wacker, J.; Wagner, R. L.; Weidenbach, R.; Wester, W. C.; Williams, H. H.; Wilson, P.; Wittich, P.; Yagil, A.; Yu, I.; Yu, S.; Yun, J. C.



Density Ratio Examples Semiparametric Statistical Formulation  

E-print Network

UMinformal Density Ratio Examples Semiparametric Statistical Formulation Combined semiparametric density estimators Semiparametric regression Application to Testicular Germ Cell Cancer Semiparametric Density Ratio Examples Semiparametric Statistical Formulation Combined semiparametric density estimators

Johnson, Raymond L.


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



12 CFR 567.8 - Leverage ratio.  

Code of Federal Regulations, 2010 CFR

...Requirements § 567.8 Leverage ratio. (a) The minimum leverage...chapter, shall consist of a ratio of core capital to adjusted...excellent asset quality, high liquidity, and good earnings. ...requirement shall consist of a ratio of core capital to...



Comparison of Body Mass Index and Waist\\/Height Ratio in Predicting Definite Coronary Artery Disease  

Microsoft Academic Search

Background: Body mass index (BMI), waist circumference (WC), waist\\/hip ratio, waist\\/height ratio (WHtR) and skin fold thickness are clinical tools enabling the evaluation of obesity. WHtR is a recently introduced index to assess central fat distribution. This study was performed to compare the prognostic value of WHtR and BMI for definite coronary artery disease (CAD). Methods: A cross-sectional study was

M. Siavash; M. Sadeghi; F. Salarifar; M. Amini; F. Shojaee-Moradie



Carbon isotopic ratios of wetland and terrace soil sequences in the Maya Lowlands of Belize and Guatemala  

Microsoft Academic Search

This article provides new data and synthesizes earlier findings on the carbon isotope ratios of the humin part of soil organic matter from a range of sites in the central Maya Lowlands. Changes down the soil profile in carbon isotope ratios can provide an important line of evidence for vegetation change and erosion over time, especially in well dated aggrading

Timothy Beach; Sheryl Luzzadder-Beach; Richard Terry; Nicholas Dunning; Stephen Houston; Thomas Garrison



Neural correlates of the Pythagorean ratio rules.  


Millennia ago Pythagoras noted a simple but remarkably powerful rule for the aesthetics of tone combinations: pairs of tones--intervals--with simple ratios such as an octave (ratio 2 : 1) or a fifth (ratio 3 : 2) were pleasant sounding (consonant), whereas intervals with complex ratios such as the major seventh (ratio 243 : 128) were harsh (dissonant). These Pythagorean ratio rules are the building blocks of Western classical music; however, their neurophysiologic basis is not known. Using functional MRI we have found the neurophysiologic correlates of the ratio rules. In musicians, the inferior frontal gyrus, superior temporal gyrus, medial frontal gyrus, inferior parietal lobule and anterior cingulate respond with progressively more activation to perfect consonances, imperfect consonances and dissonances. In nonmusicians only the right inferior frontal gyrus follows this pattern. PMID:17885594

Foss, Alexander H; Altschuler, Eric L; James, Karin H



A centrality detector concept  

NASA Astrophysics Data System (ADS)

The nucleus-nucleus impact parameter and collision geometry of a heavy ion collision are typically characterized by assigning a collision “centrality”. In all present heavy ion experiments centrality is measured indirectly, by detecting the number of particles or the energy of the particles produced in the interactions, typically at high rapidity. Centrality parameters are associated to the measured detector response using the Glauber model. This approach suffers from systematic uncertainties related to the assumptions about the particle production mechanism and limitations of the Glauber model. In the collider based experiments there is a unique possibility to measure centrality parameters by registering spectator fragments remaining from the collision. This approach does not require model assumptions and relies on the fact that spectators and participants are related via the total number of nucleons in the colliding species. This paper describes the concept of a centrality detector for heavy ion experiment, which measures the total mass number of all fragments by measuring their deflection in the magnetic field of the collider elements.

Tarafdar, Sourav; Citron, Zvi; Milov, Alexander



Shear Viscosity to Entropy Density Ratio in Six Derivative Gravity  

E-print Network

We calculate shear viscosity to entropy density ratio in presence of four derivative (with coefficient $\\alpha'$) and six derivative (with coefficient $\\alpha'^2$) terms in bulk action. In general, there can be three possible four derivative terms and ten possible six derivative terms in the Lagrangian. Among them two four derivative and eight six derivative terms are ambiguous, i.e., these terms can be removed from the action by suitable field redefinitions. Rest are unambiguous. According to the AdS/CFT correspondence all the unambiguous coefficients (coefficients of unambiguous terms) can be fixed in terms of field theory parameters. Therefore, any measurable quantities of boundary theory, for example shear viscosity to entropy density ratio, when calculated holographically can be expressed in terms of unambiguous coefficients in the bulk theory (or equivalently in terms of boundary parameters). We calculate $\\eta/s$ for generic six derivative gravity and find that apparently it depends on few ambiguous coefficients at order $\\alpha'^2$. We calculate six derivative corrections to central charges $a$ and $c$ and express $\\eta/s$ in terms of these central charges and unambiguous coefficients in the bulk theory.

Nabamita Banerjee; Suvankar Dutta



Central Europe Review  

NSDL National Science Digital Library

This new weekly online journal from Central and East European New Media Initiative (CEENMI) offers news and analysis of events in politics, society, and culture across the region. With over 45 contributors from 17 countries, the journal provides a surprising amount of coverage each week. In addition to regular columns and weekly news summaries, the journal contains several in-depth articles and special feature pieces, including a number of resources (such as articles, film and book reviews, and related links) grouped around a weekly theme. The journal also offers a weekly list of Central and East European cultural events in the UK, links to related stories from other online news sources, and an archive. Users can read the Central Europe Review at the site or receive free weekly summaries via email.


ORIC central region calculations  

SciTech Connect

The central region for the K = 100 Oak Ridge Isochronous Cyclotron, ORIC, will be modified to provide better orbit centering, focusing of orbits in the axial direction, and phase selection, in order to improve extraction efficiency, and reduce radioactive activation of cyclotron components. The central region is specifically designed for the acceleration of intense light ion beams such as 60 MeV protons and 15--100 MeV alphas. These beams will be used in the production of radioactive atoms in the Radioactive Ion Beam Project at Oak Ridge National Laboratory.

Bailey, J.D.; Dowling, D.T.; Lane, S.N.; Mosko, S.W.; Olsen, D.K.; Tatum, B.A.



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.



Central pontinemyelinosis, hyperparathyroidism, hypokalemia.  


Central pontinemyelinolysis (CPM) is one of the rare non-inflammatory demyelinating diseases of the pons and very rarely it can involve extrapontine structure as well. The exact etiopathogenesis of this condition is still unclear. Rapid correction of hyponatremia has been attributed as a most common factor, but alcoholism, malnutrition, prolonged use of diuretics, psychogenic polydipsia, post liver transplant and hypokalemia have also been attributed as a causative factor. We describe a case of hyperparathyroidism with concomitant hypercalcemia accompanied by central pontine myelinosis without hyponatremia/hyperosmolality or associated rapid corrections of sodium, which developed as a consequence of severe hypokalaemia. PMID:24251127

Kishore, Shyam; Kandasamy, D; Jyotsna, Viveka P




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.


The effect of sex ratios on suicide.  


Whereas sex ratios are likely to affect the likelihood of marriage, how sex ratios affect health and survival is underexplored. This study uses suicide as a measure of mental health and examines how suicides are affected by sex ratios. As women tend to marry men older than themselves, shrinking populations will lead to higher sex ratios (i.e., higher proportions of men) in the marriage market. Using data from Japan, I find that high sex ratios, both early-life and current, are correlated with higher male suicide rates, whereas female suicide rates are generally not affected. The results of this study have important implications for public health in countries where imbalanced sex ratios are a concern. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23943552

Kuroki, Masanori



Using single-mode bers to monitor fast Strehl ratio fluctuations  

Microsoft Academic Search

The theory of starlight coupling into single- mode bers is reviewed to show how i) the central obstruction in a telescope pupil deteriorates coupling eciency much more than one would expect from the loss of collecting area, and ii) a single-mode ber and a photometer can be used to monitor fast Strehl ratio fluc- tuations. This last point is illustrated

M. Faucherre; N. Hubin; P. Gitton



A constraint on the pair-density ratio (Z+) in an electron-positron pair wind  

Microsoft Academic Search

We derive a constraint on the pair density ratio, z+ = n+\\/np, 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, positrons, and protons. The minimum rate at which positrons are injected into the annihilation volume is given by the observed annihilation

M. D. Moscoso; J. C. Wheeler



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



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.


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



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



Gangs in Central America.  

National Technical Information Service (NTIS)

The 110th Congress maintains a keen interest in the effects of crime and gang violence in Central America and its spillover effects on the United States. Since February 2005, more than 1,758 alleged members of the violent Mara Salvatrucha (MS-13) gang hav...

C. R. Seelke



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



DELIVERABLE Central North Sea  

E-print Network Central North Sea ­ CO2 Storage Hub : Enabling CCS into a guaranteed network for transportation and storage of captured CO2. Recent studies examining the levelised

Haszeldine, Stuart


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



Strehl Ratio Meter for Focusing Segmented Mirrors 1  

NASA Technical Reports Server (NTRS)

Initial focusing segmented mirrors that must be deployed in space, such as the Next Generation Space Telescope (NGST), provide challenges not faced before in the area of adaptive optics. The devices used to focus the mirror must minimize the power used and unnecessary mechanical movement. The device described in this report requires no movable parts except for the essential actuators required to move the mirror segments. Detail description of the components can be found in Coker, 1996. The primary mirror of the NGST will consist of 9 segments, a central annular segment, surrounded by 8 segments. The entire mirror assembly will be an 8 meter nearly filled circle (with the corners of the segments clipped to allow for storage in an Atlas IIe shroud). As the segments of the primary mirror are deployed to their operational positions, they must be positioned to within small fractions of a wavelength of near infrared light. When focused, the NGST will put most of its collected li-ht into the small region near the center of its focal plane. The ratio of the total light in the diffraction limited spot about the center of the focal plane to the total light in the focal plane. The purpose of this research effort is to design and build a device that will measure Strehl ratio and to use demonstrate that the Strehl ratio can be used to focus a segmented mirror.

Olivier, Philip D.



Separated response function ratios in exclusive, forward ?(±) electroproduction.  


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 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 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. 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



Neoproterozoic crustal accretion in central Brazil  

NASA Astrophysics Data System (ADS)

Recent geochronological studies have demonstrated the existence of several Neoproterozoic orthogneiss and metavolcanic are suites (ca. 900 to 600 Ma) in the southern part of the Tocantins province, a major Neoproterozoic orogenic area in central Brazil, exposed between the Amazon and São Francisco cratons. Nd and Sr isotopic characteristics of these metamorphic suites are primitive: initial 87Sr/87Sr ratios vary from ˜0.7024 to ˜0.7042 and initial ?Nd values are positive, varying between +0.2 and +6.9. The most primitive initial Sr and Nd isotopic compositions are very similar to model depleted- mantle compositions at the time of formation of the original magmas. The mantle- like characteristics of these are suites in western Goiás contradict previous ensialic evolution models for the Tocantins province and reveal that crustal accretion processes were important in large areas of central Brazil during Neoproterozoic time.

Martins Pimentel, Márcio; Adolfo Fuck, Reinhardt



CCSSM Challenge: Graphing Ratio and Proportion  

ERIC Educational Resources Information Center

A renewed emphasis was placed on ratio and proportional reasoning in the middle grades in the Common Core State Standards for Mathematics (CCSSM). The expectation for students includes the ability to not only compute and then compare and interpret the results of computations in context but also interpret ratios and proportions as they are…

Kastberg, Signe E.; D'Ambrosio, Beatriz S.; Lynch-Davis, Kathleen; Mintos, Alexia; Krawczyk, Kathryn



Calculating Obscuration Ratios Of Contaminated Surfaces  

NASA Technical Reports Server (NTRS)

Equations derived to estimate obscuration ratios of surfaces contaminated by particles. Ratio is fraction of surface area covered by particles. Useful as index of cleanliness in clean-room operations in manufacturing of semiconductor devices, magnetic recording media, optical devices, and pharmaceutical and biotechnological products.

Barengoltz, Jack B.



Is that really your Strehl ratio?  

Microsoft Academic Search

Strehl ratio is the most commonly used metric for adaptive optics (AO) performance. It is also the most misused metric. Every Strehl ratio measurement algorithm has subtle differences that result in different measured values. This creates problems when comparing different measurements of the same AO system and even more problems when trying to compare results from different systems. To determine

Lewis C. Roberts Jr.; Marshall D. Perrin; Franck Marchis; Anand Sivaramakrishnan; Russell B. Makidon; Julian C. Christou; Bruce A. Macintosh; Lisa A. Poyneer; Marcos A. van Dam; Mitchell Troy



Economy Track: Employment to Population Ratio  

NSDL National Science Digital Library

Time plot compares the employment-population ratio - the broadest measure of people who are working in America. Allows to compare between recessions, also allows to compare between demographic groups -- by sex, race/ethnicity and educational attainment. Also shows the secular trend for employment-population ratio since 1973.

Institute, Economic P.


Losing money with a high Sharpe ratio  

Microsoft Academic Search

A simple example shows that losing all money is compatible with a very high Sharpe ratio (as computed after losing all money). However, the only way that the Sharpe ratio can be high while losing money is that there is a period in which all or almost all money is lost. This note explores the best achievable Sharpe and Sortino

Vladimir Vovk



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



Ratio Rule Mining from Multiple Data Sources  

Microsoft Academic Search

Both multiple source data mining and streaming data mining problems have attracted much attention in the past decade. In contrast to traditional association-rule mining, to capture the quantitative association knowledge, a new paradigm called Ratio Rule (RR) was proposed recently. We extend this framework to mining ratio rules from multiple source data streams which is a novel and challenging problem.

Jun Yan; Qiang Yang; Benyu Zhang; Qiansheng Cheng; Zheng Chen


Measurement of D-Meson Branching Ratios.  

National Technical Information Service (NTIS)

Charm data from 360 GeV/c (pi-)p interactions are used to give results on D-meson branching ratios. The analysis is based on 114 charm events containing 183 observed charm particle decays. The authors present topological branching ratios and decay multipl...

M. Aguilar-Benitez, W. W. M. Allison, J. F. Baland, W. Bartl, V. M. Begalli



Stable Isotope Analysis of a Middle Woodland Population from North Central Kansas  

E-print Network

This study sought to examine the paleodiet and temporality of a Middle Woodland group from five sites in north central Kansas. This goal was accomplished by submitting 21 samples for stable isotope ratios analysis (SIRA) and 12 samples for bone...

Kauffman, Greg



Scavenging ratios based on inflow air concentrations  

SciTech Connect

Scavenging ratios were calculated from field measurements made during April 1985. Event precipitation samples were collected at the surface, but air chemistry measurements in the air mass feeding the precipitation were made from an aircraft. In contrast, ratios calculated in previous studies have used air concentration and precipitation chemistry data from only surface measurements. Average scavenging ratios were calculated for SO{sub 4}{sup 2{minus}}, NO{sub 3}{sup {minus}}, NH{sub 4}{sup +}, total sulfate, total nitrate, and total ammonium for 5 events; the geometric mean of these scavenging ratios were 8.5 {times} 10{sup 5}, 5.6 {times} 10{sup 6}, 4.3 {times} 10{sup 5}, 3.4 {times} 10{sup 5}, 2.4 {times} 10{sup 6}, and 9.7 {times} 10{sup 4}, respectively. These means are similar to but less variable than previous ratios formed using only surface data.

Davis, W.E.; Dana, M.T.; Lee, R.N.; Slinn, W.G.N.; Thorp, J.M.



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



High Transformer ratios in collinear wakefield accelerators.  

SciTech Connect

Based on our previous experiment that successfully demonstrated wakefield transformer ratio enhancement in a 13.625 GHz dielectric-loaded collinear wakefield accelerator using the ramped bunch train technique, we present here a redesigned experimental scheme for even higher enhancement of the efficiency of this accelerator. Design of a collinear wakefield device with a transformer ratio R2, is presented. Using a ramped bunch train (RBT) rather than a single drive bunch, the enhanced transformer ratio (ETR) technique is able to increase the transformer ratio R above the ordinary limit of 2. To match the wavelength of the fundamental mode of the wakefield with the bunch length (sigmaz=2 mm) of the new Argonne wakefield accelerator (AWA) drive gun (where the experiment will be performed), a 26.625 GHz dielectric based accelerating structure is required. This transformer ratio enhancement technique based on our dielectric-loaded waveguide design will result in a compact, high efficiency accelerating structures for future wakefield accelerators.

Power, J. G.; Conde, M.; Yusof, Z.; Gai, W.; Jing, C.; Kanreykin, A.; Schoessow, P.; High Energy Physics; Euclid Techlabs, LLC



A global inventory of central pit craters on the Moon: Distribution, morphology, and geometry  

NASA Astrophysics Data System (ADS)

The origin of central pit craters on the Moon has long been an enigma, and a primary reason is that their geographic distribution and morphometric characteristics were unknown. We investigated a global inventory of lunar central pit craters using high-resolution image and topography data obtained from the Lunar Reconnaissance Orbiter. 56 certain and 35 probable central pit craters are found on both the lunar maria and highlands. The certain pit craters are ˜9-57 km in diameter. The average diameter ratio between the central pits and their parent craters is ˜0.12 and the average depth/diameter ratio for the central pits is ˜0.072. With irregular-shaped rims, the central pits have conical profiles and some have flat floors. The central pits occur on both crater floors and central peaks. The floor pits are generally larger, deeper, and with more irregular shape compared with summit pits. Both the summit and floor pit craters have formed in every lunar stratigraphic epoch from Nectarian to Copernican. Target properties of background terrains affect the morphology and size of central pits, but they do not determine whether or not a central pit forms during a cratering event. The lunar central pits may have formed by deformation of central peaks caused by some mechanical processes during or soon after the cratering process of their parent craters.

Xiao, Zhiyong; Zeng, Zuoxun; Komatsu, Goro




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


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.



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



Central Internet Database  

NSDL National Science Digital Library

The Department of Energy maintains the Central Internet Database Web site. Here users can generate and print reports containing nationwide data on radioactive waste, contaminated media, and spent nuclear fuel. Ready to read reports are also available including Actual and Projected Waste/Material Volumes, Waste/Material Characteristic Data (contaminants/isotopes/radioactivity), and Treatment, Storage and Disposal (TSD) Systems. The site currently contains fifty nine standard and fourteen ready to read reports


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



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.



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. PMID:20737591

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



CALIPSO lidar ratio retrieval over the ocean.  


We are demonstrating on a few cases the capability of CALIPSO to retrieve the 532 nm lidar ratio over the ocean when CloudSat surface scattering cross section is used as a constraint. We are presenting the algorithm used and comparisons with the column lidar ratio retrieved by the NASA airborne high spectral resolution lidar. For the three cases presented here, the agreement is fairly good. The average CALIPSO 532 nm column lidar ratio bias is 13.7% relative to HSRL, and the relative standard deviation is 13.6%. Considering the natural variability of aerosol microphysical properties, this level of accuracy is significant since the lidar ratio is a good indicator of aerosol types. We are discussing dependencies of the accuracy of retrieved aerosol lidar ratio on atmospheric aerosol homogeneity, lidar signal to noise ratio, and errors in the optical depth retrievals. We are obtaining the best result (bias 7% and standard deviation around 6%) for a nighttime case with a relatively constant lidar ratio (in the vertical) indicative of homogeneous aerosol type. PMID:21935239

Josset, Damien; Rogers, Raymond; Pelon, Jacques; Hu, Yongxiang; Liu, Zhaoyan; Omar, Ali; Zhai, Peng-Wang



CALIPSO Lidar Ratio Retrieval Over the Ocean  

NASA Technical Reports Server (NTRS)

We are demonstrating on a few cases the capability of CALIPSO to retrieve the 532 nm lidar ratio over the ocean when CloudSat surface scattering cross section is used as a constraint. We are presenting the algorithm used and comparisons with the column lidar ratio retrieved by the NASA airborne high spectral resolution lidar. For the three cases presented here, the agreement is fairly good. The average CALIPSO 532 nm column lidar ratio bias is 13.7% relative to HSRL, and the relative standard deviation is 13.6%. Considering the natural variability of aerosol microphysical properties, this level of accuracy is significant since the lidar ratio is a good indicator of aerosol types. We are discussing dependencies of the accuracy of retrieved aerosol lidar ratio on atmospheric aerosol homogeneity, lidar signal to noise ratio, and errors in the optical depth retrievals. We are obtaining the best result (bias 7% and standard deviation around 6%) for a nighttime case with a relatively constant lidar ratio (in the vertical) indicative of homogeneous aerosol type

Josset, Damien B.; Rogers, Raymond R.; Pelon, Jacques; Hu, Yongxiang; Liu, Zhaoyan; Omar, Ali H.; Zhai, Peng-Wang



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. PMID:24948841

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




SciTech Connect

The START (Small Tight Aspect Ratio Tokamak) experiment became operational in January 1991 at AEA Fusion Culham Laboratory. It is the only tokamak producing hot plasmas at aspect ratios as low as A = R/a approximately 1.3, and is providing valuable insight into the physical processes (such as toroidicity and trapping) involved at low aspect ratio. Three topics are discussed in this paper: equilibrium properties, including evidence of neo-classical and bootstrap effects; energy confinement studies; and MHD properties, including possible explanations for the apparent absence of the major disruption at low A.

Sykes, A [Culham Centre for Fusion Energy, Culham, UK; Peng, Yueng Kay Martin [ORNL



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.



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



Reduction ratio control for continuously variable transmission  

SciTech Connect

This patent describes a reduction ratio control for a continuously variable transmission of a motor vehicle, the continuously variable transmission being connected to an engine of the motor vehicle to be driven thereby, the reduction ratio control comprising: means for carrying out a reduction ratio change of the continuously variable transmission in such a manner as to decrease a difference between an actual value in a predetermined operating variable and a target value in the predetermined operating variable toward zero; means for determining a deceleration which the motor vehicle is subject to; means for changing the target value to a new target value in response to the deceleration after the deceleration which the motor vehicle is subjected to is determined; and the means for carrying out the reduction ratio change causes the actual value to approach the new target value quicker than it controlled the actual value to approach the target value.

Kumura, H.



Meteorological Effects on Air/Fuel Ratio  

E-print Network

METEOROLOGICAL EFFECTS ON AIR/FUEL RATIO John L. Ferri GTE Products Corporation Towanda, Pennsylvania ABSTRACT Air is a convenient and inexpensive source of oxygen for most combustion processes. However, the oxygen content of the air...METEOROLOGICAL EFFECTS ON AIR/FUEL RATIO John L. Ferri GTE Products Corporation Towanda, Pennsylvania ABSTRACT Air is a convenient and inexpensive source of oxygen for most combustion processes. However, the oxygen content of the air...

Ferri, J. L.



Ultraviolet Emission Line Ratios of Cataclysmic Variables  

E-print Network

We present a statistical analysis of the ultraviolet emission lines of cataclysmic variables (CVs) based on $\\approx 430$ ultraviolet spectra of 20 sources extracted from the International Ultraviolet Explorer Uniform Low Dispersion Archive. These spectra are used to measure the emission line fluxes of N V, Si IV, C IV, and He II and to construct diagnostic flux ratio diagrams. We investigate the flux ratio parameter space populated by individual CVs and by various CV subclasses (e.g., AM Her stars, DQ Her stars, dwarf novae, nova-like variables). For most systems, these ratios are clustered within a range of $\\sim 1$ decade for log Si IV/C IV $\\approx -0.5$ and log He II/C IV $\\approx -1.0$ and $\\sim 1.5$ decades for log N V/C IV $\\approx -0.25$. These ratios are compared to photoionization and collisional ionization models to constrain the excitation mechanism and the physical conditions of the line-emitting gas. We find that the collisional models do the poorest job of reproducing the data. The photoionization models reproduce the Si IV/C IV line ratios for some shapes of the ionizing spectrum, but the predicted N V/C IV line ratios are simultaneously too low by typically $\\sim 0.5$ decades. Worse, for no parameters are any of the models able to reproduce the observed He II/C IV line ratios; this ratio is far too small in the collisional and scattering models and too large by typically $\\sim 0.5$ decades in the photoionization models.

Christopher W. Mauche; Y. Paul Lee; Timothy R. Kallman



Central Europe Online  

NSDL National Science Digital Library

This website, a service of the European Internet Network, brings English-language news and background to users each weekday. Central Europe Online covers the Czech Republic, Poland, Hungary, Slovakia, and Slovenia. The site offers current headlines (along with the time that they were most recently updated), business news, travel information, and links to local media. New stories are drawn primarily from Reuters. An archive holds back issues. Users who want to stay current on issues affecting these regions will benefit from the professional approach this site brings to coverage.



Hybrid central plants  

SciTech Connect

The advent of double effect absorption chillers has created new opportunities for gas cooling in regions where gas prices are relatively low compared to electric prices; however, consideration of fuel price, efficiency, maintenance, and first-cost may encumber the opportunity with only slight fluctuation. A hybrid central cooling plant generally consists of two types of chillers--chillers that make use of natural gas, and electric-driven chillers. In a hybrid plant, peak cooling load requirements are met by using a combination of the two types of chillers.

Wylie, D.M.; Alvarez, R.



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



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



Central American resource studies  

SciTech Connect

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 paper presents an overview of this work -- within these proceedings are papers that deal with specific aspects of each topic, and these will be duly noted. 15 refs., 4 figs.

Van Eeckhout, E.; Laughlin, A.W.



Flooding in Central Siberia  

NASA Technical Reports Server (NTRS)

A mixture of snowmelt and ice jams in late May and June of this year caused the Taz River (left) and the Yenisey River (right) in central Siberia to overflow their banks. The flooding can be seen in this image taken on June 11, 2002, by the MODIS (Moderate Resolution Imaging Spectroradiometer) instrument aboard the Terra satellite. Normally, the rivers would resemble thin black lines in MODIS imagery. In the false-color images sage green and rusty orange is land, and water is black. Clouds are white and pink. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC



Rapidity dependence of antiproton-to-proton ratios in Au+Au collisions at root s(NN)=130 GeV  

E-print Network

Measurements, with the BRAHMS detector, of the antiproton-to-proton ratio at midrapidities and forward rapidities, are presented for Au + Au reactions at roots(NN) = 130 GeV, and for three different collision centralities. ...

Sanders, Stephen J.



