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Sample records for abundant igg4-positive plasma

  1. Refractory gastric ulcer with abundant IgG4-positive plasma cell infiltration: A case report

    Institute of Scientific and Technical Information of China (English)

    Takayoshi; Fujita; Takafumi; Ando; Masatoshi; Sakakibara; Waki; Hosoda; Hidemi; Goto

    2010-01-01

    We describe a 77-year-old man with refractory gastric ulcer that worsened after Helicobacter pylori eradication therapy.Pathology showed marked infiltration of IgG4-positive plasma cells in the gastric lesions,which led us to suspect IgG4-related sclerosing disease.To the best of our knowledge,this is the first report of IgG4-related gastric ulcer without the main manifestation of autoimmune pancreatitis.

  2. Autoimmune pancreatitis metachronously associated with retroperitoneal fibrosis with IgG4-positive plasma cell infiltration

    Institute of Scientific and Technical Information of China (English)

    Terumi Kamisawa; Pong Yui Chen; Yuyang Tu; Hitoshi Nakajima; Naoto Egawa

    2006-01-01

    Retroperitoneal fibrosis is an uncommon disorder characterized by the formation of a dense plaque of fibrous tissue in the retroperitoneum, and its etiology remains unknown. Autoimmune pancreatitis is a rare type of chronic pancreatitis characterized by fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis in the pancreas. We present a case of autoimmune pancreatitis that developed 10 mo after the occurrence of retroperitoneal fibrosis. Histological findings of the resected retroperitoneal mass were marked periureteral fibrosis with abundant infiltration of IgG4-positive plasma cells and lymphocytes and obliterative phlebitis.These findings suggest a common pathophysiological mechanism for retroperitoneal fibrosis and autoimmune pancreatitis in this case. Some cases of retroperitoneal fibrosis might be a retroperitoneal lesion of IgG4-related sclerosing disease.

  3. Oral lichen sclerosus expressing extracellular matrix proteins and IgG4-positive plasma cells.

    Science.gov (United States)

    De Aquino Xavier, Flavia Calo; Prates, Alisio Alves; Gurgel, Clarissa Araujo; De Souza, Tulio Geraldo; Andrade, Rodrigo Guimaraes; Goncalves Ramos, Eduardo Antonio; Pedreira Ramalho, Luciana Maria; Dos Santos, Jean Nunes

    2014-09-16

    Lichen sclerosus (LS) is a mucocutaneous disease with uncommon oral involvement. The etiology is not yet well understood, but LS has been associated with autoimmune, genetic, and immunological factors. We report a 47-year-old man with LS that exhibited an asymptomatic white plaque with red patches on the maxillary alveolar mucosa extending to the labial mucosa. He had no other skin disease. Positive immunostaining for tenascin and scarcity of fibronectin suggested extracellular matrix reorganization. Elastin immunostaining indicated a reduction of elastic fibers. Immunoexpression of collagen IV in blood vessels and its absence in the epithelial basement membrane, together with diffuse MMP-9 immunoexpression, suggested altered proteolytic activity. Mast cell staining bordering areas of sclerosis indicated a possible role in the synthesis of collagen. IgG4 positivity in plasma cells suggested a role in the fibrogenesis. This is an unusual presentation of oral LS and we discuss immunohistochemical findings regarding cellular and extracellular matrix components.

  4. Cronkhite-Canada syndrome polyps infiltrated with IgG4-positive plasma cells.

    Science.gov (United States)

    Fan, Ru-Ying; Wang, Xiao-Wei; Xue, Li-Jun; An, Ran; Sheng, Jian-Qiu

    2016-08-16

    Cronkhite-Canada syndrome (CCS) is a rare but serious protein-losing enteropathy, but little is known about the mechanism. Further more, misdiagnosis is common due to non-familiarity of its clinical manifestation. A 40-year-old male patient was admitted to our hospital because of diarrhea and hypogeusia associated with weight loss for 4 mo. On physical examination, skin pigmentation, dystrophic nail changes and alopecia were noted. He had no alike family history. Laboratory results revealed low levels of serum albumin (30.1 g/L, range: 35.0-55.0 g/L), serum potassium (2.61 mmol/L, range: 3.5-5.5 mmol/L) and blood glucose (2.6 mmol/L, range: 3.9-6.1 mmol/L). The erythrocyte sedimentation rate was elevated to 17 mm/h (range: 0-15 mm/h). X-ray of chest and mandible was normal. The endoscopic examination showed multiple sessile polyps in the stomach, small bowel and colorectum. Histopathologic examination of biopsies obtained from those polyps showed hyperplastic change, cystic dilatation and distortion of glands with inflammatory infiltration, eosinophilic predominance and stromal edema. Immune staining for IgG4 plasma cells was positive in polyps of stomach and colon. The patient was diagnosed of CCS and treated with steroid, he had a good response to steroid. Both histologic findings and treatment response to steroid suggested an autoimmune mechanism underling CCS. PMID:27574615

  5. Autoimmune pancreatitis with IgG4-positive plasma cell infiltration in salivary glands and biliary tract

    Institute of Scientific and Technical Information of China (English)

    Masashi Taguchi; Gentaro Aridome; Shintaro Abe; Keiichiro Kume; Mitsuo Tashiro; Mitsuyoshi Yamamoto; Yasuyuki Kihara; Hayato Nakamura; Makoto Otsuki

    2005-01-01

    A 62-year-old male was referred to our hospital because of liver dysfunction, diffuse pancreatic swelling, and trachelophyma. At admission, the patient was free of pain.Physical examination showed enlarged and palpable bilateral submandibular masses, but no palpable mass or organomegaly in the abdomen. Laboratory findings were as follows: total protein 90 g/L with γ-globulin of 37.3% (33 g/L), total bilirubin 4 mg/L, aspartate aminotransferase 39 IU/L, alanine aminotransferase 67 IU/L, γ-glutamyl transpeptidase 1 647 IU/L, and amylase 135 IU/L. Autoantibodies were negative, and tumor markers were within the normal range. Serum IgG4 level was markedly elevated (18 900 mg/L). Computed tomography (CT) showed diffuse swelling of the pancreas and dilatation of both common and intra-hepatic bile ducts. Endoscopic retrograde pancreatography (ERP) revealed diffuse irregular and narrow main pancreatic duct and stenosis of the lower common bile duct. Biopsy specimens from the pancreas, salivary gland and liver showed marked periductal IgG4-positive plasma cell infiltration with fibrosis. We considered this patient to be autoimmune pancreatitis (AIP) with fibrosclerosis of the salivary gland and biliary tract, prescribed prednisolone at an initial dose of 40 mg/d. Three months later, the laboratory data improved almost to normal. Abdominal CT reflected prominent improvement in the pancreatic lesion. Swelling of the salivary gland also improved. At present, the patient is on 10 mg/d of prednisolone without recurrence of the pancreatitis. We present here a case of AIP with fibrosclerosis of salivary gland and biliary tract.

  6. Hepatic nodular lymphoid lesion with increased IgG4-positive plasma cells associated with primary biliary cirrhosis: a report of two cases.

    Science.gov (United States)

    Calvo, Jessica; Carbonell, Nicolas; Scatton, Olivier; Marzac, Christophe; Ganne-Carrie, Nathalie; Wendum, Dominique

    2015-11-01

    The nodular lymphoid lesion of the liver known as reactive lymphoid hyperplasia or pseudolymphoma is rare and its pathogenesis is unknown. We report two cases of nodular lymphoid lesions of the liver with numerous IgG4-positive plasma cells in patients with primary biliary cirrhosis. Histologically, in both cases, the lesion showed a dense lymphoplasmacytic infiltrate with lymphoid follicles and granulomas. Fibrous tissue was scarce and without a storiform pattern. Obliterative phlebitis was not identified. The IgG4+ plasma cell counts were 82 and 76 per high power field, with an IgG4/IgG ratio of 75 and 64 %, respectively, which qualifies the lesions according to the diagnostic criteria for IgG4-related disease as « probable histological feature of IgG4-related disease ». There were no rearrangements of immunoglobulin heavy-chain genes and plasma cells had a polytypic pattern of kappa and lambda light-chain expression. The non-tumor liver showed primary biliary cirrhosis with destructive cholangitis without IgG4 plasma cells. In both cases, IgG4-related disease was not found in other organs neither at the time of diagnosis nor 3 years later. Serum IgG4 levels normalized after local ablation of the lesions. It seems unlikely that these lesions are a manifestation of IgG4-related disease. However, because the pathogenesis of both nodular lymphoid lesions and IgG4-related disease remains unclear, further studies are needed to elucidate a potential link between nodular lymphoid lesions of the liver and an increased number of IgG4 plasma cells. More definite conclusions will be possible when the pathogenesis of IgG4-related disease has been clarified.

  7. A high number of IgG4-positive cells in gastric cancer tissue is associated with tumor progression and poor prognosis.

    Science.gov (United States)

    Miyatani, Kozo; Saito, Hiroaki; Murakami, Yuki; Watanabe, Joji; Kuroda, Hirohiko; Matsunaga, Tomoyuki; Fukumoto, Yoji; Osaki, Tomohiro; Nakayama, Yuji; Umekita, Yoshihisa; Ikeguchi, Masahide

    2016-05-01

    IgG4-related disease is a newly defined disease characterized by elevated serum IgG4 levels and infiltration of affected organs by IgG4-positive plasma cells. Recently, increased IgG4 levels were reported to be closely related with malignancy. To assess the relationship between IgG4 and the progression of gastric cancer, we immunohistochemically stained in this study gastric cancer tissue samples for IgG4-positive cells using an anti-IgG4 antibody. In addition, pre- and postoperative serum concentrations of IgG4 were measured, using an enzyme-linked immunosorbent assay. In gastric cancer samples, the number of CD138-positive plasma cells was significantly lower and the number of IgG4-positive cells significantly higher than in non-cancerous gastric mucosa. The number of IgG4-positive cells was significantly correlated with gross tumor appearance, tumor depth, lymph node metastasis, venous invasion, and lymphatic invasion. Prognosis was significantly poorer in patients with a high number of IgG4-positive cells than in those with a low number. Multivariate analysis indicated that both the number of IgG4-positive cells and the depth of tumor invasion were independently prognostic of survival. In conclusion, in gastric cancer, the number of IgG4-positive cells is increased and this is closely associated with gastric cancer progression.

  8. Chemical Fractionation and Abundances in Coronal Plasma

    CERN Document Server

    Drake, J J

    2003-01-01

    Much of modern astrophysics is grounded on the observed chemical compositions of stars and the diffuse plasma that pervades the space between stars, galaxies and clusters of galaxies. X-ray and EUV spectra of the hot plasma in the outer atmospheres of stars have demonstrated that these environments are subject to chemical fractionation in which the abundances of elements can be enhanced and depleted by an order of magnitude or more. These coronal abundance anomalies are discussed and some of the physical mechanisms that might be responsible for producing them are examined. It is argued that coronal abundances can provide important new diagnostics on physical processes at work in solar and stellar coronae. It seems likely that other hot astrophysical plasmas will be subject to similar effects.

  9. Method for measuring the heavy stripped ion abundances of plasma

    International Nuclear Information System (INIS)

    A description is given of a system which uses a velocity filter and an energy filter in tandem to analyze the abundances and energy spreads of highly stripped ions. The system can also serve as a plasma diagnostic. (Auth.)

  10. Elemental abundances of flaring solar plasma - Enhanced neon and sulfur

    Science.gov (United States)

    Schmelz, J. T.

    1993-01-01

    Elemental abundances of two flares observed with the SMM Flat Crystal Spectrometer are compared and contrasted. The first had a gradual rise and a slow decay, while the second was much more impulsive. Simultaneous spectra of seven bright soft X-ray resonance lines provide information over a broad temperature range and are available throughout both flares, making these events unique in the SMM data base. For the first flare, the plasma seemed to be characterized by coronal abundances but, for the second, the plasma composition could not be coronal, photospheric, or a linear combination of both. A good differential emission measure fit required enhanced neon such that Ne/O = 0.32 +/- 0.02, a value which is inconsistent with the current models of coronal abundances based on the elemental first-ionization potential. Similar values of enhanced neon are found for flaring plasma observed by the SMM gamma-ray spectrometer, in (He-3)-rich solar energetic particle events, and in the decay phase of several long duration soft X-ray events. Sulfur is also enhanced in the impulsive flare, but not as dramatically as neon. These events are compared with two models which attempt to explain the enhanced values of neon and sulfur.

  11. Depletion of abundant plasma proteins by poly(N-isopropylacrylamide-acrylic acid) hydrogel particles

    DEFF Research Database (Denmark)

    Such-Sanmartín, Gerard; Ventura-Espejo, Estela; Jensen, Ole N

    2014-01-01

    the application of pH-sensitive poly(N-isopropylacrylamide-acrylic acid) hydrogel particles for removal of abundant plasma proteins, prior to proteome analysis by MS. Protein depletion occurs by two separate mechanisms: (1) hydrogel particles incubated with low concentrations of plasma capture abundant proteins...... at higher efficiency than low abundance proteins, which are enriched in the supernatants, whereas (2) hydrogel particles incubated with high concentrations of plasma capture and irreversibly trap abundant proteins. During the elution step, irreversibly trapped proteins remain captured while low abundance...... (SRM) liquid chromatography (LC)-MS/MS. This novel use of hydrogel particles opens new perspectives for biomarker analysis based on mass spectrometry....

  12. Do chemically saturated antihyperon abundancies signal the quark gluon plasma?

    CERN Document Server

    Greiner, C

    2000-01-01

    We first review the production and the possible chemical equilibration of strange particles at CERN-SPS energies within a microscopic hadronic transport calculation. It is shown in particular that the strange quarks are produced initially via string excitations in the primary, secondary and ternary interactions. We then further elaborate on a recent idea of antihyperon production by multi-mesonic reactions like $n_1\\pi + n_2 K \\to \\bar{Y}+p $ corresponding to the inverse of the strong binary baryon-antibaryon annihilation process. It is argued that by these reactions the (rare) antihyperons are driven towards local chemical equilibrium with pions, nucleons and kaons on a timescale of 1--3 fm/c in the still moderately baryon-dense initial hadronic environment after the termination of the prehadronic string phase. Accordingly this mechanism can provide a convenient explanation for the antihyperon yields at CERN-SPS energies without any need of a deconfined quark gluon plasma phase.

  13. Measurement of the isotopic abundance of boron-10 by inductively coupled plasma-quadrupole mass spectrometry

    International Nuclear Information System (INIS)

    This article describes the method for measuring the isotopic abundance of 10B in nuclear grade boron carbide using inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS). The results of investigation revealed that both the integration time and the dwell time have a major influence on the reproducibility of ICP-QMS measurements. As a result of optimization of the measurement conditions, reproducibility below 0.2% relative standard deviation (RSD) (0.17% RSD maximum) was achieved. In addition, the measured value of the isotopic abundance of 10B for each sample well agreed with the values measured by the TIMS. Thus, the method described in the present investigation was very effective in the analysis of isotopic abundance of 10B in B4C or H3BO3. The results of this study suggest that ICP-QMS could be applied to the precise analysis of the isotopic abundance of 10B required in the field of nuclear applications. (author)

  14. Deriving Plasma Densities and Elemental Abundances from SERTS Differential Emission Measure Analysis

    Science.gov (United States)

    Schmelz, J. T.; Kimble, J. A.; Saba, J. L. R.

    2012-01-01

    We use high-resolution spectral emission line data obtained by the SERTS instrument during three rocket flights to demonstrate a new approach for constraining electron densities of solar active region plasma.We apply differential emission measure (DEM) forward-fitting techniques to characterize the multithermal solar plasma producing the observed EUV spectra, with constraints on the high-temperature plasma from the Yohkoh Soft X-ray Telescope. In this iterative process, we compare line intensities predicted by an input source distribution to observed line intensities for multiple iron ion species, and search a broad range of densities to optimize chi-square simultaneously for the many available density-sensitive lines. This produces a density weighted by the DEM, which appears to be useful for characterizing the bulk of the emitting plasma over a significant range of temperature. This "DEM-weighted density" technique is complementary to the use of density-sensitive line ratios and less affected by uncertainties in atomic data and ionization fraction for any specific line. Once the DEM shape and the DEM-weighted density have been established from the iron lines, the relative elemental abundances can be determined for other lines in the spectrum. We have also identified spectral lines in the SERTS wavelength range that may be problematic

  15. Modelling of NO destruction in a low-pressure reactor by an Ar plasma jet: species abundances in the reactor

    Science.gov (United States)

    Kutasi, Kinga

    2011-03-01

    The destruction of NO molecules by an Ar plasma jet in a low-pressure (0.2 Torr) reactor is investigated by means of a 3D hydrodynamic model. The density distribution of species created through molecular kinetics triggered by the collision of Ar+ with NO is calculated, showing that in the case of the most abundant species a quasi-homogeneous density distribution builds up in a large part of the reactor. The conversion of NO into stable O2 and N2 molecules is followed under different plasma jet conditions and NO gas flows, and the effect of N2 addition on NO destruction is studied. It is shown that in the present system the reproduction of NO molecules on the surface through surface-assisted recombination of N and O atoms becomes impossible due to the fast disappearance of N atoms in the jet's inlet vicinity.

  16. What are the Sources of Solar Energetic Particles? Element Abundances and Source Plasma Temperatures

    CERN Document Server

    Reames, Donald V

    2015-01-01

    We have spent 50 years in heated discussion over which populations of solar energetic particles (SEPs) are accelerated at flares and which by shock waves driven out from the Sun by coronal mass ejections (CMEs). The association of the large "gradual" SEP events with shock acceleration is supported by the extensive spatial distribution of SEPs and by the delayed acceleration of the particles. The relative abundances of the elements in these gradual events are a measure of those in the ambient solar corona, differing from those in the photosphere by a widely-observed function of the first ionization potential (FIP) of the elements. SEP events we call "impulsive", the traditional "3He-rich" events with enhanced heavy-element abundances, are associated with type III radio bursts, flares, and narrow CMEs; they selectively populate flux tubes that thread a localized source, and they are fit to new particle-in-cell models of magnetic reconnection on open field lines as found in solar jets. These models help explain ...

  17. NKCC1 and NHE1 are abundantly expressed in the basolateral plasma membrane of secretory coil cells in rat, mouse, and human sweat glands

    DEFF Research Database (Denmark)

    Nejsum, Lene Niemann; Prætorius, Jeppe; Nielsen, Søren

    2005-01-01

    1 (NHE1) protein has been localized to both the duct and secretory coil of human sweat duct; however, the NHE1 abundance in the duct was not compared with that in the secretory coil. The aim of this study was to test whether mRNA encoding NKCC1, NKCC2, and Na(+)-coupled acid-base transporters...... palmar skin by immunoblotting, whereas NKCC2, NHE2, and NHE3 proteins were not detected. Immunohistochemistry was performed using sections from rat, mouse, and human palmar tissue. Immunoperoxidase labeling revealed abundant expression of NKCC1 and NHE1 in the basolateral domain of secretory coils of rat......, mouse, and human sweat glands and low expression was found in the coiled part of the ducts. In contrast, NKCC1 and NHE1 labeling was absent from rat, mouse, and human epidermis. Immunoelectron microscopy demonstrated abundant NKCC1 and NHE1 labeling of the basolateral plasma membrane of mouse sweat...

  18. Detection and quantitation of twenty-seven cytokines, chemokines and growth factors pre- and post-high abundance protein depletion in human plasma

    Directory of Open Access Journals (Sweden)

    Seong-Beom Ahn

    2014-06-01

    Full Text Available Cytokines, chemokines and growth factors (CCGFs in human plasma are analyzed for identification of biomarkers. However concentrations of CCGFs are very low; it is difficult to identify and quantify low abundance proteins in the presence of the high abundance proteins (HAPs unless HAPs are removed prior to analysis. However, there is a concern that the low abundance proteins such as CCGFs may also be removed during the HAP depletion process. In this study, we have examined whether or not depletion of the HAPs enhances detection of the CCGFs by immuno-assays. Top 14 HAPs were depleted from 10 healthy volunteers’ plasma using MARS-14 immuno-depletion column and a total of 27 CCGFs were analyzed by bead-based multiplexed immuno-assay. All 27 CCGFs were detected in neat plasma (NP, 25 were detected in flow through fraction (FT and 21 were detected in bound protein (BP fraction. Concentrations of 22 CCGFs were significantly higher in NP compared to FT and BP. Only one CCGF had higher concentration in FT compared to NP. The remaining 2 CCGFs were not different between NP and FT. It was counter-productive for the detection of 24 CCGFs after HAP removal, primarily due to post-depletion protein precipitation and/or re-suspension of pellets.

  19. Rapid Upregulation of Orai1 Abundance in the Plasma Membrane of Platelets Following Activation with Thrombin and Collagen Related Peptide

    Directory of Open Access Journals (Sweden)

    Guilai Liu

    2015-11-01

    Full Text Available Background: Blood platelets accomplish primary hemostasis following vascular injury and contribute to the orchestration of occlusive vascular disease. Platelets are activated by an increase of cytosolic Ca2+-activity ([Ca2+]i, which is accomplished by Ca2+-release from intracellular stores and subsequent store operated Ca2+ entry (SOCE through Ca2+ release activated Ca2+ channel moiety Orai1. Powerful activators of platelets include thrombin and collagen related peptide (CRP, which are in part effective by activation of small G- protein Rac1. The present study explored the influence of thrombin and CRP on Orai1 protein abundance and cytosolic Ca2+-activity ([Ca2+]i in platelets drawn from wild type mice. Methods: Orai1 protein surface abundance was quantified utilizing CF™488A conjugated antibodies, and [Ca2+]i was determined with Fluo3-fluorescence. Results: In resting platelets, Orai1 protein abundance and [Ca2+]i were low. Thrombin (0.02 U/ml and CRP (5ug/ml within 2 min increased [Ca2+]i and Orai1 protein abundance at the platelet surface. [Ca2+]i was further increased by Ca2+ ionophore ionomycin (1 µM and by store depletion with the sarcoendoplasmatic Ca2+ ATPase inhibitor thapsigargin (1 µM. However, Orai1 protein abundance at the platelet surface was not significantly affected by ionomycin and only slightly increased by thapsigargin. The effect of thrombin and CRP on Orai1 abundance and [Ca2+]i was significantly blunted by Rac1 inhibitor NSC23766 (50 µM. Conclusion: The increase of [Ca2+]i following stimulation of platelets with thrombin and collagen related peptide is potentiated by ultrarapid Rac1 sensitive translocation of Orai1 into the cell membrane.

  20. Standard test method for isotopic abundance analysis of uranium hexafluoride and uranyl nitrate solutions by multi-collector, inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2014-01-01

    1.1 This test method covers the isotopic abundance analysis of 234U, 235U, 236U and 238U in samples of hydrolysed uranium hexafluoride (UF6) by inductively coupled plasma source, multicollector, mass spectrometry (ICP-MC-MS). The method applies to material with 235U abundance in the range of 0.2 to 6 % mass. This test method is also described in ASTM STP 1344. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  1. Introduction of enteral food increases plasma GLP-2 and decreases GLP-2 receptor mRNA abundance during pig development

    DEFF Research Database (Denmark)

    Petersen, Yvette M; Hartmann, Bolette; Holst, Jens Juul;

    2003-01-01

    in these pigs. We conclude that the introduction of enteral feeding transiently increases plasma GLP-2 concentrations and decreases small intestinal GLP-2R mRNA levels during pig development. GLP-2 may play a role in the growth of the small intestine around birth and weaning via a response to enteral nutrition....... transcription polymerase chain reaction) during pre- and postnatal development and the relationship between these variables and small intestinal growth in enterally and parenterally fed fetal and newborn pigs (premature and term-delivered, 92 and 100% gestation, respectively). Plasma GLP-2 concentrations...... increased before birth, peaked in suckling 1-d-old pigs (87 +/- 14 pmol/L, P enteral infusion...

  2. Determinations of rare earth element abundance and U-Pb age of zircons using multispot laser ablation-inductively coupled plasma mass spectrometry.

    Science.gov (United States)

    Yokoyama, Takaomi D; Suzuki, Toshihiro; Kon, Yoshiaki; Hirata, Takafumi

    2011-12-01

    We have developed a new calibration technique for multielement determination and U-Pb dating of zircon samples using laser ablation-inductively coupled plasma mass spectrometry (ICPMS) coupled with galvanometric optics. With the galvanometric optics, laser ablation of two or more sample materials could be achieved in very short time intervals (~10 ms). The resulting sample aerosols released from different ablation pits or different solid samples were mixed and homogenized within the sample cell and then transported into the ICP ion source. Multiple spot laser ablation enables spiking of analytes or internal standard elements directly into the solid samples, and therefore the standard addition calibration method can be applied for the determination of trace elements in solid samples. In this study, we have measured the rare earth element (REE) abundances of two zircon samples (Nancy 91500 and Prešovice) based on the standard addition technique, using a direct spiking of analytes through a multispot laser ablation of the glass standard material (NIST SRM612). The resulting REE abundance data show good agreement with previously reported values within analytical uncertainties achieved in this study (10% for most elements). Our experiments demonstrated that nonspectroscopic interferences on 14 REEs could be significantly reduced by the standard addition technique employed here. Another advantage of galvanometric devices is the accumulation of sample aerosol released from multiple spots. In this study we have measured the U-Pb age of a zircon sample (LMR) using an accumulation of sample aerosols released from 10 separate ablation pits of low diameters (~8 μm). The resulting (238)U-(206)Pb age data for the LMR zircons was 369 ± 64 Ma, which is in good agreement with previously reported age data (367.6 ± 1.5 Ma). (1) The data obtained here clearly demonstrate that the multiple spot laser ablation-ICPMS technique can become a powerful approach for elemental and isotopic

  3. Extensive determination of glycan heterogeneity reveals an unusual abundance of high mannose glycans in enriched plasma membranes of human embryonic stem cells.

    Science.gov (United States)

    An, Hyun Joo; Gip, Phung; Kim, Jaehan; Wu, Shuai; Park, Kun Wook; McVaugh, Cheryl T; Schaffer, David V; Bertozzi, Carolyn R; Lebrilla, Carlito B

    2012-04-01

    Most cell membrane proteins are known or predicted to be glycosylated in eukaryotic organisms, where surface glycans are essential in many biological processes including cell development and differentiation. Nonetheless, the glycosylation on cell membranes remains not well characterized because of the lack of sensitive analytical methods. This study introduces a technique for the rapid profiling and quantitation of N- and O-glycans on cell membranes using membrane enrichment and nanoflow liquid chromatography/mass spectrometry of native structures. Using this new method, the glycome analysis of cell membranes isolated from human embryonic stem cells and somatic cell lines was performed. Human embryonic stem cells were found to have high levels of high mannose glycans, which contrasts with IMR-90 fibroblasts and a human normal breast cell line, where complex glycans are by far the most abundant and high mannose glycans are minor components. O-Glycosylation affects relatively minor components of cell surfaces. To verify the quantitation and localization of glycans on the human embryonic stem cell membranes, flow cytometry and immunocytochemistry were performed. Proteomics analyses were also performed and confirmed enrichment of plasma membrane proteins with some contamination from endoplasmic reticulum and other membranes. These findings suggest that high mannose glycans are the major component of cell surface glycosylation with even terminal glucoses. High mannose glycans are not commonly presented on the surfaces of mammalian cells or in serum yet may play important roles in stem cell biology. The results also mean that distinguishing stem cells from other mammalian cells may be facilitated by the major difference in the glycosylation of the cell membrane. The deep structural analysis enabled by this new method will enable future mechanistic studies on the biological significance of high mannose glycans on stem cell membranes and provide a general tool to examine

  4. High-Resolution X-ray Spectroscopy of Hercules X-1 with the XMM-Newton RGS: CNO Element Abundance Measurements and Density Diagnostics of a Photoionized Plasma

    OpenAIRE

    Jimenez-Garate, M. A.; Hailey, C. J.; Herder, J. W. den; Zane, S.; Ramsay, G

    2002-01-01

    We analyze the high-resolution X-ray spectrum of Hercules X-1, an intermediate-mass X-ray binary, which was observed with the XMM-Newton Reflection Grating Spectrometer. We measure the elemental abundance ratios by use of spectral models, and we detect material processed through the CNO-cycle. The CNO abundances, and in particular the ratio N/O > 4.0 times solar, provide stringent constraints on the evolution of the binary system. The low and short-on flux states of Her X-1 exhibit narrow lin...

  5. A deep survey of heavy element lines in planetary nebulae -- II. Recombination line abundances and evidence for ultra-cold plasma

    CERN Document Server

    Tsamis, Y G; Liu, X W; Storey, P J; Danziger, I J

    2004-01-01

    [Abridged] Deep optical observations of the spectra of 12 Galactic planetary nebulae (PNe) and 3 Magellanic Cloud PNe were presented in Paper I by Tsamis et al. (2003b), who carried out an abundance analysis using the collisionally excited forbidden lines. Here, the relative intensities of faint optical recombination lines (ORLs) from ions of carbon, nitrogen and oxygen are analysed in order to derive the abundances of these ions relative to hydrogen. We define an abundance discrepancy factor (ADF) as the ratio of the abundance derived for a heavy element ion from its recombination lines to that derived for the same ion from its ultraviolet, optical or infrared collisionally excited lines (CELs). All of the PNe in our sample are found to have ADF's that exceed unity. There is no dependence of the magnitude of the ADF upon the excitation energy of the UV, optical or IR CEL transition used, indicating that classical nebular temperature fluctuations--i.e. in a chemically homogeneous medium--are not the cause of ...

  6. Pancreatic cancer with a high serum IgG4 concentration

    Institute of Scientific and Technical Information of China (English)

    Terumi Kamisawa; Pong Yui Chen; Yuyang Tu; Hitoshi Nakajima; Naoto Egawa; Kouji Tsuruta; Atsutake Okamoto; Tsunekazu Hishima

    2006-01-01

    Differentiation between autoimmune pancreatitis and pancreatic cancer is sometimes difficult. It has been reported that serum IgG4 concentrations are significantly elevated and particularly high (>135 mg/dL) in autoimmune pancreatitis. Measurement of serum IgG4 has become a useful tool for differentiating between autoimmune pancreatitis and pancreatic cancer. However,we present a 74-year-old female with a markedly elevated serum IgG4 (433 mg/dL) who underwentpancreaticoduodenectomy for pancreatic cancer. Elevated serum IgG4 levels continued after the resection. On histology, adenocarcinoma of the pancreas accompanied with moderate lymphoplasmacytic infiltration infiltrated the lower bile duct and duodenum, but there were no findings of autoimmune pancreatitis. Although a small metastasis was detected in one parapancreatic lymph node, regional lymph nodes were swollen. Abundant IgG4-positive plasma cells infiltrated the cancerous areas of the pancreas, but only a few IgG4-positive plasma cells were detected in the noncancerous areas.Pancreatic cancer cells were not immunoreactive for IgG4. An abundant infiltration of IgG4-positive plasma cells was detected in the swollen regional lymph nodes and in the duodenal mucosa. We believe that the serum IgG4 level was elevated in this patient with pancreatic cancer as the result of an IgG4-related systemic disease that had no clinical manifestations other than lymphadenopathy.

  7. Alpha-tocotrienol is the most abundant tocotrienol isomer circulated in plasma and lipoproteins after postprandial tocotrienol-rich vitamin E supplementation

    Directory of Open Access Journals (Sweden)

    Fairus Syed

    2012-01-01

    Full Text Available Abstract Background Tocotrienols (T3 and tocopherols (T, both members of the natural vitamin E family have unique biological functions in humans. T3 are detected in circulating human plasma and lipoproteins, although at concentrations significantly lower than α-tocopherol (α-T. T3, especially α-T3 is known to be neuropotective at nanomolar concentrations and this study evaluated the postprandial fate of T3 and α-T in plasma and lipoproteins. Methods Ten healthy volunteers (5 males and 5 females were administered a single dose of vitamin E [526 mg palm tocotrienol-rich fraction (TRF or 537 mg α-T] after 7-d pre-conditioning on a T3-free diet. Blood was sampled at baseline (fasted and 2, 4, 5, 6, 8, and 24 h after supplementation. Concentrations of T and T3 isomers in plasma, triacylglycerol-rich particles (TRP, LDL, and HDL were measured at each postprandial interval. Results After TRF supplementation, plasma α-T3 and γ-T3 peaked at 5 h (α-T3: 4.74 ± 1.69 μM; γ-T3: 2.73 ± 1.27 μM. δ-T3 peaked earlier at 4 h (0.53 ± 0.25 μM. In contrast, α-T peaked at 6 h (30.13 ± 2.91 μM and 8 h (37.80 ± 3.59 μM following supplementation with TRF and α-T, respectively. α-T was the major vitamin E isomer detected in plasma, TRP, LDL, and HDL even after supplementation with TRF (composed of 70% T3. No T3 were detected during fasted states. T3 are detected postprandially only after TRF supplementation and concentrations were significantly lower than α-T. Conclusions Bio-discrimination between vitamin E isomers in humans reduces the rate of T3 absorption and affects their incorporation into lipoproteins. Although low absorption of T3 into circulation may impact some of their physiological functions in humans, T3 have biological functions well below concentration noted in this study.