Collisional Transport in a Low Aspect Ratio Tokamak -- Beyond the Drift Kinetic Formalism  

SciTech Connect

Calculations of collisional thermal and particle diffusivities in toroidal magnetic plasma confinement devices order the toroidal gyroradius to be small relative to the poloidal gyroradius. This ordering is central to what is usually referred to as neoclassical transport theory. This ordering is incorrect at low aspect ratio, where it can often be the case that the toroidal gyroradius is larger than the poloidal gyroradius. We calculate the correction to the particle and thermal diffusivities at low aspect ratio by comparing the diffusivities as determined by a full orbit code (which we refer to as omni-classical diffusion) with those from a gyroaveraged orbit code (neoclassical diffusion). In typical low aspect ratio devices the omni-classical diffusion can be up to 2.5 times the calculated neoclassical value. We discuss the implications of this work on the analysis of collisional transport in low aspect ratio magnetic confinement experiments.

D.A. Gates; R.B. White



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.



Haar expectations of ratios of random characteristic polynomials  

E-print Network

We compute Haar ensemble averages of ratios of random characteristic polynomials for the classical Lie groups K = O(N), SO(N), and USp(N). To that end, we start from the Clifford-Weyl algebera in its canonical realization on the complex of holomorphic differential forms for a C-vector space V. From it we construct the Fock representation of an orthosymplectic Lie superalgebra osp associated to V. Particular attention is paid to defining Howe's oscillator semigroup and the representation that partially exponentiates the Lie algebra representation of sp in osp. In the process, by pushing the semigroup representation to its boundary and arguing by continuity, we provide a construction of the Shale-Weil-Segal representation of the metaplectic group. To deal with a product of n ratios of characteristic polynomials, we let V = C^n \\otimes C^N where C^N is equipped with its standard K-representation, and focus on the subspace of K-equivariant forms. By Howe duality, this is a highest-weight irreducible representation of the centralizer g of Lie(K) in osp. We identify the K-Haar expectation of n ratios with the character of this g-representation, which we show to be uniquely determined by analyticity, Weyl group invariance, certain weight constraints and a system of differential equations coming from the Laplace-Casimir invariants of g. We find an explicit solution to the problem posed by all these conditions. In this way we prove that the said Haar expectations are expressed by a Weyl-type character formula for all integers N \\ge 1. This completes earlier work by Conrey, Farmer, and Zirnbauer for the case of U(N).

A. Huckleberry; A. Puettmann; M. R. Zirnbauer



Examining Earthquake Scaling Via Event Ratio Levels  

NASA Astrophysics Data System (ADS)

A challenge with using corner frequency to interpret stress parameter scaling is that stress drop and apparent stress are related to the cube of the corner frequency. In practice this leads to high levels of uncertainty in measured stress from since the uncertainty in measuring the corner frequency is cubed to determine uncertainty in the stress parameters. We develop a new approach using the low and high frequency levels of spectral ratios between two closely located events recorded at the same stations. This approach has a number of advantages over more traditional corner frequency fitting, either in spectral ratios or individual spectra. First, if the bandwidth of the spectral ratio is sufficient, the levels can be measured at many individual frequency points and averaged, reducing the measurement error. Second the apparent stress (and stress drop) are related to the high frequency level to the 3/2 power so the measurement uncertainty is not as amplified as when using the corner frequency. Finally, if the bandwidth is sufficiently broad to determine both the spectral ratio low and high frequency levels, the apparent stress (or stress drop) ratio can be determined without the need to use any other measurements (e.g., moment, fault area), which of course have their own measurement uncertainties. We will show a number examples taken from a wide variety of crustal earthquake sequences. Example of the sigmoid formed by a spectral ratio between two hypothetical events for two different cases of stress scaling using the models described in this paper. Event 1 is Mw 6.0 event and event 2 is an Mw 4.0 event. In the self-similar case both have an apparent stress of 3 MPa, in the non-self-similar case the large event apparent stress is 3 MPA and the smaller one is 1 MPa. Note that ratio reaches different constant levels. The low frequency level (LVL) is the ratio of the moments and high frequency level (HFL) depends on the stress parameters. In this paper we derive the relationships shown for the LVL and HFL values, and how these can be used to determine the apparent stress ratio between two events.

Walter, W. R.; Yoo, S.; Mayeda, K. M.; Gok, R.



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. PMID:23964258

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



Audio/Visual Ratios in Commercial Filmstrips.  

ERIC Educational Resources Information Center

Developed by the Westinghouse Electric Corporation, Video Audio Compressed (VIDAC) is a compressed time, variable rate, still picture television system. This technology made it possible for a centralized library of audiovisual materials to be transmitted over a television channel in very short periods of time. In order to establish specifications…

Gulliford, Nancy L.


Hydroxyl and Peroxy Radical Chemistry in a Rural Area of Central Pennsylvania: Observations and Model Comparisons  

Microsoft Academic Search

Atmospheric hydroxyl (OH), hydroperoxy (HO2), total peroxy (HO2 and organic peroxy radicals, RO2) mixing ratios and OH reactivity (first order OH loss rate) were measured at a rural site in central Pennsylvania during\\u000a May and June 2002. OH and HO2 mixing ratios were measured with laser induced fluorescence (LIF); HO2\\u000a + RO2 mixing ratios were measured with chemical ionization mass

Xinrong Ren; William H. Brune; Christopher A. Cantrell; Gavin D. Edwards; Terry Shirley; Andrew R. Metcalf; Robert L. Lesher



The AIMSS Project II: Dynamical-to-Stellar Mass Ratios Across the Star Cluster - Galaxy Divide  

E-print Network

The previously clear division between small galaxies and massive star clusters is now occupied by objects called ultra compact dwarfs (UCDs) and compact ellipticals (cEs). Here we combine a sample of UCDs and cEs with velocity dispersions from the AIMSS project with literature data to explore their dynamical-to-stellar mass ratios. We confirm that the mass ratios of many UCDs in the stellar mass range 10$^6$ -- 10$^9$ M$_{\\odot}$ are systematically higher than those for globular clusters which have mass ratios near unity. However, at the very highest masses in our sample, i.e. 10$^9$ -- 10$^{10}$ M$_{\\odot}$, we find that cE galaxies also have mass ratios of close to unity, indicating their central regions are mostly composed of stars. Suggested explanations for the elevated mass ratios of UCDs have included a variable IMF, a central black hole, and the presence of dark matter. Here we present another possible explanation, i.e. tidal stripping. Under various assumptions, we find that the apparent variation in...

Forbes, Duncan A; Strader, Jay; Romanowsky, Aaron J; Pota, Vincenzo; Kannappan, Sheila J; Brodie, Jean P; Huxor, Avon



Flooding in Central China  

NASA Technical Reports Server (NTRS)

During the summer of 2002, frequent, heavy rains gave rise to floods and landslides throughout China that have killed over 1,000 people and affected millions. This false-color image of the western Yangtze River and Dongting Lake in central China was acquired on August 21, 2002, by the Moderate-resolution Imaging Spectroradiometer (MODIS), flying aboard NASA's Terra spacecraft. (right) The latest flooding crisis in China centers on Dingtong Lake in the center of the image. Heavy rains have caused it to swell over its banks and swamp lakefront towns in the province of Hunan. As of August 23, 2002, more than 250,000 people have been evacuated, and over one million people have been brought in to fortify the dikes around the lake. Normally the lake would appear much smaller and more defined in the MODIS image. Credit: Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC.



Central Nervous System Cancers  

PubMed Central

Primary and metastatic tumors of the central nervous system are a heterogeneous group of neoplasms with varied outcomes and management strategies. Recently, improved survival observed in 2 randomized clinical trials established combined chemotherapy and radiation as the new standard for treating patients with pure or mixed anaplastic oligodendroglioma harboring the 1p/19q codeletion. For metastatic disease, increasing evidence supports the efficacy of stereotactic radiosurgery in treating patients with multiple metastatic lesions but low overall tumor volume. These guidelines provide recommendations on the diagnosis and management of this group of diseases based on clinical evidence and panel consensus. This version includes expert advice on the management of low-grade infiltrative astrocytomas, oligodendrogliomas, anaplastic gliomas, glioblastomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, and brain metastases. The full online version, available at, contains recommendations on additional subtypes. PMID:24029126

Nabors, Louis Burt; Ammirati, Mario; Bierman, Philip J.; Brem, Henry; Butowski, Nicholas; Chamberlain, Marc C.; DeAngelis, Lisa M.; Fenstermaker, Robert A.; Friedman, Allan; Gilbert, Mark R.; Hesser, Deneen; Holdhoff, Matthias; Junck, Larry; Lawson, Ronald; Loeffler, Jay S.; Maor, Moshe H.; Moots, Paul L.; Morrison, Tara; Mrugala, Maciej M.; Newton, Herbert B.; Portnow, Jana; Raizer, Jeffrey J.; Recht, Lawrence; Shrieve, Dennis C.; Sills, Allen K.; Tran, David; Tran, Nam; Vrionis, Frank D.; Wen, Patrick Y.; McMillian, Nicole; Ho, Maria



Central nervous system cancers.  


Primary and metastatic tumors of the central nervous system are a heterogeneous group of neoplasms with varied outcomes and management strategies. Recently, improved survival observed in 2 randomized clinical trials established combined chemotherapy and radiation as the new standard for treating patients with pure or mixed anaplastic oligodendroglioma harboring the 1p/19q codeletion. For metastatic disease, increasing evidence supports the efficacy of stereotactic radiosurgery in treating patients with multiple metastatic lesions but low overall tumor volume. These guidelines provide recommendations on the diagnosis and management of this group of diseases based on clinical evidence and panel consensus. This version includes expert advice on the management of low-grade infiltrative astrocytomas, oligodendrogliomas, anaplastic gliomas, glioblastomas, medulloblastomas, supratentorial primitive neuroectodermal tumors, and brain metastases. The full online version, available at NCCN. org, contains recommendations on additional subtypes. PMID:24029126

Nabors, Louis Burt; Ammirati, Mario; Bierman, Philip J; Brem, Henry; Butowski, Nicholas; Chamberlain, Marc C; DeAngelis, Lisa M; Fenstermaker, Robert A; Friedman, Allan; Gilbert, Mark R; Hesser, Deneen; Holdhoff, Matthias; Junck, Larry; Lawson, Ronald; Loeffler, Jay S; Maor, Moshe H; Moots, Paul L; Morrison, Tara; Mrugala, Maciej M; Newton, Herbert B; Portnow, Jana; Raizer, Jeffrey J; Recht, Lawrence; Shrieve, Dennis C; Sills, Allen K; Tran, David; Tran, Nam; Vrionis, Frank D; Wen, Patrick Y; McMillian, Nicole; Ho, Maria



He/Ar ratio: Earthquake harbinger  

NASA Astrophysics Data System (ADS)

Helium and argon, squeezed out of the earth through fissures by deep internal pressures, may signal an imminent earthquake. There has been little evidence, however, directly linking stress with gas emissions. Ryuichi Sugisaki of the earth sciences department at Nagoya University in Japan reports in the June 12 Science that the variations of the He/Ar ratio of gas bubbles in a mineral spring coincide with underground stresses caused by the earth tide.‘A comparison of the variation of strain in the ground resulting from the earth tide with the observed fluctuation of the ratio shows a good correlation,’ Sugisaki wrote. In addition, he says that the ratio fluctuation is more closely tied to the tidal strain than to atmospheric pressure or temperature.

Richman, Barbara T.


Poisson's ratio of high-performance concrete  

SciTech Connect

This article outlines an experimental and numerical study on Poisson's ratio of high-performance concrete subjected to air or sealed curing. Eight qualities of concrete (about 100 cylinders and 900 cubes) were studied, both young and in the mature state. The concretes contained between 5 and 10% silica fume, and two concretes in addition contained air-entrainment. Parallel studies of strength and internal relative humidity were carried out. The results indicate that Poisson's ratio of high-performance concrete is slightly smaller than that of normal-strength concrete. Analyses of the influence of maturity, type of aggregate, and moisture on Poisson's ratio are also presented. The project was carried out from 1991 to 1998.

Persson, B.



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.



Relativistic electron PXR and FPXR yield ratio  

NASA Astrophysics Data System (ADS)

The parametric X-radiation of relativistic electron crossing a single crystal plate is considered on the basis of dynamic diffraction theory in Laue geometry both in Bragg (PXR) and forward (FPXR) directions. Analytical expressions for spectral-angular density of these radiations in indicated directions are derived in general case of electron coulomb field asymmetric reflection from the target surface. The ratio of contributions of these radiation mechanisms into the total yield of the radiation is investigated. It is shown that the ratio of contributions of these radiation mechanisms can change sharply depending on the value of the reflection asymmetry.

Blazhevich, S.; Noskov, A.



Radioactive anomaly discrimination from spectral ratios  


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



Controlling Gas-Flow Mass Ratios  

NASA Technical Reports Server (NTRS)

Proposed system automatically controls proportions of gases flowing in supply lines. Conceived for control of oxidizer-to-fuel ratio in new gaseous-propellant rocket engines. Gas-flow control system measures temperatures and pressures at various points. From data, calculates control voltages for electronic pressure regulators for oxygen and hydrogen. System includes commercially available components. Applicable to control of mass ratios in such gaseous industrial processes as chemical-vapor depostion of semiconductor materials and in automotive engines operating on compressed natural gas.

Morris, Brian G.



C IV line ratios in the sun  

NASA Astrophysics Data System (ADS)

Theoretical electron temperature-sensitive emission-line ratios are calculated with R-matrix analysis of electron-impact excitation rates for transitions in C IV. Two of the emission-line ratios are found to agree with observational data on the sun taken with a slitless spectrograph aboard Skylab, and the two remaining lines have inaccuracies that can be attributed to blending of the 312.43 A line. The agreement between the observational and analytical data lends credence to the accuracy of the atomic data used in the analysis.

Keenan, F. P.; Conlon, E. S.; Harra, L. K.; Burke, V. M.; Widing, K. G.



Recent changes in stable lead isotope ratios in sediments of lake Zug, Switzerland  

SciTech Connect

In Switzerland, unleaded gasoline was introduced in 1985. In order to study the effects of decreasing lead emissions from gasoline on a lake sediment, profiles of lead concentrations and {sup 206}Pb/{sup 207}Pb ratios have been determined in cores from Lake Zug. Sediment samples were digested and analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Accurate dating of sediment cores was achieved using four independent methods showing the results within a range of < 10%. Pb emissions in Switzerland and Pb concentrations in the sediment correlated well. Background Pb concentrations in pre-industrial sediments were 16 {mu}g/g in Lake Zug and 13 {mu}g/g in Lake Baldegg (for comparison); background {sup 206}Pb/{sup 207}Pb ratios were 1.20 in both lakes. In Lake Zug, lead concentrations reached a maximum of 110 {mu}g/g in a depth corresponding to ca. 1970, the time of highest lead emissions. The {sup 206}Pb/{sup 207}Pb ratio profile provided additional information because this ratio of Pb used for gasoline additives in Europe ranges from 1.04 to 1.10, and the ratio of background Pb in Central Europe is about 1.20. The ratios in the sediment had a minimum of 1.13 ca. 1980 and an increase of up to 1.16 since ca. 1990. The isotope ratios reflected the fraction of Pb emissions from gasoline. 34 refs., 4 figs., 3 tabs.

Moor, H.C.; Schaller, T.; Sturm, M. [Swiss Federal Inst. of Environmental Science and Technology, Duebendorf (Switzerland)] [Swiss Federal Inst. of Environmental Science and Technology, Duebendorf (Switzerland)



Central American geologic map project  

Microsoft Academic Search

During the Northeast Quadrant Panel meeting of the Circum-Pacific Map Project held in Mexico City, February 1985, Central American panel members proposed and adopted plans for compiling a geologic map of Central America, probably at a scale of 1:500,000. A local group with participants from each country was organized and coordinated by Rolando Castillo, director, Central American School of Geology,




Merger simulations with observed diversion ratios  

Microsoft Academic Search

A common approach to merger simulations used in antitrust cases is to calibrate demand from market shares and a few additional parameters. When the products involved in the merger case are differentiated along several dimensions, the resulting diversion ratios may be very different from those based upon market shares. This again may affect the predicted post-merger price effects. This article

Lars Mathiesen; Øivind Anti Nilsen; Lars Sørgard



Merger simulations with observed diversion ratios  

Microsoft Academic Search

One approach to merger simulations used in antitrust cases is to calibrate demand from market shares and a few additional parameters. When the products involved in the merger case are differentiated along several dimensions, actual diversion ratios may be very different from those calculated from market shares. This again may affect the predicted post-merger price effects. This article shows how

Lars Mathiesen; Øivind Anti Nilsen; Lars Sørgard



Perspectives on the basic reproductive ratio  

Microsoft Academic Search

The basic reproductive ratio, R0, is defined as the expected number of secondary infections arising from a single individual during his or her entire infectious period, in a population of susceptibles. This concept is fundamental to the study of epidemiology and within-host pathogen dynamics. Most importantly, R0 often serves as a threshold parameter that predicts whether an infection will spread.

J. M. Heffernan; R. J. Smith; L. M. Wahl



Blowing Ratio Effects on Film Cooling Effectiveness  

E-print Network

The research focuses on testing the film cooling effectiveness on a gas turbine blade suction side surface. The test is performed on a five bladed cascade with a blow down facility. Four different blowing ratios are used in this study, which are 0...

Liu, Kuo-Chun



Ratio method of measuring $w$ boson mass  

SciTech Connect

This dissertation describes an alternative method of measuring the W boson mass in D0 experiment. Instead of extracting M{sub W} from the fitting of W {yields} e{nu} fast Monte Carlo simulations to W {yields} e{nu} data as in the standard method, we make the direct fit of transverse mass between W {yields} e{nu} data and Z {yields} ee data. One of the two electrons from Z boson is treated as a neutrino in the calculation of transverse mass. In ratio method, the best fitted scale factor corresponds to the ratio of W and Z boson mass (M{sub W}/M{sub Z}). Given the precisely measured Z boson mass, W mass is directly fitted from W {yields} e{nu} and Z {yields} ee data. This dissertation demonstrates that ratio method is a plausible method of measuring the W boson mass. With the 1 fb{sup -1} D0 Run IIa dataset, ratio method gives M{sub W} = 80435 {+-} 43(stat) {+-} 26(sys) MeV.

Guo, Feng; /SUNY, Stony Brook



Electronic branching ratio of the ? lepton  

E-print Network

Using data accumulated by the CLEO I detector operating at the Cornell Electron Storage Ring, we have measured the ratio R=?(??e?¯(e)?(?)) / ?(1) where ?(1) is the ? decay rate to final states with one charged particle. We find R=0...

Ammar, Raymond G.; Baringer, Philip S.; Coppage, Don; Davis, Robin E. P.; Kelly, M.; Kwak, Nowhan; Lam, H.



Effects of Thermal Conductivity Ratio in  

E-print Network

Effects of Thermal Conductivity Ratio in Helium-Cooled Divertors B. H. Mills J. D. Rader D. L a correlation for from these experimental data o 4m Re D Calculating and Ref Brantley Mills - bmills-hydraulics and improving the thermal performance of various helium-cooled divertor designs Brantley Mills - bmills


NERO-The Neutron Emission Ratio Observer  

NASA Astrophysics Data System (ADS)

The Neutron Emission Ratio Observer (NERO), has been constructed for the use at the National Superconducting Cyclotron Laboratory to work in conjunction with the NSCL Beta Counting System in order to detect ?-delayed neutrons. The design of the detector provides high and flat efficiency for a wide range of neutron energies, as well as a low neutron background.

Lorusso, Giuseppe; Pereira, Jorque; Hosmer, Paul; Kratz, Karl Ludvig; Montes, Fernando; Reeder, Paul; Santi, Peter; Schatz, Hendrik



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



Predicting Abnormal Returns Using Debt Ratios  

Microsoft Academic Search

This paper investigates the ability of the company capital structures to be used as a predictor for abnormal returns in the US stock market in the long run. The relationship between debt level and abnormal return over a three-year holding period is investigated. Robustness tests are carried out to determine the predictive ability of debt ratios when controlling for size

Brian Baturevich; Gulnur Muradoglu



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.




SciTech Connect

When routine sampling revealed greatly elevated tritium levels (3.14 x 105 Bq/L [8.5-million pCi/liter]) in the groundwater near a solid waste landfill at the Hanford Site, an innovative technique was used to assess the extent of the plume. Helium-3/helium-4 ratios, relative to ambient air-in-soil gas samples, were used to identify the tritium source and initially delineate the extent of the groundwater tritium plume. This approach is a modification of a technique developed in the late 1960s to age-date deep ocean water as part of the GEOSECS ocean monitoring program. Poreda, et al. (1) and Schlosser, et al. (2) applied this modified technique to shallow aquifers. A study was also conducted to demonstrate the concept of using helium-3 as a tool to locate vadose zone sources of tritium and tracking groundwater tritium plumes at Hanford (3). Seventy sampling points were installed around the perimeter and along four transects downgradient of the burial ground. Soil gas samples were collected, analyzed for helium isotopes, and helium-3/helium-4 ratios were calculated for these 70 points. The helium ratios indicated a vadose zone source of tritium along the northern edge of the burial ground that is likely the source of tritium in the groundwater. The helium ratios also indicate the groundwater plume is traveling east-northeast from the burial ground and that no up-gradient tritium sources are affecting the burial ground. Based on the helium ratio results, six downgradient groundwater sampling locations were identified to verify the tritium plume extent and groundwater tritium concentrations. The tritium results from the initial groundwater samples confirmed that elevated helium ratios were indicative of tritium contamination in the local groundwater. The measurement of helium isotopes in soil gas provided a rapid and cost- effective technique to define the shape and extent of tritium contamination from the burial ground. Using this soil gas sampling approach, the project team was able to identify areas where elevated tritium existed in groundwater without going to the time and expense of conducting conventional groundwater characterization sampling. The savings from this characterization approach were $1.4 million.

Ovink, R.W.; McMahon, W.J.; Borghese, J.V.; Olsen, K.B.



CFD assessment of orifice aspect ratio and mass flow ratio on jet mixing in rectangular ducts  

NASA Technical Reports Server (NTRS)

Isothermal CFD analysis was performed on axially opposed rows of jets mixing with cross flow in a rectangular duct. Laterally, the jets' centerlines were aligned with each other on the top and bottom walls. The focus of this study was to characterize the effects of orifice aspect ratio and jet-to-mainstream mass flow ratio on jet penetration and mixing. Orifice aspect ratios (L/W) of 4-to-1, 2-to-1, and 1-to-1, along with circular holes, were parametrically analyzed. Likewise, jet-to-mainstream mass flow ratios (MR) of 2.0, 0.5, and 0.25 were systematically investigated. The jet-to-mainstream momentum-flux ratio (J) was maintained at 36 for all cases, and the orifice spacing-to-duct height (S/H) was varied until optimum mixing was attained for each configuration. The numerical results showed that orifice aspect ratio (and likewise orifice blockage) had little effect on jet penetration and mixing. Based on mixing characteristics alone, the 4-to-1 slot was comparable to the circular orifice. The 4-to-1 slot has a smaller jet wake which may be advantageous for reducing emissions. However, the axial length of a 4-to-1 slot may be prohibitively long for practical application, especially for MR of 2.0. The jet-to-mainstream mass flow ratio had a more significant effect on jet penetration and mixing. For a 4-to-1 aspect ratio orifice, the design correlating parameter for optimum mixing (C = (S/H)(sq. root J)) varied from 2.25 for a mass flow ratio of 2.0 to 1.5 for a mass flow ratio of 0.25.

Bain, D. B.; Smith, C. E.; Holdeman, J. D.



The Central Bank in Colombia  

Microsoft Academic Search

In the last decade the issue of the optimal degree of central bank independence has been at the center of attention of academics and policymakers in many countries. The direction of institutional reform has almost universally been toward making central banks more independent from political pressure. The motivation of this move is linked to an increased emphasis on price stability

Alberto Alesina; Alberto Carrasquilla; RobertoSteiner



Subgraph centrality in complex networks  

Microsoft Academic Search

We introduce a new centrality measure that characterizes the participation of each node in all subgraphs in a network. Smaller subgraphs are given more weight than larger ones, which makes this measure appropriate for characterizing network motifs. We show that the subgraph centrality [ CS(i) ] can be obtained mathematically from the spectra of the adjacency matrix of the network.

Ernesto Estrada; Juan A. Rodríguez-Velázquez



Central Serous Chorioretinopathy and Glucocorticoids  

Microsoft Academic Search

Central serous chorioretinopathy is a relatively common retinal disease characterized by the accumulation of subretinal fluid at the posterior pole of the fundus, creating a circumscribed area of serous retinal detachment. It typically affects young and middle-aged men with no previous medical and family history, and no systemic symptoms or signs. However, it has been noted that central serous chorioretinopathy

Evrydiki A Bouzas; Panagiotis Karadimas; Constantin J Pournaras



Epidemiologic survey of 196 patients with congenital central hypoventilation syndrome  

Microsoft Academic Search

Summary. Thisstudyexaminedthecross-sectionalmedicalandsocialcharacteristicsofchildren diagnosed with congenital central hypoventilation syndrome (CCHS). A detailed questionnaire was mailed to all families with a child with CCHS who are affiliated with a family network or support group. The questionnaire response rate was >75% (n ¼196). Mean age was 10.22 years ? 6.6 years (SD) (range, 0.4-38 years), with a 1:1 sex ratio. Multisystem involvement was

Mary Vanderlaan; Cheryl R. Holbrook; Mei Wang; Andrew Tuell; David Gozal



A combined photovoltaic\\/thermal electric central power plant  

Microsoft Academic Search

A preliminary design and performance evaluation of the subject power plant has been completed. DC energy is produced by boiling-water-cooled gallium arsenide solar cells covering a central receiver illuminated by a heliostat field with a concentration ratio of one thousand. The steam is used to power a low pressure turbine-generator, with the exhaust steam directly condensed in a dry air

D. F. Gluck



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)



Polymeric Microring Resonator Enabling Variable Extinction Ratio  

NASA Astrophysics Data System (ADS)

A polymeric ring resonator filter enabling electrically variable extinction ratio has been implemented, incorporating a ring waveguide coupled to a bus waveguide and an electrode which is separated from it with a gap. When an electrical power is applied to the electrode, the refractive index of the polymers underneath it is lowered through the thermo-optic effect so that the guided-mode confinement in the ring is strengthened to reduce its bending loss. Consequently, for a constant bus-to-ring coupling the attenuation depth at resonant wavelengths could be adjusted electrically. As for the achieved performance, the extinction ratio was changed by ˜9 dB for the electrical power of ˜12 mW while the corresponding bending loss was improved by ˜86 dB/cm.

Song, Ju-Han; Kim, Do-Hwan; Lee, Sang-Shin



The HNC/HCN ratio in comets  

NASA Technical Reports Server (NTRS)

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.

Irvine, W. M.; Dickens, J. E.; Lovell, A. J.; Schloerb, F. P.; Senay, M.; Bergin, E. A.; Jewitt, D.; Matthews, H. E.; Ferris, J. P. (Principal Investigator)



High Hypopnea/Apnea Ratio (HAR) in Extreme Obesity  

PubMed Central

Study Objectives: The study was performed to evaluate the hypothesis that the extremely obese manifest sleep disordered breathing with a preponderance of hypopneas and relative paucity of obstructive apneas. Methods: Retrospective review of 90 adults with obstructive sleep apnea-hypopnea syndrome (OSAHS) matched for age and gender, comparing two groups, Group A: body mass index (BMI) < 35, Group B: BMI ? 45. Exclusion criteria: age < 18 years, pregnancy, ? 5 central apneas/hour, BMI ? 35 < 45. Primary Outcome Measure: Hypopnea/apnea ratio (HAR); secondary measures: obstructive apnea-hypopnea index (AHI), obstructive and central apnea indices, hypopnea index (HI), oxygen saturation (SpO2) nadir, end-tidal carbon dioxide tension (PetCO2), and presence of obesity-hypoventilation syndrome (OHS). Statistical methods: t-test for independent samples; Mann-Whitney, linear regression with natural log transformation, and Kruskal-Wallis ?2. Descriptive statistics were expressed as interquartile range, median and mean ± standard deviation, p < 0.05 considered significant. Results: Group A (n = 45): age = 50.6 ± 11.5 years, BMI = 28.9 ± 4 kg/m2; Group B (n = 45): age = 47.4 ± 12.7 years, BMI = 54.5 ± 8 kg/m2. HAR was significantly higher in Group B (38.8 ± 50.7) than Group A (10.6 ± 16.5), p = 0.0006, as was HI (28.7 ± 28.6 in B vs 12.6 ± 8.4 in A, p = 0.0005) and AHI (35.5 ± 33.8 vs 22 ± 23, p = 0.03), but not apnea index. HAR was significantly higher in Group B regardless of race, gender, or presence of OHS. The BMI was the only significant predictor of HAR (adjusted r2 = 0.138; p = 0.002) in a linear regression model with natural log transformation of the HAR performed for age, gender, race, BMI, and PetCO2. Conclusion: Extremely obese patients manifest OSAHS with a preponderance of hypopneas. Citation: Mathew R; Castriotta RJ. High hypopnea/apnea ratio (HAR) in extreme obesity. J Clin Sleep Med 2014;10(4):391-396. PMID:24733984

Mathew, Reeba; Castriotta, Richard J.



Controlling centrality in complex networks  

PubMed Central

Spectral centrality measures allow to identify influential individuals in social groups, to rank Web pages by 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 node centralities once the network structure is assigned. We face here with the inverse problem, that is, we study how to modify the centrality scores of the nodes by acting on the structure of a given network. We show that there exist particular subsets of nodes, called controlling sets, which can assign any prescribed set of centrality values to all the nodes of a graph, by cooperatively tuning the weights of their out-going links. We found that many large networks from the real world have surprisingly small controlling sets, containing even less than 5 – 10% of the nodes. PMID:22355732

Nicosia, V.; Criado, R.; Romance, M.; Russo, G.; Latora, V.



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.



Central African Republic.  


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



Symmetries and Periodicities of the Strehl Ratio  

Microsoft Academic Search

McCutchen's theorem relates the complex amplitude u(z) along the optical axis to the complex amplitude [ptilde](?,?) in the exit pupil. This relation is a Fourier transform. The assumptions made are that [ptilde] is rotationally symmetric and that the paraxial approximation applies. The normalized quantity |u(z)\\/u(0)|=S(z) is called the Strehl ratio. By using McCutchen's theorem we derive the necessary and sufficient

A. W. Lohmann; J. Ojeda-Castañeda



Noncircular, finite aspect ratio, local equilibrium model  

SciTech Connect

A tokamak equilibrium model, local to a flux surface, is introduced which is completely described in terms of nine parameters including aspect ratio, elongation, triangularity, and safety factor. By allowing controlled variation of each of these nine parameters, the model is particularly suitable for localized stability studies such as those carried out using the ballooning mode representation of the gyrokinetic equations. {copyright} {ital 1998 American Institute of Physics.}

Miller, R.L.; Chu, M.S.; Greene, J.M.; Lin-Liu, Y.R.; Waltz, R.E. [General Atomics, San Diego, California92186-5608 (United States)] [General Atomics, San Diego, California92186-5608 (United States)



Theater SBI cost-effectiveness ratios  

SciTech Connect

To address M missiles spaced at intervals longer than the constillation reconstitution time t, the defense needs at the absentee ratio N{sub a} of SBIs to fill the belt plus the M SBIs needed for the intercepts; the resulting cost effectiveness scales as M/(M + N{sub a}). N{sub a} is large and CER small for small ranges and numbers of missiles. For several-hundred missile threats, CERs are greater than unity for ranges of interest.

Canavan, G.H.



Isotope ratio determination in boron analysis  

Microsoft Academic Search

Traditionally, boron (B) isotope ratios have been determined using thermal ionization mass spectrometry (TIMS) and, to some\\u000a extent, secondary ion mass spectrometry (SIMS). Both TIMS and SIMS use a high-resolution mass analyzer, but differ in analyte\\u000a ionization methods. TIMS uses electrons from a hot filament, whereas SIMS employs an energetic primary ion beam of Ga+, Cs+, or O- for analyte

Ram N. Sah; Patrick H. Brown



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



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



Microbial respiration per unit microbial biomass depends on soil litter carbon-to-nitrogen ratio  

NASA Astrophysics Data System (ADS)

Soil microbial respiration is a central process in the terrestrial carbon (C) cycle. In this study I tested the effect of the carbon-to-nitrogen (C : N) ratio of soil litter layers on microbial respiration in absolute terms and per unit microbial biomass C. For this purpose, a global dataset on microbial respiration per unit microbial biomass C - termed the metabolic quotient (qCO2) - was compiled form literature data. It was found that the qCO2 in the soil litter layers was positively correlated with the litter C : N ratio and negatively related with the litter nitrogen (N) concentration. The positive relation between qCO2 and litter C : N ratio resulted from an increase in respiration with the C : N ratio in combination with no significant effect of the litter C : N ratio on the soil microbial biomass C concentration. The results suggest that soil microorganisms respire more C both in absolute terms and per unit microbial biomass C when decomposing N-poor substrate. Thus, the findings indicate that atmospheric N deposition, leading to decreased litter C : N ratios, might decrease microbial respiration in soils.

Spohn, M.



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


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 12days. 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. PMID:20034778

Kumar, Mathava; Ou, Yan-Liang; Lin, Jih-Gaw



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.



12 CFR 615.5206 - Permanent capital ratio computation.  

Code of Federal Regulations, 2010 CFR

... false Permanent capital ratio computation. 615.5206...5206 Permanent capital ratio computation. (a) The institution's permanent capital ratio is determined on the basis...accordance with generally accepted accounting principles except...



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...high asset quality; high liquidity; and well managed on-and...the minimum Tier 1 leverage ratio is 4 percent. In all...



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.


Combined central and peripheral demyelination.  


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



Combined central and peripheral demyelination  

PubMed Central

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



Cytoplasm-to-myonucleus ratios following microgravity  

NASA Technical Reports Server (NTRS)

The cytoplasmic volume-to-myonucleus ratio in the tibialis anterior and gastrocnemius muscles of juvenile rats after 5.4 days of microgravity was studied. Three groups of rats (n = 8 each) were used. The experimental group (space rats) was flown aboard the space shuttle Discovery (NASA, STS-48), while two ground-based groups, one hindlimb suspended (suspended rats), one non-suspended (control), served as controls. Single fibre analysis revealed a significant decrease in cross-sectional area (microns2) in the gastrocnemius for both the space and the suspended rats; in the tibialis anterior only the suspended rats showed a significant decrease. Myonuclei counts (myonuclei per mm) in both the tibialis anterior and gastrocnemius were significantly increased in the space rats but not in the suspended rats. The mean myonuclear volume (individual nuclei: microns3) in tibialis anterior fibres from the space rats, and in gastrocnemius fibres from both the space and the suspended rats, was significantly lower than that in the respective control group. Estimation of the total myonuclear volume (microns3, however, revealed no significant differences between the three groups in either the tibialis anterior or gastrocnemius. The described changes in the cross-sectional area and myonuclei numbers resulted in significant decreases in the cytoplasmic volume-to-myonucleus ratio (microns3 x 10(3)) in both muscles and for both space and suspended rats (tibialis anterior; 15.6 +/- 0.6 (space), 17.2 +/- 1.0 (suspended), 20.8 +/- 0.9 (control): gastrocnemius; 13.4 +/- 0.4 (space) and 14.9 +/- 1.1 (suspended) versus 18.1 +/- 1.1 (control)). These results indicate that even short periods of unweighting due to microgravity or limb suspension result in changes in skeletal muscle fibres which lead to significant decreases in the cytoplasmic volume-to-myonucleus ratio.

Kasper, C. E.; Xun, L.



Sex ratio, sex change, and natural selection.  

PubMed Central

We describe the analogy between the theory of natural selection on sex ratio in newborn gonochores (which will not change sex), and on the age of sex change in sequential hermaphrodites (which are all born into one sex and change to the other later on). We also discuss the conditions under which natural selection favors sequential hermaphrodites over gonochores and vice versa. We show that, in a nearly stable population of nearly constant age composition, selection favors a rare mutant if it increases the prospective reproduction of its newborn bearers that are (or while they are) members of one sex by a percentage exceeding the percentage loss to the other sex. PMID:1068478

Leigh, E G; Charnov, E L; Warner, R R



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



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...


High aspect ratio, remote controlled pumping assembly  


A miniature dual syringe-type pump assembly is described 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. 4 figs.

Brown, S.B.; Milanovich, F.P.



Air-fuel ratio feedback control system  

SciTech Connect

An air-fuel ratio feedback control system for the internal combustion engine produces a fuel supply control signal by delaying a rich or lean signal obtained by comparing the oxygen concentration in the exhaust gas with a reference value. The turning on of an idle switch operatively connected with the engine throttle valve, a predetermined time after the turning off of the idle switch and the engine speed included in a predetermined region are detected in order to delay the rich or lean signal to rich or lean side by an optimum delay time as selected according to the engine operating conditions, thus feedback controlling the amount of fuel supply.

Yoshida, S.; Hoshi, K.; Matsuo, M.; Ono, H.; Sueishi, M.; Ueda, K.



New "Golden" Ratios for Facial Beauty  

PubMed Central

In four experiments, we tested the existence of an ideal facial feature arrangement that could optimize the attractiveness of any face given its facial features. Participants made paired comparisons of attractiveness between faces with identical facial features but different eye-mouth distances and different interocular distances. We found that although different faces have varying attractiveness, individual attractiveness is optimized when the face’s vertical distance between the eyes and the mouth is approximately 36% of its length, and the horizontal distance between the eyes is approximately 46% of the face’s width. These “new” golden ratios match those of an average face. PMID:19896961

Pallett, Pamela M.; Link, Stephen; Lee, Kang



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



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



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



The CMS central hadron calorimeter  

SciTech Connect

The CMS central hadron calorimeter is a brass absorber/scintillator sampling structure. We describe details of the mechanical and optical structure. We also discuss calibration techniques, and finally the anticipated construction schedule.

Freeman, Jim [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)



Central cementifying fibroma of maxilla  

PubMed Central

Central cementifying fibroma is a bony tumor, which is believed to be derived from the cells of the periodontal ligament. Central cemento-ossifying fibroma behaves like, a benign bone neoplasm. This bone tumor consists of highly cellular, fibrous tissue that contains varying amounts of calcified tissue resembling bone, cementum, or both. Central cemento-ossifying fibromas of the mandible are common; however, they are rare in the maxilla region. This tumor is most frequent between 35 and 40 years of ages. In this report we have described a 37-year-old male with cemento-ossifying fibroma of the maxilla region with the mass that had been appeared 2-3 months prior to his first referral. Radiologic imaging such as intra-oral, panoramic, and Cone Beam CT had been performed. Histological analysis was done and finally diagnosis of central cementifying fibroma was made. The postoperative follow up at 12 months revealed no recurrence. PMID:23878576

Sheikhi, Mahnaz; Mosavat, Farzaneh; Jalalian, Faranak; Rashidipoor, Roghayeh




E-print Network

Executive Director & Chief Financial Officer Melinda Coil Bio FINANCE & OPERATIONS FACILITIES PLANNINGAll Central Staff EXECUTIVE AFFAIRS EXECUTIVE OFFICE Executive Director Bob E. Wolfson COMMUNICATIONS Organization Chart Director Deborah Brighton Bio Special Assistant Renée Daniels Bio Associate

Ponce, V. Miguel


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



Emission Ratios from SCIAMACHY simultaneous measurements  

NASA Astrophysics Data System (ADS)

The spectra of reflected and backscattered solar radiation as measured by SCIAMACHY in nadir observation mode in the UV/visible/near-infrared/short-wave-infrared spectral region contain information on the vertical columns of numerous air pollutants and therefore provide a large-scale perspective on spacious and uncertain pollution sources like biomass burnings. It will be shown that under a number of reasonable assumptions we can obtain a quantitative charac-teristics of biomass burning emissions in terms of emission ratios (ER) using only the averages of the atmospheric gas columns retrieved from the space-based simultaneous measurements. Considering for example the SCIAMACHY carbon monoxide (CO), taken as a reference car-bon component, together with the SCIAMACHY formaldehyde (HCHO) and nitrogen dioxide (NO2) columns in the scope of a well established emission quantification method we calcu-late the emission ratios, CO/HCHO and CO/NO2, over large biomass burning events in 2004 (established with the help of the AATSR fire counts product). We show that the calculated ER values are in reasonable agreement with the values obtained locally over similar biomass burning events reported in the literature. In addition, we discuss the relatively large values over the boreal forest fires in Alaska and Siberia, where ER values from local measurements were not yet reported.

Khlystova, Iryna; Richter, Andreas; Wittrock, Folkard; Burrows, John P.; Buchwitz, Michael; Bovensmann, Heinrich


Ultra-High Bypass Ratio Jet Noise  

NASA Technical Reports Server (NTRS)

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.



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.



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. PMID:23049967

Dama, Madhukar Shivajirao



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. PMID:24982993

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




SciTech Connect





Estimating the Isotope Ratio of Ecosystem Respiration Using the Keeling Plot and the Flux Ratio Method  

NASA Astrophysics Data System (ADS)

Stable carbon isotope analyses have been used in identifying global carbon sources and sinks and in partitioning ecosystem CO2 exchange into component fluxes. The isotope ratio of ecosystem respiration (? 13Cr) is a critical parameter in applying stable isotope techniques to carbon cycle problems. The commonly used Keeling plot method in estimating ? 13Cr has limitations related to: 1) insufficient range of CO2 mixing ratio; 2) high sensitivity to curve-fitting techniques; and 3) extrapolation of CO2 mixing ratio beyond observations. In this study, the Keeling plot method was examined and compared with the flux ratio approach using continuous measurements of the mixing ratios of 12CO2 and 13CO2 over an extensive corn canopy during the 2003 growing season. The seasonal variation of ? 13Cr estimated from both methods harmonized with the ecosystem phenology. The ? 13Cr started to increase (became more positive) from mid June and peaked in early August, followed by a decrease into October. The Keeling plot method agreed well with the flux ratio method in the seasonal pattern of ? 13Cr, but tended to give lower values (more negative). The discrepancy between the two approaches was significant in July and August (about 5 per mil) and relatively small in June and September (about 1 to 2 per mil). We examined this discrepancy with respect to wind direction/advection and measurement footprints. In addition, our analysis of high-frequency data (every two minutes) using the flux ratio method indicates that ? 13Cr may vary significantly at short time-scales (e.g., hourly), which could have significant implications for flux partitioning studies.

Zhang, J.; Griffis, T. J.; Baker, J. M.



Cardiorespiratory fitness associates with metabolic risk independent of central adiposity.  


This study sought to analyze the associations between cardiorespiratory fitness (CRF), waist circumference (WC) and metabolic risk in children and adolescents. Participants were 633 subjects (58.7% girls) ages 10-18 years. Metabolic risk score (MRS) was calculated from HDL-cholesterol, triglycerides, fasting glucose and mean arterial pressure. MRS was dichotomized into low and high metabolic risk (HMRS). CRF was defined as the maximal oxygen uptake (VO?max) estimated from the 20 m Shuttle Run Test. The first quartile of CRF was set as the low fitness group. The fourth quartile of WC was defined as high central adiposity. With adjustments for age, sex and WC, CRF was correlated with MRS (r=-0.095; p<0.05). WC was correlated with MRS (r=0.150; p<0.001) after adjustments for age, sex and CRF. Participants who had low fitness levels, presented higher levels of MRS (p<0.001) compared to those who were fit, even after adjustment for age, sex and WC. In comparison with subjects who were fit with normal central adiposity, an increased odds ratio (OR) for being at HMRS was found for participants who were of low fitness level with high central adiposity (OR=2.934; 95%CI= 1.690-5.092) and for those who were of low fitness with normal central adiposity (OR=2.234; 95%CI=1.116-4.279). Results suggest that CRF relates to MRS independently of central adiposity. PMID:23559413

Silva, G; Aires, L; Martins, C; Mota, J; Oliveira, J; Ribeiro, J C



Benign rolandic epilepsy: high central and low central subgroups.  


The spikes in benign rolandic epilepsy (BRE) typically involve both the central and midtemporal regions as recorded on standard EEG montages, but the seizures are characterized by sensorimotor manifestations that are rarely referrable to the temporal lobe. To study this apparent disparity, we evaluated the field distribution of interictal spikes in 33 BRE patients using closely spaced electrodes (AEEGS 1990) arranged over perisylvian cortex. None of the 33 patients showed maximum negativity in the midtemporal regions (T3/T4). Instead, maximum negativity was evident in the high central region (C3/C4) in 10 children (30.3%) and in the low central region (C5/C6) in 23 (69.7%). Hand involvement was significantly frequent (50%) in the high central group, and drooling with oromotor involvement was a distinctive symptom (65.2%) in the low central group. Our findings indicate that the spikes in patients with BRE are exclusively suprasylvian in origin and correlate with two electroclinical subgroups. PMID:7988499

Legarda, S; Jayakar, P; Duchowny, M; Alvarez, L; Resnick, T



On Monte Carlo methods for estimating ratios of normalizing constants  

Microsoft Academic Search

Recently, estimating ratios of normalizing constants has played an important role in Bayesian computations. Applications of estimating ratios of normalizing constants arise in many aspects of Bayesian statistical inference. In this article, we present an overview and discuss the current Monte Carlo methods for estimating ratios of normalizing constants. Then we propose a new ratio importance sampling method and establish

Ming-Hui Chen; Qi-Man Shao



Uncorrelated trace ratio linear discriminant analysis for undersampled problems  

Microsoft Academic Search

For linear discriminant analysis (LDA), the ratio trace and trace ratio are two basic criteria generalized from the classical Fisher criterion function, while the orthogonal and uncorrelated constraints are two common conditions imposed on the optimal linear transformation. The ratio trace criterion with both the orthogonal and uncorrelated constraints have been extensively studied in the literature, whereas the trace ratio

Lei-Hong Zhang



Isotope Ratios of Cellulose from Plants Having Different Photosynthetic Pathways  

PubMed Central

Hydrogen and carbon isotope ratios of cellulose nitrate and oxygen isotope ratios of cellulose from C3, C4, and Crassulacean acid metabolism (CAM) plants were determined for plants growing within a small area in Val Verde County, Texas. Plants having CAM had distinctly higher deuterium/hydrogen (D/H) ratios than plants having C3 and C4 metabolism. When hydrogen isotope ratios are plotted against carbon isotope ratios, each photosynthetic mode separates into a distinct cluster of points. C4 plants had many D/H ratios similar to those of C3 plants, so that hydrogen isotope ratios cannot be used to distinguish between these two photosynthetic modes. Portulaca mundula, which may have a modified photosynthetic mode between C4 and CAM, had a hydrogen isotope ratio between those of the C4 and CAM plants. When oxygen isotope ratios are plotted against carbon isotope ratios, no distinct clustering of the C4 and CAM plants occurs. Thus, oxygen isotope ratios are not useful in distinguishing between these metabolic modes. A plot of hydrogen isotope ratios versus oxygen isotope ratios for this sample set shows considerable overlap between oxygen isotope ratios of the different photosynthetic modes without a concomitant overlap in the hydrogen isotope ratios of CAM and the other two photosynthetic modes. This observation is consistent with the hypothesis that higher D/H ratios in CAM plants relative to C3 and C4 plants are due to isotopic fractionations occurring during biochemical reactions. PMID:16663460

Sternberg, Leonel O.; Deniro, Michael J.; Johnson, Hyrum B.



Sex ratio and mate preferences: a cross-cultural investigation  

Microsoft Academic Search

Sex ratio is the number of men per 100 reproductive-age women within a specified mating pool. We generated and tested two hypotheses about the cross-cultural relationships between sex ratio and mate preferences using preference ratings of 18 characteristics provided by 9809 participants and corresponding sex ratio data secured from an international organization. The Classical Sex Ratio Mate Preference Shifts Hypothesis

Emily A. Stone; Todd K. Shackelford; David M. Buss



The Next Generation Isotope Ratio MS DELTA V Advantage  

E-print Network

Plus The Next Generation Isotope Ratio MS The DELTA V isotope ratio mass spectrometers isotope ratio MS applications in the mass range up to m/z 96. Its versatility puts virtuallyThe Next Generation Isotope Ratio MS DELTA V Advantage DELTA V Plus Analyze · Detect · Measure

Lachniet, Matthew S.


Mining Adaptive Ratio Rules from Distributed Data Sources  

Microsoft Academic Search

Different from traditional association-rule mining, a new paradigm called Ratio Rule (RR) was proposed recently. Ratio rules are aimed at capturing the quantitative association knowledge, We extend this framework to mining ratio rules from distributed and dynamic data sources. This is a novel and challenging problem. The traditional techniques used for ratio rule mining is an eigen-system analysis which can

Jun Yan; Ning Liu; Qiang Yang; Benyu Zhang; Qiansheng Cheng; Zheng Chen



Effects of a Signaled Delay to Reinforcement in the Previous and Upcoming Ratios on Between-Ratio Pausing in Fixed-Ratio Schedules  

ERIC Educational Resources Information Center

Domestic hens responded under multiple fixed-ratio fixed-ratio schedules with equal fixed ratios. One component provided immediate reinforcement and the other provided reinforcement after a delay, signaled by the offset of the key light. The components were presented quasi-randomly so that all four possible transitions occurred in each session.…

Harris, Aimee; Foster, T. Mary; Levine, Joshua; Temple, William



Spatial Variability and Application of Ratios between BTEX in Two Canadian Cities  

PubMed Central

Spatial monitoring campaigns of volatile organic compounds were carried out in two similarly sized urban industrial cities, Windsor and Sarnia, ON, Canada. For Windsor, data were obtained for all four seasons at approximately 50 sites in each season (winter, spring, summer, and fall) over a three-year period (2004, 2005, and 2006) for a total of 12 sampling sessions. Sampling in Sarnia took place at 37 monitoring sites in fall 2005. In both cities, passive sampling was done using 3M 3500 organic vapor samplers. This paper characterizes benzene, toluene, ethylbenzene, o, and (m + p)-xylene (BTEX) concentrations and relationships among BTEX species in the two cities during the fall sampling periods. BTEX concentration levels and rank order among the species were similar between the two cities. In Sarnia, the relationships between the BTEX species varied depending on location. Correlation analysis between land use and concentration ratios showed a strong influence from local industries. Use one of the ratios between the BTEX species to diagnose photochemical age may be biased due to point source emissions, for example, 53 tonnes of benzene and 86 tonnes of toluene in Sarnia. However, considering multiple ratios leads to better conclusions regarding photochemical aging. Ratios obtained in the sampling campaigns showed significant deviation from those obtained at central monitoring stations, with less difference in the (m + p)/E ratio but better overall agreement in Windsor than in Sarnia. PMID:22235184

Miller, Lindsay; Xu, Xiaohong; Wheeler, Amanda; Atari, Dominic Odwa; Grgicak-Mannion, Alice; Luginaah, Isaac



Thorough tuning of the aspect ratio of gold nanorods using response surface methodology.  


In the present work a central composite design based on response surface methodology (RSM) is employed for fine tuning of the aspect ratios of seed-mediated synthesized gold nanorods (GNRs). The relations between the affecting parameters, including ratio of l-ascorbic acid to Au(3+) ions, concentrations of silver nitrate, CTAB, and CTAB-capped gold seeds, were explored using a RSM model. It is observed that the effect of each parameter on the aspect ratio of developing nanorods highly depends on the value of the other parameters. The concentrations of silver ions, ascorbic acid and seeds are found to have a high contribution in controlling the aspect ratios of NRs. The optimized parameters led to a high yield synthesis of gold nanorods with an ideal aspect ratio ranging from 1 (spherical particle) to 4.9. In addition, corresponding tunable surface Plasmon absorption band has been extended to 880 nm. The resulted nanorods were characterized by UV-visible spectrometry and transmission electron microscopy. PMID:23663667

Hormozi-Nezhad, M Reza; Robatjazi, Hossein; Jalali-Heravi, Mehdi



The AIMSS Project II: dynamical-to-stellar mass ratios across the star cluster-galaxy divide  

NASA Astrophysics Data System (ADS)

The previously clear division between small galaxies and massive star clusters is now occupied by objects called ultra-compact dwarfs (UCDs) and compact ellipticals (cEs). Here we combine a sample of UCDs and cEs with velocity dispersions from the AIMSS project with literature data to explore their dynamical-to-stellar mass ratios. We confirm that the mass ratios of many UCDs in the stellar mass range 106-109 M? are systematically higher than those for globular clusters which have mass ratios near unity. However, at the very highest masses in our sample, i.e. 109-1010 M?, we find that cE galaxies also have mass ratios of close to unity, indicating their central regions are mostly composed of stars. Suggested explanations for the elevated mass ratios of UCDs have included a variable IMF, a central black hole, and the presence of dark matter. Here we present another possible explanation, i.e. tidal stripping. Under various assumptions, we find that the apparent variation in the mass ratio with stellar mass and stellar density can be qualitatively reproduced by published tidal stripping simulations of a dwarf elliptical galaxy. In the early stages of the stripping process the galaxy is unlikely to be in virial equilibrium. At late stages, the final remnant resembles the properties of ˜107 M? UCDs. Finally, we discuss the need for more detailed realistic modelling of tidal stripping over a wider range of parameter space, and observations to further test the stripping hypothesis.