  8. High-Resolution X-ray Spectroscopy of Hercules X-1 with the XMM-Newton RGS CNO Element Abundance Measurements and Density Diagnostics of a Photoionized Plasma

    CERN Document Server

    Jiménez-Garate, M A; Den Herder, J W A; Zane, S; Ramsay, G

    2002-01-01

    We analyze the high-resolution X-ray spectrum of Hercules X-1, an intermediate-mass X-ray binary, which was observed with the XMM-Newton Reflection Grating Spectrometer. We measure the elemental abundance ratios by use of spectral models, and we detect material processed through the CNO-cycle. The CNO abundances, and in particular the ratio N/O > 4.0 times solar, provide stringent constraints on the evolution of the binary system. The low and short-on flux states of Her X-1 exhibit narrow line emission from C VI, N VI, N VII, O VII, O VIII, Ne IX, and Ne X ions. The spectra show signatures of photoionization. We measure the electron temperature, quantify photoexcitation in the He alpha lines, and set limits on the location and density of the gas. The recombination lines may originate in the accretion disk atmosphere and corona, or on the X-ray illuminated face of the mass donor (HZ Her). The spectral variation over the course of the 35 d period provides additional evidence for the precession of the disk. Duri...

  9. Genomic variants at the PINK1 locus are associated with transcript abundance and plasma nonesterified fatty acid concentrations in European whites

    DEFF Research Database (Denmark)

    Franks, P.W.; Scheele, C.; Loos, R.J.;

    2008-01-01

    .013] but not in nonobese (n=103) (OR=1.20; 95% CI: 0.82, 1.76; P=0.34) individuals. In the British cohort, several PINK1 SNPs were associated with plasma nonesterified fatty acid concentrations. Nominal genotype associations were also observed for fasting glucose, 2-h glucose, and maximal oxygen consumption, although...... these were not statistically significant after correcting for multiple testing. In primary adipocytes, Pink1 knockdown affected fatty acid binding protein 4 (Fabp4) expression, indicating that PINK1 may influence substrate metabolism. We demonstrate that PINK1 polymorphisms are associated with PINK1...

  10. Usefulness of biopsying the major duodenal papilla to diagnose autoimmune pancreatitis: A prospective study using TgG4-immunostaining

    Institute of Scientific and Technical Information of China (English)

    Terumi Kamisawa; Yuyang Tu; Hitoshi Nakajima; Naoto Egawa; Kouji Tsuruta; Atsutake Okamoto

    2006-01-01

    AIM: To examine the histological and immunohistochemical findings of biopsy specimens taken from the major duodenal papilla of autoirnrnune pancreatitis (AIP)patients.METHODS: The major duodenal papilla in the resected pancreas of 3 patients with AIP and of 5 control patients [pancreatic carcinoma (n = 3) and chronic alcoholic pancreatitis (n = 2)] was irnrnunostained using anti-CD4-T cell, CD8-T cell and IgG4 antibodies. Forceps biopsy specimens taken from the major duodenal papilla of 2patients with AIP and 5 control patients with suspected papillitis were prospectively taken during duodenoscopy and immunohistochernically examined.RESULTS: Moderate or severe lyrnphoplasrnacytic infiltration including many CD4-positive or CD8-positive T lymphocytes and IgG4-positive plasma cells (≥10/HPF),was observed in the major duodenal papilla of all 3 patients with AIP. The same findings were also detected in the biopsy specimens taken from the major duodenal papilla of 2 patients with AIP, but in controls, there were only a few (≤3/HPF) IgG4-positive plasma cells infiltrating the major duodenal papilla.CONCLUSIONS: An abundant infiltration of IgG4-positive plasma cells is specifically detected in the major duodenal papilla of patients with AIP. Although this is a preliminary study, IgG4-irnmunostaining of biopsy specimens taken from the major duodenal papilla may support the diagnosis of AIP.

  11. Nitrate transport in cucumber leaves is an inducible process involving an increase in plasma membrane H+-ATPase activity and abundance

    Directory of Open Access Journals (Sweden)

    Nikolic Miroslav

    2012-05-01

    Full Text Available Abstract Background The mechanisms by which nitrate is transported into the roots have been characterized both at physiological and molecular levels. It has been demonstrated that nitrate is taken up in an energy-dependent way by a four-component uptake machinery involving high- and low- affinity transport systems. In contrast very little is known about the physiology of nitrate transport towards different plant tissues and in particular at the leaf level. Results The mechanism of nitrate uptake in leaves of cucumber (Cucumis sativus L. cv. Chinese long plants was studied and compared with that of the root. Net nitrate uptake by roots of nitrate-depleted cucumber plants proved to be substrate-inducible and biphasic showing a saturable kinetics with a clear linear non saturable component at an anion concentration higher than 2 mM. Nitrate uptake by leaf discs of cucumber plants showed some similarities with that operating in the roots (e.g. electrogenic H+ dependence via involvement of proton pump, a certain degree of induction. However, it did not exhibit typical biphasic kinetics and was characterized by a higher Km with values out of the range usually recorded in roots of several different plant species. The quantity and activity of plasma membrane (PM H+-ATPase of the vesicles isolated from leaf tissues of nitrate-treated plants for 12 h (peak of nitrate foliar uptake rate increased with respect to that observed in the vesicles isolated from N-deprived control plants, thus suggesting an involvement of this enzyme in the leaf nitrate uptake process similar to that described in roots. Molecular analyses suggest the involvement of a specific isoform of PM H+-ATPase (CsHA1 and NRT2 transporter (CsNRT2 in root nitrate uptake. At the leaf level, nitrate treatment modulated the expression of CsHA2, highlighting a main putative role of this isogene in the process. Conclusions Obtained results provide for the first time evidence that a saturable

  12. Precision Chemical Abundance Measurements

    DEFF Research Database (Denmark)

    Yong, David; Grundahl, Frank; Meléndez, Jorge;

    2012-01-01

    This talk covers preliminary work in which we apply a strictly differential line-by-line chemical abundance analysis to high quality UVES spectra of the globular cluster NGC 6752. We achieve extremely high precision in the measurement of relative abundance ratios. Our results indicate that the ob......This talk covers preliminary work in which we apply a strictly differential line-by-line chemical abundance analysis to high quality UVES spectra of the globular cluster NGC 6752. We achieve extremely high precision in the measurement of relative abundance ratios. Our results indicate...... that the observed abundance dispersion exceeds the measurement uncertainties and that many pairs of elements show significant correlations when plotting [X1/H] vs. [X2/H]. Our tentative conclusions are that either NGC 6752 is not chemically homogeneous at the ~=0.03 dex level or the abundance variations...

  13. The Origin of Element Abundance Variations in Solar Energetic Particles

    Science.gov (United States)

    Reames, Donald V.

    2016-08-01

    Abundance enhancements, during acceleration and transport in both gradual and impulsive solar energetic particle (SEP) events, vary approximately as power laws in the mass-to-charge ratio [A/Q] of the ions. Since the Q-values depend upon the electron temperature of the source plasma, this has allowed a determination of this temperature from the pattern of element-abundance enhancements and a verification of the expected inverse-time dependence of the power of A/Q for diffusive transport of ions from the SEP events, with scattering mean free paths found to be between 0.2 and 1 AU. SEP events derived from plasma of different temperatures map into different regions in typical cross-plots of abundances, spreading the distributions. In comparisons of SEP events with temperatures above 2 MK, impulsive events show much broader non-thermal variation of abundances than do gradual events. The extensive shock waves accelerating ions in gradual events may average over much of an active region where numerous but smaller magnetic reconnections, "nanojets", produce suprathermal seed ions, thus averaging over varying abundances, while an impulsive SEP event only samples one local region of abundance variations. Evidence for a reference He/O-abundance ratio of 91, rather than 57, is also found for the hotter plasma. However, while this is similar to the solar-wind abundance of He/O, the solar-wind abundances otherwise provide an unacceptably poor reference for the SEP-abundance enhancements, generating extremely large errors.

  14. The Origin of Element Abundance Variations in Solar Energetic Particles

    Science.gov (United States)

    Reames, Donald V.

    2016-07-01

    Abundance enhancements, during acceleration and transport in both gradual and impulsive solar energetic particle (SEP) events, vary approximately as power laws in the mass-to-charge ratio [ A/Q] of the ions. Since the Q-values depend upon the electron temperature of the source plasma, this has allowed a determination of this temperature from the pattern of element-abundance enhancements and a verification of the expected inverse-time dependence of the power of A/Q for diffusive transport of ions from the SEP events, with scattering mean free paths found to be between 0.2 and 1 AU. SEP events derived from plasma of different temperatures map into different regions in typical cross-plots of abundances, spreading the distributions. In comparisons of SEP events with temperatures above 2 MK, impulsive events show much broader non-thermal variation of abundances than do gradual events. The extensive shock waves accelerating ions in gradual events may average over much of an active region where numerous but smaller magnetic reconnections, "nanojets", produce suprathermal seed ions, thus averaging over varying abundances, while an impulsive SEP event only samples one local region of abundance variations. Evidence for a reference He/O-abundance ratio of 91, rather than 57, is also found for the hotter plasma. However, while this is similar to the solar-wind abundance of He/O, the solar-wind abundances otherwise provide an unacceptably poor reference for the SEP-abundance enhancements, generating extremely large errors.

  15. OXYGEN ABUNDANCES IN CEPHEIDS

    Energy Technology Data Exchange (ETDEWEB)

    Luck, R. E.; Andrievsky, S. M. [Department of Astronomy, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-7215 (United States); Korotin, S. N.; Kovtyukh, V. V., E-mail: luck@fafnir.astr.cwru.edu, E-mail: serkor@skyline.od.ua, E-mail: val@deneb1.odessa.ua, E-mail: scan@deneb1.odessa.ua [Department of Astronomy and Astronomical Observatory, Odessa National University, Isaac Newton Institute of Chile, Odessa Branch, Shevchenko Park, 65014 Odessa (Ukraine)

    2013-07-01

    Oxygen abundances in later-type stars, and intermediate-mass stars in particular, are usually determined from the [O I] line at 630.0 nm, and to a lesser extent, from the O I triplet at 615.7 nm. The near-IR triplets at 777.4 nm and 844.6 nm are strong in these stars and generally do not suffer from severe blending with other species. However, these latter two triplets suffer from strong non-local thermodynamic equilibrium (NLTE) effects and thus see limited use in abundance analyses. In this paper, we derive oxygen abundances in a large sample of Cepheids using the near-IR triplets from an NLTE analysis, and compare those abundances to values derived from a local thermodynamic equilibrium (LTE) analysis of the [O I] 630.0 nm line and the O I 615.7 nm triplet as well as LTE abundances for the 777.4 nm triplet. All of these lines suffer from line strength problems making them sensitive to either measurement complications (weak lines) or to line saturation difficulties (strong lines). Upon this realization, the LTE results for the [O I] lines and the O I 615.7 nm triplet are in adequate agreement with the abundance from the NLTE analysis of the near-IR triplets.

  16. Immunglobulin G4-relateret sygdom er en ny inflammatorisk sygdom

    DEFF Research Database (Denmark)

    Næser, Esben Kure; Marcussen, Niels; Gregersen, Jon Waarst

    2012-01-01

    IgG4-related disease is a newly recognized inflammatory disease characterized by tissue infiltrates of IgG4 positive plasma cells. The disease was first recognized in pancreas but has now been described in nearly every organ. The diagnosis is based on the presence of dense lymphoplasmocytic...... infiltrates rich in IgG4 positive plasma cells. We describe a case of a 76-year-old man with IgG4-related disease involving the kidneys....

  17. Coronae of Stars with Supersolar Elemental Abundances

    Science.gov (United States)

    Peretz, Uria; Behar, Ehud; Drake, Stephen A.

    2015-01-01

    Coronal elemental abundances are known to deviate from the photospheric values of their parent star, with the degree of deviation depending on the first ionization potential (FIP). This study focuses on the coronal composition of stars with supersolar photospheric abundances. We present the coronal abundances of six such stars: 11 LMi, iota Hor, HR 7291, tau Boo, and alpha Cen A and B. These stars all have high-statistics X-ray spectra, three of which are presented for the first time. The abundances we measured were obtained using the line-resolved spectra of the Reflection Grating Spectrometer (RGS) in conjunction with the higher throughput EPIC-pn camera spectra onboard the XMM-Newton observatory. A collisionally ionized plasma model with two or three temperature components is found to represent the spectra well. All elements are found to be consistently depleted in the coronae compared to their respective photospheres. For 11 LMi and tau Boo no FIP effect is present, while iota Hor, HR 7291, and alpha Cen A and B show a clear FIP trend. These conclusions hold whether the comparison is made with solar abundances or the individual stellar abundances. Unlike the solar corona, where low-FIP elements are enriched, in these stars the FIP effect is consistently due to a depletion of high-FIP elements with respect to actual photospheric abundances. A comparison with solar (instead of stellar) abundances yields the same fractionation trend as on the Sun. In both cases, a similar FIP bias is inferred, but different fractionation mechanisms need to be invoked.

  18. Analysis of Isotopic Abundance of Plutonium by Multicollector-Inductively Coupled Plasma Mass Spectrometry%多接收电感耦合等离子体质谱法测量痕量钚同位素

    Institute of Scientific and Technical Information of China (English)

    张继龙; 王同兴; 李力力; 常志远; 赵永刚; 刘俊岭

    2005-01-01

    The isotopic analysis of 232Pu plutonium in 5×10-12 g/g samples using a multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) is described. IRMM-290b and uranium (UTB750) were used to correct the metrical data, and the analytical precision is about 0.5%.

  19. Abundances in galaxies

    International Nuclear Information System (INIS)

    Standard (or mildly inhomogeneous) Big Bang nucleosynthesis theory is well confirmed by abundance measurements of light elements up to 7Li and the resulting upper limit to the number of neutrino families confirmed in accelerator experiments. Extreme inhomogeneous models with a closure density in form of baryons seem to be ruled out and there is no evidence for a cosmic 'floor' to 9Be or heavier elements predicted in some versions of those models. Galaxies show a correlation between luminous mass and abundance of carbon and heavier elements, usually attributed to escape of hot gas from shallow potential wells. Uncertainties include the role of dark matter and biparametric behaviour of ellipticals. Spirals have radial gradients which may arise from a variety of causes. In our own Galaxy one can distinguish three stellar populations - disk, halo and bulge - characterised by differing metallicity distribution functions. Differential abundance effects are found among different elements in stars as a function of metallicity and presumably age, notably in the ratio of oxygen and α-particle elements to iron. These may eventually be exploitable to set a time scale for the formation of the halo, bulge and disk. (orig.)

  20. Interstellar Atomic Abundances

    CERN Document Server

    Jenkins, E B

    2003-01-01

    A broad array of interstellar absorption features that appear in the ultraviolet spectra of bright sources allows us to measure the abundances and ionization states of many important heavy elements that exist as free atoms in the interstellar medium. By comparing these abundances with reference values in the Sun, we find that some elements have abundances relative to hydrogen that are approximately consistent with their respective solar values, while others are depleted by factors that range from a few up to around 1000. These depletions are caused by the atoms condensing into solid form onto dust grains. Their strengths are governed by the volatility of compounds that are produced, together with the densities and velocities of the gas clouds. We may characterize the depletion trends in terms of a limited set of parameters; ones derived here are based on measurements of 15 elements toward 144 stars with known values of N(H I) and N(H2). In turn, these parameters may be applied to studies of the production, de...

  1. [Two cases of IgG4-related disease with pleural effusion].

    Science.gov (United States)

    Suzuki, Nobuaki; Saeki, Takako; Shimaoka, Yuichi; Kuriyama, Hideyuki; Nishibori, Takeaki; Ebe, Yusuke; Sato, Kazuhiro

    2011-02-01

    We describe 2 cases of IgG4-related disease with pleural effusion in elderly men. Both patients had elevated serum IgG4 levels, and the characteristics of their pleural effusion were similar. Patient 1 had pericardial effusion and retroperitoneal fibrosis, and a biopsy specimen from the pericardium showed infiltration of abundant IgG4-positive plasma cells with fibrosis. Because his pleurisy, pericarditis and retroperitoneal fibrosis responded to steroid therapy, we diagnosed pleurisy associated with IgG4-related disease. Patient 2 had been treated with steroids because of IgG4-related sialadenitis and interstitial pneumonitis, but pleural effusion developed. Although histopathological examination of the pleura showed infiltration of abundant IgG4-positive plasma cells with fibrosis, Mycobacterium tuberculosis was cultured from the pleural effusion, and histologic examination also showed epithelioid granuloma. Chemotherapy for tuberculosis was effective for the pleurisy, and we diagnosed tuberculous pleurisy as a complication of IgG4-related disease. In cases of IgG4-related disease associated with pleural effusion, the clinical course should be considered together with the serum IgG4 levels and pleural histology.

  2. Abundance, Excess, Waste

    Directory of Open Access Journals (Sweden)

    Rox De Luca

    2016-02-01

    Her recent work focuses on the concepts of abundance, excess and waste. These concerns translate directly into vibrant and colourful garlands that she constructs from discarded plastics collected on Bondi Beach where she lives. The process of collecting is fastidious, as is the process of sorting and grading the plastics by colour and size. This initial gathering and sorting process is followed by threading the components onto strings of wire. When completed, these assemblages stand in stark contrast to the ease of disposability associated with the materials that arrive on the shoreline as evidence of our collective human neglect and destruction of the environment around us. The contrast is heightened by the fact that the constructed garlands embody the paradoxical beauty of our plastic waste byproducts, while also evoking the ways by which those byproducts similarly accumulate in randomly assorted patterns across the oceans and beaches of the planet.

  3. Primordial Deuterium Abundance Measurements

    CERN Document Server

    Levshakov, S A; Takahara, F; Levshakov, Sergei A.; Kegel, Wilhelm H.; Takahara, Fumio

    1997-01-01

    Deuterium abundances measured recently from QSO absorption-line systems lie in the range from 3 10^{-5} to 3 10^{-4}, which shed some questions on standard big bang theory. We show that this discordance may simply be an artifact caused by inadequate analysis ignoring spatial correlations in the velocity field in turbulent media. The generalized procedure (accounting for such correlations) is suggested to reconcile the D/H measurements. An example is presented based on two high-resolution observations of Q1009+2956 (low D/H) [1,2] and Q1718+4807 (high D/H) [8,9]. We show that both observations are compatible with D/H = 4.1 - 4.6 10^{-5}, and thus support SBBN. The estimated mean value = 4.4 10^{-5} corresponds to the baryon-to-photon ratio during SBBN eta = 4.4 10^{-10} which yields the present-day baryon density Omega_b h^2 = 0.015.

  4. Relative Abundance Measurements in Plumes and Interplumes

    CERN Document Server

    Guennou, Chloé; Savin, Daniel Wolf

    2015-01-01

    We present measurements of relative elemental abundances in plumes and interplumes. Plumes are bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Previous work has found that in some coronal structures the abundances of elements with a low first ionization potential (FIP) 10 eV). We have used EIS spectroscopic observations made on 2007 March 13 and 14 over an ~24 hour period to characterize abundance variations in plumes and interplumes. To assess their elemental composition, we have used a differential emission measure (DEM) analysis, which accounts for the thermal structure of the observed plasma. We have used lines from ions of iron, silicon, and sulfur. From these we have estimated the ratio of the iron and silicon FIP bias relative to that for sulfur. From the results, we have created FIP-bias-ratio maps. We find that the FIP-bias ratio is sometimes higher in plumes than in interplumes and that this enhancement can be time dependent. These res...

  5. Deuterium Abundance in Consciousness and Current Cosmology

    Science.gov (United States)

    Rauscher, Elizabeth A.

    We utilize the deuterium-hydrogen abundances and their role in setting limits on the mass and other conditions of cosmogenesis and cosmological evolution. We calculate the dependence of a set of physical variables such as density, temperature, energy mass, entropy and other physical variable parameters through the evolution of the universe under the Schwarzschild conditions as a function from early to present time. Reconciliation with the 3°K and missing mass is made. We first examine the Schwarzschild condition; second, the geometrical constraints of a multidimensional Cartesian space on closed cosmologies, and third we will consider the cosmogenesis and evolution of the universe in a multidimensional Cartesian space, obeying the Schwarzschild condition. Implications of this model for matter creation are made. We also examine experimental evidence for closed versus open cosmologies; x-ray detection of the "missing mass" density. Also the interstellar deuterium abundance, along with the value of the Hubble constant set a general criterion on the value of the curvature constant, k. Once the value of the Hubble constant, H is determined, the deuterium abundance sets stringent restrictions on the value of the curvature constant k by an detailed discussion is presented. The experimental evidences for the determination of H and the primary set of coupled equations to determine D abundance is given. 'The value of k for an open, closed, or flat universe will be discussed in terms of the D abundance which will affect the interpretation of the Schwarzschild, black hole universe. We determine cosmology solutions to Einstein's field obeying the Schwarzschild solutions condition. With this model, we can form a reconciliation of the black hole, from galactic to cosmological scale. Continuous creation occurs at the dynamic blackhole plasma field. We term this new model the multiple big bang or "little whimper model". We utilize the deuteriumhydrogen abundances and their role in

  6. Solar System Abundances of the Elements

    CERN Document Server

    Lodders, Katharina

    2010-01-01

    Representative abundances of the chemical elements for use as a solar abundance standard in astronomical and planetary studies are summarized. Updated abundance tables for solar system abundances based on meteorites and photospheric measurements are presented.

  7. Gaseous abundances in M82

    CERN Document Server

    Ranalli, P; Origlia, L; Maiolino, R; Makishima, K; Ranalli, Piero; Comastri, Andrea; Origlia, Livia; Maiolino, Roberto; Makishima, Kazuo

    2005-01-01

    We present the preliminary analysis of a deep (100ks) XMM-Newton observation of M82. The spatial distribution of the abundances of chemical elements (Fe, O, Ne, Mg, Si, S) is investigated through narrow-band imaging analisys and spatially-resolved spectroscopy. We find that the abundances of alpha-elements follow a bipolar distribution, these elements being more abundant in the gaseous outflow than in the galaxy centre. This behaviour is found to be more marked for lighter elements (O, Ne) than for heavier elements.

  8. Chlorine Abundances in Cool Stars

    CERN Document Server

    Maas, Z G; Hinkle, K

    2016-01-01

    Chlorine abundances are reported in 15 evolved giants and one M dwarf in the solar neighborhood. The Cl abundance was measured using the vibration-rotation 1-0 P8 line of H$^{35}$Cl at 3.69851 $\\mu$m. The high resolution L-band spectra were observed using the Phoenix infrared spectrometer on the Kitt Peak Mayall 4m telescope. The average [$^{35}$Cl/Fe] abundance in stars with --0.72$<$[Fe/H]$<$0.20 is [$^{35}$Cl/Fe]=(--0.10$\\pm$0.15) dex. The mean difference between the [$^{35}$Cl/Fe] ratios measured in our stars and chemical evolution model values is (0.16$\\pm$0.15) dex. The [$^{35}$Cl/Ca] ratio has an offset of $\\sim$0.35 dex above model predictions suggesting chemical evolution models are under producing Cl at the high metallicity range. Abundances of C, N, O, Si, and Ca were also measured in our spectral region and are consistent with F and G dwarfs. The Cl versus O abundances from our sample match Cl abundances measured in planetary nebula and \\ion{H}{2} regions. In one star where both H$^{35}$Cl a...

  9. Plasma theory

    International Nuclear Information System (INIS)

    A series of lectures on plasma theory with the main headings: introduction; charged particles moving in em fields; the liquid model; transport phenomena in the plasma; wave propagation in plasmas; plasma instabilities. 57 figs. (qui)

  10. Solar and stellar photospheric abundances

    Science.gov (United States)

    Allende Prieto, Carlos

    2016-07-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  11. Surface abundances of OC supergiants

    CERN Document Server

    Martins, F; Bouret, J -C; Barba, R; Howarth, I

    2016-01-01

    Some O and B stars show unusually strong or weak lines of carbon and/or nitrogen. These objects are classified as OBN or OBC stars. It has recently been shown that nitrogen enrichment and carbon depletion are the most likely explanations for the existence of the ON class. We investigate OC stars (all being supergiants) to check that surface abundances are responsible for the observed anomalous line strengths. We perform a spectroscopic analysis of three OC supergiants using atmosphere models. A fourth star was previously studied by us. Our sample thus comprises all OC stars known to date in the Galaxy. We determine the stellar parameters and He, C, N, and O surface abundances. We show that all stars have effective temperatures and surface gravities fully consistent with morphologically normal O supergiants. However, OC stars show little, if any, nitrogen enrichment and carbon surface abundances consistent with the initial composition. OC supergiants are thus barely chemically evolved, unlike morphologically n...

  12. Solar and Stellar Photospheric Abundances

    CERN Document Server

    Prieto, Carlos Allende

    2016-01-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  13. The Origin of Element Abundance Variations in Solar Energetic Particles

    CERN Document Server

    Reames, Donald V

    2016-01-01

    Abundance enhancements, during acceleration and transport in both gradual and impulsive solar energetic particle (SEP) events, vary approximately as power laws in the mass-to-charge ratio A/Q of the ions. Since the Q values depend upon the electron temperature of the source plasma, this has allowed a determination of this temperature from the pattern of element abundance enhancements and a verification of the expected inverse-time dependence of the power of A/Q for diffusive transport of ions from the SEP events, with scattering mean free paths found to be between 0.2 and 1 AU. SEP events derived from plasma of different temperatures map into different regions in typical cross-plots of abundances, spreading the distributions. In comparisons of SEP events with temperatures above 2 MK, impulsive events show much broader non-thermal variation of abundances than do gradual events. The extensive shock waves accelerating ions in gradual events may average over much of an active region where numerous but smaller mag...

  14. Coho Abundance - Point Features [ds182

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  15. Coho Abundance - Linear Features [ds183

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  16. Chinook Abundance - Point Features [ds180

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  17. Steelhead Abundance - Linear Features [ds185

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  18. Steelhead Abundance - Point Features [ds184

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. Beginning in 1998, the Pacific States Marine...

  19. Abundance estimation and Conservation Biology

    Directory of Open Access Journals (Sweden)

    Nichols, J. D.

    2004-06-01

    Full Text Available Abundance is the state variable of interest in most population–level ecological research and in most programs involving management and conservation of animal populations. Abundance is the single parameter of interest in capture–recapture models for closed populations (e.g., Darroch, 1958; Otis et al., 1978; Chao, 2001. The initial capture–recapture models developed for partially (Darroch, 1959 and completely (Jolly, 1965; Seber, 1965 open populations represented efforts to relax the restrictive assumption of population closure for the purpose of estimating abundance. Subsequent emphases in capture–recapture work were on survival rate estimation in the 1970’s and 1980’s (e.g., Burnham et al., 1987; Lebreton et al.,1992, and on movement estimation in the 1990’s (Brownie et al., 1993; Schwarz et al., 1993. However, from the mid–1990’s until the present time, capture–recapture investigators have expressed a renewed interest in abundance and related parameters (Pradel, 1996; Schwarz & Arnason, 1996; Schwarz, 2001. The focus of this session was abundance, and presentations covered topics ranging from estimation of abundance and rate of change in abundance, to inferences about the demographic processes underlying changes in abundance, to occupancy as a surrogate of abundance. The plenary paper by Link & Barker (2004 is provocative and very interesting, and it contains a number of important messages and suggestions. Link & Barker (2004 emphasize that the increasing complexity of capture–recapture models has resulted in large numbers of parameters and that a challenge to ecologists is to extract ecological signals from this complexity. They offer hierarchical models as a natural approach to inference in which traditional parameters are viewed as realizations of stochastic processes. These processes are governed by hyperparameters, and the inferential approach focuses on these hyperparameters. Link & Barker (2004 also suggest that

  20. Plasma turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

    1998-07-01

    The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

  1. Plasma properties

    International Nuclear Information System (INIS)

    This paper discusses the following topics: MHD plasma activity: equilibrium, stability and transport; statistical analysis; transport studies; edge physics studies; wave propagation analysis; basic plasma physics and fluid dynamics; space plasma; and numerical methods

  2. Abundances in stars with exoplanets

    OpenAIRE

    Israelian, Garik

    2003-01-01

    Extensive spectroscopic studies of stars with and without planets have concluded that stars hosting planets are significantly more metal-rich than those without planets. More subtle trends of different chemical elements begin to appear as the number of detected extrasolar planetary systems continues to grow. I review our current knowledge concerning the observed abundance trends of various chemical elements in stars with exoplanets and their possible implications.

  3. Oxygen Gas Phase Abundance Revisited

    CERN Document Server

    André, M K; Howk, J C; Ferlet, R; Désert, J M; Hébrard, G; Lacour, S; Lecavelier-des-Etangs, A; Vidal-Madjar, A; Moos, H W

    2003-01-01

    We present new measurements of the interstellar gas-phase oxygen abundance along the sight lines towards 19 early-type galactic stars at an average distance of 2.6 kpc. We derive O {\\small I} column densities from {\\it HST}/STIS observations of the weak 1355 \\AA intersystem transition. We derive total hydrogen column densities [N(H {\\small I})+2N(H$_2$)] using {\\it HST}/STIS observations of \\lya and {\\it FUSE} observations of molecular hydrogen. The molecular hydrogen content of these sight lines ranges from f(H$_2$) = 2N(H$_2$)/[N(H {\\small I})+2N(H$_2$)] = 0.03 to 0.47. The average $$ of 6.3$\\times10^{21}$ cm$^{-2}$ mag$^{-1}$ with a standard deviation of 15% is consistent with previous surveys. The mean oxygen abundance along these sight lines, which probe a wide range of galactic environments in the distant ISM, is 10$^6$ \\oh = $408 \\pm 13$ (1 $\\sigma$ in the mean). %$({\\rm O/H})_{gas} = 408 \\pm 14$(1 $\\sigma$). We see no evidence for decreasing gas-phase oxygen abundance with increasing molecular hydroge...

  4. Plasma harmonics

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    Preface; Why plasma harmonics? A very brief introduction Early stage of plasma harmonic studies - hopes and frustrations New developments in plasma harmonics studies: first successes Improvements of plasma harmonics; Theoretical basics of plasma harmonics; Basics of HHG Harmonic generation in fullerenes using few-cycle pulsesVarious approaches for description of observed peculiarities of resonant enhancement of a single harmonic in laser plasmaTwo-colour pump resonance-induced enhancement of odd and even harmonics from a tin plasmaCalculations of single harmonic generation from Mn plasma;Low-o

  5. Planetary nebulae abundances and stellar evolution

    OpenAIRE

    Pottasch, S. R.; Bernard-Salas, J.

    2006-01-01

    A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted from these gradients at the distance of the Sun from the center are exactly the solar abundance. Sulfur is the exception to this; the reason for this...

  6. Plasma Medicine

    Science.gov (United States)

    Laroussi, M.; Kong, M. G.; Morfill, G.; Stolz, W.

    2012-05-01

    Foreword R. Satava and R. J. Barker; Part I. Introduction to Non-equilibrium Plasma, Cell Biology, and Contamination: 1. Introduction M. Laroussi; 2. Fundamentals of non-equilibrium plasmas M. Kushner and M. Kong; 3. Non-equilibrium plasma sources M. Laroussi and M. Kong; 4. Basic cell biology L. Greene and G. Shama; 5. Contamination G. Shama and B. Ahlfeld; Part II. Plasma Biology and Plasma Medicine: 6. Common healthcare challenges G. Isbary and W. Stolz; 7. Plasma decontamination of surfaces M. Kong and M. Laroussi; 8. Plasma decontamination of gases and liquids A. Fridman; 9. Plasma-cell interaction: prokaryotes M. Laroussi and M. Kong; 10. Plasma-cell interaction: eukaryotes G. Isbary, G. Morfill and W. Stolz; 11. Plasma based wound healing G. Isbary, G. Morfill and W. Stolz; 12. Plasma ablation, surgery, and dental applications K. Stalder, J. Woloszko, S. Kalghatgi, G. McCombs, M. Darby and M. Laroussi; Index.

  7. Range of fractionated plasma products to optimize plasma resources

    Institute of Scientific and Technical Information of China (English)

    Thierry Burnouf

    2010-01-01

    @@ HUMAN PLASMA is a source material that is crucial for the production of unique therapeutic fractionated products. Indeed, plasma contains hundreds of proteins ensuring many physiological functions. The most abun-dant proteins, albumin and immunoglobulin G (IgG) ,are present at about 35 and 10 g/L,respectively,repre-senting about 80% of all plasma proteins. However,other important therapeutic proteins include the coagu-lation factors (factor Ⅷ (F Ⅷ) ; FIX ; Von Willebrand Factor (VWF), fibrinogen) various protease inhibitors (alpha 1-antitrypsin ; antithrombin; C1-esterase) and anticoagulants (protein C) which exhibit potent physi-ological activity.

  8. Lead abundance in the uranium star CS 31082-001

    DEFF Research Database (Denmark)

    Plez, B.; Hill, V.; Cayrel, R.;

    2004-01-01

    stars:abundances- physical data and processes: nuclear reactions, nucleosynthesis, abundances- atomic data......stars:abundances- physical data and processes: nuclear reactions, nucleosynthesis, abundances- atomic data...