Forbes, Duncan A.; Norris, Mark A.; Strader, Jay; Romanowsky, Aaron J.; Pota, Vincenzo; Kannappan, Sheila J.; Brodie, Jean P.; Huxor, Avon



Compression-ratio-based seizure detection.  


For wireless seizure monitoring devices seizure detection and data compression are two critical tasks that need to be carefully designed against a very tight power budget to maximize the battery life. These two tasks are usually considered separately and algorithms for each are developed separately. In this paper, we consider having a single low-power algorithm for implementing both seizure detection and data compression. Towards that end, we investigated compression ratio (CR) as a seizure marker and show that the seizure detection can be achieved as a by-product of compression with no additional cost, and thus overall system power can be reduced. We show that the proposed method, the CR-based seizure detection has promising performance with 88% seizure detection accuracy, and 5.5 false positives per hour (FPh) without any computation overhead. PMID:24109861

Sha, Chung-Lin; Kim, Taehoon; Artan, N Sertac; Chao, H Jonathan



Beat Cepheid Period Ratios from OPAL Opacities  

E-print Network

The discovery of a large number of beat Cepheids in the Large Magellanic Cloud in the MACHO survey, provides an opportunity to compare the characteristics of such Cepheids over a range of metallicities. We produced a large grid of linear nonadiabatic pulsation models using the OPAL opacity tables and with compositions corresponding to those of the Milky Way, and the Large and Small Magellanic Clouds. Using the relationship between the period ratio and the main pulsation period, we are able to define a range of models which correspond to the observed beat Cepheids, and thereby constrain the physical characteristics of the LMC beat Cepheids. We are also able to make some predictions about the nature of the yet-to-be-discovered SMC beat Cepheids.

S. M. Morgan; D. L. Welch



Hardness ratios of different neutron spectra.  


Extensive data have been gathered in the past on the response of different detectors, based on the registration of neutron-induced fissions in bismuth, gold, tantalum and thorium by the spark-replica counter and the thin film breakdown counter. These detectors make it possible to exploit the excellent characteristics of the fission reactions for the measurements of high-energy neutrons. Most of the investigations have been carried out at the quasi-monoenergetic neutron beam facility at The Svedberg Laboratory-TSL of the Uppsala University in cooperation with the Khlopin Radium Institute (KRI). The responses of different fission detectors in the neutron energy range 35-180 MeV have been evaluated: a region where the predictive power of available nuclear reaction models and codes is not reliable yet. For neutron energy >200 MeV, the fission-detector responses have been derived from the data of the proton fission cross sections. By using the ratio of the responses of these detectors, a simple and accurate way to evaluate the spectrum hardness can be obtained, thus providing a tool to obtain spectral information needed for neutron dosimetry without the need to know the entire spectrum. Extensive data have been already obtained for the high-energy neutron spectrum from the CERN concrete facility. In the present paper, the measured values of the response ratios for different fissile detectors exposed at the CERN facility are compared with those calculated for the spectra from the same facility and from different altitudes in the atmosphere, respectively. PMID:15353650

Tommasino, L; Tripathy, S P



Evaluation of the normal-to-diseased apparent diffusion coefficient ratio as an indicator of prostate cancer aggressiveness  

PubMed Central

Background We tested the feasibility of a simple method for assessment of prostate cancer (PCa) aggressiveness using diffusion-weighted magnetic resonance imaging (MRI) to calculate apparent diffusion coefficient (ADC) ratios between prostate cancer and healthy prostatic tissue. Methods The requirement for institutional review board approval was waived. A set of 20 standardized core transperineal saturation biopsy specimens served as the reference standard for placement of regions of interest on ADC maps in tumorous and normal prostatic tissue of 22 men with PCa (median Gleason score: 7; range, 6–9). A total of 128 positive sectors were included for evaluation. Two diagnostic ratios were computed between tumor ADCs and normal sector ADCs: the ADC peripheral ratio (the ratio between tumor ADC and normal peripheral zone tissue, ADC-PR), and the ADC central ratio (the ratio between tumor ADC and normal central zone tissue, ADC-CR). The performance of the two ratios in detecting high-risk tumor foci (Gleason 8 and 9) was assessed using the area under the receiver operating characteristic curve (AUC). Results Both ADC ratios presented significantly lower values in high-risk tumors (0.48?±?0.13 for ADC-CR and 0.40?±?0.09 for ADC-PR) compared with low-risk tumors (0.66?±?0.17 for ADC-CR and 0.54?±?0.09 for ADC-PR) (p?ratio as an intrapatient-normalized diagnostic tool may be better in detecting high-grade lesions compared with analysis based on tumor ADCs alone, and may reduce the rate of biopsies. PMID:24885552



Single and double ?-/?+ ratios in heavy-ion reactions as probes of the high-density behavior of the nuclear symmetry energy  

NASA Astrophysics Data System (ADS)

Based on the isospin- and momentum-dependent hadronic transport model IBUU04, effects of the nuclear symmetry energy on the single and double ?-/?+ ratios in central reactions of Sn132+Sn124 and Sn112+Sn112 at a beam energy of 400 MeV/nucleon are studied. It is found that around the Coulomb peak of the single ?-/?+ ratio the double ?-/?+ ratio taken from the two isotopic reactions retains about the same sensitivity to the density dependence of nuclear symmetry energy. Because the double ?-/?+ ratio can significantly reduce the systematic errors, it is thus a more effective probe for the high-density behavior of the nuclear symmetry energy.

Yong, Gao-Chan; Li, Bao-An; Chen, Lie-Wen; Zuo, Wei



Structure simulation into a lamellar supramolecular network and calculation of the metal ions/ligands ratio  

PubMed Central

Background Research interest in phosphonates metal organic frameworks (MOF) has increased extremely in the last two decades, because of theirs fascinating and complex topology and structural flexibility. In this paper we present a mathematical model for ligand/metal ion ratio of an octahedral (Oh) network of cobalt vinylphosphonate (Co(vP)·H2O). Results A recurrent relationship of the ratio between the number of ligands and the number of metal ions in a lamellar octahedral (Oh) network Co(vP)·H2O, has been deducted by building the 3D network step by step using HyperChem 7.52 package. The mathematical relationship has been validated using X ray analysis, experimental thermogravimetric and elemental analysis data. Conclusions Based on deducted recurrence relationship, we can conclude prior to perform X ray analysis, that in the case of a thermogravimetric analysis pointing a ratio between the number of metal ions and ligands number around 1, the 3D network will have a central metal ion that corresponds to a single ligand. This relation is valid for every type of supramolecular network with divalent metal central ion Oh coordinated and bring valuable information with low effort and cost. PMID:22932493



Radiographic assessment of clinical root-crown ratios of permanent teeth in a healthy Korean population  

PubMed Central

PURPOSE The aim of this study was to determine the absolute value of the root/crown ratio (R/C ratio) using panoramic radiographs (PRGs) in a healthy Korean population. MATERIALS AND METHODS In total, 99 patient radiographs (of 50 males and 49 females subjects; aged 16 to 24 years old) were examined, and 2,770 teeth were analyzed. Crown lengths and root lengths were measured with modified Lind's measurements using PACS tools by two examiners in two separate sessions two months apart. All data were analyzed using SPSS. The independent t-test was used to assess for gender differences, and the paired t-test was used to compare both arches with a significance level of P<.05. RESULTS The mean R/C ratios varied from 1.29 to 1.89 (male: 1.28-1.84; females: 1.31-1.94). The highest R/C ratios were recorded for the mandibular canines (1.89), followed by the maxillary canines (1.79). The lowest R/C ratios were recorded for the maxillary second molars (1.31). In comparison with the maxillary teeth (1.29-1.78), the mandibular teeth yielded the higher R/C ratio (1.47-1.89), and this difference was significant in the females (P<.05). The difference between the genders was not statistically significant, except for the maxillary central incisors, mandibular canines and mandibular first premolars. CONCLUSION These data may enhance the understanding of the clinical R/C ratio as a useful guideline for determining the status of teeth and the ethnic difference. PMID:25006380

Yun, Hee-Jung; Jeong, Jin-Sun; Pang, Nan-Sim; Kwon, Il-Keun



Nutrient stoichiometry in Sphagnum along a nitrogen deposition gradient in highly polluted region of Central-East Europe  

Microsoft Academic Search

We investigated the variation of N:P and N:K ratio in ombrotrophic Sphagnum plants along a gradient of atmospheric N deposition from 1 to 2.5 g m?2 year?1 in Central-East Europe. The N:P and N:K ratio in Sphagnum capitula increased significantly along the N deposition gradient. Sphagnum species from the Cuspidata section were characterised by significantly lower ratios at low N deposition. When we

Martin Jiroušek; Michal Hájek; Luca Bragazza



Energy dependence of kaon production in central Pb+Pb collisions  

E-print Network

Recent results from the NA49 experiment on the energy dependence of charged kaon production in central Pb+Pb collisions are presented. First results from the new data at 80 AGeV beam energy are compared with those from lower and higher energies. A difference in the energy dependence of the / and / ratios is observed. The / ratio shows a non-monotonic behaviour with a maximum near 40 AGeV.

T. Kollegger



An insoluble residue study of the Cretaceous Cow Creek Limestone of Central Texas  

E-print Network

-size Fraction 28 Quartz Feldspar. Chert Trace minerals Constituents of the Silt-clay Fraction FELDSPAR AND CHERT ? QUARTZ RATIOS ZONATION AND CORRELATION. 28 29 31 32 36 39 Field Evidence. The upper cross-bedded limestone. The middle arenaceous... in Central Texas 17 5. Feldspar and. chert-quartz ratios and averages plotted for each section 37 6. Zonation and suggested field correlation of the Hickory Creek, Cox Crossing, Hamilton Pool, and Rebecca Creek sections 41 7. Zonation and suggested...

Morton, William Rogers



Determination of the Transient Dehumidification Characteristics of High Efficiency Central Air Conditioners  

E-print Network

Seasonal Energy Efficiency Ratio SHR Sensible Heat Ratio TOCZ Time Outside the Comfort Zone TMY Typical Meteorological Year TRNSYS TRaNsient SYstem Simulation ii SUMMARY A series of tests were performed to assesses the dehumidifying performance... of residential central air conditioners (CACs). The performance studies were based on factors such as: (i) dynamic performance (ii) the ASHRAE comfort zone, (iii) control strategy and (iv) published performance characteristic of the units. The units were...

Katipamula, S.; O'Neal, D. L.; Somasundaram, S.



N/P re-mineralization ratios across forests worldwide  

NASA Astrophysics Data System (ADS)

Decomposition of leaf litter is the primary mechanism by which nutrients are recycled in forests. Forests are a sink for atmospheric CO2, but nitrogen (N) and phosphorus (P) could limit or eliminate this ecosystem service in the future. Nutrient cycling during mineralization supplies the vast majority of nutrients to enable forest growth. Therefore, elucidating patterns by which organic N and P are mineralized by decomposing organisms or immobilized in microbial biomass is crucial to establishing controls on plant nutrient availability. Here, we compare re-mineralization N/P ratios to the stoichiometry of the initial material. We performed a meta-analysis of N and P mineralization from leaves and needles in forest ecosystems and included 112 studies, 511 litterbag sequences, and 3225 observations. Of the compiled data, net mineralization occurred in 54 studies, 372 litterbag sequences, and 1308 observations. We compare re-mineralization ratios across temperate and tropical forest systems to elucidate patterns across latitudes. We report strong and systematic regularities between decomposing litter N/P and the N/P of re-mineralization across global forests. Overall, the N/P of mineralization scales at a slope close to unity (slope = 1.4, R2=0.53, n=372), with a tendency toward higher N/P in tropical vs. temperate forests. The N/P of tropical forest re-mineralization is equal to 30/1 (R2=0.55; n=691), corresponding with the high N/P of plant foliage and litter within this biome. In contrast, the N/P of mineralization is equal to 5/1 in temperate forests (R2=0.34; n=617). A modal anomaly analysis further reveals the central tendency of mineralization N/P on that of litter, with departures from the average case tending toward a lower N/P of mineralization compared to litter substrates. These deviations suggest the potential for preferential N retention or enhanced P mineralization, or both, as opposed to more rapid N releases from decomposing organic matter. The results show that forest mineralization N/P is closely linked to the N/P of litter in a way that seems to mimic that of the global ocean environment. N/P of mineralization vs. N/P of litter. Grey symbols indicate data from each litterbag; colored symbols indicate the mean value for each litterbag sequence. Blue triangles indicate tropical forests; green plus signs indicate temperate forests. The dashed line is 1:1; the solid line is the linear regression.

Marklein, A. R.; Houlton, B. Z.




EPA Science Inventory

The hypothesis that the ratio of the adult (A) and developmental (D) toxicity of a chemical is constant across animal species has been proposed as the basis for identifying developmental hazards, both from traditional developmental toxicity screens using laboratory mammals and fr...


RESEARCH LETTERS waist/hip ratio accounted for only 18%. Waist/hip ratio  

E-print Network

with attractiveness, whereas even small changes in body-mass index radically altered the attractiveness rating (see body-mass index with narrower or wide waists. With images of real women, body-mass index and waist figure). Further analyses included other body- shape dimensions, including waist/bust ratio (upper-body

Cornelissen, Piers


Estimating the Isotope Ratio of Ecosystem Respiration Using the Keeling Plot and the Flux Ratio Method  

Microsoft Academic Search

Stable carbon isotope analyses have been used in identifying global carbon sources and sinks and in partitioning ecosystem CO2 exchange into component fluxes. The isotope ratio of ecosystem respiration (delta 13Cr) is a critical parameter in applying stable isotope techniques to carbon cycle problems. The commonly used Keeling plot method in estimating delta 13Cr has limitations related to: 1) insufficient

J. Zhang; T. J. Griffis; J. M. Baker



Analyzing Revenue Contribution Ratios: Net versus Gross Tuition and Fees Revenue Contribution Ratios.  

ERIC Educational Resources Information Center

It is argued that analysis of tuition and fees revenue contributions can enable colleges and universities to develop pricing, admissions, and student aid policies that produce desired financial outcomes. Long-term trends of three tuition and fees revenue contribution ratios are explained and illustrated. (MSE)

Jenny, Hans H.; Minter, W. John



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.



Cereal Production Ratio and NDVI in Spain  

NASA Astrophysics Data System (ADS)

Droughts are long-term phenomena affecting large regions causing significant damages both in human lives and economic losses. The use of remote sensing has proved to be very important in monitoring the growth of agricultural crops and trying to asses weather impact on crop loss. Several indices has been developed based in remote sensing data being one of them the normalized difference vegetation index (NDVI). In this study we have focus to know the correlation between NDVI data and the looses of rain fed cereal in the Spanish area where this crop is majority. For this propose data from drought damage in cereal come from the pool of agricultural insurance in Spain (AGROSEGURO) including 2007/2008 to 2011/2012 (five agricultural campaigns). This data is given as a ratio between drought party claims against the insured value of production aggregated at the agrarian region level. Medium resolution (500x500 m2) MODIS images were used during the same campaigns to estimate the eight-day composites NDVI at these locations. The NDVI values are accumulated following the normal cycle of the cereal taking in account the sowing date at different sites. At the same time, CORINE Land Cover (2006) was used to classify the pixels belonging to rain fed cereal use including a set of conditions such as pixels showing dry during summer, area in which there has been no change of use. Fallow presence is studied with particular attention as it imposes an inter annual variation between crop and bare soil and causes decreases in greenness in a pixel and mix both situations. This is more complex in the situation in which the avoid fallow and a continuous monoculture is performed. The results shown that around 40% of the area is subject to the regime of fallow while 60% have growing every year. In addition, another variation is detected if the year is humid (decrease of fallow) or dry (increase of fallow). The level of correlation between the drought damage ratios and cumulative NDVI for the cereal campaign obtained are classified according to their level of significance at 99, 95, 90 and 85%. Approximately half of the regions with high surface assurance have meaningful relationships. In the regions where no significant relationships are achieved several situations are discussed such as extreme situations in critical phenological periods that could have great influence on the final yields. Acknowledgements. This work was partially supported by ENESA under project P10 0220C-823.

Saa-Requejo, Antonio; Recuero, Laura; Palacios, Alicia; Díaz-Ambrona, Carlos G. H.; Tarquis, Ana M.



Mixing properties of coaxial jets with large velocity ratios and large inverse density ratios  

NASA Astrophysics Data System (ADS)

An experimental study was conducted to better understand the mixing properties of coaxial jets as several parameters were systematically varied, including the velocity ratio, density ratio, and the Reynolds number. Diameters of the inner and outer jet were also varied. Coaxial jets are commonly used to mix fluids due to the simplicity of their geometry and the rapid mixing that they provide. A measure of the overall mixing efficiency is the stoichiometric mixing length (Ls), which is the distance along the jet centerline where the two fluids have mixed to some desired concentration, which was selected to be the stoichiometric concentration for H2/O2 and CH4/O2 in this case. For 56 cases, the profiles of mean mixture fraction, rms mixture fraction fluctuations (unmixedness), and Ls were measured using acetone planar laser induced fluorescence diagnostics. Results were compared to three mixing models. The entrainment model of Villermaux and Rehab showed good agreement with the data, indicating that the proper non-dimensional scaling parameter is the momentum flux ratio M. The work extends the existing database of coaxial jet scalar mixing properties because it considers the specific regime of large values of both the velocity ratio and the inverse density ratio, which is the regime in which rocket injectors operate. Also the work focuses on the mixing up to Ls where previous work focused on the mixing up to the end of the inner core. The Reynolds numbers achieved for a number of cases were considerably larger than previous gas mixing studies, which insures that the jet exit boundary conditions are fully turbulent.

Alexander Schumaker, S.; Driscoll, James F.



Effect of contact ratio on spur gear dynamic load  

NASA Technical Reports Server (NTRS)

A computer simulation is presented which shows how the gear contact ratio affects the dynamic load on a spur gear transmission. The contact ratio can be affected by the tooth addendum, the pressure angle, the tooth size (diametral pitch), and the center distance. The analysis presented was performed using the NASA gear dynamics code, DANST. In the analysis, the contact ratio was varied over the range 1.20 to 2.40 by changing the length of the tooth addendum. In order to simplify the analysis, other parameters related to contact ratio were held constant. The contact ratio was found to have a significant influence on gear dynamics. Over a wide range of operating speeds, a contact ratio close to 2.0 minimized dynamic load. For low contact ratio gears (contact ratio less than 2.0), increasing the contact ratio reduced the gear dynamic load. For high contact ratio gears (contact ratio = or greater than 2.0), the selection of contact ratio should take into consideration the intended operating speeds. In general, high contact ratio gears minimized dynamic load better than low contact ratio gears.

Liou, Chuen-Huei; Lin, Hsiang Hsi; Oswald, Fred B.; Townsend, Dennis P.



Central airways remodeling in COPD patients  

PubMed Central

Background The contribution to airflow obstruction by the remodeling of the peripheral airways in chronic obstructive pulmonary disease (COPD) patients has been well documented, but less is known about the role played by the large airways. Few studies have investigated the presence of histopathological changes due to remodeling in the large airways of COPD patients. Objectives The aim of this study was to verify the presence of airway remodeling in the central airways of COPD patients, quantifying the airway smooth muscle (ASM) area and the extracellular matrix (ECM) protein deposition, both in the subepithelial region and in the ASM, and to verify the possible contribution to airflow obstruction by the above mentioned histopathological changes. Methods Biopsies of segmental bronchi spurs were performed in COPD patients and control smoker subjects and immunostained for collagen type I, versican, decorin, biglycan, and alpha-smooth muscle actin. ECM protein deposition was measured at both subepithelial, and ASM layers. Results The staining for collagen I and versican was greater in the subepithelial layer of COPD patients than in control subjects. An inverse correlation was found between collagen I in the subepithelial layer and both forced expiratory volume in 1 second and ratio between forced expiratory volume in 1 second and forced vital capacity. A statistically significant increase of the ASM area was observed in the central airways of COPD patients versus controls. Conclusion These findings indicate that airway remodeling also affects the large airways in COPD patients who have greater deposition of ECM proteins in the subepithelial layer and a larger smooth muscle area than control smoker subjects. These changes may contribute to chronic airflow obstruction in COPD patients. PMID:25214779

Pini, Laura; Pinelli, Valentina; Modina, Denise; Bezzi, Michela; Tiberio, Laura; Tantucci, Claudio



Centrally Condensed Collapse of Starless Cores  

E-print Network

Models of self-gravitating gas in the early stages of pressure-free collapse are compared for initial states which are equilibrium layers, cylinders, and Bonnor-Ebert spheres. For each geometrical case the density profile has an inner region of shallow slope surrounded by an outer region of steep slope, and the profile shape during early collapse remains similar to the profile shape of the initial equilibrium. The two-slope density structure divides the spherical collapse history into a starless infall phase and a protostellar accretion phase. The similarity of density profiles implies that Bonnor-Ebert fits to observed column density maps may not distinguish spherical cores from oblate or prolate cores, and may not distinguish static cores from collapsing cores. The velocity profiles discriminate better than the density profiles between initial geometries and between collapse ages. The infall velocity generally has a subsonic maximum value, which is approximately equal to the initial velocity dispersion times the ratio of collapse age to central free-fall time. Observations of starless core line profiles constrain collapse models. Collapse from initial states which are strongly condensed and slightly prolate is consistent with infall asymmetry observed around starless cores, and is more consistent than collapse from initial states which are weakly condensed, and/or oblate. Spherical models match observed inward speeds 0.05-0.09 km/s over 0.1-0.2 pc, if the collapse has a typical age 0.3-0.5 free fall times, and if it began from a centrally condensed state which was not in stable equilibrium. In a collapsing core, optically thin line profiles should broaden and develop two-peak structure as seen in L1544.

Philip C. Myers



Geothermal activities in Central America  

SciTech Connect

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 self-contained logging truck will be made available for use throughout Central America. An important objective of this program is to involve the private sector in resource development. 4 refs., 3 figs.

Whetten, J.T.; Hanold, R.J.



A parametric study of the breeding ratio in sodium cooled fast breeder reactors  

E-print Network

'etio fcr I'lfis ty&e ot re'c or. TbIO;Iar~metf rs elecf. e ' -rc !die isof:spic colapc siti!5r of t'Ifc core. the isotopic . Olf omit ion nf i'ilr- blanke . Plai erif. l, slid '. ;ll. 5 or geoI" etry. ACK2iO I~L SDGl'. SKT S respectfully extend my... of the study were thar e;. ch of. the fo ~r companies rriv~d at different core g c. et les. They were thc Allis Chalmers annular co&e, th. . General -'' c, t1'i ' p. . nc 0 c col & thl 1 lor couvenrloncl rcgu! al cylinder core c f Combustion Engineering...

Sobey, Thomas Milburn



Lambda-to-kaon ratio enhancement in heavy ion collisions at several TeV.  


We introduced recently a new theoretical scheme which accounts for hydrodynamically expanding bulk matter, jets, and the interaction between the two. Important for the particle production at intermediate values of transverse momentum (p(t)) are jet hadrons produced inside the fluid. They pick up quarks and antiquarks (or diquarks) from the thermal matter rather than creating them via the Schwinger mechanism-the usual mechanism of hadron production from string fragmentation. These hadrons carry plasma properties (flavor, flow) but also the large momentum of the transversely moving string segment connecting quark and antiquark (or diquark). They therefore show up at quite large values of p(t), not polluted by soft particle production. We will show that this mechanism leads to a pronounced peak in the Lambda-to-kaon ratio at intermediate p(t). The effect increases substantially with centrality, which reflects the increasing transverse size with centrality. PMID:23005282

Werner, K



Zenith polarization and color ratio during twilight.  


The excellent data of zenith polarization and color ratio (CR) during twilight obtained by Coulson at the Mauna Loa Observatory, Hawaii are subjected to a reinterpretation, especially with regard to the frequent deviations from the clear average. It is shown that a moderate lift of the earth's shadow by distant clouds (or by low level haze) will reduce the red/green CR, while greater lift shifts the CR peak to a smaller solar depression. The effect on zenith polarization at wavelengths >/=0.6 microm is seen to correspond to a slight reduction of overall polarization for a moderate lift, and for a large lift to a shift of the polarization minimum (depolarization by stratospheric aerosol) from 4 degrees solar depression angle to 2 degrees . A generally high level of polarization, but with a barely noticeable 4 degrees minimum, had also been observed earlier in Germany by Steinhorst when the stratospheric aerosol load was very small. The difference is explained by a higher and stronger aerosol layer in the tropics combined with a higher and cleaner troposphere. PMID:20372348

Volz, F E



The stellar mass ratio of GK Persei  

E-print Network

We study the absorption lines present in the spectra of the long-period cataclysmic variable GK Per during its quiescent state, which are associated with the secondary star. By comparing quiescent data with outburst spectra we infer that the donor star appears identical during the two states and the inner face of the secondary star is not noticeably irradiated by flux from the accreting regions. We obtain new values for the radial velocity semi-amplitude of the secondary star, Kk = 120.5 +- 0.7 km/s, a projected rotational velocity, Vksin i = 61.5 +- 11.8 km/s and consequently a measurement of the stellar mass ratio of GK Per, q = Mk/Mwd = 0.55 +- 0.21. The inferred white dwarf radial velocities are greater than those measured traditionally using the wings of Doppler-broadened emission lines suspected to originate in an accretion disk, highlighting the unsuitability of emission lines for mass determinations in cataclysmic variables. We determine mass limits for both components in the binary, Mk >= 0.48 +- 0.32 Msolar and Mwd >= 0.87 +- 0.24 Msolar.

L. Morales-Rueda; M. D. Still; P. Roche; J. H. Wood; J. J. Lockley



Using the central VAX cluster at ANL  

Microsoft Academic Search

This report is a manual that discusses the following topics on the Central Vax Cluster at ANL: What the Central Vax Cluster is; how the Vax Cluster works; operational policies; getting started; using tapes; printing on the Vax Cluster; developing programs in VMS; using the X window system on the Central Vax Cluster; and using Central Vax Cluster file sharing

C. M. Caruthers; S. L. Vote; D. A. Lifka; R. C. Raffenetti



Probability Tables for Mendelian Ratios with Small Numbers.  

E-print Network

for a ling. reasoi There are two questions in the study of actual ratios of inherited characters. One is to decide which one of two or more possible Men- delian ratios is the true ratio for the data. This may be impossible, and we have to content... for a ling. reasoi There are two questions in the study of actual ratios of inherited characters. One is to decide which one of two or more possible Men- delian ratios is the true ratio for the data. This may be impossible, and we have to content...

Warwick, B. L. (Bruce L.)