  9. Stark broadening data for stellar plasma research.

    Science.gov (United States)

    Dimitrijević, M. S.

    Results of an effort to provide to astrophysicists and physicists an as much as possible complete set of Stark broadening parameters needed for stellar opacity calculations, stellar atmosphere modelling, abundance determinations and diagnostics of different plasmas in astrophysics, physics and plasma technology, are presented. Stark broadening has been considered within the semiclassical perturbation, and the modified semiempirical approaches.

  10. Dusty plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Fortov, Vladimir E; Khrapak, Aleksei G; Molotkov, Vladimir I; Petrov, Oleg F [Institute for High Energy Densities, Associated Institute for High Temperatures, Russian Academy of Sciences, Moscow (Russian Federation); Khrapak, Sergei A [Max-Planck-Institut fur Extraterrestrische Physik, Garching (Germany)

    2004-05-31

    The properties of dusty plasmas - low-temperature plasmas containing charged macroparticles - are considered. The most important elementary processes in dusty plasmas and the forces acting on dust particles are investigated. The results of experimental and theoretical investigations of different states of strongly nonideal dusty plasmas - crystal-like, liquid-like, gas-like - are summarized. Waves and oscillations in dusty plasmas, as well as their damping and instability mechanisms, are studied. Some results on dusty plasma investigated under microgravity conditions are presented. New directions of experimental research and potential applications of dusty plasmas are discussed. (reviews of topical problems)

  11. Surface abundances of ON stars

    CERN Document Server

    Martins, F; Palacios, A; Howarth, I; Georgy, C; Walborn, N R; Bouret, J -C; Barba, R

    2015-01-01

    Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient, or when mass transfer in binary systems happens, chemically processed material is observed at the surface of O and B stars. ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle or not is not known. Our goal is to answer this question. We perform a spectroscopic analysis of a sample of ON stars with atmosphere models. We determine the fundamental parameters as well as the He, C, N, and O surface abundances. We also measure the projected rotational velocities. We compare the properties of the ON stars to those of normal O stars. We show that ON stars are usually helium-rich. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cann...

  12. LITERATURE SURVEY ON ISOTOPIC ABUNDANCE RATIO MEASUREMENTS - 2001-2005

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN, N.E.

    2005-08-13

    Along with my usual weekly review of the published literature for new nuclear data, I also search for new candidates for best measurements of isotopic abundances from a single source. Most of the published articles, that I previously had found in the Research Library at the Brookhaven Lab, have already been sent to the members of the Atomic Weights Commission, by either Michael Berglund or Thomas Walczyk. In the last few days, I checked the published literature for any other articles in the areas of natural variations in isotopic abundance ratios, measurements of isotopic abundance ratios on samples of extra-terrestrial material and isotopic abundance ratio measurements performed using ICPMS instruments. Hopefully this information will be of interest to members of the Commission, the sub-committee on isotopic abundance measurements (SIAM), members of the former sub-committee on natural isotopic fractionation (SNIF), the sub-committee on extra-terrestrial isotope ratios (SETIR), the RTCE Task Group and the Guidelines Task Group, who are dealing with ICPMS and TIMS comparisons. In the following report, I categorize the publications in one of four areas. Measurements performed using either positive or negative ions with Thermal Ionization Mass Spectrometer, TIMS, instruments; measurements performed on Inductively Coupled Plasma Mass Spectrometer, ICPMS, instruments; measurements of natural variations of the isotopic abundance ratios; and finally measurements on extra-terrestrial samples with instrumentation of either type. There is overlap in these areas. I selected out variations and ET results first and then categorized the rest of the papers by TIMS and ICPMS.

  13. Plasma diagnostics and atomic processes

    International Nuclear Information System (INIS)

    Spectroscopic plasma diagnostics with the use of atomic processes are discussed relating to three subjects in the followings. i) Time resolved X-ray spectra of titanium helium-like ions from tokamaks. X-ray spectra observed from tokamak plasmas are analysed with a non-ionization equilibrium model which could explain the time behavior of both spectra and ion abundances. ii) Line intensity ratios of OV ions for temperature and density diagnostics. Intensity ratios of emission lines from OV ions are calculated for use in temperature and density diagnostics. The line emissions from a tokamak are analysed for the diagnostics of plasma periphery. iii) Collisional processes in hot dense plasmas. The collisional ladder-like excitation and ionization in a hot dense plasma are discussed for the dielectronic states. This process enhances the excitation rate coefficients and decreases the resonance contributions to the excitation cross section. (author)

  14. Solar System chemical abundances corrected for systematics

    OpenAIRE

    Gonzalez, Guillermo

    2014-01-01

    The relative chemical abundances between CI meteorites and the solar photosphere exhibit a significant trend with condensation temperature. A trend with condensation temperature is also seen when the solar photospheric abundances are compared to those of nearby solar twins. We use both these trends to determine the alteration of the elemental abundances of the meteorties and the photosphere by fractionation and calculate a new set of primordial Solar System abundances.

  15. ELSA: An Integrated, Semi-Automated Nebular Abundance Package

    CERN Document Server

    Johnson, M D; Henry, R B C; Kwitter, K B

    2006-01-01

    We present ELSA, a new modular software package, written in C, to analyze and manage spectroscopic data from emission-line objects. In addition to calculating plasma diagnostics and abundances from nebular emission lines, the software provides a number of convenient features including the ability to ingest logs produced by IRAF's splot task, to semi-automatically merge spectra in different wavelength ranges, and to automatically generate various data tables in machine-readable or LaTeX format. ELSA features a highly sophisticated interstellar reddening correction scheme that takes into account temperature and density effects as well as He II contamination of the hydrogen Balmer lines. Abundance calculations are performed using a 5-level atom approximation with recent atomic data, based on R. Henry's ABUN program. Improvements planned in the near future include use of a three-region ionization model, similar to IRAF's nebular package, error propagation, and the addition of ultraviolet and infrared line analysi...

  16. Plasma waves

    CERN Document Server

    Swanson, DG

    1989-01-01

    Plasma Waves discusses the basic development and equations for the many aspects of plasma waves. The book is organized into two major parts, examining both linear and nonlinear plasma waves in the eight chapters it encompasses. After briefly discussing the properties and applications of plasma wave, the book goes on examining the wave types in a cold, magnetized plasma and the general forms of the dispersion relation that characterize the waves and label the various types of solutions. Chapters 3 and 4 analyze the acoustic phenomena through the fluid model of plasma and the kinetic effects. Th

  17. Plasma astrophysics

    CERN Document Server

    Kaplan, S A; ter Haar, D

    2013-01-01

    Plasma Astrophysics is a translation from the Russian language; the topics discussed are based on lectures given by V.N. Tsytovich at several universities. The book describes the physics of the various phenomena and their mathematical formulation connected with plasma astrophysics. This book also explains the theory of the interaction of fast particles plasma, their radiation activities, as well as the plasma behavior when exposed to a very strong magnetic field. The text describes the nature of collective plasma processes and of plasma turbulence. One author explains the method of elementary

  18. Modeling the ion abundances in Saturn's inner magnetosphere

    Science.gov (United States)

    Fleshman, B. L.; Bagenal, F.; Delamere, P. A.

    2011-12-01

    Water ejected from Enceladus's plumes provides much of the material that fills both the dense H2O torus centered on Enceladus's orbit, as well as Saturn's neutral clouds which extend at least four times farther from Saturn. Photo- and impact ionization transforms a few percent of these neutrals into the ions co-rotating with Saturn's magnetosphere, and charge exchange is responsible for a substantial redistribution among the hydrogen and water-group ions, though it does not alter the overall plasma density. In this paper, we explore ion abundances at Saturn with a chemistry model developed to include all of these processes. Building on our earlier attempts, we now include a source of neutrals from a neutral cloud model, so as to advance our description to include radial and latitudinal variations. At the same time, we now prescribe a radially-varying plasma diffusion coefficient to study the magnetosphere's inability to contain centrifigually-unstable plasma. We also are interested in the effect of hot electrons (102-103 eV) beamed along field lines into the equatorial region chiefly of interest. Our parameter study of radial diffusion and hot-electron flux is anchored to available Cassini CAPS water-group and proton abundances. Preliminary results suggest an injection of ~10 MW by hot electrons, and reveal promising radial trends in the water-group abundances that agree well with Sittler et al. (2008). We can also simulate an Enceladus torus dominated H3O+ -- a result not obtainable prior to coupling the chemistry and neutral cloud models.

  19. Planetary nebulae abundances and stellar evolution II

    NARCIS (Netherlands)

    Pottasch, S. R.; Bernard-Salas, J.

    2010-01-01

    Context. In recent years mid-and far infrared spectra of planetary nebulae have been analysed and lead to more accurate abundances. It may be expected that these better abundances lead to a better understanding of the evolution of these objects. Aims. The observed abundances in planetary nebulae are

  20. Surface abundances of ON stars

    Science.gov (United States)

    Martins, F.; Simón-Díaz, S.; Palacios, A.; Howarth, I.; Georgy, C.; Walborn, N. R.; Bouret, J.-C.; Barbá, R.

    2015-06-01

    Context. Massive stars burn hydrogen through the CNO cycle during most of their evolution. When mixing is efficient or when mass transfer in binary systems occurs, chemically processed material is observed at the surface of O and B stars. Aims: ON stars show stronger lines of nitrogen than morphologically normal counterparts. Whether this corresponds to the presence of material processed through the CNO cycle is not known. Our goal is to answer this question. Methods: We performed a spectroscopic analysis of a sample of ON stars with atmosphere models. We determined the fundamental parameters as well as the He, C, N, and O surface abundances. We also measured the projected rotational velocities. We compared the properties of the ON stars to those of normal O stars. Results: We show that ON stars are usually rich in helium. Their CNO surface abundances are fully consistent with predictions of nucleosynthesis. ON stars are more chemically evolved and rotate - on average - faster than normal O stars. Evolutionary models including rotation cannot account for the extreme enrichment observed among ON main sequence stars. Some ON stars are members of binary systems, but others are single stars as indicated by stable radial velocities. Mass transfer is therefore not a simple explanation for the observed chemical properties. Conclusions: We conclude that ON stars show extreme chemical enrichment at their surface, consistent with nucleosynthesis through the CNO cycle. Its origin is not clear at present. Based on observations obtained 1) at the Anglo-Australian Telescope; 2) at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council (NRC) of Canada, the Institut National des Science de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii; 3) at the ESO/La Silla Observatory under programs 081.D-2008, 083.D-0589, 086.D-0997; 4) the Nordic Optical Telescope, operated on the island of La

  1. Significant biases affecting abundance determinations

    Science.gov (United States)

    Wesson, Roger

    2015-08-01

    I have developed two highly efficient codes to automate analyses of emission line nebulae. The tools place particular emphasis on the propagation of uncertainties. The first tool, ALFA, uses a genetic algorithm to rapidly optimise the parameters of gaussian fits to line profiles. It can fit emission line spectra of arbitrary resolution, wavelength range and depth, with no user input at all. It is well suited to highly multiplexed spectroscopy such as that now being carried out with instruments such as MUSE at the VLT. The second tool, NEAT, carries out a full analysis of emission line fluxes, robustly propagating uncertainties using a Monte Carlo technique.Using these tools, I have found that considerable biases can be introduced into abundance determinations if the uncertainty distribution of emission lines is not well characterised. For weak lines, normally distributed uncertainties are generally assumed, though it is incorrect to do so, and significant biases can result. I discuss observational evidence of these biases. The two new codes contain routines to correctly characterise the probability distributions, giving more reliable results in analyses of emission line nebulae.

  2. Origin of Cosmic Chemical Abundances

    CERN Document Server

    Maio, Umberto

    2015-01-01

    Cosmological N-body hydrodynamic computations following atomic and molecular chemistry (e$^-$, H, H$^+$, H$^-$, He, He$^+$, He$^{++}$, D, D$^+$, H$_2$, H$_2^+$, HD, HeH$^+$), gas cooling, star formation and production of heavy elements (C, N, O, Ne, Mg, Si, S, Ca, Fe, etc.) from stars covering a range of mass and metallicity are used to explore the origin of several chemical abundance patterns and to study both the metal and molecular content during simulated galaxy assembly. The resulting trends show a remarkable similarity to up-to-date observations of the most metal-poor damped Lyman-$\\alpha$ absorbers at redshift $z\\gtrsim 2$. These exhibit a transient nature and represent collapsing gaseous structures captured while cooling is becoming effective in lowering the temperature below $\\sim 10^4\\,\\rm K$, before they are disrupted by episodes of star formation or tidal effects. Our theoretical results agree with the available data for typical elemental ratios, such as [C/O], [Si/Fe], [O/Fe], [Si/O], [Fe/H], [O/...

  3. Plasma antennas

    CERN Document Server

    Anderson, Theodore

    2011-01-01

    The plasma antenna is an emerging technology that partially or fully utilizes ionized gas as the conducting medium instead of metal to create an antenna. The key advantages of plasma antennas are that they are highly reconfigurable and can be turned on and off. The disadvantage is that the plasma antennas require energy to be ionized. This unique resource provides you with a solid understanding of the efficient design and prototype development of plasma antennas, helping you to meet the challenge of reducing the power required to ionize the gas at various plasma densities. You also find thorou

  4. Hydrocarbon Reserves: Abundance or Scarcity

    International Nuclear Information System (INIS)

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may impact on the growth

  5. Hydrocarbon Reserves: Abundance or Scarcity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    IFP and the OAPEC jointly organize a regular international seminar dealing with world oil-related problems appearing in the news. For the first time, this seminar has been opened to oil and gas company specialists, service companies, research centers and independents. This year's theme concerns oil and gas reserves: are they abundant or are we headed towards the shortages announced by some experts? This theme is especially topical in that: oil and gas currently meet two thirds of world energy needs and almost completely dominate the transport sector; the reserves declared by the OAPEC countries account for nearly half of world reserves; the price of a barrel of oil went through the roof in 2004; world energy demand is growing fast and alternative sources of energy are far from ready to take over from oil and gas in the next few decades. Since the reserves correspond to the volume it is technically and economically viable to produce, the seminar has, of course, dealt with the technical and economic questions that arise in connection with exploration and production, but it has also considered changes in the geopolitical context. Presentations by the leading companies of the OAPEC countries and by the IFP group were completed by presentation from the International Energy Agency (IEA), the United States Geological Survey (USGS), the IHS Energy Group, Total and Gaz de France. This document gathers the transparencies of the following presentations: Hydrocarbon reserves in OAPEC members countries: current and future (M. Al-Lababidi); Non OAPEC liquid reserves and production forecasts (Y. Mathieu); World oil and gas resources and production outlook (K. Chew); Global investments in the upstream (F. Birol); Total's policy in the oil and gas sector (C. de Margerie); Gaz de France's policy in the oil and gas sector (J. Abiteboul); NOC/IOC's opportunities in OPEC countries (I. Sandrea); Relationships between companies, countries and investors: How they may

  6. Stellar abundances of beryllium and CUBES

    CERN Document Server

    Smiljanic, R

    2014-01-01

    Stellar abundances of beryllium are useful in different areas of astrophysics, including studies of the Galactic chemical evolution, of stellar evolution, and of the formation of globular clusters. Determining Be abundances in stars is, however, a challenging endeavor. The two Be II resonance lines useful for abundance analyses are in the near UV, a region strongly affected by atmospheric extinction. CUBES is a new spectrograph planned for the VLT that will be more sensitive than current instruments in the near UV spectral region. It will allow the observation of fainter stars, expanding the number of targets where Be abundances can be determined. Here, a brief review of stellar abundances of Be is presented together with a discussion of science cases for CUBES. In particular, preliminary simulations of CUBES spectra are presented, highlighting its possible impact in investigations of Be abundances of extremely metal-poor stars and of stars in globular clusters.

  7. Climate and local abundance in freshwater fishes

    OpenAIRE

    Knouft, Jason H; Anthony, Melissa M.

    2016-01-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide va...

  8. Monitoring Butterfly Abundance: Beyond Pollard Walks

    OpenAIRE

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

    2012-01-01

    Most butterfly monitoring protocols rely on counts along transects (Pollard walks) to generate species abundance indices and track population trends. It is still too often ignored that a population count results from two processes: the biological process (true abundance) and the statistical process (our ability to properly quantify abundance). Because individual detectability tends to vary in space (e.g., among sites) and time (e.g., among years), it remains unclear whether index counts truly...

  9. Chemical abundances in Galactic Planetary Nebulae with Spitzer spectra

    CERN Document Server

    Garcia-Hernandez, D A

    2014-01-01

    We present new low-resolution (R~800) optical spectra of 22 Galactic PNe with Spitzer spectra. These data are combined with recent optical spectroscopic data available in the literature to construct representative samples of compact (and presumably young) Galactic disc and bulge PNe with Spitzer spectra. Attending to the nature of the dust features seen in their Spitzer spectra, Galactic disc and bulge PNe are classified according to four major dust types (oxygen chemistry or OC, carbon chemistry or CC, double chemistry or DC, featureless or F) and subtypes (amorphous and crystalline, and aliphatic and aromatic). Nebular gas abundances of He, N, O, Ne, S, Cl and Ar, as well as plasma parameters (e.g. Ne, Te) are homogeneously derived and we study the median chemical abundances and nebular properties in Galactic disc and bulge PNe depending on their Spitzer dust types and subtypes. A comparison of the derived median abundance patterns with AGB nucleosynthesis predictions show mainly that: i) DC PNe, both with ...

  10. Abundance of introduced species at home predicts abundance away in herbaceous communities

    Science.gov (United States)

    Firn, Jennifer; Moore, Joslin L.; MacDougall, Andrew S.; Borer, Elizabeth T.; Seabloom, Eric W.; HilleRisLambers, Janneke; Harpole, W. Stanley; Cleland, Elsa E.; Brown, Cynthia S.; Knops, Johannes M.H.; Prober, Suzanne M.; Pyke, David A.; Farrell, Kelly A.; Bakker, John D.; O'Halloran, Lydia R.; Adler, Peter B.; Collins, Scott L.; D'Antonio, Carla M.; Crawley, Michael J.; Wolkovich, Elizabeth M.; La Pierre, Kimberly J.; Melbourne, Brett A.; Hautier, Yann; Morgan, John W.; Leakey, Andrew D.B.; Kay, Adam; McCulley, Rebecca; Davies, Kendi F.; Stevens, Carly J.; Chu, Cheng-Jin; Holl, Karen D.; Klein, Julia A.; Fay, Phillip A.; Hagenah, Nicole; Kirkman, Kevin P.; Buckley, Yvonne M.

    2011-01-01

    Many ecosystems worldwide are dominated by introduced plant species, leading to loss of biodiversity and ecosystem function. A common but rarely tested assumption is that these plants are more abundant in introduced vs. native communities, because ecological or evolutionary-based shifts in populations underlie invasion success. Here, data for 26 herbaceous species at 39 sites, within eight countries, revealed that species abundances were similar at native (home) and introduced (away) sites - grass species were generally abundant home and away, while forbs were low in abundance, but more abundant at home. Sites with six or more of these species had similar community abundance hierarchies, suggesting that suites of introduced species are assembling similarly on different continents. Overall, we found that substantial changes to populations are not necessarily a pre-condition for invasion success and that increases in species abundance are unusual. Instead, abundance at home predicts abundance away, a potentially useful additional criterion for biosecurity programmes.

  11. Sclerosing cholecystitis associated with autoimmune pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Terumi Kamisawa; Yuyang Tu; Hitoshi Nakajima; Naoto Egawa; Kouji Tsuruta; Atsutake Okamoto; Shinichirou Horiguchi

    2006-01-01

    AIM: To evaluate the histopathological and radiological findings of the gallbladder in patients with autoimmune pancreatitis (AIP).METHODS: The radiological findings of the gallbladder of 19 AIP patients were retrospectively reviewed.Resected gallbladders of 8 AIP patients were examined histologically and were immunostained with antiIgG4 antibody. Controls consisted of gallbladders resected for symptomatic gallstones (n=10) and those removed during pancreatoduodenectomy for pancreatic carcinoma (n=10), as well as extrahepatic bile ducts and pancreases removed by pancreatoduodenectomy for pancreatic carcinoma (n=10).RESULTS: Thickening of the gallbladder wall was detected by ultrasound and/or computed tomography in 10 patients with AIP (3 severe and 7 moderate);in these patients severe stenosis of the extrahepatic bile duct was also noted. Histologically, thickening of the gallbladder was detected in 6 of 8 (75%) patients with AIP; 4 cases had transmural lymphoplasmacytic infiltration with fibrosis, and 2 cases had mucosal-based lymphoplasmacytic infiltration. Considerable transmural thickening of the extrahepatic bile duct wall with dense fibrosis and diffuse ly rnphoplasmacytic infiltration was detected in 7 patients. Immunohistochemically, severe or moderate infiltration of IgG4-positive plasma cells was detected in the gallbladder, bile duct, and pancreas of all 8 patients, but was not detected in controls.CONCLUSION: Gallbladder wall thickening with fibrosis and abundant infiltration of IgG4-positive plasma cells is frequently detected in patients with AIR We propose the use of a new term, sclerosing cholecystitis, for these cases that are induced by the same mechanism as sclerosing pancreatitis or sclerosing cholangitis in AIP.

  12. Evaluation of three high abundance protein depletion kits for umbilical cord serum proteomics

    Directory of Open Access Journals (Sweden)

    Nie Jing

    2011-05-01

    Full Text Available Abstract Background High abundance protein depletion is a major challenge in the study of serum/plasma proteomics. Prior to this study, most commercially available kits for depletion of highly abundant proteins had only been tested and evaluated in adult serum/plasma, while the depletion efficiency on umbilical cord serum/plasma had not been clarified. Structural differences between some adult and fetal proteins (such as albumin make it likely that depletion approaches for adult and umbilical cord serum/plasma will be variable. Therefore, the primary purposes of the present study are to investigate the efficiencies of several commonly-used commercial kits during high abundance protein depletion from umbilical cord serum and to determine which kit yields the most effective and reproducible results for further proteomics research on umbilical cord serum. Results The immunoaffinity based kits (PROTIA-Sigma and 5185-Agilent displayed higher depletion efficiency than the immobilized dye based kit (PROTBA-Sigma in umbilical cord serum samples. Both the PROTIA-Sigma and 5185-Agilent kit maintained high depletion efficiency when used three consecutive times. Depletion by the PROTIA-Sigma Kit improved 2DE gel quality by reducing smeared bands produced by the presence of high abundance proteins and increasing the intensity of other protein spots. During image analysis using the identical detection parameters, 411 ± 18 spots were detected in crude serum gels, while 757 ± 43 spots were detected in depleted serum gels. Eight spots unique to depleted serum gels were identified by MALDI- TOF/TOF MS, seven of which were low abundance proteins. Conclusions The immunoaffinity based kits exceeded the immobilized dye based kit in high abundance protein depletion of umbilical cord serum samples and dramatically improved 2DE gel quality for detection of trace biomarkers.

  13. Plasma physics

    CERN Document Server

    Drummond, James E

    2013-01-01

    A historic snapshot of the field of plasma physics, this fifty-year-old volume offers an edited collection of papers by pioneering experts in the field. In addition to assisting students in their understanding of the foundations of classical plasma physics, it provides a source of historic context for modern physicists. Highly successful upon its initial publication, this book was the standard text on plasma physics throughout the 1960s and 70s.Hailed by Science magazine as a ""well executed venture,"" the three-part treatment ranges from basic plasma theory to magnetohydrodynamics and microwa

  14. Plasma undulator

    International Nuclear Information System (INIS)

    Two types of the undulator which is developed as a generator of the highly brilliant light for the synchrotron radiation sources and the free electron lasers, are newly proposed using the array of slender plasmas columns. One is the magnetic field type, in which the undulator force on the relativistic electron beam is generated with the electric current flowing through the plasma columns. The other is the electric field type, in which the undulator force is generated with the periodic variation of the density between the slender plasma columns. The production methods and stabilization ones of plasma columns are discussed. (author)

  15. Climate and local abundance in freshwater fishes.

    Science.gov (United States)

    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa. PMID:27429769

  16. Taking species abundance distributions beyond individuals

    NARCIS (Netherlands)

    Morlon, Helene; White, Ethan P.; Etienne, Rampal S.; Green, Jessica L.; Ostling, Annette; Alonso, David; Enquist, Brian J.; He, Fangliang; Hurlbert, Allen; Magurran, Anne E.; Maurer, Brian A.; McGill, Brian J.; Olff, Han; Storch, David; Zillio, Tommaso; Chave, Jérôme

    2009-01-01

    The species abundance distribution (SAD) is one of the few universal patterns in ecology. Research on this fundamental distribution has primarily focused on the study of numerical counts, irrespective of the traits of individuals. Here we show that considering a set of Generalized Species Abundance

  17. Ectopic Germinal Centers and IgG4-Producing Plasmacytes Observed in Synovia of HLA-B27+ Ankylosing Spondylitis Patients with Advanced Hip Involvement

    Directory of Open Access Journals (Sweden)

    Xiugao Feng

    2015-01-01

    Full Text Available Introduction. Ectopic lymphoid neogenesis and the presence of IgG4-positive plasmacytes have been confirmed in chronic inflammatory sclerosing diseases. This study aims to investigate hip synovial tissues of ankylosing spondylitis (AS patients for IgG4-positive plasma cells and ectopic lymphoid tissues with germinal centers (GCs. Methods. Synovial samples were collected from 7 AS patients who received total hip replacement and were evaluated using immunohistochemistry for the presence of CD20+ B-cells, CD3+ T-cells, CD21+ follicular dendritic cells (FDC, and CD38+ plasma cells. Furthermore, immunoglobulin G (IgG and IgG4, IgA, IgM, and complement components C3d and C4d in synovia were evaluated. Both synovial CD21+ FDCs and IgG4-producing plasmacytes were analyzed. Results. All seven patients had severe fibrosis. Massive infiltrations of lymphocytes were found in 5 out of 7 patients’ synovia. Ectopic lymphoid tissues with CD21+ FDC networks and IgG4-positive plasma cells were observed coincidentally in two patients’ synovia. Conclusion. The pathophysiological mechanism of AS patients’ hip damage might be related to the coincidental presence of ectopic lymphoid tissue with FDCs network and IgG4-positive plasma cells identified here for the first time in AS patients’ inflamed synovial tissue.

  18. Solar Energetic Particles: Sampling Coronal Abundances

    Science.gov (United States)

    Reames, Donald V.

    1998-05-01

    In the large solar energetic particle (SEP) events, coronal mass ejections (CMEs) drive shock waves out through the corona that accelerate elements of the ambient material to MeV energies in a fairly democratic, temperature-independent manner. These events provide the most complete source of information on element abundances in the corona. Relative abundances of 22 elements from H through Zn display the well-known dependence on the first ionization potential (FIP) that distinguishes coronal and photospheric material. For most elements, the main abundance variations depend upon the gyrofrequency, and hence on the charge-to-mass ratio, Q/A, of the ion. Abundance variations in the dominant species, H and He, are not Q/A dependent, presumably because of non-linear wave-particle interactions of H and He during acceleration. Impulsive flares provide a different sample of material that confirms the Ne:Mg:Si and He/C abundances in the corona.

  19. Plasma Catalytic Extraction of Oxygen from the Martian Atmosphere Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Plasma catalytic techniques are proposed for the extraction of oxygen from the abundant carbon dioxide contained in the Martian atmosphere (95% CO2).. The Phase I...

  20. Plasma Extraction of Oxygen from Martian Atmosphere Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Plasma techniques are proposed for the extraction of oxygen from the abundant carbon dioxide contained in the Martian atmosphere (96 % CO2). In this process, CO2 is...

  1. 电感耦合等离子体质谱法测定辉钼矿中Re、Os含量质量分馏效应的校正%Correction of Mass Discrimination in the Determination of the Isotope Abundance for Rhenium and Osmium in Molybdenite by Inductively Coupled Plasma Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    屈文俊; 杜安道

    2004-01-01

    A liquid which have special 187Re/185Re and 187Os/190Os ratios was prepared using 185Re and 190Os spikes, common rheniumand osmium in molybdenite. This liquid can be used as outer standard to correct the mass bias in the determination of rhenium and osmium in molybdenite by inductively coupled plasma mass spectrometry (ICP-MS).

  2. Plasma properties

    International Nuclear Information System (INIS)

    The Magneto-Fluid Dynamics Division continues to study a broad range of problems originating in plasma physics. Its principal focus is fusion plasma physics, and most particularly topics of particular significance for the world magnetic fusion program. During the calendar year 1990 we explored a wide range of topics including RF-induced transport as a plasma control mechanism, edge plasma modelling, further statistical analysis of L and H mode tokamak plasmas, antenna design, simulation of the edge of a tokamak plasma and the L-H transition, interpretation of the CCT experimental results at UCLA, turbulent transport, studies in chaos, the validity of moment approximations to kinetic equations and improved neoclassical modelling. In more basic studies we examined the statistical mechanisms of Coulomb systems and applied plasma ballooning mode theory to conventional fluids in order to obtain novel fluid dynamics stability results. In space plasma physics we examined the problem of reconnection, the effect of Alfven waves in space environments, and correct formulation of boundary conditions of the Earth for waves in the ionosphere

  3. PLASMA DEVICE

    Science.gov (United States)

    Baker, W.R.

    1961-08-22

    A device is described for establishing and maintaining a high-energy, rotational plasma for use as a fast discharge capacitor. A disc-shaped, current- conducting plasma is formed in an axinl magnetic field and a crossed electric field, thereby creating rotational kinetic enengy in the plasma. Such energy stored in the rotation of the plasma disc is substantial and is convertible tc electrical energy by generator action in an output line electrically coupled to the plasma volume. Means are then provided for discharging the electrical energy into an external circuit coupled to the output line to produce a very large pulse having an extremely rapid rise time in the waveform thereof. (AE C)

  4. β-Microseminoprotein binds CRISP-3 in human seminal plasma

    OpenAIRE

    Udby, Lene; Lundwall, Åke; Johnsen, Anders H.; Fernlund, Per; Valtonen-André, Camilla; Blom, Anna M.; Lilja, Hans; Borregaard, Niels; Kjeldsen, Lars; Bjartell, Anders

    2005-01-01

    β -Microseminoprotein (MSP) and cysteine-rich secretory protein 3 (CRISP-3) are abundant constituents of human seminal plasma. Immunoprecipitation and gel filtration of seminal plasma proteins combined with examination of the proteins in their pure form showed that MSP and CRISP-3 form stable, non-covalent complexes. CRISP-3 binds MSP with very high affinity, as evidenced by surface plasmon resonance. Due to far higher abundance of MSP in prostatic fluid, it manifests large overcapacity for C...

  5. Silicon abundances in population I giants

    Science.gov (United States)

    Boehm-Vitense, Erika

    1992-01-01

    Silicon to carbon abundance ratios for population I giants were determined from emission lines originating in the transition layers between stellar chromospheres and coronae. For effective temperatures larger than 6200 K we find a group of stars with increased silicon to carbon but normal nitrogen to carbon abundance ratios. These stars are presumably descendents from Ap stars with increased surface silicon to carbon abundance ratios. For G stars this anomaly disappears as is to be expected due to the increased depth of the convection zone and therefore deeper mixing which dilutes the surface overabundances. The disappearance of the abundance anomalies proves that the anomalous abundances observed for the F giants are indeed only a surface phenomenon. It also proves that the same holds for their progenitors, the Ap and Am stars, as has been generally believed. Unexplained is the increased silicon to carbon abundance ratio observed for several stars cooler than 5100 L. RS CVn and related stars do not show this increased abundance ratio. There are also some giants which appear to be enriched in carbon, perhaps due to a helium flash with some mixing if the star is a clump star.

  6. Study of the primordial lithium abundance

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Lithium isotopes have attracted an intense interest because the abundance of both 6Li and 6Li from big bang nucleosynthesis (BBN) is one of the puzzles in nuclear astrophysics. Many investigations of both astrophysical observation and nucleosynthesis calculation have been carried out to solve the puzzle, but it is not solved yet. Several nuclear reactions involving lithium have been indirectly measured at China Institute of Atomic Energy, Beijing. The Standard BBN (SBBN) network calculations are then performed to investigate the primordial Lithium abundance. The result shows that these nuclear reactions have minimal effect on the SBBN abundances of 6Li and 7Li.

  7. Lithium Abundance of Metal-poor Stars

    Institute of Scientific and Technical Information of China (English)

    Hua-Wei Zhang; Gang Zhao

    2003-01-01

    High-resolution, high signal-to-noise ratio spectra have been obtained for 32 metal-poor stars. The equivalent widths of Li λ6708A were measured and the lithium abundances were derived. The average lithium abundance of 21 stars on the lithium plateau is 2.33±0.02 dex. The Lithium plateau exhibits a marginal trend along metallicity, dA(Li)/d[Fe/H] = 0.12±0.06, and no clear trend with the effective temperature. The trend indicates that the abundance of lithium plateau may not be primordial and that a part of the lithium was produced in Galactic Chemical Evolution (GCE).