Territorial Defense in Central Europe  

Microsoft Academic Search

While technological advancement in weaponry was achieved against traditional war fighting, the failures of the U.S. in Vietnam and the Soviet's failures in Afghanistan indicated the relative impotence of such advancements in the face of indigenous territorial defense. This article explores strategic issues related to the defense of Central Europe against the Soviet Union. The author argues, the lessons of

Steven L. Canby



India's interests in Central Asia  

Microsoft Academic Search

Central Asia is a new geopolitical creation which has an important strategic role to play in the coming years. It is in the middle of three super civilisations—the Islamic, the Christian and the Buddhist and is seen by many experts as one of the most vulnerable areas of instability between them. It can become a natural, historically formed buffer zone

Meena Singh Roy



Ruined Cities of Central America  

Microsoft Academic Search

IN the summary of the proceedings of the late meeting of the British Association, in the issue of NATURE for August 31, is an abstract of a paper by Captain L. Brine, R.N., On the Ruined Cities of Central America. The gallant captain is wrong in stating that the existence of these ruined cities was unknown until within a comparatively

E. Geo. Squier



Earth Works Central. [Educational Packet].  

ERIC Educational Resources Information Center

Earth Works Central is an educational curriculum tool designed to provide environmental education support for the classroom. It features environmental materials for science, geography, history, art, music, dramatics, and physical education. It includes information on creating an environmental center where kids can learn and become empowered to…

Kids for Saving Earth Worldwide, Minneapolis, MN.


LA-11906-MS Central American  

E-print Network

............................................................................ ix I. GEOLOGYAND GEOTHERMAL POTENTIAL OF THE TECUAMBURRO VOLCANO AREA OF GUATEMALALA-11906-MS Central American Energy and Resources Project An.Evaluation of'the Geothermal Potential uc-000 Issued: September 1990 An Evaluation of the GeothermalPotential of the Tecuarnburro Volcano


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



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



Investing in the Central Office  

ERIC Educational Resources Information Center

Benchmarking against similar districts, ideally higher-performing ones, can be a valuable tool for determining the appropriate level of central-office investment. Unfortunately, reliable benchmarks on district spending in teaching and learning support are not readily available. This should not preclude districts from using this valuable method to…

Shields, Regis Anne




E-print Network

BioMed Central C TIONALINTERNA CANCER CELL Page 1 of 11 (page number not for citation purposes This article is available from: © 2006 Kingsley et al; licensee BioMed

Ahmad, Sajjad


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



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



Centralized consolidation\\/recycling center  

Microsoft Academic Search

There are approximately 175 separate locations on the Hanford Site where dangerous waste is accumulated in hundreds of containers according to compatibility. Materials that are designated as waste could be kept from entering the waste stream by establishing collection points for these materials and wastes and then transporting them to a centralized consolidation\\/recycling center (hereinafter referred to as the consolidation

L. T. St. Georges; A. D. Poor



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



Readability of Central Florida Newspapers.  

ERIC Educational Resources Information Center

A study analyzed the readability of seven central Florida newspapers (one of which is a college newspaper) and "USA Today.""Rightwriter," a grammar checker and readability computer program, was used to evaluate front page articles for each of the eight newspapers. The readability formulas invoked in the readability program included the…

Olmstead, Phyllis M.


Do individual-tree growth models correctly represent height:diameter ratios of Norway spruce and Scots pine?  

PubMed Central

Height:diameter ratios are an important measure of stand stability. Because of the importance of height:diameter ratios for forest management, individual-tree growth models should correctly depict height:diameter ratios. In particular, (i) height:diameter ratios should not exceed that of very dense stands, (ii) height:diameter ratios should not fall below that of open-grown trees, (iii) height:diameter ratios should decrease with increasing spacing, (iv) height:diameter ratios for suppressed trees should be higher than ratios for dominant trees. We evaluated the prediction of height:diameter ratios by running four commonly used individual-tree growth models in central Europe: BWIN, Moses, Silva and Prognaus. They represent different subtypes of individual-tree growth models, namely models with and without an explicit growth potential and models that are either distance-dependent (spatial) or distance-independent (non-spatial). Note that none of these simulators predict height:diameter ratios directly. We began by building a generic simulator that contained the relevant equations for diameter increment, height increment, and crown size for each of the four simulators. The relevant measures of competition, site characteristics, and stand statistics were also coded. The advantage of this simulator was that it ensured that no additional constraint was being imposed on the growth equations, and that initial conditions were identical. We then simulated growth for a 15- and 30-year period for Austrian permanent research plots in Arnoldstein and in Litschau, which represent stands at different age-classes and densities. We also simulated growth of open-grown trees and compared the results to the literature. We found that the general pattern of height:diameter ratios was correctly predicted by all four individual-tree growth models, with height:diameter ratios above that of open-grown trees and below that of very dense stands. All models showed a decrease of height:diameter ratios with age and an increase with stand density. Also, the height:diameter ratios of dominant trees were always lower than that of mean trees. Although in some cases the observed and predicted height:diameter ratios matched well, there were cases where discrepancies between observed and predicted height:diameter ratios would be unacceptable for practical management predictions. PMID:21151352

Vospernik, Sonja; Monserud, Robert A.; Sterba, Hubert



Central American geologic map project  

SciTech Connect

During the Northeast Quadrant Panel meeting of the Circum-Pacific Map Project held in Mexico City, February 1985, Central American panel members proposed and adopted plans for compiling a geologic map of Central America, probably at a scale of 1:500,000. A local group with participants from each country was organized and coordinated by Rolando Castillo, director, Central American School of Geology, University of Costa Rica, for the geologic aspects, and Fernando Rudin, director, Geographic Institute of Costa Rica, for the topographic base. In 1956, the US Geological Survey published a geologic map of the region at a scale of 1:1 million. Subsequent topographic and geologic mapping projects have provided a large amount of new data. The entire area is now covered by topographic maps at a scale of 1:50,000, and these maps have been used in several countries as a base for geologic mapping. Another regional map, the Metallogenic Map of Central America (scale = 1:2 million), was published in 1969 by the Central American Research Institute for Industry (ICAITI) with a generalized but updated geologic base map. Between 1969 and 1980, maps for each country were published by local institutions: Guatemala-Belize at 1:500,000, Honduras at 1:500,000, El Salvador at 1:100,000, Nicaragua at 1:1 million, Costa Rica at 1:200,000, and Panama at 1:1 million. This information, in addition to that of newly mapped areas, served as the base for the Central American part of the Geologic-Tectonic Map of the Caribbean Region (scale = 1:2.5 million), published by the US Geological Survey in 1980, and also fro the Northeast Quadrant Maps of the Circum-Pacific Region. The new project also involves bathymetric and geologic mapping of the Pacific and Caribbean margins of the Central American Isthmus. A substantial amount of new information of the Middle America Trench has been acquired through DSDP Legs 67 and 84.

Dengo, G.



Hypothesis testing for geoacoustic environmental models using likelihood ratio  

E-print Network

Hypothesis testing for geoacoustic environmental models using likelihood ratio Christoph F Laboratory, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California; accepted 5 November 1998 A generalized likelihood ratio test is developed for testing acoustic

Buckingham, Michael


76 FR 16345 - Net Worth and Equity Ratio  

Federal Register 2010, 2011, 2012, 2013

...and 741 RIN 3133-AD87 Net Worth and Equity Ratio AGENCY...statutory definitions of ``net worth'' and ``equity ratio...700, 701, 702, and 741 Bank deposit insurance, Credit...Definitions. * * * * * (f) Net worth. Unless otherwise...



Direct Density Ratio Estimation with Dimensionality Reduction Masashi Sugiyama  

E-print Network

Direct Density Ratio Estimation with Dimensionality Reduction Masashi Sugiyama , Satoshi Hara for directly estimating the ratio of two probability density functions without going through density estimation such as non-stationarity adaptation, outlier detection, conditional density estima- tion, feature selection

Sugiyama, Masashi


Learning and Teaching Ratio and Proportion: Research Implications  

NSDL National Science Digital Library

This is a chapter describing the theory and lesson planning for teaching ratio and rate problems. The authors describe how students use reasoning about multiplication and division to solve ratio and rate problems.

Gioielli, Martha



Phylogenetic diversity in cadmium : phosphorus ratio regulation by marine phytoplankton  

E-print Network

Phylogenetic diversity in cadmium : phosphorus ratio regulation by marine phytoplankton Z. V Abstract We examined the effect of irradiance and growth rate on cadmium : phosphorus ratio in five species


Ultra-short nacelles for low fan pressure ratio propulsors  

E-print Network

This thesis addresses the uncharted inlet and nacelle design space for low pressure ratio fans for advanced aeroengines. A key feature in low fan pressure ratio (FPR) propulsors with short inlets and nacelles is the increased ...

Peters, Andreas, Ph. D. Massachusetts Institute of Technology



Rationale of the Ratio Image in Multispectral Remote Sensing.  

National Technical Information Service (NTIS)

A simple mathematical interpretation of the properties of ratio images derived from LANDSAT and other sources of multispectral imagery is presented. A spectral signature is defined which is well represented by ratios of pairs of spectral bands and can be ...

G. W. Wecksung, J. R. Breedlove




PubMed Central

Domestic hens responded under multiple fixed-ratio fixed-ratio schedules with equal fixed ratios. One component provided immediate reinforcement and the other provided reinforcement after a delay, signaled by the offset of the key light. The components were presented quasirandomly so that all four possible transitions occurred in each session. The delay was varied over 0, 4, 8, 16, and 32 s with fixed-ratio 5 schedules, and over 0, 8 and 32 s with fixed-ratio 1, 15 and 40 schedules. Main effects of fixed-ratio value and delay duration were detected on between-ratio pauses. Pauses were longer when the multiple-schedule stimulus correlated with a delayed-reinforcer component was presented, with the longest pauses occurring at the transition from a component with an immediate reinforcer to one with a delayed reinforcer. Pause durations were shortest during immediate components. Overall, both the presence or absence of a delay in the upcoming component, and the presence or absence of a delay in the preceding component affected pause length, but the upcoming delay had the larger effect. Thus changes in delay had similar effects to past reports of the effects of changes in response force, response requirement, and reinforcer magnitude in multiple fixed-ratio fixed-ratio schedules. PMID:23144507

Harris, Aimee; Foster, T. Mary; Levine, Joshua; Temple, William



Estimating Methane Emissions from Central California  

NASA Astrophysics Data System (ADS)

A three-month time series of continuous CH4 mixing ratio measurements obtained from a tall-tower are applied in an inverse model to estimate regional surface emissions of CH4 in Central California. Simulated CH4 mixing ratios are calculated based on spatially resolved a priori CH4 emission estimates and simulated atmospheric transport. Atmospheric transport and surface influences (footprints) are computed using the Stochastic Time-Inverted Lagrangian Transport (STILT) model driven by customized output from the Weather Research and Forecasting (WRF) model. An uncertainty analysis is performed that propagates measurement and model errors through the inverse model to provide quantitative uncertainties in the estimated CH4 emissions. WRF-STILT predictions of daytime planetary boundary layer (PBL) heights are found to be over-estimated by a factor of 1.33 ± 0.13 (1s) through comparison with PBL heights estimated from a wind profiler located near the tower site for October, 2007. The inverse model estimates of CH4 emissions are performed in three ways. First, geometric linear regressions of modeled and measured CH4 mixing ratios obtains slopes of 0.95 ± 0.14 and 1.12 ± 0.12 for the October and Oct.-Dec., 2007 periods respectively, suggesting that total a priori CH4 emissions estimates are consistent with the atmospheric measurements and the transport model. Second, a Baysian inverse analysis of the Oct.-Dec., 2007 period obtains posterior scaling factors for CH4 suggesting that landfills and crop agriculuture are lower and livestock and petroleum emissions are higher than a priori estimates respectively. Third, a Baysian analysis of uncertainty, using 13 spatial sub-regions as basis functions, shows that the CH4 measurements significantly reduce posterior uncertainties in CH4 emissions relative the a priori assumptions for only the three sub-regions nearest the tower site. This suggests that a regional network of measurement sites will be necessary to provide high-accuracy retrievals of surface CH4 emissions for multiple regions comprising California's CH4 emissions.

Zhao, C.; Fischer, M. L.; Andrews, A. E.; Eluszkiewicz, J.; MacDonald, C. P.; Nehrkorn, T.; Hirsch, A. I.



Enantiomer Ratios of Meteoritic Sugar Derivatives  

NASA Technical Reports Server (NTRS)

Carbonaceous meteorites contain a diverse suite of soluble organic compounds. Studies of these compounds reveal the Solar System's earliest organic chemistry. Among the classes of organic compounds found in meteorites are keto acids (pyruvic acid, etc.), hydroxy tricarboxylic acids (1), amino acids, amides, purines and pyrimidines. The Murchison and Murray meteorites are the most studied for soluble and insoluble organic compounds and organic carbon phases. The majority of (indigenous) meteoritic compounds are racemic, (i.e., their D/L enantiomer ratios are 50:50). However, some of the more unusual (non-protein) amino acids contain slightly more of one enantiomer (usually the L) than the other. This presentation focuses on the enantiomer analyses of three to six-carbon (3C to 6C) meteoritic sugar acids. The molecular and enantiomer analysis of corresponding sugar alcohols will also be discussed. Detailed analytical procedures for sugar-acid enantiomers have been described. Results of several meteorite analyses show that glyceric acid is consistently racemic (or nearly so) as expected of non-biological mechanisms of synthesis. Also racemic are 4-C deoxy sugar acids: 2-methyl glyceric acid; 2,4-dihydroxybutyric acid; 2,3-dihydroxybutyric acid (two diastereomers); and 3,4-dihydroxybutyric acid. However, a 4C acid, threonic acid, has never been observed as racemic, i.e., it possesses a large D excess. In several samples of Murchison and one of GRA 95229 (possibly the most pristine carbonaceous meteorite yet analyzed) threonic acid has nearly the same D enrichment. In Murchison, preliminary isotopic measurements of individual threonic acid enantiomers point towards extraterrestrial sources of the D enrichment. Enantiomer analyses of the 5C mono-sugar acids, ribonic, arabinonic, xylonic, and lyxonic also show large D excesses. It is worth noting that all four of these acids (all of the possible straight-chained 5C sugar acids) are present in meteorites, including the rare lyxonic acid, and their relative abundances are in equilibrium proportions. In addition (in contrast to the above D-only excesses), some of the above acids are found in biology as the L enantiomer. Whether rare are common, all of the 6C sugar acids that are present in sufficient amounts to allow enantiomer analysis (Mannonic, gluconic, altronic, talonic, idonic, gulonic, and galactonic) also, apparently, possess significant D excesses.

Cooper, George



Inferences about ungulate population dynamics derived from age ratios  

USGS Publications Warehouse

Age ratios (e.g., calf:cow for elk and fawn:doe for deer) are used regularly to monitor ungulate populations. However, it remains unclear what inferences are appropriate from this index because multiple vital rate changes can influence the observed ratio. We used modeling based on elk (Cervus elaphus) life-history to evaluate both how age ratios are influenced by stage-specific fecundity and survival and how well age ratios track population dynamics. Although all vital rates have the potential to influence calf:adult female ratios (i.e., calf:xow ratios), calf survival explained the vast majority of variation in calf:adult female ratios due to its temporal variation compared to other vital rates. Calf:adult female ratios were positively correlated with population growth rate (??) and often successfully indicated population trajectories. However, calf:adult female ratios performed poorly at detecting imposed declines in calf survival, suggesting that only the most severe declines would be rapidly detected. Our analyses clarify that managers can use accurate, unbiased age ratios to monitor arguably the most important components contributing to sustainable ungulate populations, survival rate of young and ??. However, age ratios are not useful for detecting gradual declines in survival of young or making inferences about fecundity or adult survival in ungulate populations. Therefore, age ratios coupled with independent estimates of population growth or population size are necessary to monitor ungulate population demography and dynamics closely through time.

Harris, N. C.; Kauffman, M. J.; Mills, L. S.



Inheritance of progeny sex ratio in Urtica dioica  

Microsoft Academic Search

Seed samples collected from female Urtica dioica plants in the field showed considerable inter-family variation in the sex ratio (faction of males). To investigate the inheritance pattern of the sex ratio trait, crosses were performed between individual male and female plants from different sex ratio families. Our results suggest, at least for the families studied here, that maternal parents strongly




Strehl ratio for focusing into biaxially birefringent media  

E-print Network

Strehl ratio for focusing into biaxially birefringent media Sjoerd Stallinga Philips Research manuscript received June 11, 2004; accepted June 21, 2004 The Strehl ratio for focusing into biaxially birefringent media with small birefringence is investigated. An analytical expression for the Strehl ratio

Stallinga, Sjoerd


Final Report on Isotope Ratio Techniques for Light Water Reactors  

SciTech Connect

The Isotope Ratio Method (IRM) is a technique for estimating the energy or plutonium production in a fission reactor by measuring isotope ratios in non-fuel reactor components. The isotope ratios in these components can then be directly related to the cumulative energy production with standard reactor modeling methods.

Gerlach, David C.; Gesh, Christopher J.; Hurley, David E.; Mitchell, Mark R.; Meriwether, George H.; Reid, Bruce D.



A Probabilistic Analysis of the Ratio Spectrum Mark D. Skowronski  

E-print Network

the analytic expressions that de- scribe the behavior of the ratio spectrum for a white noise model. 1 to avoid the treatment of impulse functions in the spectral description of a sig- nal. The ratio spectrum is motivated by computational advantages over standard techniques. Figure 1 illustrates the ratio spectrum

Harris, John G.


Droop of the Fractional Turn Ratio Pulse Transformer  

Microsoft Academic Search

In order to successfully design a solid-state modulator with the fractional turn ratio transformer for C band magnetron, the parameters of the fractional turn ratio pulse transformer must be chosen carefully. The rise time and fall time of the fractional turn ratio pulse transformer can be calculated the same as the traditional pulse transformer, but its droop cannot be calculated

Gan Kongyin; Li Ming; Shan Lijun; Hu Heping



Reducing the convergence ratio of high gain ICF targets  

Microsoft Academic Search

Two ways of reducing the convergence ratio of high gain inertially confined fusion (ICF) targets have been studied using computer simulations. The convergence ratio decreases faster than predicted by the simple geometrical scaling law when the initial gaseous D-T density of the target is increased. Reducing the convergence ratio by changing the driver pulse shape is not energy efficient because

Yuli Pan



Density Ratio Estimation: A New Versatile Tool for Machine Learning  

E-print Network

Density Ratio Estimation: A New Versatile Tool for Machine Learning Masashi Sugiyama Department based on the ratio of prob- ability densities has been proposed recently and gathers a great deal of attention in the machine learning and data mining communities [1­17]. This density ratio framework includes

Sugiyama, Masashi


Conditional Density Estimation via Least-Squares Density Ratio Estimation  

E-print Network

781 Conditional Density Estimation via Least-Squares Density Ratio Estimation Masashi Sugiyama a novel method of con- ditional density estimation. Our basic idea is to express the conditional density in terms of the ratio of unconditional densities, and the ratio is directly estimated without going through

Sugiyama, Masashi


Void-containing materials with tailored Poisson’s ratio  

Microsoft Academic Search

Assuming square, hexagonal, and random packed arrays of nonoverlapping identical parallel cylindrical voids dispersed in an aluminum matrix, we have calculated numerically the concentration dependence of the transverse Poisson’s ratios. It was shown that the transverse Poisson’s ratio of the hexagonal and random packed arrays approached 1 upon increasing the concentration of voids while the ratio of the square packed

Olga A. Goussev; Peter Richner; Michael G. Rozman; Andrei A. Gusev



Void-containing materials with tailored Poisson's ratio  

Microsoft Academic Search

Assuming square, hexagonal, and random packed arrays of nonoverlapping identical parallel cylindrical voids dispersed in an aluminum matrix, we have calculated numerically the concentration dependence of the transverse Poisson's ratios. It was shown that the transverse Poisson's ratio of the hexagonal and random packed arrays approached 1 upon increasing the concentration of voids while the ratio of the square packed

Olga A. Goussev; Peter Richner; Michael G. Rozman; Andrei A. Gusev



Auditory Discrimination of Frequency Ratios: The Octave Singularity  

ERIC Educational Resources Information Center

Sensitivity to frequency ratios is essential for the perceptual processing of complex sounds and the appreciation of music. This study assessed the effect of ratio simplicity on ratio discrimination for pure tones presented either simultaneously or sequentially. Each stimulus consisted of four 100-ms pure tones, equally spaced in terms of…

Bonnard, Damien; Micheyl, Christophe; Semal, Catherine; Dauman, Rene; Demany, Laurent



Amniotic Fluid Lecithin: Sphingomyelin Ratio and Fetal Lung Development  

Microsoft Academic Search

The normal range and trends of the ratio between lecithin and sphingomyelin in the amniotic fluid, estimated on thin-layer chromatograms, have been established for the last trimester. The accuracy of the ratio as an index of fetal lung development and of the risk of neonatal respiratory distress has been confirmed. The usual increase in the ratio towards term was not

C. R. Whitfield; W. H. Chan; W. B. Sproule; A. D. Stewart



Yield Strength Ratio and Liquefaction Analysis of Slopes and Embankments  

E-print Network

Yield Strength Ratio and Liquefaction Analysis of Slopes and Embankments Scott M. Olson, A.M.ASCE,1 in ground subjected to a static shear stress, i.e., sloping ground, using the yield strength ratio, su(yield and standard penetration resistances. These yield strength ratios and previously published liquefied strength


Yield Strength Ratio and Liquefaction Analysis of Slopes and Embankments  

Microsoft Academic Search

A procedure is proposed to evaluate the triggering of liquefaction in ground subjected to a static shear stress, i.e., sloping ground, using the yield strength ratio, s u(yield)\\/ v0 . Thirty liquefaction flow failures were back analyzed to evaluate shear strengths and strength ratios mobilized at the triggering of liquefaction. Strength ratios mobilized during the static liquefaction flow failures ranged

Scott M. Olson



Isotope yield ratios of fragments from heavy-ion reactions  

SciTech Connect

Isotope yield ratios produced in collisions of 35 MeV/nucleon {sup 14}N with targets of C, Ni, Ag, and Ho have an exponential dependence on total neutron-to-proton ratio. A statistical multifragmentation model including particle emission from excited fragments predicted such behavior for yield ratios measured earlier at the higher energy of 84 MeV/nucleon.

Deak, F.; Kiss, A. (Department of Atomic Physics, Eoetvoes University, Puskin utca 5-7, H-1088 Budapest, Hungary (HU)); Seres, Z. (Central Research Institute for Physics, H-1525 Budapest 114, Hungary (HU)); Galonsky, A.; Heilbronn, L. (National Superconducting Cyclotron Laboratory and Department of Physics Astronomy, Michigan State University, East Lansing, Michigan 48824 (USA))



A Bayesian Approach to Hardness Ratios for non-Bayesians  

E-print Network

A Bayesian Approach to Hardness Ratios for non-Bayesians John E. Davis> December 18, 2007 1 Introduction Hardness ratios are often used in situations where there may not be enough. The computation of confidence limits for hardness ratios has been addressed by others ([Park et al.(2006), Jin et

Davis, John E.


Ratio and group size in day care programs  

Microsoft Academic Search

Literature on the influences of ratio and group size on children's development in day care is reviewed. Relatively few studies are responsible for the widely held beliefs about the influence of ratio and group size on children's development. When measured separately, ratio and group size are sometimes, but not always related to children's development. Some significant relationships are not in

Loraine Dunn



Chloride/bromide and chloride/fluoride ratios of domestic sewage effluents and associated contaminated ground water  

SciTech Connect

To establish geochemical tools for tracing the origin of ground water contamination, the authors examined the variations of Cl/Br and Cl/F (weight) ratios in (1) domestic waste water from the Dan Region Sewage Reclamation Project and from reservoirs in the central coast of Israel; (2) associated contaminated ground water; and (3) pristine ground water from the Mediterranean coastal aquifer of Israel. The data show that supply water, anthropogenic NaCl and fluoridation control the Cl/Br and Cl/F ratios of domestic waste water, and conventional sewage treatment does not affect the anthropogenic inorganic signals. The Cl/Br ratios of ground water contaminated with sewage effluent reflect conservative mixing proportions of sewage and regional ground water components. Sensitivity tests demonstrate that it is possible to detect and distinguish sewage contamination from marine ratios after a sewage contribution of 5 to 15% is mixed with regional ground water. Mixing with Br-enriched fresh water however, would reduce this sensitivity. Since the high Cl/Br signal of sewage effluents is distinguishable from other anthropogenic sources with low Cl/Br ratios and from natural contamination sources, Cl/Br ratios can therefore be a useful inorganic tracer for identification of the origin of contaminated ground water. The Cl/F ratios of sewage-contaminated ground water were higher than those in the original sewage effluent, which suggests retention of fluoride into the aquifer solid phase.

Vengosh, A.; Pankratov, I. [Hydrological Service, Jerusalem (Israel)



Comparison of Event Detection Methods for Centralized Sensor Networks  

NASA Technical Reports Server (NTRS)

The development of an Integrated Vehicle Health Management (IVHM) for space vehicles has become a great concern. Smart Sensor Networks is one of the promising technologies that are catching a lot of attention. In this paper, we propose to a qualitative comparison of several local event (hot spot) detection algorithms in centralized redundant sensor networks. The algorithms are compared regarding their ability to locate and evaluate the event under noise and sensor failures. The purpose of this study is to check if the ratio performance/computational power of the Mote Fuzzy Validation and Fusion algorithm is relevant compare to simpler methods.

Sauvageon, Julien; Agogiono, Alice M.; Farhang, Ali; Tumer, Irem Y.



Cone erg subnormality to red flash in central retinal vein occlusion: A predictor of ocular neovascularization?  

Microsoft Academic Search

In patients with unilateral central retinal vein occlusion (CRVO), we retrospectively examined whether cone electroretinogram (ERG) subnormality to red flash (ratio of the b-wave amplitude in the CRVO eye to that in the normal fellow eye <1) found at the time of diagnosis of the CRVO was a predictor of later ocular neovascularisation. Ganzfeld ERG cone and rod responses had

Monique S Roy; Cynthia J Mackay; Peter Gouras



Impact of Geomaterial Properties and Rainfall on Landslides in Central Taiwan  

Microsoft Academic Search

The aim of this study is to present data of landslides triggered by typhoons and earthquakes, and to discuss the relationship between landslides, geomaterial properties and rainfall. From 1996 to 2004, in the catchments of Tachia River and Chenyoulan River of central Taiwan, four typhoons and earthquakes triggered landsliding events were studied. Investigation results show that landslide ratios increased from

G. Lin; N. Tsou; H. Chen



Essays in monetary policy conduction and its effectiveness: monetary policy rules, probability forecasting, central bank accountability, and the sacrifice ratio  

E-print Network

trust and encouragement. I benefited greatly from enlightening conversations with Professors John Nichols, Allan Love, George Davis, Rich Woodward, Rudy Nayga, Ron Griffin, James Richardson, Vicky Salin, Dror Goldberg, William Neilson, and Thomas... it was needed. I also want to acknowledge the helpful assistance that I got from Norma Pantoja, Lindsey Nelson, Adrienne Blaskey, Ruth Hicks, Stella Garcia, Cindy Fazzino, and Michelle Zinn. Graduate school would not have been so bearable if it were...

Gabriel, Casillas Olvera,



The effect of a reciprocal peat transplant between two contrasting Central European sites on C cycling and C isotope ratios  

Microsoft Academic Search

An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czech Republic. Both sites were 100% Sphagnum-covered, with no vascular plants, and no hummocks and hollows. Atmospheric depositions of sulfur were up to 10 times higher at the northern site Velke jerabi jezero (VJJ), compared to the southern site Cervene blato (CB). Forty-cm deep peat cores, 10-cm

M. Novak; L. Zemanova; F. Buzek; I. Jackova; M. Adamova; A. Komarek; M. A. Vile; R. Kelman Wieder; M. Stepanova



The effect of a reciprocal peat transplant between two contrasting Central European sites on C cycling and C isotope ratios  

NASA Astrophysics Data System (ADS)

An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czech Republic. Both sites were 100% Sphagnum-covered, with no vascular plants, and no hummocks and hollows. Atmospheric depositions of sulfur were up to 10 times higher at the northern site Velke jerabi jezero (VJJ), compared to the southern site Cervene blato (CB). Forty-cm deep peat cores, 10-cm in diameter, were used as transplants and controls in five replicates. Our objective was to evaluate whether CO2 and CH4 emissions from Sphagnum peat bogs are governed mainly by organic matter quality in the substrate, or by environmental conditions. Emission rates and ?13C values of CO2 and CH4 were measured in the laboratory at time t=18 months. All measured parameters converged to those of the host site, indicating that, at least in the short-term perspective, environmental conditions were a more important control of greenhouse gas emissions than organic carbon quality in the substrate. Since sulfate reducers outcompete methanogens, we hypothesized that the S-polluted site VJJ should have lower methane emissions than CB. In fact, the opposite was true, with significantly (p<0.01) higher methane emissions from VJJ. Additionally, as a first step in an effort to link C isotope composition of emitted gases and residual peat substrate, we determined whether multiple vertical ?13C profiles in peat agree. A high degree of within-site homogeneity in ?13C was found. When a specific vertical ?13C trend was seen in one peat core, the same trend was also seen in all the remaining peat cores from the wetland. The ?13C value increased downcore at both CB and VJJ. At VJJ, however, 20 cm below surface, a reversal to lower ?13C downcore was seen. Based on 210Pb dating, peat at 20-cm depth at VJJ was only 15 years old. Increasing ?13C values in VJJ peat accumulated between 1880-1990 could not be caused by assimilation of atmospheric CO2 gradually enriched in the light isotope 12C due to fossil fuel burning. Rather they were a result of a combination of isotope fractionations accompanying assimilation and mineralization of Sphagnum C. These isotope fractionations may record information about past changes in C storage in wetlands.

Novak, M.; Zemanova, L.; Buzek, F.; Jackova, I.; Adamova, M.; Komarek, A.; Vile, M. A.; Kelman Wieder, R.; Stepanova, M.



Processes affecting oxygen isotope ratios of atmospheric and ecosystem sulfate in two contrasting forest catchments in Central Europe  

SciTech Connect

Sulfate aerosols are harmful as respirable particles. They also play a role as cloud condensation nuclei and have radiative effects on global climate. A combination of {delta}{sup 18}O-SO{sub 4} data with catchment sulfur mass balances was used to constrain processes affecting S cycling in the atmosphere and spruce forests of the Czech Republic. Extremely high S fluxes via spruce throughfall and runoff were measured at Jezeri (49 and 80 kg S ha{sup -1} yr{sup -1}, respectively). The second catchment, Na Lizu, was 10 times less polluted. In both catchments, {delta}{sup 18}O-SO{sub 4} decreased in the following order: open-area precipitation {gt} throughfall {gt} runoff. The 180-SO{sub 4} values of throughfall exhibited a seasonal pattern at both sites, with maxima in summer and minima in winter. This seasonal pattern paralleled {delta}{sup 18}O-H{sub 2}O values, which were offset by -18{per_thousand}. Sulfate in throughfall was predominantly formed by heterogeneous (aqueous) oxidation of SO{sub 2}. Wet-deposited sulfate in an open area did not show systematic {delta}{sup 18}O-SO{sub 4} trends, suggesting formation by homogeneous (gaseous) oxidation and/or transport from large distances. The percentage of incoming S that is organically cycled in soil was similar under the high and the low pollution. High-temperature {sup 18}O-rich sulfate was not detected, which contrasts with North American industrial sites. 29 refs., 4 figs., 3 tabs.

Martin Novak; Myron J. Mitchell; Iva Jackova; Frantisek Buzek; Jana Schweigstillova; Lucie Erbanova; Richard Prikryl; Daniela Fottova [Czech Geological Survey, Prague (Czech Republic). Department of Geochemistry



Search for Quark Compositeness with the Dijet Centrality Ratio in pp Collisions at s?=7??TeV  

E-print Network

of ntot;i [30,31]. We compare the value ofRLL in the data with distributions of the expected values for both hypotheses, obtained from ensembles of pseu- doexperiments, to either claim the discovery of quark compositeness or to set exclusion bounds...

Baringer, Philip S.; Bean, Alice; Benelli, Gabriele; Grachov, Oleg A.; Murray, Michael J.; Noonan, Danny; Radicci, Valeria; Sanders, Stephen J.; Wood, Jeffrey Scott; Zhukova, Victoria; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.



Elevated sacroilac joint uptake ratios in systemic lupus erythematosus  

SciTech Connect

Sacroiliac joint radiographs and radionuclide sacroiliac joint uptake ratios were obtained on 14 patients with active systemic lupus erythematosus. Elevated joint ratios were found unilaterally in two patients and bilaterally in seven patients when their lupus was active. In patients whose disease became quiescent, the uptake ratios returned to normal. Two patients had persistently elevated ratios with continued clinical and laboratory evidence of active lupus. Mild sacroiliac joint sclerosis and erosions were detected on pelvic radiographs in these same two patients. Elevated quantitative sacroiliac joint uptake ratios may occur as a manifestation of active systemic lupus erythematosus.

De Smet, A.A.; Mahmood, T.; Robinson, R.G.; Lindsley, H.B.



A centralized audio presentation manager  

SciTech Connect

The centralized audio presentation manager addresses the problems which occur when multiple programs running simultaneously attempt to use the audio output of a computer system. Time dependence of sound means that certain auditory messages must be scheduled simultaneously, which can lead to perceptual problems due to psychoacoustic phenomena. Furthermore, the combination of speech and nonspeech audio is examined; each presents its own problems of perceptibility in an acoustic environment composed of multiple auditory streams. The centralized audio presentation manager receives abstract parameterized message requests from the currently running programs, and attempts to create and present a sonic representation in the most perceptible manner through the use of a theoretically and empirically designed rule set.

Papp, A.L. III; Blattner, M.M.



Anthropoecological investigations in Central Asia.  


The results of anthropoecological investigations in Central Asia are described. From 1976 to 1991 about 6,000 individuals of both sexes were examined. 2,500 of them were children from 7 to 17 years. The program included the study of body build, metabolic rates, genetic markers and demographic structures. Different groups of Tuvins, Khakass, Mountain and Abakan Shortsys, Altai-kijis, Telengits, Teleuts, Kazakhs, and several groups of Mongols and Khotons were studied. It was shown that some patterns of body build and physiological traits of native populations of Central Asia partly reflect the influence of the geographical environment. The differences observed between various populations of the region may be explained by ecological reasons and not only by ethnic differentiation. PMID:16079568

Alexeeva, Tatyana I



Familial central retinal vein occlusion  

Microsoft Academic Search

AimTo report four cases of central retinal vein occlusion (CRVO) in a French family.Patients and methodsOphthalmological examination and medical work-up of seven members of the family.ResultsThere were four cases of CRVO in two consecutive generations. Three of them had CRVO in both eyes. Arterial hypertension was present in two, associated to glaucoma in one. Medical work-up did not reveal additional

J-F Girmens; S Scheer; E Héron; J-A Sahel; E Tournier-Lasserve; M Paques



Central Asia Active Fault Database  

NASA Astrophysics Data System (ADS)

The ongoing collision of the Indian subcontinent with Asia controls active tectonics and seismicity in Central Asia. This motion is accommodated by faults that have historically caused devastating earthquakes and continue to pose serious threats to the population at risk. Despite international and regional efforts to assess seismic hazards in Central Asia, little attention has been given to development of a comprehensive database for active faults in the region. To address this issue and to better understand the distribution and level of seismic hazard in Central Asia, we are developing a publically available database for active faults of Central Asia (including but not limited to Afghanistan, Tajikistan, Kyrgyzstan, northern Pakistan and western China) using ArcGIS. The database is designed to allow users to store, map and query important fault parameters such as fault location, displacement history, rate of movement, and other data relevant to seismic hazard studies including fault trench locations, geochronology constraints, and seismic studies. Data sources integrated into the database include previously published maps and scientific investigations as well as strain rate measurements and historic and recent seismicity. In addition, high resolution Quickbird, Spot, and Aster imagery are used for selected features to locate and measure offset of landforms associated with Quaternary faulting. These features are individually digitized and linked to attribute tables that provide a description for each feature. Preliminary observations include inconsistent and sometimes inaccurate information for faults documented in different studies. For example, the Darvaz-Karakul fault which roughly defines the western margin of the Pamir, has been mapped with differences in location of up to 12 kilometers. The sense of motion for this fault ranges from unknown to thrust and strike-slip in three different studies despite documented left-lateral displacements of Holocene and late Pleistocene landforms observed near the fault trace.

Mohadjer, Solmaz; Ehlers, Todd A.; Kakar, Najibullah



Segetal vegetation of Central Yakutia  

Microsoft Academic Search

Seven associations of segetal vegetation are distinguished for the vast arable lands of Central Yakutia. Low species richness\\u000a and the prevalence of annual weeds are the main features of these communities. Only two dominant speciesSphallerocarpus gracilis andSaussurea amara represent Asian types of areals. Other dominantsFallopia convolvulus, Elytrigia repens, Chenopodium album, Brassica campestris, Lappula squarrosa, Scutellaria galericulata,\\u000a Thlaspi arvense, Avena fatua

B. M. Mirkin; N. P. Slepcova; K. E. Kononov



Central Tendency: Mean, Mode, Median  

NSDL National Science Digital Library

This learning unit from Regents Exam Prep Center will help students learning to calculate mean, mode and median. The unit includes a lesson plan, practice examples, a teacher's guide and a worksheet. The term "measures of central tendency" is explained as finding the mean, median and mode of a set of data. The example of a set of test scores is used to demonstrate finding these measures. Links are also included which explain how to find these measurements using a graphing calculator.



Central Cascadia subduction zone creep  

NASA Astrophysics Data System (ADS)

Cascadia between 43°N and 46°N has reduced interseismic uplift observed in geodetic data and coseismic subsidence seen in multiple thrust earthquakes, suggesting elevated persistent fault creep in this section of the subduction zone. We estimate subduction thrust "decade-scale" locking and crustal block rotations from three-component continuous Global Positioning System (GPS) time series from 1997 to 2013, as well as 80 year tide gauge and leveling-derived uplift rates. Geodetic observations indicate coastal central Oregon is rising at a slower rate than coastal Washington, southern Oregon and northern California. Modeled locking distributions suggest a wide locking transition zone that extends inland under central Oregon. Paleoseismic records of multiple great earthquakes along Cascadia indicate less subsidence in central Oregon. The Cascade thrust under central Oregon may be partially creeping for at least 6500 years (the length of the paleoseismic record) reducing interseismic uplift and resulting in reduced coseismic subsidence. Large accretions of Eocene age basalt (Siletzia terrane) between 43°N and 46°N may be less permeable compared to surrounding terranes, potentially increasing pore fluid pressures along the fault interface resulting in a wide zone of persistent fault creep. In a separate inversion, three-component GPS time series from 1 July 2005 to 1 January 2011 are used to estimate upper plate deformation, locking between slow-slip events (SSEs), slip from 16 SSEs and an earthquake mechanism. Cumulative SSEs and tectonic tremor are weakest between 43°N and 46°N where partial fault creep is increased and Siletzia terrane is thick, suggesting that surrounding rock properties may influence the mode of slip.

Schmalzle, Gina M.; McCaffrey, Robert; Creager, Kenneth C.



Central configurations in three dimensions  

Microsoft Academic Search

We consider the equilibria of point particles under the action of two body\\u000acentral forces in which there are both repulsive and attractive interactions,\\u000aoften known as central configurations, with diverse applications in physics, in\\u000aparticular as homothetic time-dependent solutions to Newton's equations of\\u000amotion and as stationary states in the One Component Plasma model.\\u000aConcentrating mainly on the case

Richard A. Battye; Gary W. Gibbons; Paul M. Sutcliffe



Tectonics of the central Andes  

NASA Technical Reports Server (NTRS)

Acquisition of nearly complete coverage of Thematic Mapper data for the central Andes between about 15 to 34 degrees S has stimulated a comprehensive and unprecedented study of the interaction of tectonics and climate in a young and actively developing major continental mountain belt. The current state of the synoptic mapping of key physiographic, tectonic, and climatic indicators of the dynamics of the mountain/climate system are briefly reviewed.

Bloom, Arthur L.; Isacks, Bryan L.; Fielding, Eric J.; Fox, Andrew N.; Gubbels, Timothy L.



PAH diagnostic ratios for the identification of pollution emission sources.  


Polycyclic aromatic hydrocarbon (PAH) diagnostic ratios have recently come into common use as a tool for identifying and assessing pollution emission sources. Some diagnostic ratios are based on parent PAHs, others on the proportions of alkyl-substituted to non-substituted molecules. The ratios are applicable to PAHs determined in different environmental media: air (gas + particle phase), water, sediment, soil, as well as biomonitor organisms such as leaves or coniferous needles, and mussels. These ratios distinguish PAH pollution originating from petroleum products, petroleum combustion and biomass or coal burning. The compounds involved in each ratio have the same molar mass, so it is assumed they have similar physicochemical properties. Numerous studies show that diagnostic ratios change in value to different extents during phase transfers and environmental degradation. The paper reviews applications of diagnostic ratios, comments on their use and specifies their limitations. PMID:22243855

Tobiszewski, Marek; Namie?nik, Jacek



Generalization of Ryan's theorem: Probing tidal coupling with gravitational waves from nearly circular, nearly equatorial, extreme-mass-ratio inspirals  

SciTech Connect

Extreme-mass-ratio inspirals (EMRIs) and intermediate-mass-ratio inspirals (IMRIs) - binaries in which a stellar-mass object spirals into a massive black hole or other massive, compact body - are important sources of gravitational waves for LISA and LIGO, respectively. Thorne has speculated that the waves from EMRIs and IMRIs encode, in principle, all the details of (i) the central body's spacetime geometry (metric), (ii) the tidal coupling (energy and angular momentum exchange) between the central body and orbiting object, and (iii) the evolving orbital elements. Fintan Ryan has given a first partial proof that this speculation is correct: Restricting himself to nearly circular, nearly equatorial orbits and ignoring tidal coupling, Ryan proved that the central body's metric is encoded in the waves. In this paper we generalize Ryan's theorem. Retaining Ryan's restriction to nearly circular and nearly equatorial orbits, and dropping the assumption of no tidal coupling, we prove that Thorne's conjecture is nearly fully correct: the waves encode not only the central body's metric but also the evolving orbital elements and (in a sense slightly different from Thorne's conjecture) the evolving tidal coupling.

Li Chao [Theoretical Astrophysics, California Institute of Technology, Pasadena, California 91125 (United States); Lovelace, Geoffrey [Center for Radiophysics and Space Research, Cornell University, Ithaca, New York 14853 (United States)



Increasing interannual and altitudinal ozone mixing ratios in the Catalan Pyrenees  

NASA Astrophysics Data System (ADS)

Interannual, seasonal, daily and altitudinal patterns of tropospheric ozone mixing ratios, as well as ozone phytotoxicity and the relationship with NO x precursors and meteorological variables were monitored in the Central Catalan Pyrenees (Meranges valley and Forest of Guils) over a period of 5 years (2004-2008). Biweekly measurements using Radiello passive samplers were taken along two altitudinal transects comprised of thirteen stations ranging from 1040 to 2300 m a.s.l. Visual symptoms of ozone damage in Bel-W3 tobacco cultivars were evaluated biweekly for the first three years (2004-2006). High ozone mixing ratios, always above forest and vegetation protection AOT40 thresholds, were monitored every year. In the last 14 years, the AOT40 (Apr-Sept.) has increased significantly by 1047 ?g m -3 h per year. Annual means of ozone mixing ratios ranged between 38 and 67 ppb v (38 and 74 ppb v during the warm period) at the highest site (2300 m) and increased at a rate of 5.1 ppb v year -1. The ozone mixing ratios were also on average 35-38% greater during the warm period and had a characteristic daily pattern with minimum values in the early morning, a rise during the morning and a decline overnight, that was less marked the higher the altitude. Whereas ozone mixing ratios increased significantly with altitude from 35 ppb v at 1040 m-56 ppb v at 2300 m (on average for 2004-2007 period), NO 2 mixing ratios decreased with altitude from 5.5 ppb v at 1040 m-1 ppb v at 2300 m. The analysis of meteorological variables and NO x values suggests that the ozone mainly originated from urban areas and was transported to high-mountain sites, remaining aloft in absence of NO. Ozone damage rates increased with altitude in response to increasing O 3 mixing ratios and a possible increase in O 3 uptake due to more favorable microclimatic conditions found at higher altitude, which confirms Bel-W3 as a suitable biomonitor for ozone concentrations during summer time. Compared to the valley-bottom site the annual means of ozone mixing ratios are 37% larger in the higher sites. Thus the AOT40 for the forest and vegetation protection threshold is greatly exceeded at higher sites. This could have substantial effects on plant life at high altitudes in the Pyrenees.

Díaz-de-Quijano, Maria; Peñuelas, Josep; Ribas, Àngela



Ratio of Trunk to Leg Volume as a New Body Shape Metric for Diabetes and Mortality  

PubMed Central

Background Body shape is a known risk factor for diabetes and mortality, but the methods estimating body shape, BMI and waist circumference are crude. We determined whether a novel body shape measure, trunk to leg volume ratio, was independently associated with diabetes and mortality. Methods Data from the National Health and Nutritional Examination Survey 1999–2004, a study representative of the US population, were used to generate dual-energy X-ray absorptiometry-derived trunk to leg volume ratio and determine its associations to diabetes, metabolic covariates, and mortality by BMI category, gender, and race/ethnicity group. Results The prevalence of pre-diabetes and diabetes increased with age, BMI, triglycerides, blood pressure, and decreased HDL level. After adjusting for covariates, the corresponding fourth to first quartile trunk to leg volume ratio odds ratios (OR) were 6.8 (95% confidence interval [CI], 4.9–9.6) for diabetes, 3.9 (95% CI, 3.0–5.2) for high triglycerides, 1.8 (95% CI, 1.6–2.1) for high blood pressure, 3.0 (95% CI, 2.4–3.8) for low HDL, 3.6 (95% CI, 2.8–4.7) for metabolic syndrome, and 1.76 (95% CI, 1.20–2.60) for mortality. Additionally, trunk to leg volume ratio was the strongest independent measure associated with diabetes (P<0.001), even after adjusting for BMI and waist circumference. Even among those with normal BMI, those in the highest quartile of trunk to leg volume ratio had a higher likelihood of death (5.5%) than those in the lowest quartile (0.2%). Overall, trunk to leg volume ratio is driven by competing mechanisms of changing adiposity and lean mass. Conclusions A high ratio of trunk to leg volume showed a strong association to diabetes and mortality that was independent of total and regional fat distributions. This novel body shape measure provides additional information regarding central adiposity and appendicular wasting to better stratify individuals at risk for diabetes and mortality, even among those with normal BMI. PMID:23874736

Wilson, Joseph P.; Kanaya, Alka M.; Fan, Bo; Shepherd, John A.



BioMed Central Page & of &2  

E-print Network

BioMed Central Page & of &2 (page number not for citation purposes) Reproductive Biology and Rapraeger; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution

Rapraeger, Alan C.


Training Educational Administrators in Central America  

ERIC Educational Resources Information Center

Training of educational administrators in Central America is described and evaluated and future prospects are discussed. It is recommended that the six countries of Central America cooperate to achieve educational reform. (Author/DB)

Bernede, Jean-Francois



Exploration of Extreme Mass Ratio Inspirals with a Tree Code  

NASA Astrophysics Data System (ADS)

Extreme mass ratio inspirals (EMRIs), in which a stellar-mass object spirals into a supermassive black hole, are critical gravitational wave sources for the Laser Interferometer Space Antenna (LISA) because of their potential as precise probes of strong gravity. They are although thought to contribute to the flares observed in a few active galactic nuclei that have been attributed to tidal disruption of stars. There are, however, large uncertainties about the rates and properties of EMRIs. The reason is that their galactic nuclear environments contain millions of stars around a central massive object, and their paths must be integrated with great precision to include properly effects such as secular resonances, which accumulate over many orbits. Progress is being made on all fronts, but current numerical options are either profoundly computationally intensive (direct N-body integrators, which in addition do not currently have the needed long-term accuracy) or require special symmetry or other simplifications that may compromise the realism of the results (Monte Carlo and Fokker-Planck codes). We propose to undertake extensive simulations of EMRIs using tree codes that we have adapted to the problem. Tree codes are much faster than direct N-body simulations, yet they are powerful and flexible enough to include nonideal physics such as triaxiality, arbitrary mass spectra, post-Newtonian corrections, and secular evolutionary effects such as resonant relaxation and Kozai oscillations to the equations of motion. We propose to extend our codes to include these effects and to allow separate tracking of special ? that will represent binaries, thus allowing us to follow their interactions and evolution. In our development we will compare our results for a few tens of thousands of particles with a state of the art direct N-body integrator, to evaluate the accuracy of our code and discern systematic effects. This will allow detailed yet fast examinations of large-N systems, especially when relativistic effects are important. This work has direct relevance to the most recently stated NASA Strategic Goals and Science Outcomes, and to the Astrophysics Theory Program in particular. It addresses in particular Strategic Goal 2, fourth Outcome: Discover how the universe works, explore how the universe began and evolved into its present form, and search for life elsewhere. Under the category of Astrophysics, this work addresses the overall strategic goal: Discover the origin, structure, evolution, and destiny of the universe, and search for Earth-like planets.

Miller, Michael


Internal jugular vein: Peripheral vein adrenocorticotropic hormone ratio in patients with adrenocorticotropic hormone-dependent Cushing's syndrome: Ratio calculated from one adrenocorticotropic hormone sample each from right and left internal jugular vein during corticotrophin releasing hormone stimulation test  

PubMed Central

Background: Demonstration of central: Peripheral adrenocorticotropic hormone (ACTH) gradient is important for diagnosis of Cushing's disease. Aim: The aim was to assess the utility of internal jugular vein (IJV): Peripheral vein ACTH ratio for diagnosis of Cushing's disease. Materials and Methods: Patients with ACTH-dependent Cushing's syndrome (CS) patients were the subjects for this study. One blood sample each was collected from right and left IJV following intravenous hCRH at 3 and 5 min, respectively. A simultaneous peripheral vein sample was also collected with each IJV sample for calculation of IJV: Peripheral vein ACTH ratio. IJV sample collection was done under ultrasound guidance. ACTH was assayed using electrochemiluminescence immunoassay (ECLIA). Results: Thirty-two patients participated in this study. The IJV: Peripheral vein ACTH ratio ranged from 1.07 to 6.99 (n = 32). It was more than 1.6 in 23 patients. Cushing's disease could be confirmed in 20 of the 23 cases with IJV: Peripheral vein ratio more than 1.6. Four patients with Cushing's disease and 2 patients with ectopic ACTH syndrome had IJV: Peripheral vein ACTH ratio less than 1.6. Six cases with unknown ACTH source were excluded for calculation of sensitivity and specificity of the test. Conclusion: IJV: Peripheral vein ACTH ratio calculated from a single sample from each IJV obtained after hCRH had 83% sensitivity and 100% specificity for diagnosis of CD. PMID:23776865

Chittawar, Sachin; Bhattacharya, Saptarshi; Sahoo, Jai Prakash; Prakash, Siva; Bhalla, Ashu Seith; Kandasamy, Devasenathipathy; Arora, Arundeep; Gupta, Nandita; Tandon, Nikhil; Goswami, Ravinder; Khadgawat, Rajesh; Jyotsna, Viveka P.; Karak, Ashish Kumar; Bal, Chandra Sekhar; Pandey, Ravindra Mohan; Kumar, Guresh; Ammini, Ariachery C.



A High Aspect Ratio Microelectrode Array for Mapping Neural Activity in-vitro  

PubMed Central

A novel high-aspect-ratio penetrating microelectrode array was designed and fabricated for the purpose of recording neural activity. The array allows two dimensional recording of 64 sites in vitro with high aspect ratio penetrating electrodes. Traditional surface electrode arrays, although easy to fabricate, do not penetrate to the viable tissue such as central hippocampus slices and thus have a lower signal/noise ratio and lower selectivity than a penetrating array. In the unfolded hippocampus preparation, the CA1–CA3 pyramidal cell layer in the whole unfolded rodent hippocampus preparation is encased by the alveus on one side and the Schaffer tract on the other and requires penetrating electrodes for high signal to noise ratio recording. An array of 64 electrode spikes, each with a target height of 200 ?m and diameter of 20?m, was fabricated in silicon on a transparent glass substrate. The impedance of the individual electrodes was measured to be approximately 1.5M?± 497k?. The signal to noise ratio was measured and found to be 19.4 ± 3 dB compared to 3.9 ± 0.8 dB S/N for signals obtained with voltage sensitive dye RH414. A mouse unfolded hippocampus preparation was bathed in solution containing 50 micro-molar 4-Amino Pyridine and a complex two dimensional wave of activity was recorded using the array. These results indicate that this novel penetrating electrode array is able to obtain data superior to that of voltage sensitive dye techniques for broad field two-dimensional neuronal activity recording. When used with the unfolded hippocampus preparation, the combination forms a uniquely capable tool for imaging hippocampal network activity in the entire hippocampus. PMID:22179041

Kibler, Andrew B.; Jamieson, Brian G.; Durand, Dominique M.