  8. Plasma physics

    International Nuclear Information System (INIS)

    This report contains the papers delivered at the AEB - Natal University summer school on plasma physics held in Durban during January 1979. The following topics were discussed: Tokamak devices; MHD stability; trapped particles in tori; Tokamak results and experiments; operating regime of the AEB Tokamak; Tokamak equilibrium; high beta Tokamak equilibria; ideal Tokamak stability; resistive MHD instabilities; Tokamak diagnostics; Tokamak control and data acquisition; feedback control of Tokamaks; heating and refuelling; neutral beam injection; radio frequency heating; nonlinear drift wave induced plasma transport; toroidal plasma boundary layers; microinstabilities and injected beams and quasilinear theory of the ion acoustic instability

  9. Iron abundance in the atmosphere of Arcturus

    CERN Document Server

    Sheminova, V A

    2015-01-01

    Abundance of iron in the atmosphere of Arcturus has been determined from the profiles or regions of the profiles of the weak lines sensitive to iron abundance. The selected lines of Fe I and Fe II were synthesized with the MARCS theoretical models of the atmosphere. From the observed profiles of lines available with a high spectral resolution in the atlas by Hinkle and Wallace (2005), the values of the iron abundance $A = 6.95 \\pm 0.03$ and the radial-tangential macroturbulent velocity $5.6 \\pm 0.2$ km/s were obtained for Arcturus. The same physical quantities were found for the Sun as a star; they are $7.42 \\pm 0.02$ and $3.4 \\pm 0.3$ km/s, respectively. For Arcturus, the iron abundance relative to the solar one was determined with the differential method as [Fe/H] $=-0.48 \\pm 0.02$.

  10. Chemical abundance analysis of 19 barium stars

    CERN Document Server

    Yang, G C; Spite, M; Chen, Y Q; Zhao, G; Zhang, B; Liu, G Q; Liu, Y J; Liu, N; Deng, L C; Spite, F; Hill, V; Zhang, C X

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures, surface gravities, metallicity and microturbulent velocity) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their light elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn and Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-ca...

  11. SWFSC/MMTD: Vaquita Abundance Survey 1997

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1997, the Southwest Fisheries Science Center (SWFSC) conducted a survey designed to estimate the abundance of vaquita, the Gulf of California harbor porpoise...

  12. Chinook Abundance - Linear Features [ds181

    Data.gov (United States)

    California Department of Resources — The dataset 'ds181_Chinook_ln' is a product of the CalFish Adult Salmonid Abundance Database. Data in this shapefile are collected from stream sections or reaches...

  13. Testing Relationships between Energy and Vertebrate Abundance

    International Nuclear Information System (INIS)

    Understanding what drives variation in the abundance of organisms is fundamental to evolutionary ecology and wildlife management. Yet despite its importance, there is still great uncertainty about the main factors influencing variation in vertebrate abundance across taxa. We believe valuable knowledge and increased predictive power could be gained by taking into account both the intrinsic factors of species and the extrinsic factors related to environmental surroundings in the commonly cited RQ model, which provides a simple conceptual framework valid at both the interspecific and the intraspecific scales. Approaches comparing studies undertaken at different spatial and taxonomic scales could be key to our ability to better predict abundance, and thanks to the increased availability of population size data, global geographic datasets, and improved comparative methods, there might be unprecedented opportunities to (1) gain a greater understanding of vertebrate abundance patterns and (2) test existing theories on free-ranging animals.

  14. Primordial Deuterium Abundance and Cosmic Baryon Density

    OpenAIRE

    Hogan, Craig J.

    1994-01-01

    The comparison of cosmic abundances of the light elements with the density of baryonic stars and gas in the universe today provides a critical test of big bang theory and a powerful probe of the nature of dark matter. A new technique allows determination of cosmic deuterium abundances in quasar absorption clouds at large redshift, allowing a new test of big bang homogeneity in diverse, very distant systems. The first results of these studies are summarized, along with their implications. The ...

  15. Estimating whale abundance using sparse hydrophone arrays

    OpenAIRE

    Harris, Danielle Veronica

    2012-01-01

    Passive acoustic monitoring has been used to investigate many aspects of marine mammal ecology, although methods to estimate absolute abundance and density using acoustic data have only been developed in recent years. The instrument configuration in an acoustic survey determines which abundance estimation methods can be used. Sparsely distributed arrays of instruments are useful because wide geographic areas can be covered. However, instrument spacing in sparse arrays is such that the same...

  16. Spatial scaling of species abundance distributions

    OpenAIRE

    Borda-de-Água, Luís; Borges, Paulo A. V.; Hubbell, Stephen P.; Pereira, Henrique M

    2012-01-01

    Copyright © 2012 The Authors. Ecography © 2012 Nordic Society Oikos. Species abundance distributions are an essential tool in describing the biodiversity of ecological communities. We now know that their shape changes as a function of the size of area sampled. Here we analyze the scaling properties of species abundance distributions by using the moments of the logarithmically transformed number of individuals. We find that the moments as a function of area size are well fitted by power law...

  17. How selection structures species abundance distributions

    OpenAIRE

    Magurran, A.E; Henderson, P. A.

    2012-01-01

    How do species divide resources to produce the characteristic species abundance distributions seen in nature? One way to resolve this problem is to examine how the biomass (or capacity) of the spatial guilds that combine to produce an abundance distribution is allocated among species. Here we argue that selection on body size varies across guilds occupying spatially distinct habitats. Using an exceptionally well-characterized estuarine fish community, we show that biomass is concentrated in l...

  18. Modelling Void Abundance in Modified Gravity

    CERN Document Server

    Voivodic, Rodrigo; Llinares, Claudio; Mota, David F

    2016-01-01

    We use a spherical model and an extended excursion set formalism with drifting diffusive barriers to predict the abundance of cosmic voids in the context of general relativity as well as f(R) and symmetron models of modified gravity. We detect spherical voids from a suite of N-body simulations of these gravity theories and compare the measured void abundance to theory predictions. We find that our model correctly describes the abundance of both dark matter and galaxy voids, providing a better fit than previous proposals in the literature based on static barriers. We use the simulation abundance results to fit for the abundance model free parameters as a function of modified gravity parameters, and show that counts of dark matter voids can provide interesting constraints on modified gravity. For galaxy voids, more closely related to optical observations, we find that constraining modified gravity from void abundance alone may be significantly more challenging. In the context of current and upcoming galaxy surv...

  19. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    Science.gov (United States)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  20. TEA: A Code Calculating Thermochemical Equilibrium Abundances

    Science.gov (United States)

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2016-07-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. and Eriksson. It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature–pressure pairs. We tested the code against the method of Burrows & Sharp, the free thermochemical equilibrium code Chemical Equilibrium with Applications (CEA), and the example given by Burrows & Sharp. Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is available under a reproducible-research, open-source license via https://github.com/dzesmin/TEA.

  1. Report on carbon and nitrogen abundance studies

    Science.gov (United States)

    Boehm-Vitense, Erika

    1991-01-01

    The aim of the proposal was to determine the nitrogen to carbon abundance ratios from transition layer lines in stars with different T(sub eff) and luminosities. The equations which give the surface emission line fluxes and the measured ratio of the NV to CIV emission line fluxes are presented and explained. The abundance results are compared with those of photospheric abundance studies for stars in common with the photospheric investigations. The results show that the analyses are at least as accurate as the photospheric determinations. These studies can be extended to F and early G stars for which photospheric abundance determinations for giants are hard to do because molecular bands become too weak. The abundance determination in the context of stellar evolution is addressed. The N/C abundance ratio increases steeply at the point of evolution for which the convection zone reaches deepest. Looking at the evolution of the rotation velocities v sin i, a steep decrease in v sin i is related to the increasing depth of the convection zone. It is concluded that the decrease in v sin i for T(sub eff) less than or approximately = 5800 K is most probably due to the rearrangement of the angular momentum in the stars due to deep convective mixing. It appears that the convection zone is rotating with nearly depth independent angular momentum. Other research results and ongoing projects are discussed.

  2. Planetary nebulae abundances and stellar evolution

    CERN Document Server

    Pottasch, S R

    2006-01-01

    A summary is given of planetary nebulae abundances from ISO measurements. It is shown that these nebulae show abundance gradients (with galactocentric distance), which in the case of neon, argon, sulfur and oxygen (with four exceptions) are the same as HII regions and early type star abundance gradients. The abundance of these elements predicted from these gradients at the distance of the Sun from the center are exactly the solar abundance. Sulfur is the exception to this; the reason for this is discussed. The higher solar neon abundance is confirmed; this is discussed in terms of the results of helioseismology. Evidence is presented for oxygen destruction via ON cycling having occurred in the progenitors of four planetary nebulae with bilobal structure. These progenitor stars had a high mass, probably greater than 5 solar masses. This is deduced from the high values of He/H and N/H found in these nebulae. Formation of nitrogen, helium and carbon are discussed. The high mass progenitors which showed oxygen de...

  3. Plasma chromograninx

    DEFF Research Database (Denmark)

    Goetze, Jens P; Hilsted, Linda M; Rehfeld, Jens F;

    2014-01-01

    Cardiovascular risk assessment remains difficult in elderly patients. We examined whether chromogranin A (CgA) measurement in plasma may be valuable in assessing risk of death in elderly patients with symptoms of heart failure in a primary care setting. A total of 470 patients (mean age 73 years......) were followed for 10 years. For CgA plasma measurement, we used a two-step method including a screening test and a confirmative test with plasma pre-treatment with trypsin. Cox multivariable proportional regression and receiver-operating curve (ROC) analyses were used to assess mortality risk...... of follow-up showed significant additive value of CgA confirm measurements compared with NT-proBNP and clinical variables. CgA measurement in the plasma of elderly patients with symptoms of heart failure can identify those at increased risk of short- and long-term mortality....

  4. Plasma Cleaning

    Science.gov (United States)

    Hintze, Paul E.

    2016-01-01

    NASA's Kennedy Space Center has developed two solvent-free precision cleaning techniques: plasma cleaning and supercritical carbon dioxide (SCCO2), that has equal performance, cost parity, and no environmental liability, as compared to existing solvent cleaning methods.

  5. Plasma technology

    International Nuclear Information System (INIS)

    IREQ was contracted by the Canadian Electrical Association to review plasma technology and assess the potential for application of this technology in Canada. A team of experts in the various aspects of this technology was assembled and each team member was asked to contribute to this report on the applications of plasma pertinent to his or her particular field of expertise. The following areas were examined in detail: iron, steel and strategic-metals production; surface treatment by spraying; welding and cutting; chemical processing; drying; and low-temperature treatment. A large market for the penetration of electricity has been identified. To build up confidence in the technology, support should be provided for selected R and D projects, plasma torch demonstrations at full power, and large-scale plasma process testing

  6. Plasma Speaker

    OpenAIRE

    Kovář, J

    2015-01-01

    The article describes the design and construction of one-channel plasma speaker. Absence of mechanical membrane gives the plasma speaker no frequency limitation. The design consists of power source to supply control electronic for signal modulation, converter and output transformer. Modulation of audio signal is realized by integrated circuit TL 594 that provides the PWM modulation. Duty cycle and frequency is adjusted by potentiometers. Dual forward converter is used to voltage amplification...

  7. Plasma confinement

    CERN Document Server

    Hazeltine, R D

    2003-01-01

    Detailed and authoritative, this volume examines the essential physics underlying international research in magnetic confinement fusion. It offers readable, thorough accounts of the fundamental concepts behind methods of confining plasma at or near thermonuclear conditions. Designed for a one- or two-semester graduate-level course in plasma physics, it also represents a valuable reference for professional physicists in controlled fusion and related disciplines.

  8. Coherent structures and transport in drift wave plasma turbulence

    DEFF Research Database (Denmark)

    Korsholm, Søren Bang

    Fusion energy research aims at developing fusion power plants providing safe and clean energy with abundant fuels. Plasma turbulence induced transport of energy and particles is a performance limiting factor for fusion devices. Hence the understanding of plasma turbulence is important...

  9. Solar abundances with the SPICE spectral imager on Solar Orbiter

    Science.gov (United States)

    Giunta, Alessandra; Haberreiter, Margit; Peter, Hardi; Vial, Jean-Claude; Harrison, Richard; Parenti, Susanna; Innes, Davina; Schmutz, Werner; Buchlin, Eric; Chamberlin, Phillip; Thompson, William; Bocchialini, Karine; Gabriel, Alan; Morris, Nigel; Caldwell, Martin; Auchere, Frederic; Curdt, Werner; Teriaca, Luca; Hassler, Donald M.; DeForest, Craig; Hansteen, Viggo; Carlsson, Mats; Philippon, Anne; Janvier, Miho; Wimmer-Schweingruber, Robert; Griffin, Douglas; Baudin, Frederic; Davila, Joseph; Fludra, Andrzej; Waltham, Nick; Eccleston, Paul; Gottwald, Alexander; Klein, Roman; Hanley, John; Walls, Buddy; Howe, Chris; Schuehle, Udo; Gyo, Manfred; Pfiffner, Dany

    2016-07-01

    Elemental composition of the solar atmosphere and in particular abundance bias of low and high First Ionization Potential (FIP) elements are a key tracer of the source regions of the solar wind. These abundances and their spatio-temporal variations, as well as the other plasma parameters , will be derived by the SPICE (Spectral Imaging of the Coronal Environment) EUV spectral imager on the upcoming Solar Orbiter mission. SPICE is designed to provide spectroheliograms (spectral images) using a core set of emission lines arising from ions of both low-FIP and high-FIP elements. These lines are formed over a wide range of temperatures, enabling the analysis of the different layers of the solar atmosphere. SPICE will use these spectroheliograms to produce dynamic composition maps of the solar atmosphere to be compared to in-situ measurements of the solar wind composition of the same elements (i.e. O, Ne, Mg, Fe). This will provide a tool to study the connectivity between the spacecraft (the Heliosphere) and the Sun. We will discuss the SPICE capabilities for such composition measurements.

  10. Clonal growth and plant species abundance

    Science.gov (United States)

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-01-01

    Background and Aims Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf–height–seed) traits and by actual performance in the botanical garden. Methods Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area – height – seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. Key Results After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Conclusions Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially

  11. Expression of microRNAs in Horse Plasma and Their Characteristic Nucleotide Composition

    Science.gov (United States)

    Lee, Seungwoo; Hwang, Seungwoo; Yu, Hee Jeong; Oh, Dayoung; Choi, Yu Jung; Kim, Myung-Chul; Kim, Yongbaek; Ryu, Doug-Young

    2016-01-01

    MicroRNAs (miRNAs) in blood plasma are stable under high levels of ribonuclease activity and could function in tissue-to-tissue communication, suggesting that they may have distinctive structural characteristics compared with non-circulating miRNAs. In this study, the expression of miRNAs in horse plasma and their characteristic nucleotide composition were examined and compared with non-plasma miRNAs. Highly expressed plasma miRNA species were not part of the abundant group of miRNAs in non-plasma tissues, except for the eca-let-7 family. eca-miR-486-5p, -92a, and -21 were among the most abundant plasma miRNAs, and their human orthologs also belong to the most abundant group of miRNAs in human plasma. Uracil and guanine were the most common nucleotides of both plasma and non-plasma miRNAs. Cytosine was the least common in plasma and non-plasma miRNAs, although levels were higher in plasma miRNAs. Plasma miRNAs also showed higher expression levels of miRNAs containing adenine and cytosine repeats, compared with non-plasma miRNAs. These observations indicate that miRNAs in the plasma have a unique nucleotide composition. PMID:26731407

  12. Expression of microRNAs in Horse Plasma and Their Characteristic Nucleotide Composition.

    Directory of Open Access Journals (Sweden)

    Seungwoo Lee

    Full Text Available MicroRNAs (miRNAs in blood plasma are stable under high levels of ribonuclease activity and could function in tissue-to-tissue communication, suggesting that they may have distinctive structural characteristics compared with non-circulating miRNAs. In this study, the expression of miRNAs in horse plasma and their characteristic nucleotide composition were examined and compared with non-plasma miRNAs. Highly expressed plasma miRNA species were not part of the abundant group of miRNAs in non-plasma tissues, except for the eca-let-7 family. eca-miR-486-5p, -92a, and -21 were among the most abundant plasma miRNAs, and their human orthologs also belong to the most abundant group of miRNAs in human plasma. Uracil and guanine were the most common nucleotides of both plasma and non-plasma miRNAs. Cytosine was the least common in plasma and non-plasma miRNAs, although levels were higher in plasma miRNAs. Plasma miRNAs also showed higher expression levels of miRNAs containing adenine and cytosine repeats, compared with non-plasma miRNAs. These observations indicate that miRNAs in the plasma have a unique nucleotide composition.

  13. Linking species abundance distributions in numerical abundance and biomass through simple assumptions about community structure

    OpenAIRE

    Henderson, Peter A.; Magurran, Anne E

    2010-01-01

    Species abundance distributions (SADs) are widely used as a tool for summarizing ecological communities but may have different shapes, depending on the currency used to measure species importance. We develop a simple plotting method that links SADs in the alternative currencies of numerical abundance and biomass and is underpinned by testable predictions about how organisms occupy physical space. When log numerical abundance is plotted against log biomass, the species lie within an approximat...

  14. Enhanced abundances in three large-diameter mixed-morphology supernova remnants

    OpenAIRE

    Lazendic, J.; Slane, P.

    2005-01-01

    We present an X-ray study of three mixed-morphology supernova remnants (SNRs), HB 21, CTB 1 and HB 3, using archival ASCA and ROSAT data. These data are complemented by archival Chandra X-ray Observatory data for CTB 1 and XMM-Newton X-ray Observatory data for HB 3. The spectra from HB 21 and HB 3 are well-described with a single-temperature thermal plasma in ionization equilibrium, while a two-temperature thermal plasma is found in CTB 1. We found enhanced abundances in all three SNRs. The e...

  15. Transition Region Abundance Measurements During Impulsive Heating Events

    CERN Document Server

    Warren, Harry P; Doschek, George A; Feldman, Uri

    2015-01-01

    It is well established that elemental abundances vary in the solar atmosphere and that this variation is organized by first ionization potential (FIP). Previous studies have shown that in the solar corona low-FIP elements, such as Fe, Si, Mg, and Ca, are generally enriched relative to high-FIP elements, such as C, N, O, Ar, and Ne. In this paper we report on measurements of plasma composition made during impulsive heating events observed at transition region temperatures with the Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode. During these events the intensities of O IV, V, and VI emission lines are enhanced relative to emission lines from Mg V, VI, and VII and Si VI and VII and indicate a composition close to that of the photosphere. Long-lived coronal fan structures, in contrast, show an enrichment of low-FIP elements. We conjecture that the plasma composition is an important signature of the coronal heating process, with impulsive heating leading to the evaporation of unfractionated material from...

  16. Transition Region Abundance Measurements During Impulsive Heating Events

    Science.gov (United States)

    Warren, Harry P.; Brooks, David H.; Doschek, George A.; Feldman, Uri

    2016-06-01

    It is well established that elemental abundances vary in the solar atmosphere and that this variation is organized by first ionization potential (FIP). Previous studies have shown that in the solar corona, low-FIP elements such as Fe, Si, Mg, and Ca, are generally enriched relative to high-FIP elements such as C, N, O, Ar, and Ne. In this paper we report on measurements of plasma composition made during impulsive heating events observed at transition region temperatures with the Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode. During these events the intensities of O iv, v, and vi emission lines are enhanced relative to emission lines from Mg v, vi, and vii and Si vi and vii, and indicate a composition close to that of the photosphere. Long-lived coronal fan structures, in contrast, show an enrichment of low-FIP elements. We conjecture that the plasma composition is an important signature of the coronal heating process, with impulsive heating leading to the evaporation of unfractionated material from the lower layers of the solar atmosphere and higher-frequency heating leading to long-lived structures and the accumulation of low-FIP elements in the corona.

  17. The iron abundance of the Magellanic Bridge

    CERN Document Server

    Dufton, P L; Thompson, H M A; Street, R A

    2008-01-01

    High-resolution HST ultra-violet spectra for five B-type stars in the Magellanic Bridge and in the Large and Small Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates obtained from late-type stars or the optical lines in B-type stars by approximately 0.5 dex. This may be due to systematic errors possibly arising from non-LTE effects or from errors in the atomic data as similar low Fe abundances having previously been reported from the analysis of the ultra-violet spectra of Galactic early-type stars. The iron abundance estimates for all three Bridge targets appear to be significantly lower than those found for the SMC and LMC by approximately -0.5 dex and -0.8 dex respectively and these differential results should not be affected by any systematic errors present in the absolute abundance estimates. These differential iron abundance estimates are consistent with the underabundances for C, N, O, Mg and Si of approximately -1.1 dex relative to our...

  18. Oxygen abundance maps of CALIFA galaxies

    CERN Document Server

    Zinchenko, I A; Grebel, E K; Sanchez, S F; Vilchez, J M

    2016-01-01

    We construct maps of the oxygen abundance distribution across the disks of 88 galaxies using CALIFA data release 2 (DR2) spectra. The position of the center of a galaxy (coordinates on the plate) were also taken from the CALIFA DR2. The galaxy inclination, the position angle of the major axis, and the optical radius were determined from the analysis of the surface brightnesses in the SDSS $g$ and $r$ bands of the photometric maps of SDSS data release 9. We explore the global azimuthal abundance asymmetry in the disks of the CALIFA galaxies and the presence of a break in the radial oxygen abundance distribution. We found that there is no significant global azimuthal asymmetry for our sample of galaxies, i.e., the asymmetry is small, usually lower than 0.05 dex. The scatter in oxygen abundances around the abundance gradient has a comparable value, $\\lesssim 0.05$ dex. A significant (possibly dominant) fraction of the asymmetry can be attributed to the uncertainties in the geometrical parameters of these galaxie...

  19. Good abundances from bad spectra; 1, techniques

    CERN Document Server

    Bryn, J; Wyse, R F G; Gilmore, Gerard; Wyse, Rosemary F G

    1995-01-01

    We have developed techniques to extract true iron abundances and surface gravities from spectra of the type provided by the multiple-object fibre-fed spectroscopic radial-velocity surveys underway with 2dF, HYDRA, NESSIE, and the forthcoming Sloan survey. Our method is optimised for low S/N, intermediate resolution blue spectra of G stars. Spectroscopic indices sensitive to iron abundance and gravity are defined from a set of narrow (few Angstrom) wavelength intervals, and calibrated using synthetic spectra. We have also defined a single abundance indicator which is able to provide useful iron abundance information from spectra having S/N ratios as low as 10 per Angstrom. The theoretical basis and calibration using synthetic spectra are described in this paper. The empirical calibration of these techniques by application to observational data is described in Jones, Wyse and Gilmore (PASP July 1995). The technique provides precise iron abundances, with zero-point correct to \\sim 0.1 dex, and is reliable, with ...

  20. Why is Trichodesmium abundant in the Kuroshio?

    Science.gov (United States)

    Shiozaki, T.; Takeda, S.; Itoh, S.; Kodama, T.; Liu, X.; Hashihama, F.; Furuya, K.

    2015-12-01

    The genus Trichodesmium is recognized as an abundant and major diazotroph in the Kuroshio, but the reason for this remains unclear. The present study investigated the abundance of Trichodesmium spp. and nitrogen fixation together with concentrations of dissolved iron and phosphate in the Kuroshio and its marginal seas. We performed the observations near the Miyako Islands, which form part of the Ryukyu Islands, situated along the Kuroshio, since our satellite analysis suggested that material transport could occur from the islands to the Kuroshio. Trichodesmium spp. bloomed (> 20 000 filaments L-1) near the Miyako Islands, abundance was high in the Kuroshio and the Kuroshio bifurcation region of the East China Sea, but was low in the Philippine Sea. The abundance of Trichodesmium spp. was significantly correlated with the total nitrogen fixation activity. The surface concentrations of dissolved iron (0.19-0.89 nM) and phosphate (differences in Trichodesmium spp. abundance and nitrogen fixation. Numerical particle-tracking experiments simulated the transportation of water around the Ryukyu Islands to the Kuroshio. Our results indicate that Trichodesmium growing around the Ryukyu Islands could be advected into the Kuroshio.

  1. Abundances of Molecular Species in Barnard 68

    CERN Document Server

    Francesco, J D; Welch, W J; Bergin, E A; Francesco, James Di; Hogerheijde, Michiel R.; Welch, William J.; Bergin, Edwin A.

    2002-01-01

    Abundances for 5 molecules (C18O, CS, NH3, H2CO, and C3H2) and 1 molecular ion (N2H+) and upper limits for the abundances of 1 molecule (13CO) and 1 molecular ion (HCO+) are derived for gas within the Bok globule Barnard 68 (B68). The abundances were determined using our own BIMA millimeter interferometer data and single-dish data gathered from the literature, in conjunction with a Monte Carlo radiative transfer model. Since B68 is the only starless core to have its density structure strongly constrained via extinction mapping, a major uncertainty has been removed from these determinations. All abundances for B68 are lower than those derived for translucent and cold dense clouds, but perhaps only significantly for N2H+, NH3, and C3H2. Depletion of CS toward the extinction peak of B68 is hinted at by the large offset between the extinction peak and the position of maximum CS line brightness. Abundances derived here for C18O and N2H+ are consistent with other, recently determined values at positions observed in...

  2. Monster Sawtooth Activity in Ohmically Heated HT-7 Plasma

    Institute of Scientific and Technical Information of China (English)

    胡立群; 石跃江; 刘胜侠

    2001-01-01

    Experimental properties of monster sawtooth activities in ohmic HT-7 plasma are presented in this paper. The monster sawtooth activities belong to global fluctuations and are characterized with a series of large core collapses on SXR intensity traces with a long period, a large amplitude fluctuation and a large inversion radius. However, they emerge without apparent deterioration of plasma confinement and without major plasma disruption. During the events,long partial sawtooth collapses and abundant MHD phenomena are also observed.

  3. Plasma metallization

    CERN Document Server

    Crowther, J M

    1997-01-01

    Many methods are currently used for the production of thin metal films. However, all of these have drawbacks associated with them, for example the need for UHV conditions, high temperatures, exotic metal precursors, or the inability to coat complex shaped objects. Reduction of supported metal salts by non-isothermal plasma treatment does not suffer from these drawbacks. In order to produce and analyse metal films before they become contaminated, a plasma chamber which could be attached directly to a UHV chamber with XPS capability was designed and built. This allowed plasma treatment of supported metal salts and surface analysis by XPS to be performed without exposure of the metal film to the atmosphere. Non-equilibrium plasma treatment of Nylon 66 supported gold(lll) chloride using hydrogen as the feed gas resulted in a 95% pure gold film, the remaining 5% of the film being carbon. If argon or helium were used as the feed gases during plasma treatment the resultant gold films were 100% pure. Some degree of s...

  4. Planetary Nebula Abundances and Morphology: Probing the Chemical Evolution of the Milky Way

    CERN Document Server

    Stanghellini, L; Cunha, K; Manchado, A; Villaver, E

    2006-01-01

    This paper presents a homogeneous study of abundances in a sample of 79 northern galactic planetary nebulae whose morphological classes have been uniformly determined. Ionic abundances and plasma diagnostics were derived from selected optical line strengths in the literature, and elemental abundances were estimated with the Ionization Correction Factor developed by Kingsbourgh & Barlow (1994). We compare the elemental abundances to the final yields obtained from stellar evolution models of low-and intermediate-mass stars, and we confirm that most Bipolar planetary nebulae have high nitrogen and helium abundance, and are the likely progeny of stars with main-sequence mass larger than 3 solar masses. We derive =0.27, and discuss the implication of such a high ratio in connection with the solar neon abundance. We determine the galactic gradients of oxygen and neon, and found Delta log (O/H)/Delta R=-0.01 dex/kpc$ and Delta log (Ne/H)/Delta R=-0.01 dex/kpc. These flat PN gradients do not reconcile with galact...

  5. Plasma dynamo

    CERN Document Server

    Rincon, F; Schekochihin, A A; Valentini, F

    2015-01-01

    Magnetic fields pervade the entire Universe and, through their dynamical interactions with matter, affect the formation and evolution of astrophysical systems from cosmological to planetary scales. How primordial cosmological seed fields arose and were further amplified to $\\mu$Gauss levels reported in nearby galaxy clusters, near equipartition with kinetic energy of plasma motions and on scales of at least tens of kiloparsecs, is a major theoretical puzzle still largely unconstrained by observations. Extragalactic plasmas are weakly collisional (as opposed to collisional magnetohydrodynamic fluids), and whether magnetic-field growth and its sustainment through an efficient dynamo instability driven by chaotic motions is possible in such plasmas is not known. Fully kinetic numerical simulations of the Vlasov equation in a six-dimensional phase space necessary to answer this question have until recently remained beyond computational capabilities. Here, we show by means of such simulations that magnetic-field a...

  6. Plasma properties

    International Nuclear Information System (INIS)

    A cursory examination of the research activities of the Magneto-Fluid Dynamics Division for the calendar year 1988 shows the effects of the gradual transformation of the group. Although our principal activity, fusion plasma physics research, is unchanged, the work shows closer ties to problems relevant to present experiments than previously. Most notable is the concentrated effort on tokamak equilibrium and transport. We are exploring the implication of turbulence induced transport, resistive MHD effects, neoclassical transport, and possible interpretations of transport based on classical phenomena. In addition, one of our members has chosen to focus on problems of enhanced statistical methods for interpretation of experiments. All of this activity preceded the Tokamak Transport Initiative and reflects our active involvement and concern with the world-wide tokamak program. Since equilibrium and transport are by no means the only theoretical plasma physics problems affecting fusion devices we continue substantial efforts in wave propagation and heating, particle simulation of plasmas, stability theory, enhancement of numerical algorithms, and general plasma physics. We are attempting to develop effective numerical schemes for the Boltzmann equation, adaptive grid methods for MHD, and particle simulation of boundary and antenna effects. Many of these topics reflect our continuing concern to maintain a modest effort in the development of theoretical models and tools for problems of real significance to fusion, but not necessarily of immediate highest priority. We select problems which we expect to become extremely important in the future. Our space plasma physics activities, funded by agencies other than DOE, transfers knowledge learned in fusion plasma physics to another area and conversely stimulates work also relevant to fusion problems

  7. ''Dusty plasmas''

    International Nuclear Information System (INIS)

    The field of ''dusty plasmas'' promises to be a very rewarding topic of research for the next decade or so, not only from the academic point of view where the emphasis is on developing the theory of the often complex collective and non-linear processes, but also from the point of view of applications in astrophysics, space physics, environmental and energy research. In this ''comment'' we should like to sketch the current development of this fast growing and potentially very important research area. We will discuss the new features of ''dusty'' plasmas in the most general terms and then briefly mention some successful applications and effects which have already been examined. (author)

  8. Solar neon abundances from gamma-ray spectroscopy and He-3-rich particle events

    Science.gov (United States)

    Reames, D. V.; Ramaty, R.; Von Rosenvinge, T. T.

    1988-01-01

    Ambient solar atmospheric abundances derived from gamma-ray spectroscopy are compared with observations of solar energetic particles. Agreement is found between the gamma-ray-derived Ne/O ratio and the corresponding mean ratio for He-3-rich flares. Both of these values are significantly higher than inferred coronal Ne/O ratios. It is suggested that the mean Ne/O ratio in He-3-rich flares reflects the composition of the flare plasma rather than the acceleration process.

  9. Plasma physics and engineering

    CERN Document Server

    Fridman, Alexander

    2011-01-01

    Part I: Fundamentals of Plasma Physics and Plasma ChemistryPlasma in Nature, in the Laboratory, and in IndustryOccurrence of Plasma: Natural and Man MadeGas DischargesPlasma Applications, Plasmas in IndustryPlasma Applications for Environmental ControlPlasma Applications in Energy ConversionPlasma Application for Material ProcessingBreakthrough Plasma Applications in Modern TechnologyElementary Processes of Charged Species in PlasmaElementary Charged Particles in Plasma and Their Elastic and Inelastic CollisionsIonization ProcessesMechanisms of Electron Losses: The Electron-Ion RecombinationEl

  10. Abundance and Impact of Doubly Charged Polyatomic Argon Interferences in ICPMS Spectra.

    Science.gov (United States)

    Hattendorf, Bodo; Gusmini, Bianca; Dorta, Ladina; Houk, Robert S; Günther, Detlef

    2016-07-19

    Doubly charged molecular ions of alkaline earth metals and argon could be identified as spectral interferences in an inductively coupled plasma mass spectrometer. These molecular ions were found to occur at abundances reaching about 10(-4) relative to the alkaline earth atomic ion abundances. They can thus substantially affect ultratrace analyses and, when present at similar concentration as the analyte elements, also isotope ratio measurements. For the case of Cu and Zn isotope ratio analyses, the same mass concentration of Sr was found to alter the measured (63)Cu/(65)Cu and (64)Zn/(66)Zn isotope ratios by -0.036‰ to -0.95‰ due to SrAr(2+), appearing at m/Q 63 and 64. BaAr(2+) can affect Sr isotope analyses, MgAr(2+) may impair S isotope ratio measurements, while CaAr(2+) may cause interference to Ca(+) isotopes. The abundances of the doubly charged molecular ions were higher than those of the corresponding singly charged species, which is in accordance with their generally higher bond dissociation energies. The relative abundances were found to depend significantly on the inductively coupled plasma (ICP) operating conditions and generally increase with increasing carrier gas flow rates or lower gas temperature of the ICP. They also increase by about an order of magnitude when a desolvated aerosol is introduced to the ICP. PMID:27306032

  11. Simulation of arthropod abundance from plant composition

    Directory of Open Access Journals (Sweden)

    WenJun Zhang

    2011-04-01

    Full Text Available The relationship between arthropod abundance and plant composition is extremely complex. It is very hard to develop a mechanistic model to describe the relationship. This study aimed to simulate arthropod abundance from plant composition on grassland using an artificial neural network developed by the author, and to compare simulation performances between the neural network and conventional models. The results revealed that there were complex interactions between plants and arthropods, and the arthropod abundance on grassland was significantly determined of plant families and their cover-degrees rather than plant species and their cover-degrees. Neural network exhibited a better simulation performance than multivariate regression and response surface model. Cross validation indicated that prediction performance of neural network was also superior to these models. It was concluded that neural network is an effective tool to model arthropod abundance from plant composition on grassland. A moderate dimensionality for input space may be determined to produce a reasonably trained neural network. Such procedures for dimensionality reduction as PCE, etc., were suggested being used in the data treatment in neural network modeling. A high dimensionality for input space and a few samples in the input set would result in the deficient learning of neural network. Randomization procedure for sample submission would help to eliminate the sequence correlation but may result in a worse performance in simulation and prediction. It was suggested that randomization procedure could be used to the sample submission for these situations with a lot of samples and a lower dimensionality.