Reanalysis of S-to-P amplitude ratios for gross attenuation structure, Long Valley caldera, California  

SciTech Connect

Because of the strong interest in the magmatism and volcanism at Long Valley caldera, eastern California, and because of recent sifnigicant improvements in our knowledge of the caldera velocity structure and earthquake locations, I have reanalyzed the local-earthquake S-to-P amplitude-ratio data of Sanders (1984) for the gross three-dimensional attenuation structure of the upper 10 km of Long Valley caldera. The primary goals of the analysis are to provide more accurate constraints on the depths of the attenuation anomalies using improved knowledge of the ray locations and an objective inversion procedure. The new image of the high S wave attenuation anomaly in the west-central cadlera suggests that the top of the principal anomaly is at 7-km depth, which is 2 km deeper than previously determined. Because of poor resolution in much of the region, some of the data remain unsatisfied by the final attenuation model. This unmodeled data may imply unresolved attenuation anomalies, perhaps small anomalies in the kilometer or two just above the central-caldera anomaly and perhaps a larger anomaly at about 7-km depth in the northwest caldera or somewhere beneath the Mono Craters. The central-caldera S wave attenuation anomaly has a location similar to mapped regions of low teleseismic P wave velocity, crustal inflation, reduced density, and aseismicity, strongly suggesting magmatic association.

Sanders, C.O. [Arizona State Univ., Tempe, AZ (United States)



Program Building Committee's Central Planning Group.  

E-print Network

Tooe ZTA245.7 8873 Y)O./3~ The Texas A&M (stem r ultural ~ion ~ervrce Damet C Plannstlel. Director College Stallon Program Building Committee's CENTRAL PLANNING GROUP 8-1344 Authors: Burl B. Richardson , Extension Program Specialist... and Mary G. Marshall, Extension Program Specialist Program -Building Committee's CENTRAL PLANNING GROUP This leaflet describes the role of the central planning group in the program development process_ The central planning group is the highest...

Richardson, Burl B.; Marshall, Mary G.



Prediction of -lactam position and orientation in the central cavity of the component of bacterial AcrAB-TolC multidrug efflux pump AcrB  

E-print Network

Prediction of -lactam position and orientation in the central cavity of the component of bacterial position/orientation in the central cavity, with experimental location of DEQ (green), CPF (light blue), ET moment components, polarizabilities) and steric (principal moments of intertia and their ratios

Ferreira, Márcia M. C.


Ground Motion Scaling in the Central Apennines  

NASA Astrophysics Data System (ADS)

We analyzed weak motion seismograms collected between 1992 and 1999 in order to study the characteristics of excitation and propagation of seismic waves in Central Apennines. Data were provided by a network run in Abruzzo by the Servizio Sismico Nazionale (SSN). The network was made by 32 three-component digital stations (21-bit Mars88-FD) coupled with 1-Hz seismometers (Mark L4C-3D). We selected a data set of 1,200 events characterized by good signal-to-noise ratios, putting together a set of about 18,000 waveforms for the analysis. On the one hand, the entire Apennines fold-and-thrust belt was previously studied by Malagnini et al. (2000), although the set of data available at that time only allowed them to treat the entire region (from Garfagnana-Lunigiana, in the Northern Apennines, to the Calabrian Arch to the South) as structurally homogeneous. The data set described here, on the other hand, allows a detailed study on the central part of the Apennines chain, where the hypothesis of crustal homogeneity is not an overly gross approximation. The study on ground motion scaling was carried out through the techniques described by recent papers by Malagnini and co-workers, and yielded stable attenuation results. With respect to the model proposed by Malagnini et al. (2000), we described our results in terms of a slightly different geometrical spreading function and crustal attenuation parameter Q(f). Specifically, the frequency dependence of the crustal parameter Q(f) obtained in this study is higher than that previously found for the entire Apennines by Malagnini et al. (2000). The mentioned differences reflect the strong variability of the characteristics of the crust in the Apennines, both in terms of velocity structure, depth to the Moho, fluid circulation and heat flow. More studies are in progress in the Northern and Southern Apennines, in order to obtain a better understanding of the ground motion scaling in the entire fold-and-thrust belt. Regional attenuation models are being used for the compilation of a detailed hazard map of the entire Italian territory.

del Pinto, C.; Malagnini, L.; Akinci, A.; de Luca, G.



Hemodilution therapy in central retinal vein occlusion  

Microsoft Academic Search

Systemic hemorheologic abnormalities may play a part in the pathogenesis of central retinal vein occlusions. A statistically significant elevation of plasma viscosity was found in patients with acute central retinal vein occlusion compared with control patients. Local retinal blood flow parameters including arteriovenous passage time and mean arterial dye bolus velocity were significantly altered in the central retinal vein occlusion

Sebastian Wolf; Oliver Arend; Bernd Bertram; Andreas Remky; Karin Schulte; Kenneth J. Wald; Martin Reim



West Central Texas Regional Transportation Final Report  

E-print Network

WEST CENTRAL TEXAS REGIONAL REGIONAL TRANSPORTATION TRANSPORTATION FINAL REPORT NOVEMBER 2006 West Central Texas Regional Transit Coordination Plan Final Report and Executive Summary November 2006 A&R Consulting The Goodman... Workshops 177 Appendix C - Public Meetings 183 West Central Texas Regional Transit Coordination Plan Final Report and Executive Summary November 2006 A&R Consulting The Goodman Corporation November 2006 3 EXECUTIVE SUMMARY...

West Central Texas Council of Governments


Central Bank Communication and Policy Effectiveness  

Microsoft Academic Search

A notable change in central banking over the past 15 years has been a world-wide movement toward increased communication by central banks about their policy decisions, the targets that they seek to achieve through those decisions, and the central bank's view of the economy's likely future evolution. This paper considers the role of such communication in the successful conduct of

Michael Woodford



Timetabling & Space Management Central Student Calendaring Service  

E-print Network

Timetabling & Space Management Central Student Calendaring Service Throughout Semester 1 of this academic year 13/14, ISS have successfully trialled a new timetable calendaring service "Calsync is available centrally and uses the information on the central timetabling software to produce a student

Harman, Neal.A.


49 CFR 71.6 - Central zone.  

Code of Federal Regulations, 2010 CFR

...Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.6 Central zone...third zone, the central standard time zone, includes that part of the United...between the eastern and central standard time zones described in § 71.5 and east...



49 CFR 71.6 - Central zone.  

Code of Federal Regulations, 2011 CFR

...Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.6 Central zone...third zone, the central standard time zone, includes that part of the United...between the eastern and central standard time zones described in § 71.5 and east...



49 CFR 71.6 - Central zone.  

Code of Federal Regulations, 2012 CFR

...Secretary of Transportation STANDARD TIME ZONE BOUNDARIES § 71.6 Central zone...third zone, the central standard time zone, includes that part of the United...between the eastern and central standard time zones described in § 71.5 and east...



CASWW Dissertations in Central Asian Studies  

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. It currently contains information on approximately 250 recent dissertations in Central Asian Studies completed in universities worldwide. These are listed by author, institution, subject keywords, or in one of 25 major subject headings.


Think Globally, Act Locally, Plan (Also) Centrally  

Microsoft Academic Search

When an environmental studies curriculum was developed for senior high schools in Israel, special attention was paid to the methodological approach, to content selection, and to the integration of central and school-based curriculum strategies. While central curriculum teams usually have an advantage in their better access to budgets, to specialized sources of information, and to central examination bodies, local teachers

Abraham Blum



Interspecies comparisons of A/D ratios: A/D ratios are not constant across species.  


The hypothesis that the ratio of the adult (A) and developmental (D) toxicity of a chemical is constant across animal species has been proposed as the basis for identifying developmental hazards, both from traditional developmental toxicity screens using laboratory mammals and from alternative systems such as the coelenterate Hydra attenuata. The purpose of this study was to determine whether A/D ratios are constant across species. The developmental and adult toxicity of 14 chemicals was assessed in four phylogenetically different species. The chemicals tested were aminopterin, bromodeoxyuridine, cadmium chloride, caffeine, congo red, dinocap, dinoseb, diphenylhydantoin, epinephrine, ethylenethiourea, 2-methoxyethanol, mirex, all-trans-retinoic acid, and trypan blue. These chemicals are representative of a variety of toxic mechanisms and a range of potencies. Species used were the CD-1 mouse (Mus musculus), South African clawed frog (Xenopus laevis), fathead minnow (Pimephales promelas), and fruit fly (Drosophila melanogaster). The mouse is a commonly used model for developmental toxicity. The other species are known to be sensitive to mammalian toxicants and have well-studied embryologies. Mice were exposed to chemicals either po or by sc injection using a standard Segment II protocol in which pregnant mice are administered the test agent on a daily basis from Gestation Days 6 to 15, adult toxicity is evaluated during and after treatment, and developmental toxicity is evaluated in fetuses at term. The exposure duration spans the period of organ formation in the embryo. The other species were exposed to test agents for a developmentally comparable period. This was from blastulation (shortly after fertilization) to the free-swimming tadpole stage in Xenopus (4 days); from blastulation to the free-swimming fry stage in Pimephales (7 days); and for the entire larval period, the period of development of the imaginal discs, in Drosophila (6 days). Adults of each species were exposed to test agents for 4, 7, and 6 days, respectively. The route of exposure was via the water column in the two aquatic species and via the diet in Drosophila. Statistical lowest observed effect level (LOEL) and no observed effect level (NOEL) values were generated for adult and developmental toxicity in each species. A/D ratios were calculated using both LOEL and NOEL values.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:1843185

Daston, G P; Rogers, J M; Versteeg, D J; Sabourin, T D; Baines, D; Marsh, S S



The effect of clay minerals on diasterane/sterane ratios  

NASA Astrophysics Data System (ADS)

To examine the effect of clay minerals on diasterane/sterane ratios, the mineral compositions of three sample sets of sedimentary rocks displaying a wide range of diasterane/sterane ratios were analysed quantitatively. Diasterane/sterane ratios do not to correlate with clay content but depend on the amount of clay relative to the amount of organic matter (clay/TOC ratios). This correlation may explain the high diasterane/sterane ratios in crude oils and extracts derived from certain carbonate source rocks. Based on the concentrations of regular and rearranged steroids in the sample sets, it is proposed that diasterenes are partly reduced to diasteranes and partly degraded during diagenesis in a ratio largely determined by the availability of clay minerals. It is suggested that the hydrogen atoms required for reduction of the diasterenes originate from the water in the interlayers of clay minerals.

van Kaam-Peters, Heidy M. E.; Köster, Jürgen; van der Gaast, Sjierk J.; Dekker, Marlèn; de Leeuw, Jan W.; Sinninghe Damsté, Jaap S.



Observation of Enhanced Transformer Ratio in Collinear Wakefield Acceleration  

SciTech Connect

One approach to future high energy particle accelerators is based on the wakefield principle: a leading high-charge drive bunch is used to excite fields in an accelerating structure or plasma that in turn accelerates a trailing low-charge witness bunch. The transformer ratio R is defined as the ratio of the maximum energy gain of the witness bunch to the maximum energy loss of the drive bunch. In general, R<2 for this configuration. A number of techniques have been proposed to overcome the transformer ratio limitation. We report here the first experimental study of the ramped bunch train (RBT) technique in a dielectric based accelerating structure. A single drive bunch was replaced by two bunches with charge ratio of 1 ratio 2.5 and a separation of 10.5 wavelengths of the fundamental mode. An average measured transformer ratio enhancement by a factor of 1.31 over the single drive bunch case was obtained.

Jing, C.; Kanareykin, A.; Schoessow, P. [Euclid Techlabs LLC, Solon, Ohio 44139 (United States); Power, J. G.; Conde, M.; Yusof, Z.; Gai, W. [High Energy Physics Division, Argonne National Laboratory, Argonne, Illinois-60439 (United States)



On carbon and oxygen isotope ratios in starburst galaxies: New data from NGC253 and Mrk231 and their implications  

E-print Network

Using the IRAM 30-m telescope, CN and CO isotopologues have been measured toward the central regions of the nearby starburst galaxy NGC253 and the prototypical ultraluminous infrared galaxy Mrk231. In NGC253, the 12C/13C ratio is 40+-10. Assuming that the ratio also holds for the CO emitting gas, this yields 16O/18O = 145+-36 and 16O/17O = 1290+-365 and a 32S/34S ratio close to that measured for the local interstellar medium (20-25). No indication for vibrationally excited CN is found. Peak line intensity ratios between NGC253 and Mrk231 are ~100 for 12C16O and 12C18O J=1-0, while the ratio for 13C16O J=1-0 is ~250. This and similar 13CO and C18O line intensities in the J=1-0 and 2-1 transitions of Mrk231 suggest 12C/13C ~ 100 and 16O/18O ~ 100, in agreement with values obtained for the less evolved ultraluminous merger Arp220. Also accounting for other extragalactic data, 12C/13C ratios appear to vary over a full order of magnitude, from >100 in ultraluminous high redshift galaxies to ~100 in more local such...

Henkel, C; Ao, Y; Aalto, S; Danielson, A L R; Papadopoulos, P P; Garcia-Burillo, S; Aladro, R; Impellizzeri, C M V; Mauersberger, R; Martin, S; Harada, N



Central Saudi Arabia, Persian Gulf  

NASA Technical Reports Server (NTRS)

This panoramic view of Central Saudi Arabia and the Persian Gulf (28.0N, 47.0E) dramatically illustrates the stark beauty of the deserts. Riyadh, the capital city, lies in the foreground, with the Persian Gulf in the middle and Iran in the background. The coastal oil terminals of Al Hufuf and Ad Dammam are also visible. Black smudges of soot from the oil fires set during the Gulf War can be seen on the sands to the north and south of Kuwait City.



Centralized Storm Information System (CSIS)  

NASA Technical Reports Server (NTRS)

A final progress report is presented on the Centralized Storm Information System (CSIS). The primary purpose of the CSIS is to demonstrate and evaluate real time interactive computerized data collection, interpretation and display techniques as applied to severe weather forecasting. CSIS objectives pertaining to improved severe storm forecasting and warning systems are outlined. The positive impact that CSIS has had on the National Severe Storms Forecast Center (NSSFC) is discussed. The benefits of interactive processing systems on the forecasting ability of the NSSFC are described.

Norton, C. C.



Changing sex ratio in the United States, 1969–1995  

Microsoft Academic Search

Objective: To determine if the sex ratio of live births in the United States has changed during the 27 years from 1969 through 1995.Design: Regression analysis of secular trends in sex ratios.Setting: Population-based data.Patient(s): Liveborn infants in the United States 1969–1995.Main Outcome Measure(s): Sex of liveborn infant.Result(s): The sex ratio (number of male births divided by number of female births)

Michele Marcus; John Kiely; Fujie Xu; Michael McGeehin; Richard Jackson; Tom Sinks



Precise and accurate isotope ratio measurements by ICP-MS  

Microsoft Academic Search

The precise and accurate determination of isotope ratios by inductively coupled plasma mass spectrometry (ICP-MS) and laser\\u000a ablation ICP-MS (LA-ICP-MS) is important for quite different application fields (e.g. for isotope ratio measurements of stable\\u000a isotopes in nature, especially for the investigation of isotope variation in nature or age dating, for determining isotope\\u000a ratios of radiogenic elements in the nuclear industry,

J. Sabine Becker; Hans-Joachim Dietze



Hedging with zero-value at risk hedge ratio  

Microsoft Academic Search

In this paper we derive a new mean-risk hedge ratio based on the concept of Value at Risk (VaR). The proposed zero-VaR hedge ratio has an analytical solution and it converges to the MV hedge ratio under a pure martingale process or normality. A bivariate constant correlation GARCH(1,1) model with an error correction term is employed to estimate expected returns

Jui-Cheng Hung; Chien-Liang Chiu; Ming-Chih Lee



Method of Poisson's ratio imaging within a material part  

NASA Technical Reports Server (NTRS)

The present invention is directed to a method of displaying the Poisson's ratio image of a material part. In the present invention longitudinal data is produced using a longitudinal wave transducer and shear wave data is produced using a shear wave transducer. The respective data is then used to calculate the Poisson's ratio for the entire material part. The Poisson's ratio approximations are then used to displayed the image.

Roth, Don J. (Inventor)



Using single-mode fibers to monitor fast Strehl ratio fluctuations. Application to a 3.6 m telescope corrected by adaptive optics  

Microsoft Academic Search

The theory of starlight coupling into single-mode fibers is reviewed to show how i) the central obstruction in a telescope pupil deteriorates coupling efficiency much more than one would expect from the loss of collecting area, and ii) a single-mode fiber and a photometer can be used to monitor fast Strehl ratio fluctuations. This last point is illustrated with experimental

V. Coudé du Foresto; M. Faucherre; N. Hubin; P. Gitton



Blue lobes in the Hydra A cluster central galaxy  

NASA Technical Reports Server (NTRS)

We present new U- and I-band images of the centrally dominant galaxy in the Hydra A cluster, obtained with the 2.5 m Isaac Newton Telescope at La Palma. The galaxy is centered in a poor, X-ray-luminous cluster whose gaseous intracluster medium is apparently cooling at a rate of m-dot(sub CF) approximately 3000 solar masses/yr. The galaxy's structure is that of a normal giant elliptical galaxy, apart from the central approximately 8 x 6 arcsec (approximately 12 x 9 kpc) region which contains an unusually blue, lobelike structure that is spatially coincident with a luminous emission-line nebula in rotation about the nucleus. Based on near spatial coincidence of the central continuum structure and the emission-line nebula, we suggest that the blue continuum is due to a warm stellar population in a central disk. In order to isolate and study the structure of the disk, we have subtracted a smooth galactic background model from the U-band image. The disk's surface brightness profiles along its major and minor axes decline roughly exponentially with radius. The disk's axial ratio is consistent with a nearly edge-on thick disk or a thin disk that is inclined with respect to the line of sight. The bluest regions, located a few arcsec on either side of the nucleus (giving the lobelike appearance), may be due to locally enhanced star formation or a seeing-blurred ring of young stars embedded in the disk observed nearly edge-on. If star-formation is occurring with the local initial mass function, the central color, surface brightness, and dynamical mass would be consistent with models for star formation at a rate of less than and approximately 1 solar masses/yr which has persisted for the past approximately 10(exp 9) yr, a short burst (10(exp 7) yr) of star formation at a rate of approximately 30 solar masses/yr which occurred less than and approximately 10(exp 8) yr ago, or an instantaneous burst of star formation which occurred approximately 5 x 10(exp 7) yr ago. While the young population contributes approximately 30%-40% of the central U-band luminosity, its mass would be less than and approximately 1% to less than and approximately 10% (10(exp 8) solar masses - 2 x 10(exp 9) solar masses of the galaxy's central dynamical mass. We consider a number of possible origins for the disk material.

Mcnamara, Brian R.



Focus on peripherally inserted central catheters in critically ill patients.  


Venous access devices are of pivotal importance for an increasing number of critically ill patients in a variety of disease states and in a variety of clinical settings (emergency, intensive care, surgery) and for different purposes (fluids or drugs infusions, parenteral nutrition, antibiotic therapy, hemodynamic monitoring, procedures of dialysis/apheresis). However, healthcare professionals are commonly worried about the possible consequences that may result using a central venous access device (CVAD) (mainly, bloodstream infections and thrombosis), both peripherally inserted central catheters (PICCs) and centrally inserted central catheters (CICCs). This review aims to discuss indications, insertion techniques, and care of PICCs in critically ill patients. PICCs have many advantages over standard CICCs. First of all, their insertion is easy and safe -due to their placement into peripheral veins of the arm- and the advantage of a central location of catheter tip suitable for all osmolarity and pH solutions. Using the ultrasound-guidance for the PICC insertion, the risk of hemothorax and pneumothorax can be avoided, as well as the possibility of primary malposition is very low. PICC placement is also appropriate to avoid post-procedural hemorrhage in patients with an abnormal coagulative state who need a CVAD. Some limits previously ascribed to PICCs (i.e., low flow rates, difficult central venous pressure monitoring, lack of safety for radio-diagnostic procedures, single-lumen) have delayed their start up in the intensive care units as common practice. Though, the recent development of power-injectable PICCs overcomes these technical limitations and PICCs have started to spread in critical care settings. Two important take-home messages may be drawn from this review. First, the incidence of complications varies depending on venous accesses and healthcare professionals should be aware of the different clinical performance as well as of the different risks associated with each type of CVAD (CICCs or PICCs). Second, an inappropriate CVAD choice and, particularly, an inadequate insertion technique are relevant-and often not recognized-potential risk factors for complications in critically ill patients. We strongly believe that all healthcare professionals involved in the choice, insertion or management of CVADs in critically ill patients should know all potential risk factors of complications. This knowledge may minimize complications and guarantee longevity to the CVAD optimizing the risk/benefit ratio of CVAD insertion and use. Proper management of CVADs in critical care saves lines and lives. Much evidence from the medical literature and from the clinical practice supports our belief that, compared to CICCs, the so-called power-injectable peripherally inserted central catheters are a good alternative choice in critical care. PMID:25374804

Cotogni, Paolo; Pittiruti, Mauro



Focus on peripherally inserted central catheters in critically ill patients  

PubMed Central

Venous access devices are of pivotal importance for an increasing number of critically ill patients in a variety of disease states and in a variety of clinical settings (emergency, intensive care, surgery) and for different purposes (fluids or drugs infusions, parenteral nutrition, antibiotic therapy, hemodynamic monitoring, procedures of dialysis/apheresis). However, healthcare professionals are commonly worried about the possible consequences that may result using a central venous access device (CVAD) (mainly, bloodstream infections and thrombosis), both peripherally inserted central catheters (PICCs) and centrally inserted central catheters (CICCs). This review aims to discuss indications, insertion techniques, and care of PICCs in critically ill patients. PICCs have many advantages over standard CICCs. First of all, their insertion is easy and safe -due to their placement into peripheral veins of the arm- and the advantage of a central location of catheter tip suitable for all osmolarity and pH solutions. Using the ultrasound-guidance for the PICC insertion, the risk of hemothorax and pneumothorax can be avoided, as well as the possibility of primary malposition is very low. PICC placement is also appropriate to avoid post-procedural hemorrhage in patients with an abnormal coagulative state who need a CVAD. Some limits previously ascribed to PICCs (i.e., low flow rates, difficult central venous pressure monitoring, lack of safety for radio-diagnostic procedures, single-lumen) have delayed their start up in the intensive care units as common practice. Though, the recent development of power-injectable PICCs overcomes these technical limitations and PICCs have started to spread in critical care settings. Two important take-home messages may be drawn from this review. First, the incidence of complications varies depending on venous accesses and healthcare professionals should be aware of the different clinical performance as well as of the different risks associated with each type of CVAD (CICCs or PICCs). Second, an inappropriate CVAD choice and, particularly, an inadequate insertion technique are relevant-and often not recognized-potential risk factors for complications in critically ill patients. We strongly believe that all healthcare professionals involved in the choice, insertion or management of CVADs in critically ill patients should know all potential risk factors of complications. This knowledge may minimize complications and guarantee longevity to the CVAD optimizing the risk/benefit ratio of CVAD insertion and use. Proper management of CVADs in critical care saves lines and lives. Much evidence from the medical literature and from the clinical practice supports our belief that, compared to CICCs, the so-called power-injectable peripherally inserted central catheters are a good alternative choice in critical care. PMID:25374804

Cotogni, Paolo; Pittiruti, Mauro



Central vein stenosis: a nephrologist's perspective.  


Central vein stenosis is commonly associated with placement of central venous catheters and devices. Central vein stenosis can jeopardize the future of arteriovenous fistula and arteriovenous graft in the ipsilateral extremity. Occurrence of central vein stenosis in association with indwelling intravascular devices including short-term, small-diameter catheters such as peripherally inserted central catheters, long-term hemodialysis catheters, as well as pacemaker wires, has been recognized for over two decades. Placement of multiple catheters, longer duration, location in subclavian vein, and placement on the left-hand side of neck seem to predispose to the development of central vein stenosis. Endothelial injury with subsequent changes in the vessel wall results in development of microthrombi, smooth muscle proliferation, and central vein stenosis. Central vein stenosis is often asymptomatic in nondialysis patients, but can result in edema of ipsilateral extremity and breast when challenged by increased flow from an arteriovenous fistula or arteriovenous graft. Bilateral central vein stenosis or superior vena cava stenosis can produce a clinical picture of superior vena cava syndrome, associated with engorgement of face and neck. Endovascular interventions are the mainstay of management of central vein stenosis. Percutaneous angioplasty and stent placement for elastic and recurring lesions can restore the functionality of the vascular access, at least temporarily. Frequent or multiple interventions are usually required. In recalcitrant cases, surgical bypass of the obstruction is an option. In resistant cases with severe symptoms, occlusion of the functioning vascular access will usually provide relief of symptoms. Further study of mechanisms of development of central vein stenosis and search for a targeted therapy is likely to lead to better ways of managing central vein stenosis. Prevention of central vein stenosis is the key to avoid access failure and other complications from central vein stenosis and relies upon avoidance of central vein stenosis placement and timely placement of arteriovenous fistula in prospective dialysis patient. PMID:17244123

Agarwal, Anil K; Patel, Bhairavi M; Haddad, Nabil J



FMR1 CGG Expansions: Prevalence and Sex Ratios  

PubMed Central

We have estimated the prevalence of FMR1 premutation and gray zone CGG repeat expansions in a population-based sample of 19,996 male and female adults in Wisconsin and compared the observed sex ratios of the prevalence of FMR1 CGG premutation and gray zone expansions to theoretical sex ratios. The female premutation prevalence was 1 in 148 and comparable to past research, but the male premutation prevalence of 1 in 290 is somewhat higher than most previous estimates. The female:male premutation prevalence ratio is in line with the theoretically predicted sex ratio. The prevalence of CGG repeats in the gray zone (45–54 repeats) was 1 in 33 females and 1 in 62 males. The prevalence of the “expanded” gray zone (defined here as 41–54 CGG repeats) was 1 in 14 females and 1 in 22 males, leading to a female:male ratio of 1.62 (95% confidence interval 1.39–1.90). This female:male ratio was significantly lower than the expected ratio of 2.0. We examined results from three previously published FMR1 prevalence studies and found similar female:male ratios for CGG repeats in this “expanded” gray zone range (pooled female:male ratio across all four studies 1.66, 95% confidence interval 1.51–1.82). Further research is needed to understand the apparent excess prevalence of males with CGG repeats in this range. PMID:23740716

Maenner, Matthew J.; Baker, Mei W.; Broman, Karl W.; Tian, Jianan; Barnes, Janel K.; Atkins, Anne; McPherson, Elizabeth; Hong, Jinkuk; Brilliant, Murray H.; Mailick, Marsha R.