  12. North Sea Elasmobranchs: distribution, abundance and biodiversity

    NARCIS (Netherlands)

    Daan, N.; Heessen, H.J.L.; Hofstede, ter R.

    2005-01-01

    Based on data from various international and national surveys, an overview is given of the fine-scale distribution (resolution of 20¿longitude * 10¿ latitude; ¿ 10*10 nm) and trends in abundance of elasmobranch species reported from the North Sea. Presence-absence maps are produced based on 4 survey

  13. The Galactic Thick Disk Stellar Abundances

    CERN Document Server

    Prochaska, J X; Carney, B W; McWilliam, A; Wolfe, A M; Prochaska, Jason X.; Naumov, Sergei O.; Carney, Bruce W.; William, Andrew Mc; Wolfe, Arthur M.

    2000-01-01

    We present first results from a program to measure the chemical abundances of a large (N>30) sample of thick disk stars with the principal goal of investigating the formation history of the Galactic thick disk. Our analysis confirms previous studies of O and Mg in the thick disk stars which reported enhancements in excess of the thin disk population. Furthermore, the observations of Si, Ca, Ti, Mn, Co, V, Zn, Al, and Eu all argue that the thick disk population has a distinct chemical history from the thin disk. With the exception of V and Co, the thick disk abundance patterns match or tend towards the values observed for halo stars with [Fe/H]~-1. This suggests that the thick disk stars had a chemical enrichment history similar to the metal-rich halo stars. With the possible exception of Si, the thick disk abundance patterns are in excellent agreement with the chemical abundances observed in the metal-poor bulge stars suggesting the two populations formed from the same gas reservoir at a common epoch. We disc...

  14. Nitrous Oxide Production by Abundant Benthic Macrofauna

    DEFF Research Database (Denmark)

    Stief, Peter; Schramm, Andreas

    that do not ingest large quantities of microorganisms produced insignificant amounts of nitrous oxide. Ephemera danica, a very abundant mayfly larva, was monitored monthly in a nitrate-polluted stream. Nitrous oxide production by this filter-feeder was highly dependent on nitrate availability...

  15. The Abundance of Large Arcs From CLASH

    Science.gov (United States)

    Xu, Bingxiao; Postman, Marc; Meneghetti, Massimo; Coe, Dan A.; Clash Team

    2015-01-01

    We have developed an automated arc-finding algorithm to perform a rigorous comparison of the observed and simulated abundance of large lensed background galaxies (a.k.a arcs). We use images from the CLASH program to derive our observed arc abundance. Simulated CLASH images are created by performing ray tracing through mock clusters generated by the N-body simulation calibrated tool -- MOKA, and N-body/hydrodynamic simulations -- MUSIC, over the same mass and redshift range as the CLASH X-ray selected sample. We derive a lensing efficiency of 15 ± 3 arcs per cluster for the X-ray selected CLASH sample and 4 ± 2 arcs per cluster for the simulated sample. The marginally significant difference (3.0 σ) between the results for the observations and the simulations can be explained by the systematically smaller area with magnification larger than 3 (by a factor of ˜4) in both MOKA and MUSIC mass models relative to those derived from the CLASH data. Accounting for this difference brings the observed and simulated arc statistics into full agreement. We find that the source redshift distribution does not have big impact on the arc abundance but the arc abundance is very sensitive to the concentration of the dark matter halos. Our results suggest that the solution to the "arc statistics problem" lies primarily in matching the cluster dark matter distribution.

  16. Will Abundant Natural Gas Solve Climate Change?

    Science.gov (United States)

    McJeon, H. C.; Edmonds, J.; Bauer, N.; Leon, C.; Fisher, B.; Flannery, B.; Hilaire, J.; Krey, V.; Marangoni, G.; Mi, R.; Riahi, K.; Rogner, H.; Tavoni, M.

    2015-12-01

    The rapid deployment of hydraulic fracturing and horizontal drilling technologies enabled the production of previously uneconomic shale gas resources in North America. Global deployment of these advanced gas production technologies could bring large influx of economically competitive unconventional gas resources to the energy system. It has been hoped that abundant natural gas substituting for coal could reduce carbon dioxide (CO2) emissions, which in turn could reduce climate forcing. Other researchers countered that the non-CO2 greenhouse gas (GHG) emissions associated with shale gas production make its lifecycle emissions higher than those of coal. In this study, we employ five state-of-the-art integrated assessment models (IAMs) of energy-economy-climate systems to assess the full impact of abundant gas on climate change. The models show large additional natural gas consumption up to +170% by 2050. The impact on CO2 emissions, however, is found to be much smaller (from -2% to +11%), and a majority of the models reported a small increase in climate forcing (from -0.3% to +7%) associated with the increased use of abundant gas. Our results show that while globally abundant gas may substantially change the future energy market equilibrium, it will not significantly mitigate climate change on its own in the absence of climate policies.

  17. Abundance of Terrestrial Planets by Microlensing

    OpenAIRE

    Yock, Philip

    2000-01-01

    Terrestrial planets may be detected using the gravitational microlensing technique. This was demonstrated in the high magnification event MACHO-98-BLG-35. Observing strategies aimed at measuring the abundance of terrestrial planets are discussed, using both existing telescopes and planned telescopes.

  18. PLASMA SPECTROSCOPY

    NARCIS (Netherlands)

    Jaspers, R. J. E.

    2010-01-01

    A brief introduction into the spectroscopy of fusion plasmas is presented. Basic principles of the emission of ionic, atomic and molecular radiation is explained and a survey of the effects, which lead to the population of the respective excited levels, is given. Line radiation, continuum radiation,

  19. Non-Salmonid Abundance - Line Features [ds186

    Data.gov (United States)

    California Department of Resources — The CalFish Abundance Database contains a comprehensive collection of anadromous fisheries abundance information. The "Other Fish" category contains data collected...

  20. Chemical abundances and kinematics of barium stars

    Science.gov (United States)

    de Castro, D. B.; Pereira, C. B.; Roig, F.; Jilinski, E.; Drake, N. A.; Chavero, C.; Sales Silva, J. V.

    2016-07-01

    In this paper, we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scaleheight, radial velocities, abundances of the Na, Al, α-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local thermodynamic equilibrium model atmospheres of Kurucz and the spectral analysis code MOOG. We found that the metallicities, the temperatures and the surface gravities for barium stars cannot be represented by a single Gaussian distribution. The abundances of α-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anticorrelated with the metallicity. Our kinematical analysis showed that 90 per cent of the barium stars belong to the thin disc population. Based on their luminosities, none of the barium stars are luminous enough to be an asymptotic giant branch star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.

  1. Magnetoresistive waves in plasmas

    International Nuclear Information System (INIS)

    The self-generated magnetic field of a current diffusing into a plasma between conductors can magnetically insulate the plasma. Propagation of magnetoresistive waves in plasmas is analyzed. Applications to plasma opening switches are discussed

  2. Chemical abundance analysis of 19 barium stars

    Science.gov (United States)

    Yang, Guo-Chao; Liang, Yan-Chun; Spite, Monique; Chen, Yu-Qin; Zhao, Gang; Zhang, Bo; Liu, Guo-Qing; Liu, Yu-Juan; Liu, Nian; Deng, Li-Cai; Spite, Francois; Hill, Vanessa; Zhang, Cai-Xia

    2016-01-01

    We aim at deriving accurate atmospheric parameters and chemical abundances of 19 barium (Ba) stars, including both strong and mild Ba stars, based on the high signal-to-noise ratio and high resolution Echelle spectra obtained from the 2.16 m telescope at Xinglong station of National Astronomical Observatories, Chinese Academy of Sciences. The chemical abundances of the sample stars were obtained from an LTE, plane-parallel and line-blanketed atmospheric model by inputting the atmospheric parameters (effective temperatures Teff, surface gravities log g, metallicity [Fe/H] and microturbulence velocity ξt) and equivalent widths of stellar absorption lines. These samples of Ba stars are giants as indicated by atmospheric parameters, metallicities and kinematic analysis about UVW velocity. Chemical abundances of 17 elements were obtained for these Ba stars. Their Na, Al, α- and iron-peak elements (O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Ni) are similar to the solar abundances. Our samples of Ba stars show obvious overabundances of neutron-capture (n-capture) process elements relative to the Sun. Their median abundances of [Ba/Fe], [La/Fe] and [Eu/Fe] are 0.54, 0.65 and 0.40, respectively. The Y I and Zr I abundances are lower than Ba, La and Eu, but higher than the α- and iron-peak elements for the strong Ba stars and similar to the iron-peak elements for the mild stars. There exists a positive correlation between Ba intensity and [Ba/Fe]. For the n-capture elements (Y, Zr, Ba, La), there is an anti-correlation between their [X/Fe] and [Fe/H]. We identify nine of our sample stars as strong Ba stars with [Ba/Fe] >0.6 where seven of them have Ba intensity Ba=2-5, one has Ba=1.5 and another one has Ba=1.0. The remaining ten stars are classified as mild Ba stars with 0.17<[Ba/Fe] <0.54.

  3. Relative abundance determinations in extremely metal poor giants. II. Transition probabilities and the abundance determinations

    International Nuclear Information System (INIS)

    The abundances of Fe and other elements are determined for a star of intermediate metallicity and for nine extremely metal poor stars, including two members of the globular cluster M92 and CD -38 deg 245. The accuracy of the transition probabilities for Fe I and other elements is evaluated. The distribution of the abundances of other elements with respect to Fe is the same for most of the cases studied. Manganese is the only element that shows a different relative abundance in an extremely metal poor star. 120 refs

  4. Plasmas Granulares

    OpenAIRE

    Conde López, Luis; Donoso Vargas, Jose Manuel; Sánchez Torres, Antonio; Tkachenko, Igor Mijail; Cal, Eduardo de la; Carralero Ortiz, Daniel; Pablos, José Luis

    2011-01-01

    Los plasmas granulares son gases total o parcialmente ionizados que, además de iones electrones y átomos neutros, contienen partículas sólidas con carga eléctrica. Dichas partículas cargadas, de tamaño mesoscópico, dan lugar a nuevos fenómenos colectivos con una dinámica característica. Este tipo de plasmas aparecen en sistemas físicos tan diversos como son los reactores de fusión por confinamiento magnético, los sistemas de procesado de semiconductores o en medios astrofísicos. Se presenta u...

  5. Relative Quantification of Several Plasma Proteins during Liver Transplantation Surgery

    Science.gov (United States)

    Parviainen, Ville; Joenväärä, Sakari; Tukiainen, Eija; Ilmakunnas, Minna; Isoniemi, Helena; Renkonen, Risto

    2011-01-01

    Plasma proteome is widely used in studying changes occurring in human body during disease or other disturbances. Immunological methods are commonly used in such studies. In recent years, mass spectrometry has gained popularity in high-throughput analysis of plasma proteins. In this study, we tested whether mass spectrometry and iTRAQ-based protein quantification might be used in proteomic analysis of human plasma during liver transplantation surgery to characterize changes in protein abundances occurring during early graft reperfusion. We sampled blood from systemic circulation as well as blood entering and exiting the liver. After immunodepletion of six high-abundant plasma proteins, trypsin digestion, iTRAQ labeling, and cation-exchange fractionation, the peptides were analyzed by reverse phase nano-LC-MS/MS. In total, 72 proteins were identified of which 31 could be quantified in all patient specimens collected. Of these 31 proteins, ten, mostly medium-to-high abundance plasma proteins with a concentration range of 50–2000 mg/L, displayed relative abundance change of more than 10%. The changes in protein abundance observed in this study allow further research on the role of several proteins in ischemia-reperfusion injury during liver transplantation and possibly in other surgery. PMID:22187521

  6. Relative quantification of several plasma proteins during liver transplantation surgery.

    Science.gov (United States)

    Parviainen, Ville; Joenväärä, Sakari; Tukiainen, Eija; Ilmakunnas, Minna; Isoniemi, Helena; Renkonen, Risto

    2011-01-01

    Plasma proteome is widely used in studying changes occurring in human body during disease or other disturbances. Immunological methods are commonly used in such studies. In recent years, mass spectrometry has gained popularity in high-throughput analysis of plasma proteins. In this study, we tested whether mass spectrometry and iTRAQ-based protein quantification might be used in proteomic analysis of human plasma during liver transplantation surgery to characterize changes in protein abundances occurring during early graft reperfusion. We sampled blood from systemic circulation as well as blood entering and exiting the liver. After immunodepletion of six high-abundant plasma proteins, trypsin digestion, iTRAQ labeling, and cation-exchange fractionation, the peptides were analyzed by reverse phase nano-LC-MS/MS. In total, 72 proteins were identified of which 31 could be quantified in all patient specimens collected. Of these 31 proteins, ten, mostly medium-to-high abundance plasma proteins with a concentration range of 50-2000 mg/L, displayed relative abundance change of more than 10%. The changes in protein abundance observed in this study allow further research on the role of several proteins in ischemia-reperfusion injury during liver transplantation and possibly in other surgery.

  7. Relative Quantification of Several Plasma Proteins during Liver Transplantation Surgery

    Directory of Open Access Journals (Sweden)

    Ville Parviainen

    2011-01-01

    Full Text Available Plasma proteome is widely used in studying changes occurring in human body during disease or other disturbances. Immunological methods are commonly used in such studies. In recent years, mass spectrometry has gained popularity in high-throughput analysis of plasma proteins. In this study, we tested whether mass spectrometry and iTRAQ-based protein quantification might be used in proteomic analysis of human plasma during liver transplantation surgery to characterize changes in protein abundances occurring during early graft reperfusion. We sampled blood from systemic circulation as well as blood entering and exiting the liver. After immunodepletion of six high-abundant plasma proteins, trypsin digestion, iTRAQ labeling, and cation-exchange fractionation, the peptides were analyzed by reverse phase nano-LC-MS/MS. In total, 72 proteins were identified of which 31 could be quantified in all patient specimens collected. Of these 31 proteins, ten, mostly medium-to-high abundance plasma proteins with a concentration range of 50–2000 mg/L, displayed relative abundance change of more than 10%. The changes in protein abundance observed in this study allow further research on the role of several proteins in ischemia-reperfusion injury during liver transplantation and possibly in other surgery.

  8. The predominant cholecystokinin in human plasma and intestine is cholecystokinin-33

    DEFF Research Database (Denmark)

    Rehfeld, J F; Sun, G; Christensen, T;

    2001-01-01

    Cholecystokinin (CCK) occurs in multiple molecular forms; the major ones are CCK-58, -33, -22, and -8. Their relative abundance in human plasma and intestine, however, is debated. To settle the issue, extracts of intestinal biopsies and plasma from 10 human subjects have been examined...... is the second most abundant ( approximately 34% and 30%, respectively). In contrast, CCK-58 is less abundant in human intestines ( approximately 18%) and plasma ( approximately 11%). Its predominance in feline intestines, however, was confirmed. Hence, the results show a significant species variation...

  9. The primordial deuterium abundance problems and prospects

    CERN Document Server

    Levshakov, S A; Kegel, W H; Levshakov, Sergei A.; Takahara, Fumio; Kegel, Wilhelm H.

    1997-01-01

    The current status of extragalactic deuterium abundance is discussed using two examples of `low' and `high' D/H measurements. We show that the discordance of these two types of D abundances may be a consequence of the spatial correlations in the stochastic velocity field. Within the framework of the generalized procedure (accounting for such effects) one finds good agreement between different observations and the theoretical predictions for standard big bang nucleosynthesis (SBBN). In particular, we show that the deuterium absorption seen at z = 2.504 toward Q1009+2956 and the H+D Ly-alpha profile observed at z = 0.701 toward Q1718+4807 are compatible with D/H $\\sim 4.1 - 4.6\\times10^{-5}$. This result supports SBBN and, thus, no inhomogeneity is needed. The problem of precise D/H measurements is discussed.

  10. Earth Abundant Element Type I Clathrate Phases

    Directory of Open Access Journals (Sweden)

    Susan M. Kauzlarich

    2016-08-01

    Full Text Available Earth abundant element clathrate phases are of interest for a number of applications ranging from photovoltaics to thermoelectrics. Silicon-containing type I clathrate is a framework structure with the stoichiometry A8-xSi46 (A = guest atom such as alkali metal that can be tuned by alloying and doping with other elements. The type I clathrate framework can be described as being composed of two types of polyhedral cages made up of tetrahedrally coordinated Si: pentagonal dodecahedra with 20 atoms and tetrakaidecahedra with 24 atoms in the ratio of 2:6. The cation sites, A, are found in the center of each polyhedral cage. This review focuses on the newest discoveries in the group 13-silicon type I clathrate family: A8E8Si38 (A = alkali metal; E = Al, Ga and their properties. Possible approaches to new phases based on earth abundant elements and their potential applications will be discussed.

  11. Attenuation of species abundance distributions by sampling.

    Science.gov (United States)

    Shimadzu, Hideyasu; Darnell, Ross

    2015-04-01

    Quantifying biodiversity aspects such as species presence/ absence, richness and abundance is an important challenge to answer scientific and resource management questions. In practice, biodiversity can only be assessed from biological material taken by surveys, a difficult task given limited time and resources. A type of random sampling, or often called sub-sampling, is a commonly used technique to reduce the amount of time and effort for investigating large quantities of biological samples. However, it is not immediately clear how (sub-)sampling affects the estimate of biodiversity aspects from a quantitative perspective. This paper specifies the effect of (sub-)sampling as attenuation of the species abundance distribution (SAD), and articulates how the sampling bias is induced to the SAD by random sampling. The framework presented also reveals some confusion in previous theoretical studies. PMID:26064626

  12. The primordial helium abundance from updated emissivities

    CERN Document Server

    Aver, Erik; Porter, R L; Skillman, Evan D

    2013-01-01

    Observations of metal-poor extragalactic H II regions allow the determination of the primordial helium abundance, Y_p. The He I emissivities are the foundation of the model of the H II region's emission. Porter, Ferland, Storey, & Detisch (2012) have recently published updated He I emissivities based on improved photoionization cross-sections. We incorporate these new atomic data and update our recent Markov Chain Monte Carlo analysis of the dataset published by Izotov, Thuan, & Stasinska (2007). As before, cuts are made to promote quality and reliability, and only solutions which fit the data within 95% confidence level are used to determine the primordial He abundance. The previously qualifying dataset is almost entirely retained and with strong concordance between the physical parameters. Overall, an upward bias from the new emissivities leads to a decrease in Y_p. In addition, we find a general trend to larger uncertainties in individual objects (due to changes in the emissivities) and an increase...

  13. Abundances in the diffuse interstellar medium

    International Nuclear Information System (INIS)

    The wealth of interstellar absorption line data obtained with the Copernicus and IUE satellites has opened up a new era in studies of the interstellar gas. It is now well established that certain elements, generally those with high condensation temperatures, are substantially under-abundant in the gas-phase relative to total solar or cosmic abundances. This depletion of elements is due to the existence of solid material in the form of dust grains in the interstellar medium. Surprisingly, however, recent surveys indicate that even volatile elements such as Zn and S are significantly depleted in many sight lines. Developments in this field which have been made possible by the large base of UV interstellar absorption line data built up over recent years are reviewed and the implications of the results for our understanding of the physical processes governing depletion are discussed. (author)

  14. Plasma physics

    CERN Document Server

    Cairns, R A

    1985-01-01

    This book is intended as an introduction to plasma physics at a level suitable for advanced undergraduates or beginning postgraduate students in physics, applied mathematics or astrophysics. The main prerequisite is a knowledge of electromagnetism and of the associated mathematics of vector calculus. SI units are used throughout. There is still a tendency amongst some plasma physics researchers to· cling to C.g.S. units, but it is the author's view that universal adoption of SI units, which have been the internationally agreed standard since 1960, is to be encouraged. After a short introductory chapter, the basic properties of a plasma con­ cerning particle orbits, fluid theory, Coulomb collisions and waves are set out in Chapters 2-5, with illustrations drawn from problems in nuclear fusion research and space physics. The emphasis is on the essential physics involved and (he theoretical and mathematical approach has been kept as simple and intuitive as possible. An attempt has been made to draw attention t...

  15. Air plasma effect on dental disinfection

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, S.; Murata, R. M.; Saxena, D. [Department of Basic Sciences and Craniofacial Biology, College of Dentistry, New York University, New York, New York 10010 (United States); Kuo, S. P.; Chen, C. Y.; Huang, K. J. [Department of Electrical and Computer Engineering, Polytechnic Institute of New York University, Brooklyn, New York 11202 (United States); Popovic, S. [Department of Physics, Old Dominion University, Norfolk, Virginia 23529 (United States)

    2011-07-15

    A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

  16. Air plasma effect on dental disinfection

    Science.gov (United States)

    Duarte, S.; Kuo, S. P.; Murata, R. M.; Chen, C. Y.; Saxena, D.; Huang, K. J.; Popovic, S.

    2011-07-01

    A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

  17. Metal Abundances in the Hot Interstellar Medium in Early-Type Galaxies Observed with ASCA

    CERN Document Server

    Matsushita, K; Makishima, K; Matsushita, Kyoko; Ohashi, Takaya; Makishima, Kazuo

    2000-01-01

    We have analyzed ASCA data of 27 early-type galaxies, and studied the properties of their X-ray emitting ISM (Inter Stellar Medium) in detail. We found that overlapping lines and free-bound continuum cause strong coupling in the derived abundances of various elements. The abundance determination is also difficult due to the uncertainties in the Fe-L atomic physics, because Fe-L lines couple with O and Ne K-lines. However, when abundances of $\\alpha$-elements are fixed, all the plasma codes give similar Fe abundances with a scattering of only 20-30%. To relax the strong coupling among the elements, we included 20% systematic errors in the Fe-L region of the spectra. Then, in X-ray luminous galaxies, the derived abundance of Fe and $\\alpha$-elements both became $\\sim 1$ solar within a factor of 2. This result relaxes the previous severe discrepancy between the ISM and stellar metallicities. The ISM metallicity in X-ray fainter galaxies is still uncertain, but we can at least constrain that contribution from typ...

  18. Water Abundance in Molecular Cloud Cores

    CERN Document Server

    Snell, R L; Ashby, M L N; Bergin, E A; Chin, G; Erickson, N R; Goldsmith, P F; Harwit, M; Kleiner, S C; Koch, D G; Neufeld, D A; Patten, B M; Plume, R; Schieder, R; Stauffer, J R; Tolls, V; Wang, Z; Winnewisser, G; Zhang, Y F; Melnick, G J

    2000-01-01

    We present Submillimeter Wave Astronomy Satellite (SWAS) observations of the 1_{10}-1_{01} transition of ortho-water at 557 GHz toward 12 molecular cloud cores. The water emission was detected in NGC 7538, Rho Oph A, NGC 2024, CRL 2591, W3, W3(OH), Mon R2, and W33, and was not detected in TMC-1, L134N, and B335. We also present a small map of the water emission in S140. Observations of the H_2^{18}O line were obtained toward S140 and NGC 7538, but no emission was detected. The abundance of ortho-water relative to H_2 in the giant molecular cloud cores was found to vary between 6x10^{-10} and 1x10^{-8}. Five of the cloud cores in our sample have previous water detections; however, in all cases the emission is thought to arise from hot cores with small angular extents. The water abundance estimated for the hot core gas is at least 100 times larger than in the gas probed by SWAS. The most stringent upper limit on the ortho-water abundance in dark clouds is provided in TMC-1, where the 3-sigma upper limit on the ...

  19. The shape of terrestrial abundance distributions.

    Science.gov (United States)

    Alroy, John

    2015-09-01

    Ecologists widely accept that the distribution of abundances in most communities is fairly flat but heavily dominated by a few species. The reason for this is that species abundances are thought to follow certain theoretical distributions that predict such a pattern. However, previous studies have focused on either a few theoretical distributions or a few empirical distributions. I illustrate abundance patterns in 1055 samples of trees, bats, small terrestrial mammals, birds, lizards, frogs, ants, dung beetles, butterflies, and odonates. Five existing theoretical distributions make inaccurate predictions about the frequencies of the most common species and of the average species, and most of them fit the overall patterns poorly, according to the maximum likelihood-related Kullback-Leibler divergence statistic. Instead, the data support a low-dominance distribution here called the "double geometric." Depending on the value of its two governing parameters, it may resemble either the geometric series distribution or the lognormal series distribution. However, unlike any other model, it assumes both that richness is finite and that species compete unequally for resources in a two-dimensional niche landscape, which implies that niche breadths are variable and that trait distributions are neither arrayed along a single dimension nor randomly associated. The hypothesis that niche space is multidimensional helps to explain how numerous species can coexist despite interacting strongly. PMID:26601249

  20. Elemental abundances and classification of CEMP stars

    CERN Document Server

    Allen, Dinah M; Rossi, Silvia; Beers, Tim C; Tsangarides, Stelios A

    2012-01-01

    We present a detailed study of Carbon-Enhanced Metal-Poor (CEMP) stars, based on high-resolution spectroscopic observations of a sample of 18 stars. The stellar spectra for this sample were obtained at the 4.2m William Herschel Telescope (WHT) in 2001 and 2002, using the Utrecht Echelle Spectrograph (UES), at a resolving power R ~52000 and S/N ~ 40, covering the wavelength range lambda-lambda 3700-5700 A. The atmospheric parameters determined for this sample indicate temperatures ranging from 4750 C to 7100 K, log g from 1.5 to 4.3, and metallicities -3.0 <= [Fe/H] <= -1.7. Elemental abundances for C, Na, Mg, Sc, Ti, Cr, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, Gd, Dy are determined. Abundances for an additional 109 stars were taken from the literature and combined with the data of our sample. The literature sample reveals a lack of reliable abundance estimates for species that might be associated with the r-process elements for about 67% of CEMP stars, preventing a complete understanding of this clas...

  1. Stellar Mixing and the Primordial Lithium Abundance

    CERN Document Server

    Pinsonneault, M H; Walker, T P; Narayanan, V K

    2002-01-01

    We compare the properties of recent samples of the lithium abundances in halo stars to one another and to the predictions of theoretical models including rotational mixing, and we examine the data for trends with metal abundance. We find from a KS test that in the absence of any correction for chemical evolution, the Ryan, Norris, & Beers (1999} sample is fully consistent with mild rotational mixing induced depletion and, therefore, with an initial lithium abundance higher than the observed value. Tests for outliers depend sensitively on the threshold for defining their presence, but we find a 10$--$45% probability that the RNB sample is drawn from the rotationally mixed models with a 0.2 dex median depletion (with lower probabilities corresponding to higher depletion factors). When chemical evolution trends (Li/H versus Fe/H) are treated in the linear plane we find that the dispersion in the RNB sample is not explained by chemical evolution; the inferred bounds on lithium depletion from rotational mixing...

  2. Chemical abundances and kinematics of barium stars

    CERN Document Server

    de Castro, D B; Roig, F; Jilinski, E; Drake, N A; Chavero, C; Silva, J V Sales

    2016-01-01

    In this paper we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scale height, radial velocities, abundances of the Na, Al, $alpha$-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code {\\sc moog}. We found that the metallicities, the temperatures and the surface gravities for barium stars can not be represented by a single gaussian distribution. The abundances of $alpha$-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heav...

  3. Abundances In Very Metal Poor Dwarf Stars

    CERN Document Server

    Cohen, J G; McWilliam, A; Shectman, S; Thompson, I; Wasserburg, G J; Ivans, I I; Dehn, M; Karlsson, T; Melendez, J; Cohen, Judith G.; Christlieb, Norbert; William, Andrew Mc; Shectman, Steve; Thompson, Ian; Ivans, Inese; Dehn, Matthias; Karlsson, Torgny

    2004-01-01

    We discuss the detailed composition of 28 extremely metal-poor dwarfs, 22 of which are from the Hamburg/ESO Survey, based on Keck Echelle spectra. Our sample has a median [Fe/H] of -2.7 dex, extends to -3.5 dex, and is somewhat less metal-poor than was expected from [Fe/H](HK,HES) determined from low resolution spectra. Our analysis supports the existence of a sharp decline in the distribution of halo stars with metallicity below [Fe/H] = -3.0 dex. So far no additional turnoff stars with [Fe/H]}<-3.5 have been identified in our follow up efforts. For the best observed elements between Mg and Ni, we find that the abundance ratios appear to have reached a plateau, i.e. [X/Fe] is approximately constant as a function of [Fe/H], except for Cr, Mn and Co, which show trends of abundance ratios varying with [Fe/H]. These abundance ratios at low metallicity correspond approximately to the yield expected from Type II SN with a narrow range in mass and explosion parameters; high mass Type II SN progenitors are requir...

  4. How selection structures species abundance distributions

    Science.gov (United States)

    Magurran, Anne E.; Henderson, Peter A.

    2012-01-01

    How do species divide resources to produce the characteristic species abundance distributions seen in nature? One way to resolve this problem is to examine how the biomass (or capacity) of the spatial guilds that combine to produce an abundance distribution is allocated among species. Here we argue that selection on body size varies across guilds occupying spatially distinct habitats. Using an exceptionally well-characterized estuarine fish community, we show that biomass is concentrated in large bodied species in guilds where habitat structure provides protection from predators, but not in those guilds associated with open habitats and where safety in numbers is a mechanism for reducing predation risk. We further demonstrate that while there is temporal turnover in the abundances and identities of species that comprise these guilds, guild rank order is conserved across our 30-year time series. These results demonstrate that ecological communities are not randomly assembled but can be decomposed into guilds where capacity is predictably allocated among species. PMID:22787020

  5. Aerial survey estimates of fallow deer abundance

    Science.gov (United States)

    Gogan, Peter J.; Gates, Natalie B.; Lubow, Bruce C.; Pettit, Suzanne

    2012-01-01

    Reliable estimates of the distribution and abundance of an ungulate species is essential prior to establishing and implementing a management program. We used ground surveys to determine distribution and ground and aerial surveys and individually marked deer to estimate the abundance of fallow deer (Dama dama) in north-coastal California. Fallow deer had limited distribution and heterogeneous densities. Estimated post-rut densities across 4 annual surveys ranged from a low of 1.4 (SE=0.2) deer/km2 to a high of 3.3 (se=0.5) deer/km2 in a low density stratum and from 49.0 (SE=8.3) deer/km2 to 111.6 deer/km2 in a high density stratum. Sightability was positively influenced by the presence of white color-phase deer in a group and group size, and varied between airial and ground-based observers and by density strata. Our findings underscore the utility of double-observer surveys and aerial surveys with individually marked deer, both incorporating covariates to model sightability, to estimate deer abundance.

  6. CH abundance gradient in TMC-1

    CERN Document Server

    Suutarinen, Aleksi; Harju, Jorma; Heikkilä, Arto; Hotzel, Stephan; Juvela, Mika; Millar, Tom J; Walsh, Catherina; Wouterloot, Jan Gerard Amos

    2011-01-01

    We observed the 9-cm Lambda-doubling lines of CH along the dense filament of TMC-1. The CH column densities were compared with the total H2 column densities derived using the 2MASS NIR data and previously published SCUBA maps and with OH column densities derived using previous observations with Effelsberg. We also modelled the chemical evolution of TMC-1 adopting physical conditions typical of dark clouds using the UMIST Database for Astrochemistry gas-phase reaction network to aid the interpretation of the observed OH/CH abundance ratios. The CH column density has a clear peak in the vicinity of the cyanopolyyne maximum of TMC-1. The fractional CH abundance relative to H2 increases steadily from the northwestern end of the filament where it lies around 1.0e-8, to the southeast where it reaches a value of 2.0e-8. The OH and CH column densities are well correlated, and we obtained OH/CH abundance ratios of ~ 16 - 20. These values are clearly larger than what has been measured recently in diffuse interstellar g...

  7. Physics of the plasma universe

    CERN Document Server

    Peratt, Anthony L

    2015-01-01

    Today many scientists recognize plasma as the key element to understanding new observations in near-Earth, interplanetary, interstellar, and intergalactic space; in stars, galaxies, and clusters of galaxies, and throughout the observable universe. Physics of the Plasma Universe, 2nd Edition is an update of observations made across the entire cosmic electromagnetic spectrum over the two decades since the publication of the first edition. It addresses paradigm changing discoveries made by telescopes, planetary probes, satellites, and radio and space telescopes. The contents are the result of the author's 37 years research at Livermore and Los Alamos National Laboratories, and the U.S. Department of Energy. This book covers topics such as the large-scale structure and the filamentary universe; the formation of magnetic fields and galaxies, active galactic nuclei and quasars, the origin and abundance of light elements, star formation and the evolution of solar systems, and cosmic rays. Chapters 8 and 9 are based ...

  8. Galactic abundance gradients from Cepheids : On the iron abundance gradient around 10-12 kpc

    OpenAIRE

    Lemasle, B.; Francois, P.; Piersimoni, A.; Pedicelli, S.; Bono, G.; Laney, C. D.; Primas, F.; Romaniello, M.

    2008-01-01

    Context: Classical Cepheids can be adopted to trace the chemical evolution of the Galactic disk since their distances can be estimated with very high accuracy. Aims: Homogeneous iron abundance measurements for 33 Galactic Cepheids located in the outer disk together with accurate distance determinations based on near-infrared photometry are adopted to constrain the Galactic iron gradient beyond 10 kpc. Methods: Iron abundances were determined using high resolution Cepheid spectra collected wit...

  9. Abundant Solar Nebula Solids in Comets

    Science.gov (United States)

    Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Nguyen, A. N.; Clemett, S.

    2016-01-01

    Comets have been proposed to consist of unprocessed interstellar materials together with a variable amount of thermally annealed interstellar grains. Recent studies of cometary solids in the laboratory have shown that comets instead consist of a wide range of materials from across the protoplanetary disk, in addition to a minor complement of interstellar materials. These advances were made possible by the return of direct samples of comet 81P/Wild 2 coma dust by the NASA Stardust mission and recent advances in microscale analytical techniques. Isotopic studies of 'cometary' chondritic porous interplanetary dust particles (CP-IDPs) and comet 81P/Wild 2 Stardust samples show that preserved interstellar materials are more abundant in comets than in any class of meteorite. Identified interstellar materials include sub-micron-sized presolar silicates, oxides, and SiC dust grains and some fraction of the organic material that binds the samples together. Presolar grain abundances reach 1 weight percentage in the most stardust-rich CP-IDPs, 50 times greater than in meteorites. Yet, order of magnitude variations in presolar grain abundances among CP-IDPs suggest cometary solids experienced significant variations in the degree of processing in the solar nebula. Comets contain a surprisingly high abundance of nebular solids formed or altered at high temperatures. Comet 81P/Wild 2 samples include 10-40 micron-sized, refractory Ca- Al-rich inclusion (CAI)-, chondrule-, and ameboid olivine aggregate (AOA)-like materials. The O isotopic compositions of these refractory materials are remarkably similar to their meteoritic counterparts, ranging from 5 percent enrichments in (sup 16) O to near-terrestrial values. Comet 81P/Wild 2 and CP-IDPs also contain abundant Mg-Fe crystalline and amorphous silicates whose O isotopic compositions are also consistent with Solar System origins. Unlike meteorites, that are dominated by locally-produced materials, comets appear to be composed of

  10. A high-efficiency superhydrophobic plasma separator.

    Science.gov (United States)

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M; Yang, Shu; Bau, Haim H

    2016-02-01

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method.

  11. A high-efficiency superhydrophobic plasma separator.

    Science.gov (United States)

    Liu, Changchun; Liao, Shih-Chuan; Song, Jinzhao; Mauk, Michael G; Li, Xuanwen; Wu, Gaoxiang; Ge, Dengteng; Greenberg, Robert M; Yang, Shu; Bau, Haim H

    2016-02-01

    To meet stringent limit-of-detection specifications for low abundance target molecules, a relatively large volume of plasma is needed for many blood-based clinical diagnostics. Conventional centrifugation methods for plasma separation are not suitable for on-site testing or bedside diagnostics. Here, we report a simple, yet high-efficiency, clamshell-style, superhydrophobic plasma separator that is capable of separating a relatively large volume of plasma from several hundred microliters of whole blood (finger-prick blood volume). The plasma separator consists of a superhydrophobic top cover with a separation membrane and a superhydrophobic bottom substrate. Unlike previously reported membrane-based plasma separators, the separation membrane in our device is positioned at the top of the sandwiched whole blood film to increase the membrane separation capacity and plasma yield. In addition, the device's superhydrophobic characteristics (i) facilitates the formation of well-defined, contracted, thin blood film with a high contact angle; (ii) minimizes biomolecular adhesion to surfaces; (iii) increases blood clotting time; and (iv) reduces blood cell hemolysis. The device demonstrated a "blood in-plasma out" capability, consistently extracting 65 ± 21.5 μL of plasma from 200 μL of whole blood in less than 10 min without electrical power. The device was used to separate plasma from Schistosoma mansoni genomic DNA-spiked whole blood with a recovery efficiency of >84.5 ± 25.8%. The S. mansoni genomic DNA in the separated plasma was successfully tested on our custom-made microfluidic chip by using loop mediated isothermal amplification (LAMP) method. PMID:26732765

  12. Can occupancy-abundance models be used to monitor wolf abundance?

    Directory of Open Access Journals (Sweden)

    M Cecilia Latham

    Full Text Available Estimating the abundance of wild carnivores is of foremost importance for conservation and management. However, given their elusive habits, direct observations of these animals are difficult to obtain, so abundance is more commonly estimated from sign surveys or radio-marked individuals. These methods can be costly and difficult, particularly in large areas with heavy forest cover. As an alternative, recent research has suggested that wolf abundance can be estimated from occupancy-abundance curves derived from "virtual" surveys of simulated wolf track networks. Although potentially more cost-effective, the utility of this approach hinges on its robustness to violations of its assumptions. We assessed the sensitivity of the occupancy-abundance approach to four assumptions: variation in wolf movement rates, changes in pack cohesion, presence of lone wolves, and size of survey units. Our simulations showed that occupancy rates and wolf pack abundances were biased high if track surveys were conducted when wolves made long compared to short movements, wolf packs were moving as multiple hunting units as opposed to a cohesive pack, and lone wolves were moving throughout the surveyed landscape. We also found that larger survey units (400 and 576 km2 were more robust to changes in these factors than smaller survey units (36 and 144 km2. However, occupancy rates derived from large survey units rapidly reached an asymptote at 100% occupancy, suggesting that these large units are inappropriate for areas with moderate to high wolf densities (>15 wolves/1,000 km2. Virtually-derived occupancy-abundance relationships can be a useful method for monitoring wolves and other elusive wildlife if applied within certain constraints, in particular biological knowledge of the surveyed species needs to be incorporated into the design of the occupancy surveys. Further, we suggest that the applicability of this method could be extended by directly incorporating some of its

  13. Abundance anomalies in tidal disruption events

    Science.gov (United States)

    Kochanek, C. S.

    2016-05-01

    The ˜10 per cent of tidal disruption events (TDEs) due to stars more massive than M* ≳ M⊙ should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ˜25 per cent on average because it becomes inaccessible once it is sequestered in the high-density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main-sequence star can be enhanced in helium by factors of 2-3 for debris at a common orbital period. These helium abundance variations may be a contributor to the observed diversity of hydrogen and helium line strengths in TDEs. A still more striking anomaly is the rapid enhancement of nitrogen and the depletion of carbon due to the CNO cycle - stars with M* ≳ M⊙ quickly show an increase in their average N/C ratio by factors of 3-10. Because low-mass stars evolve slowly and high-mass stars are rare, TDEs showing high N/C will almost all be due to ˜1-2 M⊙ stars disrupted on the main sequence. Like helium, portions of the debris will show still larger changes in C and N, and the anomalies decline as the star leaves the main sequence. The enhanced [N/C] abundance ratio of these TDEs provides the first natural explanation for the rare, nitrogen-rich quasars and may also explain the strong nitrogen emission seen in ultraviolet spectra of ASASSN-14li.

  14. Immunodepletion of high-abundant proteins from acute and chronic wound fluids to elucidate low-abundant regulators in wound healing

    Directory of Open Access Journals (Sweden)

    Chojnacki Caroline

    2010-12-01

    Full Text Available Abstract Background The process of wound healing consists of several well distinguishable and finely tuned phases. For most of these phases specific proteins have been characterized, although the underlying mechanisms of regulation are not yet fully understood. It is an open question as to whether deficits in wound healing can be traced back to chronic illnesses such as diabetes mellitus. Previous research efforts in this field focus largely on a restricted set of marker proteins due to the limitations detection by antibodies imposes. For mechanistic purposes the elucidation of differences in acute and chronic wounds can be addressed by a less restricted proteome study. Mass spectrometric (MS methods, e.g. multi dimensional protein identification technology (MudPIT, are well suitable for this complex theme of interest. The human wound fluid proteome is extremely complex, as is human plasma. Therefore, high-abundant proteins often mask the mass spectrometric detection of lower-abundant ones, which makes a depletion step of such predominant proteins inevitable. Findings In this study a commercially available immunodepletion kit was evaluated for the detection of low-abundant proteins from wound fluids. The dynamic range of the entire workflow was significantly increased to 5-6 orders of magnitude, which makes low-abundant regulatory proteins involved in wound healing accessible for MS detection. Conclusion The depletion of abundant proteins is absolutely necessary in order to analyze highly complex protein mixtures such as wound fluids using mass spectrometry. For this the used immunodepletion kit is a first but important step in order to represent the entire dynamic range of highly complex protein mixtures in the future.

  15. Abundance and diversity of marine microbial eukaryotes

    OpenAIRE

    Pernice, Massimo Ciro

    2014-01-01

    [EN]Microeukaryotes are important ecological players in any kind of ecosystem, most notably in the ocean, and it is therefore essential to collect information about their abundance and diversity. To achieve this general goal this thesis was structured in two parts. The first part represents an effort to define our “diversity unit” from studies based on the well-known cloning and Sanger sequencing approach. Basically, we wanted to establish a solid baseline for the second part of the thesis. W...

  16. Abundance Anomalies In Tidal Disruption Events

    OpenAIRE

    Kochanek, C. S.

    2015-01-01

    The ~10% of tidal disruption events (TDEs) due to stars more massive than the Sun should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ~25% on average because it becomes inaccessible once it is sequestered in the high density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main sequence star can be enhanced in helium by factors of ...

  17. North Sea Elasmobranchs: distribution, abundance and biodiversity

    OpenAIRE

    Daan, N.; Heessen, H.J.L.; Hofstede, ter, AHM Arthur

    2005-01-01

    Based on data from various international and national surveys, an overview is given of the fine-scale distribution (resolution of 20¿longitude * 10¿ latitude; ¿ 10*10 nm) and trends in abundance of elasmobranch species reported from the North Sea. Presence-absence maps are produced based on 4 surveys, which help to delineate distribution limits of the less common species, while maps in terms of catch rates (International Bottom Trawl Survey data only) are given for the seven most common shark...

  18. Estimating the relationship between abundance and distribution

    DEFF Research Database (Denmark)

    Rindorf, Anna; Lewy, Peter

    2012-01-01

    provide unbiased estimates of the relationship when estimated from count data. The indices investigated include the proportion of empty samples, the proportion of structurally empty samples, Lloyds index of patchiness, measures derived from Lorenz curves (such as D95 and the Gini index), and measures...... based on Euclidean distance to the centre of gravity of the spatial distribution. Only the proportion of structurally empty areas, Lloyds index, and indices of the distance to the centre of gravity of the spatial distribution are unbiased at all levels of abundance. The remaining indices generate...

  19. Detecting significant changes in protein abundance

    Directory of Open Access Journals (Sweden)

    Kai Kammers

    2015-06-01

    Full Text Available We review and demonstrate how an empirical Bayes method, shrinking a protein's sample variance towards a pooled estimate, leads to far more powerful and stable inference to detect significant changes in protein abundance compared to ordinary t-tests. Using examples from isobaric mass labelled proteomic experiments we show how to analyze data from multiple experiments simultaneously, and discuss the effects of missing data on the inference. We also present easy to use open source software for normalization of mass spectrometry data and inference based on moderated test statistics.

  20. Neon and Oxygen Abundances and Abundance Ratio in the Solar Corona

    Science.gov (United States)

    Landi, E.; Testa, P.

    2015-02-01

    In this work we determine the Ne/O abundance ratio from Solar and Heliospheric Observatory (SOHO)/Solar Ultraviolet Measurement of Emitted Radiation (SUMER) off-disk observations of quiescent streamers over the 1996-2008 period. We find that the Ne/O ratio is approximately constant over solar cycle 23 from 1996 to 2005, at a value of 0.099 ± 0.017 this value is lower than the transition region determinations from the quiet Sun used to infer the neon photospheric abundance from the oxygen photospheric abundance. Also, the Ne/O ratio we determined from SUMER is in excellent agreement with in situ determinations from ACE/SWICS. In 2005-2008, the Ne/O abundance ratio increased with time and reached 0.25 ± 0.05, following the same trend found in the slowest wind analyzed by ACE/SWICS. Further, we measure the absolute abundance in the corona for both oxygen and neon from the data set of 1996 November 22, obtaining A o = 8.99 ± 0.04 and A Ne = 7.92 ± 0.03, and we find that both elements are affected by the first ionization potential (FIP) effect, with oxygen being enhanced by a factor of 1.4-2.1 over its photospheric abundance, and neon being changed by a factor of 0.75-1.20. We conclude that the Ne/O ratio is not constant in the solar atmosphere, both in time and at different heights, and that it cannot be reliably used to infer the neon abundance in the photosphere. Also, we argue that the FIP effect was less effective during the minimum of solar cycle 24, and that the Ne/O = 0.25 ± 0.05 value measured at that time is closer to the true photospheric value, leading to a neon photospheric abundance larger than assumed by ≈40%. We discuss the implications of these results for the solar abundance problem, for the FIP effect, and for the identification of the source regions of the solar wind.

  1. Solar Flare Element Abundances from the Solar Assembly for X-rays (SAX) on MESSENGER

    CERN Document Server

    Dennis, B R; Schwartz, R A; Tolbert, A K; Starr, R D; Nittler, L R

    2015-01-01

    X-ray spectra in the range $1.5-8.5$~keV have been analyzed for 526 large flares detected with the Solar Assembly for X-rays (SAX) on the Mercury {\\em MESSENGER} spacecraft between 2007 and 2013. For each flare, the temperature and emission measure of the emitting plasma were determined from the spectrum of the continuum. In addition, with the SAX energy resolution of 0.6 keV (FWHM) at 6~keV, the intensities of the clearly resolved Fe-line complex at 6.7~keV and the Ca-line complex at 3.9~keV were determined, along with those of unresolved line complexes from S, Si, and Ar at lower energies. Comparisons of these line intensities with theoretical spectra allow the abundances of these elements relative to hydrogen to be derived, with uncertainties due to instrument calibration and the unknown temperature distribution of the emitting plasma. While significant deviations are found for the abundances of Fe and Ca from flare to flare, the abundances averaged over all flares are found to be enhanced over photospheri...

  2. An Accurate Calculation of the Big-Bang Prediction for the Abundance of Primordial Helium

    CERN Document Server

    López, R E; Lopez, Robert E.; Turner, Michael S.

    1999-01-01

    Within the standard model of particle physics and cosmology we have calculated the big-bang prediction for the primordial abundance of Helium to a theoretical uncertainty of $0.1 \\pct$ $(\\delta Y_P = \\pm 0.0002)$. At this accuracy the uncertainty in the abundance is dominated by the experimental uncertainty in the neutron mean lifetime, $\\tau_n = 885.3 \\pm 2.0 \\rm{sec}$. The following physical effects were included in the calculation: the zero and finite-temperature radiative, Coulomb and finite-nucleon mass corrections to the weak rates; order-$\\alpha$ quantum-electrodynamic correction to the plasma density, electron mass, and neutrino temperature; and incomplete neutrino decoupling. New results for the finite-temperature radiative correction and the QED plasma correction were used. In addition, we wrote a new and independent nucleosynthesis code to control numerical errors to less than 0.1\\pct. Our predictions for the \\EL[4]{He} abundance are summarized with an accurate fitting formula. Summarizing our work...

  3. Aldosterone-mineralocorticoid receptor promotes urine prostasin through glomerular barrier injury and not tissue abundance

    DEFF Research Database (Denmark)

    Stolzenburg Oxlund, Christina; Kurt, B.; Schwarzensteiner, I.;

    2015-01-01

    Objective: Low salt intake or infusion with the mineralocorticoid hormone aldosterone increases the abundance of proteolytically activated gamma ENaC in rat kidney. Prostasin is a serine proteinase GPI-anchored to the apical membrane of renal principal cells. It was hypothesized that the aldoster......Objective: Low salt intake or infusion with the mineralocorticoid hormone aldosterone increases the abundance of proteolytically activated gamma ENaC in rat kidney. Prostasin is a serine proteinase GPI-anchored to the apical membrane of renal principal cells. It was hypothesized...... that the aldosterone- mineralocorticoid receptor (MR) pathway maintains prostasin abundance in human kidney. Design and method: Urine and plasma prostasin was measured by ELISA in urine and plasma from a cohort of type-2 diabetes patients (n = 112) with treatment resistant hypertension before and after intervention......-i/ANGII receptor blocker compared to patients given no medication; in kidney membranes from adrenalectomized rats compared to control and in kidney and colon membranes from aldosterone synthase-/- mice compared to wild type littermates. Conclusions: Kidney tissue prostasin is not regulated by aldosterone whereas...

  4. Metal Abundances of KISS Galaxies. V. Nebular Abundances of Fifteen Intermediate Luminosity Star-Forming Galaxies

    CERN Document Server

    Hirschauer, Alec S; Bresolin, Fabio; Saviane, Ivo; Yegorova, Irina

    2015-01-01

    We present high S/N spectroscopy of 15 emission-line galaxies (ELGs) cataloged in the KPNO International Spectroscopic Survey (KISS), selected for their possession of high equivalent width [O III] lines. The primary goal of this study was to attempt to derive direct-method ($T_e$) abundances for use in constraining the upper-metallicity branch of the $R_{23}$ relation. The spectra cover the full optical region from [O II]{\\lambda}{\\lambda}3726,3729 to [S III]{\\lambda}{\\lambda}9069,9531 and include the measurement of [O III]{\\lambda}4363 in 13 objects. From these spectra, we determine abundance ratios of helium, nitrogen, oxygen, neon, sulfur, and argon. We find these galaxies to predominantly possess oxygen abundances in the range of 8.0 $\\lesssim$ 12+log(O/H) $\\lesssim$ 8.3. We present a comparison of direct-method abundances with empirical SEL techniques, revealing several discrepancies. We also present a comparison of direct-method oxygen abundance calculations using electron temperatures determined from e...

  5. Non-additive effects of genotypic diversity increase floral abundance and abundance of floral visitors.

    Directory of Open Access Journals (Sweden)

    Mark A Genung

    Full Text Available BACKGROUND: In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. METHODOLOGY/PRINCIPAL FINDINGS: Using an experimental common garden that manipulated genotypic diversity (the number of distinct genotypes per plot of Solidago altissima, we document that genotypic diversity of a dominant plant can indirectly influence flower visitor abundance. Across two years, we found that 1 plant genotype explained 45% and 92% of the variation in flower visitor abundance in 2007 and 2008, respectively; and 2 plant genotypic diversity had a positive and non-additive effect on floral abundance and the abundance of flower visitors, as plots established with multiple genotypes produced 25% more flowers and received 45% more flower visits than would be expected under an additive model. CONCLUSIONS/SIGNIFICANCE: These results provide evidence that declines in genotypic diversity may be an important but little considered factor for understanding plant-pollinator dynamics, with implications for the global decline in pollinators due to reduced plant diversity in both agricultural and natural ecosystems.

  6. A plasma-membrane E-MAP reveals links of the eisosome with sphingolipid metabolism and endosomal trafficking

    DEFF Research Database (Denmark)

    Aguilar, Pablo S; Fröhlich, Florian; Rehman, Michael;

    2010-01-01

    The plasma membrane delimits the cell and controls material and information exchange between itself and the environment. How different plasma-membrane processes are coordinated and how the relative abundance of plasma-membrane lipids and proteins is homeostatically maintained are not yet understo...

  7. Element Abundances through the Cosmic Ages

    CERN Document Server

    Pettini, M

    2003-01-01

    The horizon for studies of element abundances has expanded dramatically in the last ten years. Once the domain of astronomers concerned chiefly with stars and nearby galaxies, this field has now become a key component of observational cosmology, as technological advances have made it possible to measure the abundances of several chemical elements in a variety of environments at redshifts up to z = 4, when the universe was in its infancy. In this series of lectures I summarise current knowledge on the chemical make-up of distant galaxies observed directly in their starlight, and of interstellar and intergalactic gas seen in absorption against the spectra of bright background sources. The picture which is emerging is one where the universe at z = 3 already included many of the constituents of today's galaxies-even at these early times we see evidence for Population I and II stars, while the `smoking gun' for Population III objects may be hidden in the chemical composition of the lowest density regions of the in...

  8. Abundance Anomalies In Tidal Disruption Events

    CERN Document Server

    Kochanek, C S

    2015-01-01

    The ~10% of tidal disruption events (TDEs) due to stars more massive than the Sun should show abundance anomalies due to stellar evolution in helium, carbon and nitrogen, but not oxygen. Helium is always enhanced, but only by up to ~25% on average because it becomes inaccessible once it is sequestered in the high density core as the star leaves the main sequence. However, portions of the debris associated with the disrupted core of a main sequence star can be enhanced in helium by factors of 2-3 for debris at a common orbital period. These helium abundance variations may be a contributor to the observed diversity of hydrogen and helium line strengths in TDEs. A still more striking anomaly is the rapid enhancement of nitrogen and the depletion of carbon due to the CNO cycle -- stars more massive than the Sun quickly show an increase in their average N/C ratio by factors of 3-10. Because low mass stars evolve slowly and high mass stars are rare, TDEs showing high N/C will almost all be due to 1-2Msun stars disr...

  9. Occupancy as a surrogate for abundance estimation

    Directory of Open Access Journals (Sweden)

    MacKenzie, D. I.

    2004-06-01

    Full Text Available In many monitoring programmes it may be prohibitively expensive to estimate the actual abundance of a bird species in a defined area, particularly at large spatial scales, or where birds occur at very low densities. Often it may be appropriate to consider the proportion of area occupied by the species as an alternative state variable. However, as with abundance estimation, issues of detectability must be taken into account in order to make accurate inferences: the non-detection of the species does not imply the species is genuinely absent. Here we review some recent modelling developments that permit unbiased estimation of the proportion of area occupied, colonization and local extinction probabilities. These methods allow for unequal sampling effort and enable covariate information on sampling locations to be incorporated. We also describe how these models could be extended to incorporate information from marked individuals, which would enable finer questions of population dynamics (such as turnover rate of nest sites by specific breeding pairs to be addressed. We believe these models may be applicable to a wide range of bird species and may be useful for investigating various questions of ecological interest. For example, with respect to habitat quality, we might predict that a species is more likely to have higher local extinction probabilities, or higher turnover rates of specific breeding pairs, in poor quality habitats.

  10. Fluorine Abundances in the Milky Way Bulge

    CERN Document Server

    Cunha, K; Gibson, B K

    2008-01-01

    Fluorine (19F) abundances are derived in a sample of 6 bulge red giants in Baade's Window. These giants span a factor of 10 in metallicity and this is the first study to define the behavior of 19F with metallicity in the bulge. The bulge results show an increase in F/O with increasing oxygen. This trend overlaps what is found in the disk at comparable metallicities, with the most oxygen-rich bulge target extending the disk trend. The increase in F/O in the disk arises from 19F synthesis in both asymptotic giant branch (AGB) stars and metal-rich Wolf-Rayet (WR) stars through stellar winds. The lack of an s-process enhancement in the most fluorine-rich bulge giant in this study, suggests that WR stars represented a larger contribution than AGB stars to 19F production in the bulge when compared to the disk. If this result for fluorine is combined with the previously published overall decline in the O/Mg abundance ratios in metal-rich bulge stars, it suggests that WR winds played a role in shaping chemical evolut...

  11. Elemental Abundances of Solar Sibling Candidates

    CERN Document Server

    Ramirez, I; Bobylev, V V; Roederer, I U; Lambert, D L; Endl, M; Cochran, W D; MacQueen, P J; Wittenmyer, R A

    2014-01-01

    Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high resolution, high signal-to-noise ratio spectra for 30 of these objects to determine, using detailed elemental abundance analysis, if they could be true solar siblings. Only two of the candidates are found to have solar chemical composition. Updated modeling of the stars' past orbits in a realistic Galactic potential reveals that one of them, HD162826, satisfies both chemical and dynamical conditions for being a sibling of the Sun. Measurements of rare-element abundances for this star further confirm its solar composition, with the only possible exception of Sm. Analysis of long-term high-precision radial velocity data rules out the presence of hot Jupiters and confirms that this star is not in a binary system. We find that chemical tagging does not necessarily benefit from studying a...

  12. Beryllium abundances in stars hosting giant planets

    CERN Document Server

    Santos, N C; Israelian, G; Mayor, M; Rebolo, R; García-Gíl, A; Pérez de Taoro, M R; Randich, S

    2002-01-01

    We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the structure and evolution of the associated stars. Predictions from current models are compared with the derived abundances and suggestions are provided to explain the observed inconsistencies. We show that while still not clear, the results suggest that theoretical models may have to be revised for stars with Teff<5500K. On the other hand, a comparison between planet host and non-planet host stars shows no clear difference between both populations. Although preliminary, this result favors a ``primordial'' origin for the metallicity ``excess'' observed for the planetary host stars. Under this assumption, i.e. that there would be no differences between stars with and without giant planets, the light element depletion pattern of our sample of stars may also be used to further investigate and constraint Li and Be deple...

  13. Oxygen Abundance Measurements of SHIELD Galaxies

    CERN Document Server

    Haurberg, Nathalie C; Cannon, John M; Marshall, Melissa V

    2015-01-01

    We have derived oxygen abundances for 8 galaxies from the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). The SHIELD survey is an ongoing study of very low-mass galaxies, with M$_{\\rm HI}$ between 10$^{6.5}$ and 10$^{7.5}$ M$_{\\odot}$, that were detected by the Arecibo Legacy Fast ALFA (ALFALFA) survey. H$\\alpha$ images from the WIYN 3.5m telescope show that these 8 SHIELD galaxies each possess one or two active star-forming regions which were targeted with long-slit spectral observations using the Mayall 4m telescope at KPNO. We obtained a direct measurement of the electron temperature by detection of the weak [O III] $\\lambda$4363 line in 2 of the HII regions. Oxygen abundances for the other HII regions were estimated using a strong-line method. When the SHIELD galaxies are plotted on a B-band luminosity-metallicity diagram they appear to suggest a slightly shallower slope to the relationship than normally seen. However, that offset is systematically reduced when the near-infrared luminosity is used ins...

  14. Manganese abundances in Galactic bulge red giants

    CERN Document Server

    Barbuy, B; Zoccali, M; Minniti, D; Renzini, A; Ortolani, S; Gomez, A; Trevisan, M; Dutra, N

    2013-01-01

    Manganese is mainly produced in type II SNe during explosive silicon burning, in incomplete Si-burning regions, and depends on several nucleosynthesis environment conditions, such as mass cut beween the matter ejected and falling back onto the remnant, electron and neutron excesses, mixing fallback, and explosion energy. Manganese is also produced in type Ia SNe. The aim of this work is the study of abundances of the iron-peak element Mn in 56 bulge giants, among which 13 are red clump stars. Four bulge fields along the minor axis are inspected. The study of abundances of Mn-over-Fe as a function of metallicity in the Galactic bulge may shed light on its production mechanisms. High-resolution spectra were obtained using the FLAMES+UVES spectrograph on the Very Large Telescope. The spectra were obtained within a program to observe 800 stars using the GIRAFFE spectrograph, together with the present UVES spectra. We aim at identifying the chemical evolution of manganese, as a function of metallicity, in the Gala...

  15. Automatic abundance analysis of high resolution spectra

    CERN Document Server

    Bonifacio, P; Bonifacio, Piercarlo; Caffau, Elisabetta

    2003-01-01

    We describe an automatic procedure for determining abundances from high resolution spectra. Such procedures are becoming increasingly important as large amounts of data are delivered from 8m telescopes and their high-multiplexing fiber facilities, such as FLAMES on ESO-VLT. The present procedure is specifically targeted for the analysis of spectra of giants in the Sgr dSph; however, the procedure may be, in principle, tailored to analyse stars of any type. Emphasis is placed on the algorithms and on the stability of the method; the external accuracy rests, ultimately, on the reliability of the theoretical models (model-atmospheres, synthetic spectra) used to interpret the data. Comparison of the results of the procedure with the results of a traditional analysis for 12 Sgr giants shows that abundances accurate at the level of 0.2 dex, comparable with that of traditional analysis of the same spectra, may be derived in a fast and efficient way. Such automatic procedures are not meant to replace the traditional ...

  16. The Coronal Abundance Anomalies of M Dwarfs

    CERN Document Server

    Wood, Brian E; Karovska, Margarita

    2012-01-01

    We analyze Chandra X-ray spectra of the M0 V+M0 V binary GJ 338. As quantified by X-ray surface flux, these are the most inactive M dwarfs ever observed with X-ray grating spectroscopy. We focus on measuring coronal abundances, in particular searching for evidence of abundance anomalies related to First Ionization Potential (FIP). In the solar corona and wind, low FIP elements are overabundant, which is the so-called "FIP effect." For other stars, particularly very active ones, an "inverse FIP effect" is often observed, with low FIP elements being underabundant. For both members of the GJ 338 binary, we find evidence for a modest inverse FIP effect, consistent with expectations from a previously reported correlation between spectral type and FIP bias. This amounts to strong evidence that all M dwarfs should exhibit the inverse FIP effect phenomenon, not just the active ones. We take the first step towards modeling the inverse FIP phenomenon in M dwarfs, building on past work that has demonstrated that MHD wav...

  17. Improved plasma accelerator

    Science.gov (United States)

    Cheng, D. Y.

    1971-01-01

    Converging, coaxial accelerator electrode configuration operates in vacuum as plasma gun. Plasma forms by periodic injections of high pressure gas that is ionized by electrical discharges. Deflagration mode of discharge provides acceleration, and converging contours of plasma gun provide focusing.

  18. Plasma Free Metanephrines

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Plasma Free Metanephrines Share this page: Was this page helpful? Also known as: Plasma Metanephrines Formal name: Fractionated Plasma Free Metanephrines (Metanephrine ...

  19. Plasma physics and fusion plasma electrodynamics

    CERN Document Server

    Bers, Abraham

    2016-01-01

    Plasma is a ubiquitous state of matter at high temperatures. The electrodynamics of plasmas encompasses a large number of applications, from understanding plasmas in space and the stars, to their use in processing semiconductors, and their role in controlled energy generation by nuclear fusion. This book covers collective and single particle dynamics of plasmas for fully ionized as well as partially ionized plasmas. Many aspects of plasma physics in current fusion energy generation research are addressed both in magnetic and inertial confinement plasmas. Linear and nonlinear dynamics in hydrodynamic and kinetic descriptions are offered, making both simple and complex aspects of the subject available in nearly every chapter. The approach of dividing the basic aspects of plasma physics as "linear, hydrodynamic descriptions" to be covered first because they are "easier", and postponing the "nonlinear and kinetic descriptions" for later because they are "difficult" is abandoned in this book. For teaching purpose...

  20. Forms and genesis of species abundance distributions

    Directory of Open Access Journals (Sweden)

    Evans O. Ochiaga

    2015-12-01

    Full Text Available Species abundance distribution (SAD is one of the most important metrics in community ecology. SAD curves take a hollow or hyperbolic shape in a histogram plot with many rare species and only a few common species. In general, the shape of SAD is largely log-normally distributed, although the mechanism behind this particular SAD shape still remains elusive. Here, we aim to review four major parametric forms of SAD and three contending mechanisms that could potentially explain this highly skewed form of SAD. The parametric forms reviewed here include log series, negative binomial, lognormal and geometric distributions. The mechanisms reviewed here include the maximum entropy theory of ecology, neutral theory and the theory of proportionate effect.

  1. TEA: A Code for Calculating Thermochemical Equilibrium Abundances

    OpenAIRE

    Blecic, Jasmina; Harrington, Joseph; Bowman, M. Oliver

    2015-01-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. (1958) and Eriksson (1971). It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method o...