42 CFR 403.215 - Loss ratio standards.  

Code of Federal Regulations, 2010 CFR

...purposes of loss ratio requirements, policies issued as a result of solicitation of individuals through the mail or by mass media advertising are considered individual policies. State Regulatory...



3D near-surface soil response from H/V ambient-noise ratios  

USGS Publications Warehouse

The applicability of the horizontal-to-vertical (H/V) ambient-noise spectral ratio for characterizing earthquake site effects caused by nearsurface topography and velocity structures was evaluated at sites underlain by thick (i.e. >100 m) sediment deposits near the southern-end of the New Madrid seismic zone in the central United States. Three-component ambient-noise and velocity models derived from seismic (shearwave) refraction/reflection surveys showed that a relatively horizontal, sharp shear-wave velocity interface in the soil column resulted in an H/V spectral ratio with a single well-defined peak. Observations at sites with more than one sharp shear-wave velocity contrast and horizontally arranged soil layers resulted in at least two well-defined H/V spectral ratio peaks. Furthermore, at sites where there were sharp shear-wave velocity contrasts in nonhorizontal, near-surface soil layers, the H/V spectra exhibited a broad-bandwidth, relatively low amplitude signal instead of a single well-defined peak. ?? 2002 Elsevier Science Ltd. All rights reserved.

Wollery, E.W.; Street, R.



The 2500-km Altai Range is located in the central part of the Central Asia Orogenic  

E-print Network

ABSTRACT The 2500-km Altai Range is located in the central part of the Central Asia Orogenic System The Central Asia Orogenic System is one of the largest Phanerozoic orogenic belts in the world (Fig. 1 by Windley et al., 2007, and references therein). Two contrasting mechanisms for Central Asia Orogenic System

Manning, Craig


Central Asia from Within REES 399 Special Studies in Central Asian Literature CRN 42400  

E-print Network

Central Asia from Within REES 399 Special Studies in Central Asian Literature CRN 42400 2, Central Asia has achieved increasing prominence as a player in global affairs and as a subject of academic study. Today's Central Asia is the heir of rich literary and artistic traditions descended from local

Oregon, University of


Intraocular pressure and central visual field of normal tension glaucoma  

PubMed Central

AIM—To study whether damage in the central 30° field of normal tension glaucoma (NTG) is relatively heterogeneous or homogeneous with respect to intraocular pressure (IOP) related damage.?METHODS—Using the results of Humphrey perimeter examinations, the central 30° field was divided into four subfields; superior and inferior hemifields excluding the caecocentral field (30-2 program) and superior and inferior 10° hemifields (10-2 program). In 103 NTG cases, the intraindividual bilateral difference in the mean of total deviations (mean TD) in the four subfields was analysed by multiple linear regression to correct the effects of factors other than IOP. Explanatory variables were the intraindividual bilateral difference in the mean of clinic IOP (IOPmean), that in the ratio of area of peripapillary atrophy corresponding to each subfield to disc area, and that in myopic refraction.?RESULTS—The intraindividual bilateral difference in the mean TD was significantly and negatively correlated with that in IOPmean in three of the above four subfields (p<0.005) and correlation tended to be negative (p=0.07) in the superior 10° hemifield.?CONCLUSIONS—Diffuse IOP related damage was suggested in the central 30° field of NTG; greater extent of the damage in the above four subfields was correlated with higher mean IOP. The present findings may have clinical implications.?? PMID:9486025

Araie, M.; Kitazawa, M.; Koseki, N.



Geothermal initiatives in Central America  

SciTech Connect

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 in the Guanacaste Province of Costa Rica are being explored. Well-logging activities are in progress in the production wells at the Miravalles geothermal field in Costa Rica, and preparations are being made for logging critical wells at Ahuachapan in El Salvador. A self-contained logging truck, complete with high-temperature logging cable and logging tools designed for geothermal service, is being fabricated and will be made available for dedicated use throughout Central America. Geochemical and isotopic analyses of water samples collected in Panama are being evaluated to select a high-priority geothermal site in that country. Application of low- and medium-enthalpy geothermal fluids for industrial and agricultural processes is being investigated in Guatemala.

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



Central vascular catheters and infections.  


Newborn infants in critical conditions require a permanent intra-venous line to allow for the administration of fluids, parenteral nutrition and drugs. The use of central venous catheters, however, is associated with an increased risk of infections, leading to prolongation of length of stay and higher hospitalization costs, particularly in extremely preterm infants. Dwell time is a significant factor for complications, with a predicted risk of catheter related infections of about 4 per 1000 catheter-days. To reduce the incidence of complications, several requirements must be met, including adequate staff and resources to provide education, training, and quality improvement programs, within a culture of communication and teamwork. Rigorous reporting schedule on line care and the implementation of unique bundle elements, the use of health care failure mode and effect analysis, the judicious use of antibiotics through an antimicrobial stewardship strategy, the application of specific antifungal prophylaxis are among the most effective interventions, while the addition of heparin to parenteral solution, or the use of antibiotic plus heparin lock therapy are under evaluation. Nursing assistance plays a fundamental role in managing central venous lines and in reducing or preventing the incidence of infection, by the application of several complex professional strategies. PMID:24709460

Dioni, Elisabetta; Franceschini, Renata; Marzollo, Roberto; Oprandi, Daniela; Chirico, Gaetano



Collyriclosis in Central European hirundines.  


Cutaneous monostome trematode Collyriclum faba (Bremser in Schmalz 1831) is a digenetic flatworm with unknown life cycle. Here, we provide the first compelling evidence that despite low prevalence of the parasite, European hirundines are parasitized by this species. First host record for sand martin (Riparia riparia) and first European host record for barn swallow (Hirundo rustica) is provided. The birds were captured and checked in ten European and Middle Eastern countries, stretching from Ireland to Bahrain, but only samples from Central Europe (Czech Republic, Hungary and Poland) were positive for C. faba. In total, 164,582 sand martins and 100,443 barn swallows were examined, and seven and two birds had cutaneous C. faba cysts. Even though over 40% of the birds captured were juveniles, all but one infected individuals were adults, equally both males and females. The prevalence of the parasite on Central European hirundines were calculated as one in 20,641 for sand martins and one in 4,484 for barn swallows. All the infected birds were captured in close vicinity of water bodies. All the cysts were found close to the vent or on the legs. No adverse effects on its bird hosts were observed. PMID:21380577

Heneberg, Petr; Szép, Tibor; Iciek, Tomasz; Literák, Ivan



Primary hypersomnias of central origin.  


Hypersomnia is a frequently encountered symptom in clinical practice. The cardinal manifestation is inappropriate daytime sleepiness, common to all types of hypersomnias. Hypersomnias of central origin are a rare cause of excessive daytime sleepiness, much rarer than the hypersomnia related to other pathologies, such as sleep-disordered breathing. Narcolepsy, with or without cataplexy, remains the most well studied of the primary hypersomnias. Although recognized more than a century ago, it was not until the end of the 20th century that major breakthroughs led to a better understanding of the disease, with hope of more specific therapies. The authors review the major aspects of this disorder, including the newer treatment modalities. Idiopathic hypersomnia is also part of the primary hypersomnias. Although difficult to diagnose, certain peculiarities stand out to help us differentiate it from the more commonly seen narcolepsy. The recurrent hypersomnias, particularly the Kleine-Levin syndrome, will be discussed. This rare disorder has been studied more closely in the last few years with abundant epidemiologic data assembled through literature and worldwide case reviews. Understanding the primary central hypersomnias warrants a thorough look from the original description, as well as a peek at the future, while more efficacious diagnostic and therapeutic interventions are currently being developed. PMID:19742411

Frenette, Eric; Kushida, Clete A



Chernobyl fallout in southern and central Finland.  


To study the levels and distributions of radionuclides released in the Chernobyl accident, we sampled surface peat from 62 sites in Southern and Central Finland and measured 131I, 134Cs, 137Cs, 132Te, 140Ba, 103Ru, 90Sr, 141Ce, and 95Zr. The distribution of fallout activities was highly uneven, depending on movement of the contaminated air mass and rainfall distribution during the critical days. The highest values observed were 420 kBq m-2 of 131I and 70 kBq m-2 of 137Cs. The nuclide ratios showed wide and partly unexpected variations. The high-boiling-point, or nonvolatile, elements Ce and Zr were spread mostly on a 200-km-wide zone extending across Finland from southwest to northeast. The more volatile elements, I, Ce, and Te, showed quite a different, more widespread, fallout distribution, while an intermediate behavior was observed for Ba, Ru, and possibly Sr. These results can be explained by assuming that pulverized nuclear fuel material released in the reactor explosion on 26 April reached Finland via Poland and the Baltic Sea and traversed the country along the above-mentioned narrow zone, while volatile material, evaporated in the reactor fire from 26 April to 5 May, arrived in several waves and was consequently more widely and evenly spread. From their elemental melting and boiling points, Ru and Mo would appear to belong to the nonvolatile group and Sr to the volatile. Yet, their actual behaviors were opposite; Ru in particular was found in the nonvolatile as well as the volatile fallout, possibly because Ru activities were present in the fuel partly in the metallic state and partly as volatile oxides. PMID:1995514

Jantunen, M; Reponen, A; Kauranen, P; Vartiainen, M



Skylab S-192 ratio codes of soil, mineral, and rock spectra for ratio image selection and interpretation  

NASA Technical Reports Server (NTRS)

A limited theoretical systems study is made of the Skylab S-192 12-channel multispectral scanner's capabilities for geological remote sensing. Laboratory spectra of rocks, minerals, soils, and some vegetation were used to rank the twelve channels and the best twelve of the 66 possible nonreciprocal spectral ratios according to their ability to discriminate among 17 classes of geological targets. Environmental and instrumental noise sources were ignored. The S-192 should be most useful for discriminating minerals deposited by hydrothermal alteration, weathering, and evaporation. Discrimination of igneous rocks will be difficult. Ratio images are recommended over automatic discrimination methods for those geological targets that can be enhanced by ratio imaging. Ratio codes were found for the twelve highest ranked ratios, for use in selecting the ratio images which will best enhance a target of interest. They can also be searched for false alarm candidates for a given target.

Vincent, R. K.; Pillars, W. W.



Weight, fat mass, and central distribution of fat increase when women use depot-medroxyprogesterone acetate for contraception  

Microsoft Academic Search

OBJECTIVE:To compare longitudinal changes in weight, body fat, and ratio of central to peripheral fat mass among first-time depot-medroxyprogesterone acetate (DMPA) users to women using no hormonal contraception, and to evaluate user characteristics associated with that change.DESIGN:Prospective longitudinal study.SUBJECTS:Healthy women, aged 18–35 y, using DMPA for contraception (n=178) and women using no hormonal contraception (n=145).MEASUREMENTS:Weight, body fat, and the central

M K Clark; J S Dillon; M Sowers; S Nichols



Spatial distribution of adult Anopheles darlingi and Anopheles albimanus in relation to riparian habitats in Belize, Central America  

Microsoft Academic Search

Collections of Anopheles darlingi Root and An. albimanus Wiedemann from central and northern Belize were conducted as landing captures from 6:30 to 8:00 p.m. to define spatial distributions and outdoor:indoor ratios of biting during the early evening. In central Belize, collections were made at 31 houses in riparian zones (W1 km from rivers) and 14 houses in upland zones (>1

Donald R. Roberts; Sylvie Manguin; Eliska Rejmankova; Richard Andre; Ralph E. Harbach; Errol Vanzie; Shilpa Hakre; Jorge Polanco


Sex ratios in fetuses and liveborn infants with autosomal aneuploidy  

SciTech Connect

Ten data sources were used substantially to increase the available data for estimating fetal and livebirth sex ratios for Patau (trisomy 13), Edwards (trisomy 18), and Down (trisomy 21) syndromes and controls. The fetal sex ratio estimate was 0.88 (N = 584) for trisomy 13, 0.90 (N = 1702) for trisomy 18, and 1.16 (N = 3154) for trisomy 21. All were significantly different from prenatal controls (1.07). The estimated ratios in prenatal controls were 1.28 (N = 1409) for CVSs and 1.06 (N = 49427) for amniocenteses, indicating a clear differential selection against males, mostly during the first half of fetal development. By contrast, there were no sex ratio differences for any of the trisomies when comparing gestational ages <16 and >16 weeks. The livebirth sex ratio estimate was 0.90 (N = 293) for trisomy 13, 0.63 (N = 497) for trisomy 18, and 1.15 (N = 6424) for trisomy 21, the latter two being statistically different than controls (1.05) (N = 3660707). These ratios for trisomies 13 and 18 were also statistically different than the ratio for trisomy 21. Only in trisomy 18 did the sex ratios in fetuses and livebirths differ, indicating a prenatal selection against males >16 weeks. No effects of maternal age or race were found on these estimates for any of the fetal or livebirth trisomies. Sex ratios for translocations and mosaics were also estimated for these aneuploids. Compared to previous estimates, these results are less extreme, most likely because of larger sample sizes and less sample bias. They support the hypothesis that these trisomy sex ratios are skewed at conception, or become so during embryonic development through differential intrauterine selection. The estimate for Down syndrome livebirths is also consistent with the hypothesis that its higher sex ratio is associated with paternal nondisjunction. 36 refs., 5 tabs.

Heuther, C.A.; Martin, R.L.M.; Stoppelman, S.M. [Univ. of Cincinnati, OH (United States)] [and others



Body composition analysis: Cellular level modeling of body component ratios  

PubMed Central

During the past two decades, a major outgrowth of efforts by our research group at St. Luke’s-Roosevelt Hospital is the development of body composition models that include cellular level models, models based on body component ratios, total body potassium models, multi-component models, and resting energy expenditure-body composition models. This review summarizes these models with emphasis on component ratios that we believe are fundamental to understanding human body composition during growth and development and in response to disease and treatments. In-vivo measurements reveal that in healthy adults some component ratios show minimal variability and are relatively ‘stable’, for example total body water/fat-free mass and fat-free mass density. These ratios can be effectively applied for developing body composition methods. In contrast, other ratios, such as total body potassium/fat-free mass, are highly variable in vivo and therefore are less useful for developing body composition models. In order to understand the mechanisms governing the variability of these component ratios, we have developed eight cellular level ratio models and from them we derived simplified models that share as a major determining factor the ratio of extracellular to intracellular water ratio (E/I). The E/I value varies widely among adults. Model analysis reveals that the magnitude and variability of each body component ratio can be predicted by correlating the cellular level model with the E/I value. Our approach thus provides new insights into and improved understanding of body composition ratios in adults. PMID:21643542

Wang, Z.; Heymsfield, S.B.; Pi-Sunyer, F.X.; Gallagher, D.; Pierson, R.N.



Effect of specific heat ratio, impeller tip running clearance, and compressor insulation on high-pressure-ratio centrifugal compressor modeling  

Microsoft Academic Search

Results are displayed which show the effect of gas specific heat ratio, impeller tip running clearance, and compressor insulation on modeling of a high-pressure-ratio compressor's performance. The data were obtained using a low-speed-of-sound gas and a compressor previously tested extensively in air. Duplication of the air inlet specific heat ratio was found to be essential to modeling of the air-equivalent

J. A. Block; P. W. Runstadler Jr.



New Examination of the Traditional Raman Lidar Technique II: Temperature Dependence Aerosol Scattering Ratio and Water Vapor Mixing Ratio Equations  

NASA Technical Reports Server (NTRS)

In a companion paper, the temperature dependence of Raman scattering and its influence on the Raman water vapor signal and the lidar equations was examined. New forms of the lidar equation were developed to account for this temperature sensitivity. Here we use those results to derive the temperature dependent forms of the equations for the aerosol scattering ratio, aerosol backscatter coefficient, extinction to backscatter ratio and water vapor mixing ratio. Pertinent analysis examples are presented to illustrate each calculation.

Whiteman, David N.; Abshire, James B. (Technical Monitor)




E-print Network

AFGHANISTAN'S OTHER NEIGHBORS: IRAN, CENTRAL ASIA, AND CHINA CONFERENCE REPORT Organized.........................................................................................................................9 AFGHANISTAN AND CENTRAL ASIA ..........................................................................................9 Ethnicity and Culture: Afghanistan and Central Asia as Different Worlds

Spence, Harlan Ernest


Atmospheric inverse estimates of methane emissions from Central California  

NASA Astrophysics Data System (ADS)

Methane mixing ratios measured at a tall tower are compared to model predictions to estimate surface emissions of CH4 in Central California for October-December 2007 using an inverse technique. Predicted CH4 mixing ratios are calculated based on spatially resolved a priori CH4 emissions and simulated atmospheric trajectories. The atmospheric trajectories, along with surface footprints, are computed using the Weather Research and Forecast (WRF) coupled to the Stochastic Time-Inverted Lagrangian Transport (STILT) model. An uncertainty analysis is performed to provide quantitative uncertainties in estimated CH4 emissions. Three inverse model estimates of CH4 emissions are reported. First, linear regressions of modeled and measured CH4 mixing ratios obtain slopes of 0.73 ± 0.11 and 1.09 ± 0.14 using California-specific and Edgar 3.2 emission maps, respectively, suggesting that actual CH4 emissions were about 37 ± 21% higher than California-specific inventory estimates. Second, a Bayesian "source" analysis suggests that livestock emissions are 63 ± 22% higher than the a priori estimates. Third, a Bayesian "region" analysis is carried out for CH4 emissions from 13 subregions, which shows that inventory CH4 emissions from the Central Valley are underestimated and uncertainties in CH4 emissions are reduced for subregions near the tower site, yielding best estimates of flux from those regions consistent with "source" analysis results. The uncertainty reductions for regions near the tower indicate that a regional network of measurements will be necessary to provide accurate estimates of surface CH4 emissions for multiple regions.

Zhao, Chuanfeng; Andrews, Arlyn E.; Bianco, Laura; Eluszkiewicz, Janusz; Hirsch, Adam; MacDonald, Clinton; Nehrkorn, Thomas; Fischer, Marc L.



Distribution of Potential Hydrothermally Altered Rocks in Central Colorado Derived From Landsat Thematic Mapper Data: A Geographic Information System Data Set  

USGS Publications Warehouse

As part of the Central Colorado Mineral Resource Assessment Project, the digital image data for four Landsat Thematic Mapper scenes covering central Colorado between Wyoming and New Mexico were acquired and band ratios were calculated after masking pixels dominated by vegetation, snow, and terrain shadows. Ratio values were visually enhanced by contrast stretching, revealing only those areas with strong responses (high ratio values). A color-ratio composite mosaic was prepared for the four scenes so that the distribution of potentially hydrothermally altered rocks could be visually evaluated. To provide a more useful input to a Geographic Information System-based mineral resource assessment, the information contained in the color-ratio composite raster image mosaic was converted to vector-based polygons after thresholding to isolate the strongest ratio responses and spatial filtering to reduce vector complexity and isolate the largest occurrences of potentially hydrothermally altered rocks.

Knepper, Daniel H., Jr.



Combination of carbon isotope ratio with hydrogen isotope ratio determinations in sports drug testing.  


Carbon isotope ratio (CIR) analysis has been routinely and successfully applied to doping control analysis for many years to uncover the misuse of endogenous steroids such as testosterone. Over the years, several challenges and limitations of this approach became apparent, e.g., the influence of inadequate chromatographic separation on CIR values or the emergence of steroid preparations comprising identical CIRs as endogenous steroids. While the latter has been addressed recently by the implementation of hydrogen isotope ratios (HIR), an improved sample preparation for CIR avoiding co-eluting compounds is presented herein together with newly established reference values of those endogenous steroids being relevant for doping controls. From the fraction of glucuronidated steroids 5?-pregnane-3?,20?-diol, 5?-androst-16-en-3?-ol, 3?-Hydroxy-5?-androstane-11,17-dione, 3?-hydroxy-5?-androstan-17-one (ANDRO), 3?-hydroxy-5?-androstan-17-one (ETIO), 3?-hydroxy-androst-5-en-17-one (DHEA), 5?- and 5?-androstane-3?,17?-diol (5aDIOL and 5bDIOL), 17?-hydroxy-androst-4-en-3-one and 17?-hydroxy-androst-4-en-3-one were included. In addition, sulfate conjugates of ANDRO, ETIO, DHEA, 3?-hydroxy-5?-androstan-17-one plus 17?- and androst-5-ene-3?,17?-diol were considered and analyzed after acidic solvolysis. The results obtained for the reference population encompassing n = 67 males and females confirmed earlier findings regarding factors influencing endogenous CIR. Variations in sample preparation influenced CIR measurements especially for 5aDIOL and 5bDIOL, the most valuable steroidal analytes for the detection of testosterone misuse. Earlier investigations on the HIR of the same reference population enabled the evaluation of combined measurements of CIR and HIR and its usefulness regarding both steroid metabolism studies and doping control analysis. The combination of both stable isotopes would allow for lower reference limits providing the same statistical power and certainty to distinguish between the endo- or exogenous origin of a urinary steroid. PMID:23568614

Piper, Thomas; Emery, Caroline; Thomas, Andreas; Saugy, Martial; Thevis, Mario



Construct validity of a diagnostic ratio measure of gender stereotypes  

Microsoft Academic Search

We examined the construct validity of C. L. Martin's [(1987), “A Ratio Measure of Sex Stereotyping,” Journal of Personality and Social Psychology, Vol. 52, pp. 489–499] diagnostic ratio method for measuring consensual gender stereotypes and individual differences in gender stereotyping. This method is based on estimates that respondents make for percentages of men and women that possess gender stereotypic personality

Albert A. Cota; Anne Reid; Kenneth L. Dion



Sex ratio and Wolbachia infection in the ant Formica exsecta  

E-print Network

Sex ratio and Wolbachia infection in the ant Formica exsecta LAURENT KELLER* , CATHY LIAUTARD , MAX, Division of Population Biology, PO Box 17, FIN-00014 Helsinki, Finland Sex allocation data in social Hymenoptera provide some of the best tests of kin selection, parent± ospring con¯ict and sex ratio theories

Alvarez, Nadir


Strehl ratio with low sensitivity to spherical aberration  

Microsoft Academic Search

The influence that Seidel spherical aberration has on the irradiance distribution along the optical axis, or the Strehl ratio versus defocus, is expressed in terms of a differential operator. This permits to describe separately the following two effects: a focal shift and a shape variations. The authors analyze two annular apodizers that reduce the shape variation of the Strehl ratio

J. Ojeda-Castañeda; P. Andrés; A. Díaz



The Ratio of Public Investment in Education in China  

ERIC Educational Resources Information Center

Based on cross-section data worldwide and time series data in China, the essay is intended to make an analysis of the factors which have impacts on the ratio of public investment in education by using econometric models and then the future ratio may be predicted. Conclusions are as follows. First, the proportion of fiscal revenue to GDP (gross…

Liu, Zeyun; Yuan, Liansheng



Adaptive air\\/fuel ratio controller for internal combustion engine  

Microsoft Academic Search

An air\\/fuel ratio controller for an internal combustion engine including two memories each having numbers stored at locations addressed by engine operating points with the locations addressed by the engine operating points being updated during closed loop operation in accord with the value of a closed loop adjustment of the air\\/fuel ratio. Each memory location in the first memory is

A. F. Chiesa; D. G. Evans; J. R. Norford; J. A. Zahorchak



A theoretically based determination of bowen-ratio fetch requirements  

USGS Publications Warehouse

Determination of fetch requirements for accurate Bowen-ratio measurements of latent- and sensible-heat fluxes is more involved than for eddy-correlation measurements because Bowen-ratio sensors are located at two heights, rather than just one. A simple solution to the diffusion equation is used to derive an expression for Bowen-ratio fetch requirements, downwind of a step change in surface fluxes. These requirements are then compared to eddy-correlation fetch requirements based on the same diffusion equation solution. When the eddy-correlation and upper Bowen-ratio sensor heights are equal, and the available energy upwind and downwind of the step change is constant, the Bowen-ratio method requires less fetch than does eddy correlation. Differences in fetch requirements between the two methods are greatest over relatively smooth surfaces. Bowen-ratio fetch can be reduced significantly by lowering the lower sensor, as well as the upper sensor. The Bowen-ratio fetch model was tested using data from a field experiment where multiple Bowen-ratio systems were deployed simultaneously at various fetches and heights above a field of bermudagrass. Initial comparisons were poor, but improved greatly when the model was modified (and operated numerically) to account for the large roughness of the upwind cotton field.

Stannard, D.I.



Fixed- and Variable-Ratio Reinforcement of Reading Performance.  

ERIC Educational Resources Information Center

The effects of fixed-ratio and variable-ratio reinforcement classroom reading performance was investigated. Subjects were 50 boys and 50 girls from four grade-2 classrooms of one elementary school. The subjects were divided into three reading levels, above-average, average, and below-average, and were randomly assigned to (1) a no-reinforcement…

George, John E.


Riparian Sediment Delivery Ratio: Stiff Diagrams and Artifical Neural Networks  

EPA Science Inventory

Various methods are used to estimate sediment transport through riparian buffers and grass jilters with the sediment delivery ratio having been the most widely applied. The U.S. Forest Service developed a sediment delivery ratio using the stiff diagram and a logistic curve to int...


Muonic K beta \\/ K alpha ratios from pure elements  

Microsoft Academic Search

K beta \\/ beta alpha ratios of muonic X-ray spectra from 28 pure elements have been measured with Ge detectors. The correlation of these ratios with properties of the target material and positron life-times is analyzed with statistical correlation theory.

R. Bergmann; H. Daniel; T. von Egidy; F. J. Hartmann; J. J. Reidy; W. Wilhelm



Anisotropic polyurethane foam with Poisson's ratio greater than 1  

E-print Network

Anisotropic polyurethane foam with Poisson's ratio greater than 1 Lee, T. and Lakes, R. S., "Anisotropic polyurethane foam with Poisson's ratio greater than 1", Journal of Materials Science , 32, 2397-cell polyurethane foam, heating above the softening point, followed by cooling under axial strain. 1. Introduction

Lakes, Roderic


Solar flare alpha to proton ratio changes following interplanetary disturbances  

Microsoft Academic Search

A discussion is presented on the half hour averaged low energy solar alpha to solar proton flux ratios observed following the three large solar flares of May 23, 1967. One of the large changes observed in the particle ratios (following a sudden commencement (SC) storm observed on the earth) is interpreted as due to a source effect. The second large

L. J. Lanzerotti; M. F. Robbins



Liquefied strength ratio from liquefaction flow failure case histories  

Microsoft Academic Search

The shear strength of liquefied soil, su(LIQ), mobilized during a liquefaction flow failure is normalized with re- spect to the vertical effective stress ( ? vo ' ) prior to failure to evaluate the liquefied strength ratio, su(LIQ)\\/? vo ' . Liquefied strength r