  2. Plasma-wall interaction; Interaction plasma paroi

    Energy Technology Data Exchange (ETDEWEB)

    Reichle, R

    2004-07-01

    This document gathers the 43 slides presented in the framework of the week long lecture 'hot plasmas 2004' and dedicated to plasma-wall interaction in a tokamak. This document is divided into 4 parts: 1) thermal load on the wall, power extraction and particle recovery, 2) basic edge plasma physics, 3) processes that drive the plasma-solid interaction, and 4) material conditioning (surface treatment...) for ITER.

  3. Halo abundances within the cosmic web

    Science.gov (United States)

    Alonso, D.; Eardley, E.; Peacock, J. A.

    2015-03-01

    We investigate the dependence of the mass function of dark-matter haloes on their environment within the cosmic web of large-scale structure. A dependence of the halo mass function on large-scale mean density is a standard element of cosmological theory, allowing mass-dependent biasing to be understood via the peak-background split. On the assumption of a Gaussian density field, this analysis can be extended to ask how the mass function depends on the geometrical environment: clusters, filaments, sheets and voids, as classified via the tidal tensor (the Hessian matrix of the gravitational potential). In linear theory, the problem can be solved exactly, and the result is attractively simple: the conditional mass function has no explicit dependence on the local tidal field, and is a function only of the local density on the filtering scale used to define the tidal tensor. There is nevertheless a strong implicit predicted dependence on geometrical environment, because the local density couples statistically to the derivatives of the potential. We compute the predictions of this model and study the limits of their validity by comparing them to results deduced empirically from N-body simulations. We have verified that, to a good approximation, the abundance of haloes in different environments depends only on their densities, and not on their tidal structure. In this sense we find relative differences between halo abundances in different environments with the same density which are smaller than ˜13 per cent. Furthermore, for sufficiently large filtering scales, the agreement with the theoretical prediction is good, although there are important deviations from the Gaussian prediction at small, non-linear scales. We discuss how to obtain improved predictions in this regime, using the `effective-universe' approach.

  4. Abundant thorium as an alternative nuclear fuel

    International Nuclear Information System (INIS)

    It has long been known that thorium-232 is a fertile radioactive material that can produce energy in nuclear reactors for conversion to electricity. Thorium-232 is well suited to a variety of reactor types including molten fluoride salt designs, heavy water CANDU configurations, and helium-cooled TRISO-fueled systems. Among contentious commercial nuclear power issues are the questions of what to do with long-lived radioactive waste and how to minimize weapon proliferation dangers. The substitution of thorium for uranium as fuel in nuclear reactors has significant potential for minimizing both problems. Thorium is three times more abundant in nature than uranium. Whereas uranium has to be imported, there is enough thorium in the United States alone to provide adequate grid power for many centuries. A well-designed thorium reactor could produce electricity less expensively than a next-generation coal-fired plant or a current-generation uranium-fueled nuclear reactor. Importantly, thorium reactors produce substantially less long-lived radioactive waste than uranium reactors. Thorium-fueled reactors with molten salt configurations and very high temperature thorium-based TRISO-fueled reactors are both recommended for priority Generation IV funding in the 2030 time frame. - Highlights: • Thorium is an abundant nuclear fuel that is well suited to three advanced reactor configurations. • Important thorium reactor configurations include molten salt, CANDU, and TRISO systems. • Thorium has important nuclear waste disposal advantages relative to pressurized water reactors. • Thorium as a nuclear fuel has important advantages relative to weapon non-proliferation

  5. Lectures in plasma diagnostics

    International Nuclear Information System (INIS)

    This paper discusses the following topics on plasma diagnostics: Electric probes in flowing and magnetized plasmas; Electron cyclotron emission absorption; Magnetic diagnostics; Spectroscopy; and Thomson Scattering

  6. Normal mode analysis of pair plasma with drifting species

    International Nuclear Information System (INIS)

    Pair-ion plasmas consisting of C60+ and C60- ions have been generated in laboratory using fullerene as an ion source1,2. In addition, electron-positron plasmas are believed to be abundant in many astrophysical environments from pulsars to quasars3,4. In laboratory also, electron-positron pair plasma has been generated with the help of ultraintense lasers5 and by trapping of positron in a magnetic mirror configuration by electron cyclotron resonance heating6. Since plasmas are nonlinear and dispersive media, it would be very much interesting to examine whether such pair-plasmas support the excitation of solitary waves and solitons. This has motivated us to do analytical calculations for studying the modes of solitary wave propagation. One-dimensional two-fluid plasma having streaming positrons and electrons is studied through normal mode analysis. We analyze how many types of modes propagate in these plasmas and also compare our results with previously explored models by other researchers. We obtained the dispersion relation and solved for the phase velocity of the acoustic modes. Although the dispersion relation predicts four types of the modes, only two types of the modes (namely fast and slow mode) are possible in the present plasma model. We find all the roots to be real. Therefore, it may be inferred that the instability may be possible in the present plasma model. (basic plasma physics, plasma theory and modeling (bp))

  7. Abundances of Galactic Anticenter Planetary Nebulae and the Oxygen Abundance Gradient in the Galactic Disk

    CERN Document Server

    Henry, R B C; Jaskot, Anne E; Balick, Bruce; Morrison, Michael A; Milingo, Jacquelynne B

    2010-01-01

    We have obtained spectrophotometric observations of 41 anticenter planetary nebulae (PNe) located in the disk of the Milky Way. Electron temperatures and densities, as well as chemical abundances for He, N, O, Ne, S, Cl, and Ar were determined. Incorporating these results into our existing database of PN abundances yielded a sample of 124 well-observed objects with homogeneously-determined abundances extending from 0.9-21 kpc in galactocentric distance. We performed a detailed regression analysis which accounted for uncertainties in both oxygen abundances and radial distances in order to establish the metallicity gradient across the disk to be: 12+log(O/H)=(9.09+/-.05) - (0.058+/-.006) x Rg, with Rg in kpc. While we see some evidence that the gradient steepens at large galactocentric distances, more objects toward the anticenter need to be observed in order to confidently establish the true form of the metallicity gradient. We find no compelling evidence that the gradient differs between Peimbert Types I and ...

  8. Abundances in the Ejecta of Core Collapse Supernova Remnants, G350.1-0.3 and G349.7+0.2

    CERN Document Server

    Yasumi, Masato; Nakashima, Shinya; Uchida, Hiroyuki; Sugawara, Ryusuke; Tsuru, Takeshi Go; Tanaka, Takaaki; Koyama, Katsuji

    2014-01-01

    We present Suzaku results of the two Galactic supernova remnants (SNRs), G350.1-0.3 and G349.7+0.2. We find Al and Ni K alpha lines from both the SNRs for the first time, in addition to previously detected K-shell lines of Mg, Si, S, Ar, Ca and Fe. The spectra are well described by two optically thin thermal plasmas: a low-temperature (low-kT) plasma in collisional ionization equilibrium and a high-temperature (high-kT) plasma in non-equilibrium ionization. Since the low-kT plasma has solar metal abundances, it is thought to be of interstellar medium origin. The high-kT plasma has super-solar abundances, hence it is likely to be of ejecta origin. The abundance patterns of the ejecta components are similar to those of core-collapse supernovae with the progenitor mass of ~15-25 M_solar for G350.1-0.3 and ~35-40 M_solar for G349.7+0.2. We find extremely high abundances of Ni compared to Fe (Z_Ni/Z_Fe ~8). Based on the measured column densities between the SNRs and the near sky background, we propose that G350.1-...

  9. Gravitationally induced particle production and its impact on the WIMP abundance

    Directory of Open Access Journals (Sweden)

    I. Baranov

    2015-12-01

    Full Text Available A large set of independent astronomical observations have provided a strong evidence for nonbaryonic dark matter in the Universe. One of the most investigated candidates is an unknown long-lived Weakly Interacting Massive Particle (WIMP which was in thermal equilibrium with the primeval plasma. Here we investigate the WIMP abundance based on the relativistic kinetic treatment for gravitationally induced particle production recently proposed in the literature (Lima and Baranov, 2014 [16]. The new evolution equation is deduced and solved both numerically and through a semi-analytical approach. The predictions of the WIMP observables are discussed and compared with the ones obtained in the standard approach.

  10. Fusion plasma physics

    CERN Document Server

    Stacey, Weston M

    2012-01-01

    This revised and enlarged second edition of the popular textbook and reference contains comprehensive treatments of both the established foundations of magnetic fusion plasma physics and of the newly developing areas of active research. It concludes with a look ahead to fusion power reactors of the future. The well-established topics of fusion plasma physics -- basic plasma phenomena, Coulomb scattering, drifts of charged particles in magnetic and electric fields, plasma confinement by magnetic fields, kinetic and fluid collective plasma theories, plasma equilibria and flux surface geometry, plasma waves and instabilities, classical and neoclassical transport, plasma-materials interactions, radiation, etc. -- are fully developed from first principles through to the computational models employed in modern plasma physics. The new and emerging topics of fusion plasma physics research -- fluctuation-driven plasma transport and gyrokinetic/gyrofluid computational methodology, the physics of the divertor, neutral ...

  11. Protein abundance profiling of the Escherichia coli cytosol

    DEFF Research Database (Denmark)

    Ishihama, Y.; Schmidt, T.; Rappsilber, J.;

    2008-01-01

    sample. Using a combination of LC-MS/MS approaches with protein and peptide fractionation steps we identified 1103 proteins from the cytosolic fraction of the Escherichia coli strain MC4100. A measure of abundance is presented for each of the identified proteins, based on the recently developed em...... protein and mRNA abundance in E. coli cells. Conclusion: Abundance measurements for more than 1000 E. coli proteins presented in this work represent the most complete study of protein abundance in a bacterial cell so far. We show significant associations between the abundance of a protein and its...

  12. Abundance of sardine fish species in Bangladesh

    Directory of Open Access Journals (Sweden)

    Roy Bikram Jit

    2012-06-01

    Full Text Available The study was conducted during January, 2012 to December 2012 in the sardine fisheries which is occurred both in artisanal and industrial fishing sector in the marine water of the Bay of Bengal of Bangladesh region. During this study period the total landing amounts by weight of sardines were 7352.99 MT, among these 23.76% (1747.22 MT was exploited by the artisanal mechanized boats and 76.24% (5605.77 MT captured through different industrial fishing trawlers and contributed 17.51% of the total marine fish production by commercial fish trawlers during the study period. 4 sardine species have been recorded from our marine territory. Among them, 2 sardine species are highly abundant, Sardinella fimbriata total production volumes was 5495.79 MT (74.74% contributed 1747.22MT (31.79% from the artisanal and 3748.57MT (68.21% from the industrial sector and Dussumieria acuta production amounts was 1857.20MT (25.26% contributed only from the industrial fishing sector.Species wise contribution shows that S. fimbriata contributed 100% in the artisanal sector and in the industrial fishing S. fimbriata contributed 66.87% and D. acuta contributed the rest 33.13%. The distribution of the S. fimbriata is within 10-20 meters depth and abundance was observed in the southern part of the South patches and South of south patches (N: 210.09// -22, E: 920.04/-07 to N: 200.45/-25, E: 920.18/-56 and 10-50m depth in onshore and off shore areas in the north-west to north-east of Middle ground (Kohinoor point -N: 210.36/.23, E: 900.06/.43 to N: 210.18/.18, E 910.17/.57. The distribution of the D. acuta is within 40-60 m. depth and abundance was observed in the north-west to north-east of Middle ground areas (Kohinoor point - N: 210.36/.23, E: 900.06/.43 to N: 210.18/.18, E 910.17/.57 and south-west to south-east of Middle ground (Kohinoor point- N: 200-17/.29, E: 900.15/.21 to N: 200.29/.56, E: 910.24/.22 in the Bay of Bengal of Bangladesh region. The peak capture season of

  13. IgG4 related sclerosing mastitis: expanding the morphological spectrum of IgG4 related diseases.

    Science.gov (United States)

    Chougule, Abhijit; Bal, Amanjit; Das, Ashim; Singh, Gurpreet

    2015-01-01

    IgG4 related disease (IgG4RD) is a recently recognised condition characterised by mass forming lesions associated with storiform fibrosis, obliterative phlebitis, lymphoplasmacytic infiltrate rich in IgG4 positive plasma cells and elevated serum IgG4 levels. Although rare, mammary involvement has been reported as IgG4 related sclerosing mastitis, the morphological counterpart of a growing family of IgG4 related diseases. A total of 17 cases belonging to mass forming benign inflammatory breast lesions such as plasma cell mastitis, granulomatous lobular mastitis, non-specific mastitis and inflammatory pseudotumour were investigated as a possible member of IgG4 related sclerosing mastitis. Clinical, radiological, histopathological and immunohistochemistry findings were noted in all cases. Cases diagnosed as inflammatory pseudotumour showed all the histopathological features of IgG4RD along with increased number of IgG4 positive plasma cells and IgG4/IgG ratio >40%. However, only a few IgG4 positive cells were seen in plasma cell mastitis, granulomatous lobular mastitis and non-specific mastitis cases. These cases also did not fulfill the morphological criteria for the diagnosis of IgG4 related diseases. IgG4RD should be excluded in plasma cell rich lesions diagnosed on core biopsies by IgG4 immunostaining. This can avoid unnecessary surgery as IgG4 related diseases respond to simple and effective steroid treatment.

  14. The Solar Heavy Element Abundances: I. Constraints from Stellar Interiors

    CERN Document Server

    Delahaye, F; Delahaye, Franck; Pinsonneault, Marc

    2005-01-01

    The latest solar atmosphere models include non-LTE corrections and 3D hydrodynamic convection simulations. These models predict a significant reduction in the solar metal abundance, which leads to a serious conflict between helioseismic data and the predictions of solar interiors models. We demonstrate that the helioseismic constraints on the surface convection zone depth and helium abundance combined with stellar interiors models can be used to define the goodness of fit for a given chemical composition. After a detailed examination of the errors in the theoretical models we conclude that models constructed with the older solar abundances are consistent (<2 \\sigma) with the seismic data. Models constructed with the proposed new low abundance scale are strongly disfavored, disagreeing at the 15 \\sigma level. We then use the sensitivity of the seismic properties to abundance changes to invert the problem and infer a seismic solar heavy element abundance mix with two components: meteoritic abundances, and th...

  15. Dielectrophoretic capture of low abundance cell population using thick electrodes

    Science.gov (United States)

    Marchalot, Julien; Chateaux, Jean-François; Faivre, Magalie; Mertani, Hichem C.; Ferrigno, Rosaria; Deman, Anne-Laure

    2015-01-01

    Enrichment of rare cell populations such as Circulating Tumor Cells (CTCs) is a critical step before performing analysis. This paper presents a polymeric microfluidic device with integrated thick Carbon-PolyDimethylSiloxane composite (C-PDMS) electrodes designed to carry out dielectrophoretic (DEP) trapping of low abundance biological cells. Such conductive composite material presents advantages over metallic structures. Indeed, as it combines properties of both the matrix and doping particles, C-PDMS allows the easy and fast integration of conductive microstructures using a soft-lithography approach while preserving O2 plasma bonding properties of PDMS substrate and avoiding a cumbersome alignment procedure. Here, we first performed numerical simulations to demonstrate the advantage of such thick C-PDMS electrodes over a coplanar electrode configuration. It is well established that dielectrophoretic force (FDEP) decreases quickly as the distance from the electrode surface increases resulting in coplanar configuration to a low trapping efficiency at high flow rate. Here, we showed quantitatively that by using electrodes as thick as a microchannel height, it is possible to extend the DEP force influence in the whole volume of the channel compared to coplanar electrode configuration and maintaining high trapping efficiency while increasing the throughput. This model was then used to numerically optimize a thick C-PDMS electrode configuration in terms of trapping efficiency. Then, optimized microfluidic configurations were fabricated and tested at various flow rates for the trapping of MDA-MB-231 breast cancer cell line. We reached trapping efficiencies of 97% at 20 μl/h and 78.7% at 80 μl/h, for 100 μm thick electrodes. Finally, we applied our device to the separation and localized trapping of CTCs (MDA-MB-231) from a red blood cells sample (concentration ratio of 1:10). PMID:26392836

  16. Dust-Plasma Interactions

    International Nuclear Information System (INIS)

    Our theoretical research on dust-plasma interactions has concentrated on three main areas: (a)studies of grain charging and applications; (b) waves and instabilities in weakly correlated dusty plasma with applications to space and laboratory plasmas; (c) waves in strongly coupled dusty plasmas.

  17. Late Embryogenesis Abundant (LEA) proteins in legumes.

    Science.gov (United States)

    Battaglia, Marina; Covarrubias, Alejandra A

    2013-01-01

    Plants are exposed to different external conditions that affect growth, development, and productivity. Water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. Plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. One of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration, at the last stage of embryogenesis, hence named Late Embryogenesis Abundant (LEA) proteins. LEA proteins also accumulate in response to water limitation in vegetative tissues, and have been classified in seven groups based on their amino acid sequence similarity and on the presence of distinctive conserved motifs. These proteins are widely distributed in the plant kingdom, from ferns to angiosperms, suggesting a relevant role in the plant response to this unfavorable environmental condition. In this review, we analyzed the LEA proteins from those legumes whose complete genomes have been sequenced such as Phaseolus vulgaris, Glycine max, Medicago truncatula, Lotus japonicus, Cajanus cajan, and Cicer arietinum. Considering their distinctive motifs, LEA proteins from the different groups were identified, and their sequence analysis allowed the recognition of novel legume specific motifs. Moreover, we compile their transcript accumulation patterns based on publicly available data. In spite of the limited information on these proteins in legumes, the analysis and data compiled here confirm the high correlation between their accumulation and water deficit, reinforcing their functional relevance under this detrimental conditions. PMID:23805145

  18. Abundance Profiles in Low-Mass Galaxies

    CERN Document Server

    Kobulnicky, H A

    1997-01-01

    The nitrogen and oxygen abundances in the warm ionized gas of low-mass, metal-poor galaxies appear surprisingly homogeneous considering the prevalence of large HII regions, which contain hundreds of massive stars. Of the six galaxies with extensive optical spectroscopy, only the largest and most metal-rich, the LMC, shows evidence for a chemical gradient akin to those commonly seen in spirals. Furthermore, no significant localized chemical fluctuations are found in the vicinity of young star clusters, despite large expected chemical yields of massive stars. An ad-hoc fine-tuning of the release, dispersal and mixing rates could give rise to the observed homogeneity, but a more probable explanation is that fresh ejecta reside in a hard-to-observe hot or cold phase. In any case, the observations indicate that heavy elements which have already mixed with the warm interstellar medium are homogeneously dispersed. Mixing of fresh ejecta with the surrounding warm ISM apparently requires longer than the lifetimes of t...

  19. Late Embryogenesis Abundant (LEA proteins in legumes

    Directory of Open Access Journals (Sweden)

    Marina eBattaglia

    2013-06-01

    Full Text Available Plants are exposed to different external conditions that affect growth, development, and productivity. Water deficit is one of these adverse conditions caused by drought, salinity, and extreme temperatures. Plants have developed different responses to prevent, ameliorate or repair the damage inflicted by these stressful environments. One of these responses is the activation of a set of genes encoding a group of hydrophilic proteins that typically accumulate to high levels during seed dehydration, at the last stage of embryogenesis, hence named Late Embryogenesis Abundant (LEA proteins. LEA proteins also accumulate in response to water limitation in vegetative tissues, and have been classified in seven groups based on their amino acid sequence similarity and on the presence of distinctive conserved motifs. These proteins are widely distributed in the plant kingdom, from ferns to angiosperms, suggesting a relevant role in the plant response to this unfavorable environmental condition. In this review, we analyzed the LEA proteins from those legumes whose complete genomes have been sequenced such as Phaseolus vulgaris, Glycine max, Medicago truncatula, Lotus japonicus, Cajanus cajan and Cicer arietinum. Considering their distinctive motifs, LEA proteins from the different groups were identified, and their sequence analysis allowed the recognition of novel legume specific motifs. Moreover, we compile their transcript accumulation patterns based on publicly available data. In spite of the limited information on these proteins in legumes, the analysis and data compiled here confirms the high correlation between their accumulation and water deficit, reinforcing their functional relevance under this detrimental conditions.

  20. Comparing halo bias from abundance and clustering

    CERN Document Server

    Hoffmann, Kai; Gaztanaga, Enrique

    2015-01-01

    We model the abundance of haloes in the $\\sim(3 \\ \\text{Gpc}/h)^3$ volume of the MICE Grand Challenge simulation by fitting the universal mass function with an improved Jack-Knife error covariance estimator that matches theory predictions. We present unifying relations between different fitting models and new predictions for linear ($b_1$) and non-linear ($c_2$ and $c_3$) halo clustering bias. Different mass function fits show strong variations in their overall poor performance when including the low mass range ($M_h \\lesssim 3 \\ 10^{12} \\ M_{\\odot}/h$) in the analysis, which indicates noisy friends-of-friends halo detection given the MICE resolution ($m_p \\simeq 3 \\ 10^{10} \\ M_{\\odot}$/h). Together with fits from the literature we find an overall variance in the amplitudes of around $10%$ in the low mass and up to $50%$ in the high mass (galaxy cluster) range ($M_h > 10^{14} \\ M_{\\odot}/h$). These variations propagate into a $10%$ change in $b_1$ predictions and a $50%$ change in $c_2$ or $c_3$. Despite the...

  1. Introduction to plasma dynamics

    CERN Document Server

    Morozov, A I

    2013-01-01

    As the twenty-first century progresses, plasma technology will play an increasing role in our lives, providing new sources of energy, ion-plasma processing of materials, wave electromagnetic radiation sources, space plasma thrusters, and more. Studies of the plasma state of matter not only accelerate technological developments but also improve the understanding of natural phenomena. Beginning with an introduction to the characteristics and types of plasmas, Introduction to Plasma Dynamics covers the basic models of classical diffuse plasmas used to describe such phenomena as linear and shock w

  2. Non-Additive Effects of Genotypic Diversity Increase Floral Abundance and Abundance of Floral Visitors

    OpenAIRE

    Mark A Genung; Jean-Philippe Lessard; Claire B Brown; Bunn, Windy A.; Cregger, Melissa A.; W M Nicholas Reynolds; Emmi Felker-Quinn; Stevenson, Mary L.; Hartley, Amanda S.; Gregory M. Crutsinger; Schweitzer, Jennifer A.; Bailey, Joseph K.

    2010-01-01

    BACKGROUND: In the emerging field of community and ecosystem genetics, genetic variation and diversity in dominant plant species have been shown to play fundamental roles in maintaining biodiversity and ecosystem function. However, the importance of intraspecific genetic variation and diversity to floral abundance and pollinator visitation has received little attention. METHODOLOGY/PRINCIPAL FINDINGS: Using an experimental common garden that manipulated genotypic diversity (the number of dist...

  3. 2 D gel based analysis of biological variability of the human plasma proteome

    DEFF Research Database (Denmark)

    Rentsch, Maria Louise; Jessen, Flemming

    Human blood plasma is a valuable specimen for the biomarker discovery process, since it is easily accessible and contains proteins that are synthesised, secreted or lost from cells and tissue. In this way, changes in plasma proteome reflect the current state of the organism. The analysis of plasma...... proteome is yet challenging due to the huge dynamic range of protein abundance. When evaluating a potential biomarker, stable basal level of the protein is needed before it can be considered a functional biomarker. However, basal level differences of plasma proteins are naturally occurring between...... by one-week interval. Blood samples were drawn before the meal intake and five times during 24 hours for proteome analysis. Plasma was fractionated by use of IgY-12 spin column depleting the 12 highly abundant proteins and further processed for two-dimensional gel electrophoresis. The plasma proteome...

  4. A case of tubulointerstitial nephritis in IgG4-related systemic disease with markedly enlarged kidneys.

    Science.gov (United States)

    Mise, Naobumi; Tomizawa, Yutaka; Fujii, Akiko; Yamaguchi, Yutaka; Sugimoto, Tokuichiro

    2009-06-01

    IgG4-related systemic disease, including autoimmune pancreatitis, is a multi-organ disorder characterized by elevated serum immunoglobulin G4 (IgG4) concentration and IgG4-positive plasma cell infiltration. We report the case of a 67-year-old man with IgG4-related tubulointerstitial nephritis, presenting with markedly enlarged kidneys and renal dysfunction. The serum IgG4 level was elevated with 4200 mg/dl and pathological examination revealed patchy, clearly fringed areas of IgG4-positive plasma cell infiltration and advanced fibrosis in the renal parenchyma, perirenal tissue and lymph nodes. With oral prednisolone at a dose of 60 mg daily, a contraction of the kidneys and an improvement of renal function were observed. No recurrence of the disease was observed during the reduction of prednisolone to 2 mg daily over 4 years.

  5. Abundance models improve spatial and temporal prioritization of conservation resources.

    Science.gov (United States)

    Johnston, Alison; Fink, Daniel; Reynolds, Mark D; Hochachka, Wesley M; Sullivan, Brian L; Bruns, Nicholas E; Hallstein, Eric; Merrifield, Matt S; Matsumoto, Sandi; Kelling, Steve

    2015-10-01

    Conservation prioritization requires knowledge about organism distribution and density. This information is often inferred from models that estimate the probability of species occurrence rather than from models that estimate species abundance, because abundance data are harder to obtain and model. However, occurrence and abundance may not display similar patterns and therefore development of robust, scalable, abundance models is critical to ensuring that scarce conservation resources are applied where they can have the greatest benefits. Motivated by a dynamic land conservation program, we develop and assess a general method for modeling relative abundance using citizen science monitoring data. Weekly estimates of relative abundance and occurrence were compared for prioritizing times and locations of conservation actions for migratory waterbird species in California, USA. We found that abundance estimates consistently provided better rankings of observed counts than occurrence estimates. Additionally, the relationship between abundance and occurrence was nonlinear and varied by species and season. Across species, locations prioritized by occurrence models had only 10-58% overlap with locations prioritized by abundance models, highlighting that occurrence models will not typically identify the locations of highest abundance that are vital for conservation of populations. PMID:26591443

  6. The plasma membrane proteome of germinating barley embryos

    DEFF Research Database (Denmark)

    Hynek, Radovan; Svensson, Birte; Jensen, O.N.;

    2009-01-01

    with amphiphilicity and low abundance of membrane proteins. A fraction enriched in plasma membranes was prepared from embryos dissected from 18 h germinated barley seeds using aqueous two-phase partitioning. Reversed-phase chromatography on C-4 resin performed in micro-spin columns with stepwise elution by 2-propanol...

  7. Reanalysis of the interstellar CH abundance

    International Nuclear Information System (INIS)

    A detailed investigation of the term structure of the X2II, A2Δ, B2Σ-, and C2Σ+ systems of CH is presented, as well as a discussion of a number of errors that have been found with respect to the historical analysis of the interstellar CH abundance. The primary cause for these errors is the neglect of the Λ doubling of the ground state. The effects of including this splitting are the following: (1) the oscillator strength doubles for each line arising from the ground state of the B-X and C-X electronic systems; (2) the 4300, 3886, and 3143 A lines each consist of a blend of two lines separated by 1.43, 1.28, and 2.17 km s-1, respectively; (3) the line at 3886 A arises solely from the upper half of the Λ doublet, and the lines at 3890 and 3878 A arise from the lower half of the Λ doublet; (4) the line at 3143 A arises solely from the lower half of the Λ doublet, and the lines at 3146 and 3137 A arise from the upper half of the Λ doublet; (5) the excitation temperature (a measure of the relative level population) of the ground-state Λ doublet has been calculated for the interstellar CH along the line of sight toward four stars (zeta Per, zeta Oph, X Per, and chi Oph) using published equivalent withs. The excitation temperature appears to be less than zero toward X Per and zeta Per, indicating that the population of the ground-state Λ doublet is inverted. The level populations along other lines of sight are known to be inverted from observations of the radio CH lines; this is the first detection of a radio maser by optical methods

  8. Testing spherical evolution for modelling void abundances

    Science.gov (United States)

    Achitouv, Ixandra; Neyrinck, Mark; Paranjape, Aseem

    2015-08-01

    We compare analytical predictions of void volume functions to those measured from N-body simulations, detecting voids with the ZOBOV void finder. We push to very small, non-linear voids, below few Mpc radius, by considering the unsampled dark matter density field. We also study the case where voids are identified using haloes. We develop analytical formula for the void abundance of both the excursion set approach and the peaks formalism. These formulas are valid for random walks smoothed with a top-hat filter in real space, with a large class of realistic barrier models. We test the extent to which the spherical evolution approximation, which forms the basis of the analytical predictions, models the highly aspherical voids that occur in the cosmic web, and are found by a watershed-based algorithm such as ZOBOV. We show that the volume function returned by ZOBOV is quite sensitive to the choice of treatment of subvoids, a fact that has not been appreciated previously. For reasonable choices of subvoid exclusion, we find that the Lagrangian density δv of the ZOBOV voids - which is predicted to be a constant δv ≈ -2.7 in the spherical evolution model - is different from the predicted value, showing substantial scatter and scale dependence. This result applies to voids identified at z = 0 with effective radius between 1 and 10 h-1 Mpc. Our analytical approximations are flexible enough to give a good description of the resulting volume function; however, this happens for choices of parameter values that are different from those suggested by the spherical evolution assumption. We conclude that analytical models for voids must move away from the spherical approximation in order to be applied successfully to observations, and we discuss some possible ways forward.

  9. Nitrogen abundances in damped Lyalpha absorbers

    Science.gov (United States)

    Zafar, T.; Centurión, M.; Molaro, P.; Péroux, C.; D'Odorico, V.; Vladilo, G.

    Nitrogen is thought to have both primary and secondary origins depending on whether the seed carbon and oxygen are produced by the star itself (primary) or already present in the interstellar medium (secondary) from which star forms. Damped Lyalpha (DLA) and sub-DLA systems with typical metallicities of -3.0≲ Z/Z⊙ ≲ -0.5 are excellent tools to study nitrogen production. We made a search for nitrogen in the European Southern Observatory (ESO) Ultraviolet Visual Echelle Spectrograph (UVES) advanced data products (EUADP) database. In the EUADP database, we find 10 new measurements and 9 upper limits of nitrogen. We further compiled DLA/sub-DLA data from the literature with estimates available of nitrogen and alpha -elements. This yields a total of 98 systems, i.e. the largest nitrogen abundance sample investigated so far. In agreement with previous studies, we indeed find a bimodal [N/alpha ] behaviour: three-quarter systems show a mean value of [N/alpha ] =-0.87 with a scatter of 0.21 dex and one-quarter shows ratios clustered at [N/alpha ] = -1.43 with a lower dispersion of 0.13 dex. The high [N/alpha ] group is consistent with the blue compact dwarves and dwarf irregular galaxies, suggesting primary nitrogen production. The low [N/alpha ] group is the lowest ever observed in any astrophysical site and probably provides an evidence of the primary production by fast rotating massive stars in young sites. Moreover, we find a transition between the two [N/alpha ] groups around [N/H] ≃-2.5. The transition is not abrupt and there are a few systems lying in the transition region. Additional observations of DLAs/sub-DLAs below [N/H] <-2.5 would provide more clues.

  10. Colloidal Plasmas : Basic physics of colloidal plasmas

    Indian Academy of Sciences (India)

    C B Dwivedi

    2000-11-01

    Colloidal plasma is a distinct class of the impure plasmas with multispecies ionic composition. The distinction lies in the phase distribution of the impurity-ion species. The ability to tailor the electrostatic interactions between these colloidal particles provides a fertile ground for scientists to investigate the fundamental aspects of the Coulomb phase transition behavior. The present contribution will review the basic physics of the charging mechanism of the colloidal particles as well as the physics of the collective normal mode behavior of the general multi-ion species plasmas. Emphasis will be laid on the clarification of the prevailing confusing ideas about distinct qualities of the various acoustic modes, which are likely to exist in colloidal plasmas as well as in normal multi-ion species plasmas. Introductory ideas about the proposed physical models for the Coulomb phase transition in colloidal plasma will also be discussed.

  11. How cholesterol homeostasis is regulated by plasma membrane cholesterol in excess of phospholipids

    OpenAIRE

    Lange, Yvonne; Ye, Jin; Steck, Theodore L.

    2004-01-01

    How do cells sense and control their cholesterol levels? Whereas most of the cell cholesterol is located in the plasma membrane, the effectors of its abundance are regulated by a small pool of cholesterol in the endoplasmic reticulum (ER). The size of the ER compartment responds rapidly and dramatically to small changes in plasma membrane cholesterol around the normal level. Consequently, increasing plasma membrane cholesterol in vivo from just below to just above the basal level evoked an ac...

  12. Evolution of dispersion in the cosmic deuterium abundance

    Science.gov (United States)

    Dvorkin, Irina; Vangioni, Elisabeth; Silk, Joseph; Petitjean, Patrick; Olive, Keith A.

    2016-05-01

    Deuterium is created during big bang nucleosynthesis, and, in contrast to the other light stable nuclei, can only be destroyed thereafter by fusion in stellar interiors. In this Letter, we study the cosmic evolution of the deuterium abundance in the interstellar medium (ISM) and its dispersion using realistic galaxy evolution models. We find that models that reproduce the observed metal abundance are compatible with observations of the deuterium abundance in the local ISM and z ˜ 3 absorption line systems. In particular, we reproduce the low astration factor which we attribute to a low global star formation efficiency. We calculate the dispersion in deuterium abundance arising from different structure formation histories in different parts of the Universe. Our model also predicts a tight correlation between deuterium and metal abundances which could be used to measure the primordial deuterium abundance.

  13. Radial molecular abundances and gas cooling in starless cores

    CERN Document Server

    Sipilä, O

    2012-01-01

    Aims: We aim to simulate radial profiles of molecular abundances and the gas temperature in cold and heavily shielded starless cores by combining chemical and radiative transfer models. Methods: A determination of the dust temperature in a modified Bonnor-Ebert sphere is used to calculate initial radial molecular abundance profiles. The abundances of selected cooling molecules corresponding to two different core ages are then extracted to determine the gas temperature at two time steps. The calculation is repeated in an iterative process yielding molecular abundances consistent with the gas temperature. Line emission profiles for selected substances are calculated using simulated abundance profiles. Results: The gas temperature is a function of time; the gas heats up as the core gets older because the cooling molecules are depleted onto grain surfaces. The contributions of the various cooling molecules to the total cooling power change with time. Radial chemical abundance profiles are non-trivial: different s...

  14. Shallow extra mixing in solar twins inferred from Be abundances

    CERN Document Server

    Maia, M Tucci; Castro, M; Asplund, M; Ramírez, I; Monroe, T R; Nascimento, J D do; Yong, D

    2015-01-01

    Lithium and beryllium are destroyed at different temperatures in stellar interiors. As such, their relative abundances offer excellent probes of the nature and extent of mixing processes within and below the convection zone. We determine Be abundances for a sample of eight solar twins for which Li abundances have previously been determined. The analyzed solar twins span a very wide range of age, 0.5-8.2 Gyr, which enables us to study secular evolution of Li and Be depletion. We gathered high-quality UVES/VLT spectra and obtained Be abundances by spectral synthesis of the Be II 313 nm doublet. The derived beryllium abundances exhibit no significant variation with age. The more fragile Li, however, exhibits a monotonically decreasing abundance with increasing age. Therefore, relatively shallow extra mixing below the convection zone is necessary to simultaneously account for the observed Li and Be behavior in the Sun and solar twins.

  15. TEA: A Code for Calculating Thermochemical Equilibrium Abundances

    CERN Document Server

    Blecic, Jasmina; Bowman, M Oliver

    2015-01-01

    We present an open-source Thermochemical Equilibrium Abundances (TEA) code that calculates the abundances of gaseous molecular species. The code is based on the methodology of White et al. (1958) and Eriksson (1971). It applies Gibbs free-energy minimization using an iterative, Lagrangian optimization scheme. Given elemental abundances, TEA calculates molecular abundances for a particular temperature and pressure or a list of temperature-pressure pairs. We tested the code against the method of Burrows & Sharp (1999), the free thermochemical equilibrium code CEA (Chemical Equilibrium with Applications), and the example given by White et al. (1958). Using their thermodynamic data, TEA reproduces their final abundances, but with higher precision. We also applied the TEA abundance calculations to models of several hot-Jupiter exoplanets, producing expected results. TEA is written in Python in a modular format. There is a start guide, a user manual, and a code document in addition to this theory paper. TEA is ...

  16. Clinical relevance of drug binding to plasma proteins

    Science.gov (United States)

    Ascenzi, Paolo; Fanali, Gabriella; Fasano, Mauro; Pallottini, Valentina; Trezza, Viviana

    2014-12-01

    Binding to plasma proteins highly influences drug efficacy, distribution, and disposition. Serum albumin, the most abundant protein in plasma, is a monomeric multi-domain macromolecule that displays an extraordinary ligand binding capacity, providing a depot and carrier for many endogenous and exogenous compounds, such as fatty acids and most acidic drugs. α-1-Acid glycoprotein, the second main plasma protein, is a glycoprotein physiologically involved in the acute phase reaction and is the main carrier for basic and neutral drugs. High- and low-density lipoproteins play a limited role in drug binding and are natural drug delivery system only for few lipophilic drugs or lipid-based formulations. Several factors influence drug binding to plasma proteins, such as pathological conditions, concurrent administration of drugs, sex, and age. Any of these factors, in turn, influences drug efficacy and toxicity. Here, biochemical, biomedical, and biotechnological aspects of drug binding to plasma proteins are reviewed.

  17. Active control of magneto-hydrodynamic instabilities in hot plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Igochine, Valentin (ed.) [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

    2015-04-01

    Written and edited by leading plasma physics researchers. Provides a toolkit for scientists and engineers aiming to optimize plasma performance. Comprehensive treatment of different plasma instabilities. During the past century, world-wide energy consumption has risen dramatically, which leads to a quest for new energy sources. Fusion of hydrogen atoms in hot plasmas is an attractive approach to solve the energy problem, with abundant fuel, inherent safety and no long-lived radioactivity. However, one of the limits on plasma performance is due to the various classes of magneto-hydrodynamic instabilities that may occur. The physics and control of these instabilities in modern magnetic confinement fusion devices is the subject of this book. Written by foremost experts, the contributions will provide valuable reference and up-to-date research reviews for ''old hands'' and newcomers alike.

  18. Nonlinear plasma wave in magnetized plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Bulanov, Sergei V. [Kansai Photon Science Institute, JAEA, Kizugawa, Kyoto 619-0215 (Japan); Prokhorov Institute of General Physics, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny, Moscow region 141700 (Russian Federation); Esirkepov, Timur Zh.; Kando, Masaki; Koga, James K. [Kansai Photon Science Institute, JAEA, Kizugawa, Kyoto 619-0215 (Japan); Hosokai, Tomonao; Zhidkov, Alexei G. [Photon Pioneers Center, Osaka University, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Japan Science and Technology Agency, CREST, 2-1, Yamadaoka, Suita, Osaka 565-0871 (Japan); Kodama, Ryosuke [Photon Pioneers Center, Osaka University, 2-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2013-08-15

    Nonlinear axisymmetric cylindrical plasma oscillations in magnetized collisionless plasmas are a model for the electron fluid collapse on the axis behind an ultrashort relativisically intense laser pulse exciting a plasma wake wave. We present an analytical description of the strongly nonlinear oscillations showing that the magnetic field prevents closing of the cavity formed behind the laser pulse. This effect is demonstrated with 3D PIC simulations of the laser-plasma interaction. An analysis of the betatron oscillations of fast electrons in the presence of the magnetic field reveals a characteristic “Four-Ray Star” pattern.

  19. Fundamentals of Plasma Physics

    Science.gov (United States)

    Bellan, Paul M.

    2008-07-01

    Preface; 1. Basic concepts; 2. The Vlasov, two-fluid, and MHD models of plasma dynamics; 3. Motion of a single plasma particle; 4. Elementary plasma waves; 5. Streaming instabilities and the Landau problem; 6. Cold plasma waves in a magnetized plasma; 7. Waves in inhomogeneous plasmas and wave energy relations; 8. Vlasov theory of warm electrostatic waves in a magnetized plasma; 9. MHD equilibria; 10. Stability of static MHD equilibria; 11. Magnetic helicity interpreted and Woltjer-Taylor relaxation; 12. Magnetic reconnection; 13. Fokker-Planck theory of collisions; 14. Wave-particle nonlinearities; 15. Wave-wave nonlinearities; 16. Non-neutral plasmas; 17. Dusty plasmas; Appendix A. Intuitive method for vector calculus identities; Appendix B. Vector calculus in orthogonal curvilinear coordinates; Appendix C. Frequently used physical constants and formulae; Bibliography; References; Index.

  20. Elements of plasma technology

    CERN Document Server

    Wong, Chiow San

    2016-01-01

    This book presents some fundamental aspects of plasma technology that are important for beginners interested to start research in the area of plasma technology . These include the properties of plasma, methods of plasma generation and basic plasma diagnostic techniques. It also discusses several low cost plasma devices, including pulsed plasma sources such as plasma focus, pulsed capillary discharge, vacuum spark and exploding wire; as well as low temperature plasmas such as glow discharge and dielectric barrier discharge which the authors believe may have potential applications in industry. The treatments are experimental rather than theoretical, although some theoretical background is provided where appropriate. The principles of operation of these devices are also reviewed and discussed.

  1. Autoimmune pancreatitis can develop into chronic pancreatitis

    OpenAIRE

    Maruyama, Masahiro; Watanabe, Takayuki; Kanai, Keita; Oguchi, Takaya; Asano, Jumpei; Ito, Tetsuya; Ozaki, Yayoi; Muraki, Takashi; Hamano, Hideaki; ARAKURA, Norikazu; Kawa, Shigeyuki

    2014-01-01

    Autoimmune pancreatitis (AIP) has been recognized as a distinct type of pancreatitis that is possibly caused by autoimmune mechanisms. AIP is characterized by high serum IgG4 and IgG4-positive plasma cell infiltration in affected pancreatic tissue. Acute phase AIP responds favorably to corticosteroid therapy and results in the amelioration of clinical findings. However, the long-term prognosis and outcome of AIP remain unclear. We have proposed a working hypothesis that AIP can develop into o...

  2. Radial molecular abundances and gas cooling in starless cores

    OpenAIRE

    Sipilä, O.

    2012-01-01

    Aims: We aim to simulate radial profiles of molecular abundances and the gas temperature in cold and heavily shielded starless cores by combining chemical and radiative transfer models. Methods: A determination of the dust temperature in a modified Bonnor-Ebert sphere is used to calculate initial radial molecular abundance profiles. The abundances of selected cooling molecules corresponding to two different core ages are then extracted to determine the gas temperature at two time steps. The c...

  3. Abundance and Diversity of Viruses in Six Delaware Soils

    OpenAIRE

    Williamson, Kurt E.; Radosevich, Mark; Wommack, K. Eric

    2005-01-01

    The importance of viruses in marine microbial ecology has been established over the past decade. Specifically, viruses influence bacterial abundance and community composition through lysis and alter bacterial genetic diversity through transduction and lysogenic conversion. By contrast, the abundance and distribution of viruses in soils are almost completely unknown. This study describes the abundance and diversity of autochthonous viruses in six Delaware soils: two agricultural soils, two coa...

  4. Cross-Scale Interactions and the Distribution-Abundance Relationship

    OpenAIRE

    Werner, Earl E.; Davis, Christopher J.; Skelly, David K.; Relyea, Rick A.; Benard, Michael F.; McCauley, Shannon J.

    2014-01-01

    Positive interspecific relationships between local abundance and extent of regional distribution are among the most ubiquitous patterns in ecology. Although multiple hypotheses have been proposed, the mechanisms underlying distribution-abundance (d-a) relationships remain poorly understood. We examined the intra- and interspecific distribution-abundance relationships for a metacommunity of 13 amphibian species sampled for 15 consecutive years. Mean density of larvae in occupied ponds was posi...

  5. A Data-intensive Assessment of the Species Abundance Distribution

    OpenAIRE

    Baldridge, Elita

    2013-01-01

    The hollow curve species abundance distribution describes the pattern of large numbers of rare species and a small number of common species in a community. The species abundance distribution is one of the most ubiquitous patterns in nature and many models have been proposed to explain the mechanisms that generate this pattern. While there have been numerous comparisons of species abundance distribution models, most of these comparisons only use a small subset of available models, focus on a s...

  6. Occupancy, spatial variance, and the abundance of species

    OpenAIRE

    He, F.; Gaston, K J

    2003-01-01

    A notable and consistent ecological observation known for a long time is that spatial variance in the abundance of a species increases with its mean abundance and that this relationship typically conforms well to a simple power law (Taylor 1961). Indeed, such models can be used at a spectrum of spatial scales to describe spatial variance in the abundance of a single species at different times or in different regions and of different species across the same set of areas (Tayl...

  7. Ecological niche structure and rangewide abundance patterns of species

    OpenAIRE

    Martínez-Meyer, Enrique; Díaz-Porras, Daniel; Peterson, A. Townsend; Yáñez-Arenas, Carlos

    2013-01-01

    Spatial abundance patterns across species' ranges have attracted intense attention in macroecology and biogeography. One key hypothesis has been that abundance declines with geographical distance from the range centre, but tests of this idea have shown that the effect may occur indeed only in a minority of cases. We explore an alternative hypothesis: that species' abundances decline with distance from the centroid of the species' habitable conditions in environmental space (the ecological nic...

  8. Positive Interspecific Relationship between Temporal Occurrence and Abundance in Insects

    OpenAIRE

    Scrosati, Ricardo A; Ruth D Patten; Lauff, Randolph F.

    2011-01-01

    One of the most studied macroecological patterns is the interspecific abundance-occupancy relationship, which relates species distribution and abundance across space. Interspecific relationships between temporal distribution and abundance, however, remain largely unexplored. Using data for a natural assemblage of tabanid flies measured daily during spring and summer in Nova Scotia, we found that temporal occurrence (proportion of sampling dates in which a species occurred in an experimental t...

  9. Modelling occurrence and abundance of species when detection is imperfect

    Science.gov (United States)

    Royle, J. Andrew; Nichols, J.D.; Kery, M.

    2005-01-01

    Relationships between species abundance and occupancy are of considerable interest in metapopulation biology and in macroecology. Such relationships may be described concisely using probability models that characterize variation in abundance of a species. However, estimation of the parameters of these models in most ecological problems is impaired by imperfect detection. When organisms are detected imperfectly, observed counts are biased estimates of true abundance, and this induces bias in stated occupancy or occurrence probability. In this paper we consider a class of models that enable estimation of abundance/occupancy relationships from counts of organisms that result from surveys in which detection is imperfect. Under such models, parameter estimation and inference are based on conventional likelihood methods. We provide an application of these models to geographically extensive breeding bird survey data in which alternative models of abundance are considered that include factors that influence variation in abundance and detectability. Using these models, we produce estimates of abundance and occupancy maps that honor important sources of spatial variation in avian abundance and provide clearly interpretable characterizations of abundance and occupancy adjusted for imperfect detection.

  10. The Stellar Oxygen Abundance Gradient in M33

    Science.gov (United States)

    Monteverde, M. I.; Herrero, A.; Lennon, D. J.; Kudritzki, R.-P.

    1997-01-01

    We report here first results concerning stellar oxygen abundances in M33. Non-LTE model atmosphere and non-LTE line formation calculations were used to determine the oxygen abundance of B-type supergiants. By choosing stars located at different projected radial distances to the center of M33, we are able to determine the oxygen abundance gradient, for which we obtain a value of -0.16 +/- 0.06 dex kpc-1. This is the first time that the oxygen stellar abundance gradient has been determined in a spiral galaxy other than the Milky Way.

  11. Parent Stars of Extrasolar Planets. IX. Lithium Abundances

    OpenAIRE

    Gonzalez, Guillermo

    2008-01-01

    We compare the Li abundances of a sample of stars with planets discovered with the Doppler method to a sample of stars without detected planets. We prepared the samples by combining the Li abundances reported in several recent studies in a consistent way. Our results confirm recent claims that the Li abundances of stars with planets are smaller than those of stars without planets near the solar temperature. We also find that the vsini and $R^{'}_{\\rm HK}$ anomalies correlate with the Li abund...

  12. Progress of International Low-Temperature Plasma Research Overview of the 15th International Symposium on Plasma Chemistry

    Institute of Scientific and Technical Information of China (English)

    吴承康

    2001-01-01

    International Symposium on Plasma Chemistry (ISPC) is the most influencial international symposium on science and technology research of low-temperature plasma, especially in the fields related to materials processing. People can be rightly informed of the current devel oping trend of this field from the contents of these symposia. This paper vill introduce briefly a general overview of the 15th ISPC. As viewed from the number of papers and their contents, there is still abundant research on thermal plasma, and the needs for micro-electronic technology and high performance films have driven forward continuous and intensive development of the research on low-pressure, non-equilibrium plasmas, while the research on normal pressure, non-equilibrium plasma has become a new highlight in this field.``

  13. Reviews of plasma physics

    CERN Document Server

    2008-01-01

    "Reviews of Plasma Physics Volume 24," edited by V.D. Shafranov, presents two reviews from the cutting-edge of Russian plasma physics research. The first review by V.A. Rozhansky devoted to the mechanisms of transverse conductivity and generation of self-consistent electric fields in strongly ionized magnetized plasma. The second review by O.G. Bakunin considers numerous aspects of turbulent transport in plasma and fluids. This review is focused on scaling arguments for describing anomalous diffusion in the presence of complex structures. These topics are especially important for fusion plasma research, plasma astrophysics, discharge physics, and turbulence

  14. Plasma Ion Sources

    International Nuclear Information System (INIS)

    A wide variety of ion source types has been developed. Ion sources can provide beams of hundreds of amperes for fusion applications, nano-amperes for microprobe trace analysis and broad beams for ion implantation, space thrusters, industrial polymerisation and food sterilisation. Also it can be used in medical, military and accelerators applications. In this paper, three different types of plasma ion sources with different means for producing the discharge current and the ions extracting current from the plasma are studied. The various plasma described include, d.c glow discharge plasma, arc discharge plasma and radio frequency discharge plasma

  15. International movement of plasma and plasma contracting.

    Science.gov (United States)

    Farrugia, A

    2005-01-01

    Plasma fractionation is a global business characterised by technological stability, increasing consolidation and a high level of regulatory oversight. All these factors affect the ease with which plasma derivatives can be accessed in the world market. As domestic regulatory measures in the first world blood economies become increasingly resonant to the precautionary approach, the availability of plasma as a raw material, as well as its cost, become an increasingly significant component in the cost of the final product. This decreases the amount of plasma which fractionators are able to allocate for export activities. Also, regulatory standards in the country of manufacture will reflect priorities in that country which may not be similar to those in export markets, but which will affect entry to those markets. While many countries possess a fractionation capacity, the limiting factor in supply worldwide is the amount of plasma available, and nationalistic drivers for each country to have its own plant are inimical to product safety and supply. Rather, the provision of sufficient supplies of domestic plasma should be the focus of resource allocation, with a choice of an appropriate contract fractionator. However, contract fractionation too may be affected by domestic considerations unrelated to the needs of the country of plasma origin. This chapter will review the global plasma market and the influences on plasma and plasma product movement across national borders. Problems in ensuring adequate safety and supply will be identified, and some tentative approaches to the amelioration of current barriers to the provision of plasma derivatives will be outlined. PMID:16050160

  16. Abundances of the heavy elements in the Magellanic Clouds. I. Metal abundances of F-type supergiants

    International Nuclear Information System (INIS)

    Metal abundances of eight F-type supergiants in each of the Magellanic Clouds were determined using the results of high-resolution spectroscopy analysis of these stars, together with new Stromgren uvby and Cousins (1980) BVRI photometry. It was found that the mean Fe abundance (Fe/H) for the SMC is -0.65 + or - 0.2 dex, and the mean Fe abundance for the LMC is -0.30 + or - 0.2 dex. The abundances of stars in both the SMC and LMC appear relatively uniform, and the abundances of the elements relative to Fe are very similar in both Magellanic Clouds and in Canopus (the carbon-to-iron abundances are the same for all three). It was also found that Nd and Sm are overabundant in both clouds, supporting the trends found by Spite et al. (1988) for the three SMC stars they studied. 140 refs

  17. Electron thermal transport in tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Konings, J.A.

    1994-11-30

    The process of fusion of small nuclei thereby releasing energy, as it occurs continuously in the sun, is essential for the existence of mankind. The same process applied in a controlled way on earth would provide a clean and an abundant energy source, and be the long term solution of the energy problem. Nuclear fusion requires an extremely hot (10{sup 8} K) ionized gas, a plasma, that can only be maintained if it is kept insulated from any material wall. In the so called `tokamak` this is achieved by using magnetic fields. The termal insulation, which is essential if one wants to keep the plasma at the high `fusion` temperature, can be predicted using basic plasma therory. A comparison with experiments in tokamaks, however, showed that the electron enery losses are ten to hundred times larger than this theory predicts. This `anomalous transport` of thermal energy implies that, to reach the condition for nuclear fusion, a fusion reactor must have very large dimensions. This may put the economic feasibility of fusion power in jeopardy. Therefore, in a worldwide collaboration, physicists study tokamak plasmas in an attempt to understand and control the energy losses. From a scientific point of view, the mechanisms driving anomalous transport are one of the challenges in fudamental plasma physics. In Nieuwegein, a tokamak experiment (the Rijnhuizen Tokamak Project, RTP) is dedicated to the study of anomalous transport, in an international collaboration with other laboratories. (orig./WL).

  18. Electron thermal transport in tokamak plasmas

    International Nuclear Information System (INIS)

    The process of fusion of small nuclei thereby releasing energy, as it occurs continuously in the sun, is essential for the existence of mankind. The same process applied in a controlled way on earth would provide a clean and an abundant energy source, and be the long term solution of the energy problem. Nuclear fusion requires an extremely hot (108 K) ionized gas, a plasma, that can only be maintained if it is kept insulated from any material wall. In the so called 'tokamak' this is achieved by using magnetic fields. The termal insulation, which is essential if one wants to keep the plasma at the high 'fusion' temperature, can be predicted using basic plasma therory. A comparison with experiments in tokamaks, however, showed that the electron enery losses are ten to hundred times larger than this theory predicts. This 'anomalous transport' of thermal energy implies that, to reach the condition for nuclear fusion, a fusion reactor must have very large dimensions. This may put the economic feasibility of fusion power in jeopardy. Therefore, in a worldwide collaboration, physicists study tokamak plasmas in an attempt to understand and control the energy losses. From a scientific point of view, the mechanisms driving anomalous transport are one of the challenges in fudamental plasma physics. In Nieuwegein, a tokamak experiment (the Rijnhuizen Tokamak Project, RTP) is dedicated to the study of anomalous transport, in an international collaboration with other laboratories. (orig./WL)

  19. Plasma amino acids

    Science.gov (United States)

    Plasma amino acids is a screening test done on infants that looks at the amounts of amino ... Laboratory error High or low amounts of individual plasma amino acids must be considered with other information. ...

  20. Detecting novel low-abundant transcripts in Drosophila

    DEFF Research Database (Denmark)

    Lee, Sanggyu; Bao, Jingyue; Zhou, Guolin;

    2005-01-01

    Increasing evidence suggests that low-abundant transcripts may play fundamental roles in biological processes. In an attempt to estimate the prevalence of low-abundant transcripts in eukaryotic genomes, we performed a transcriptome analysis in Drosophila using the SAGE technique. We collected 244...

  1. Spatio-temporal abundance and dispersal of Culicoides

    DEFF Research Database (Denmark)

    Kirkeby, Carsten

    . These models need to have proper input regarding the abundance and behavior of the vectors. If no vectors are present in an area, the disease will not spread. Thus the vector abundance is a very important factor for models of vector-borne diseases. This PhD project investigates different key factors important...

  2. Variation in rank abundance replicate samples and impact of clustering

    NARCIS (Netherlands)

    Neuteboom, J.H.; Struik, P.C.

    2005-01-01

    Calculating a single-sample rank abundance curve by using the negative-binomial distribution provides a way to investigate the variability within rank abundance replicate samples and yields a measure of the degree of heterogeneity of the sampled community. The calculation of the single-sample rank a

  3. A protocol for sampling vascular epiphyte richness and abundance

    NARCIS (Netherlands)

    J.H.D. Wolf; S.R. Gradstein; N.M. Nadkarni

    2009-01-01

    The sampling of epiphytes is fraught with methodological difficulties. We present a protocol to sample and analyse vascular epiphyte richness and abundance in forests of different structure (SVERA). Epiphyte abundance is estimated as biomass by recording the number of plant components in a range of

  4. The end of abundance. Economic solutions to water scarcity

    NARCIS (Netherlands)

    Zetland, D.J.

    2011-01-01

    In a past of abundance, we had clean water to meet our demands for showers, pools, farms and rivers. Our laws and customs did not need to regulate or ration demand. Over time, our demand has grown, and scarcity has replaced abundance. We don't have as much clean water as we want. We can respond to t

  5. The implicit assumption of symmetry and the species abundance distribution

    NARCIS (Netherlands)

    Alonso, David; Ostling, Annette; Etienne, Rampal S.

    2008-01-01

    Species abundance distributions (SADs) have played a historical role in the development of community ecology. They summarize information about the number and the relative abundance of the species encountered in a sample from a given community. For years ecologists have developed theory to characteri

  6. Plasma physics an introduction

    CERN Document Server

    Fitzpatrick, Richard

    2014-01-01

    Plasma Physics: An Introduction is based on a series of university course lectures by a leading name in the field, and thoroughly covers the physics of the fourth state of matter. This book looks at non-relativistic, fully ionized, nondegenerate, quasi-neutral, and weakly coupled plasma. Intended for the student market, the text provides a concise and cohesive introduction to plasma physics theory, and offers a solid foundation for students wishing to take higher level courses in plasma physics.

  7. ANOMALOUS RELATIVE AR/CA CORONAL ABUNDANCES OBSERVED BY THE HINODE/EUV IMAGING SPECTROMETER NEAR SUNSPOTS

    Energy Technology Data Exchange (ETDEWEB)

    Doschek, G. A.; Warren, H. P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Feldman, U. [Artep, Inc., 2922 Excelsior Springs Court, Ellicott City, MD 21042 (United States)

    2015-07-20

    In determining the element abundance of argon (a high first ionization potential; FIP element) relative to calcium (a low FIP element) in flares, unexpectedly high intensities of two Ar xiv lines (194.40, 187.96 Å) relative to a Ca xiv line (193.87 Å) intensity were found in small (a few arcseconds) regions near sunspots in flare spectra recorded by the Extreme-ultraviolet Imaging Spectrometer on the Hinode spacecraft. In the most extreme case the Ar xiv line intensity relative to the Ca xiv intensity was 7 times the value expected from the photospheric abundance ratio, which is about 30 times the abundance of argon relative to calcium in active regions, i.e., the measured Ar/Ca abundance ratio is about 10 instead of 0.37 as in active regions. The Ar xiv and Ca xiv lines are formed near 3.4 MK and have very similar contribution functions. This is the first observation of the inverse FIP effect in the Sun. Other regions show increases of 2–3 over photospheric abundances, or just photospheric abundances. This phenomenon appears to occur rarely and only over small areas of flares away from the regions containing multi-million degree plasma, but more work is needed to quantify the occurrences and their locations. In the bright hot regions of flares the Ar/Ca abundance ratio is coronal, i.e., the same as in active regions. In this Letter we show three examples of the inverse FIP effect.

  8. Wave and plasma heating

    International Nuclear Information System (INIS)

    In the field of wave heating absorption studies of plasma magnetic waves in the theta pinch are extended to axially inhomogeneous waves. In the Plasmaus 4 experiment direct plasma production has been accomplished for overcritical densities and high magnetic fields. The numerical methods developed at IPF for plasma simulation studies have been applied successfully to further problems. (orig./GG)

  9. The Plasma Universe

    Science.gov (United States)

    Suplee, Curt

    2009-09-01

    Preface; 1. The fourth state of matter; 2. The music and dance of plasmas; 3. The Sun-Earth connection; 4. Bringing the Sun to Earth: the story of controlled thermonuclear fusion; 5. The cosmic plasma theater: galaxies, stars, and accretion disks; 6. Putting plasmas to work; Index.

  10. Abundance Survey of M and K Dwarf Stars

    Energy Technology Data Exchange (ETDEWEB)

    Woolf, Vincent M. [Astronomy Department, University of Washington, Seattle, WA 98133 (United States); Wallerstein, George [Astronomy Department, University of Washington, Seattle, WA 98133 (United States)

    2005-07-25

    We report the measurement of chemical abundances in 35 low-mass main sequence (M and K dwarf) stars. We have measured the abundance of 12 elements in Kapteyn's Star, a nearby halo M subdwarf. The abundances indicate an iron abundance of [Fe/H] = -0.98, which is about 0.5 dex smaller than that measured in the only previous published measurement using atomic absorption lines. We have measured Fe and Ti abundances in 35 M and K dwarfs with -2.39 [Fe/H] +0.21 using atomic absorption lines, mostly in the 8000A <{lambda} < 8850A range. These will be used to calibrate photometric and low-resolution spectrum metallicity indices for low mass dwarfs, which will make metallicity estimates for these stars more certain. We also describe some difficulties encountered which are not normally necessary to consider when studying warmer stars.

  11. Causality of the relationship between geographic distribution and species abundance

    DEFF Research Database (Denmark)

    Borregaard, Michael Krabbe; Rahbek, Carsten

    2010-01-01

    The positive relationship between a species' geographic distribution and its abundance is one of ecology's most well-documented patterns, yet the causes behind this relationship remain unclear. Although many hypotheses have been proposed to account for distribution-abundance relationships none ha......, in a framework that facilitates a comparison between them. We identify and discuss the central factors governing the individual mechanisms, and elucidate their effect on empirical patterns.......The positive relationship between a species' geographic distribution and its abundance is one of ecology's most well-documented patterns, yet the causes behind this relationship remain unclear. Although many hypotheses have been proposed to account for distribution-abundance relationships none have...... attained unequivocal support. Accordingly, the positive association in distribution-abundance relationships is generally considered to be due to a combination of these proposed mechanisms acting in concert. In this review, we suggest that much of the disparity between these hypotheses stems from...

  12. Carbon and nitrogen abundances determined from transition layer lines

    Science.gov (United States)

    Boehm-Vitense, Erika; Mena-Werth, Jose

    1992-01-01

    The possibility of determining relative carbon, nitrogen, and silicon abundances from the emission-line fluxes in the lower transition layers between stellar chromospheres and coronae is explored. Observations for main-sequence and luminosity class IV stars with presumably solar element abundances show that for the lower transition layers Em = BT sup -gamma. For a given carbon abundance the constants gamma and B in this relation can be determined from the C II and C IV emission-line fluxes. From the N V and S IV lines, the abundances of these elements relative to carbon can be determined from their surface emission-line fluxes. Ratios of N/C abundances determined in this way for some giants and supergiants agree within the limits of errors with those determined from molecular bands. For giants, an increase in the ratio of N/C at B-V of about 0.8 is found, as expected theoretically.

  13. Basic concept in plasma diagnostics

    OpenAIRE

    Rai, V. N.

    2014-01-01

    This paper presents the basic concept of various plasma diagnostics used for the study of plasma characteristics in different plasma experiments ranging from low temperature to high energy density plasma.

  14. Carbon and nitrogen abundance variations in globular cluster red giants

    Science.gov (United States)

    Martell, Sarah L.

    2008-06-01

    This dissertation describes investigations into two of the persistent questions of elemental abundances in Galactic globular clusters: the phenomenon of deep mixing, observed through the progressive depletion of surface carbon abundance as stars evolve along the red giant branch, and abundance bimodality, a phenomenon observed only in globular clusters, in which a subset of stars in a given globular cluster have a distinctive pattern of elemental enhancements and depletions relative to the Solar pattern. The first chapter gives an introduction to the history of globular cluster abundance studies, with particular focus on low-resolution spectroscopy. For both deep mixing and abundance bimodality, the leading theoretical models and the data which support and challenge them are laid out. Each section ends with a description of presently-unanswered questions; these are the motivation for the various projects contained in this dissertation. The second chapter describes the use of molecular handstrengths for determining elemental abundances from low-resolution spectra, and introduces a new CH bandstrength index that is designed to be sensitive to carbon abundance and insensitive to nitrogen abundance in Pop. II red giants over a wide range of metallicity. Various CH indices defined elsewhere in the literature are also discussed, and are shown to have comparable accuracy to the new index only over a limited range of stellar properties. Carbon abundances determined using the new CH index are compared to literature abundances for a few stars, and general concordance with published abundances is found. The third chapter contains a large-scale application of the new CH index: a survey of present-day carbon abundances and calculated carbon depletion rates in bright red giants belonging to eleven Galactic globular clusters spanning the full metallicity range of halo globular clusters. Targets were selected with similar evolutionary states, were observed with one instrument on

  15. Plasma diagnostics in industry

    International Nuclear Information System (INIS)

    Plasma processing forms an invaluable part of semiconductor device manufacturing. For the most part, commercial tools have relied on an empirical process for their evolution and relied exclusively on plasma characterization only at the development stage. As this industry advances there is the need to provide non-invasive plasma characterization and diagnostics on the processing equipment, in order to provide more control over the plasma properties. We outline some of the typical configurations used in the industry and describe two of the measurement techniques we have developed for the characterization of these industrial plasma sources. (author)

  16. Cyclotron waves in plasma

    CERN Document Server

    Lominadze, D G

    2013-01-01

    Cyclotron Waves in Plasma is a four-chapter text that covers the basic physical concepts of the theory of cyclotron waves and cyclotron instabilities, brought about by the existence of steady or alternating plasma currents flowing perpendicular to the magnetic field.This book considers first a wide range of questions associated with the linear theory of cyclotron oscillations in equilibrium plasmas and in electron plasmas in metals and semiconductors. The next chapter deals with the parametric excitation of electron cyclotron oscillations in plasma in an alternating electric field. A chapter f

  17. Physics of Partially Ionized Plasmas

    Science.gov (United States)

    Krishan, Vinod

    2016-05-01

    Figures; Preface; 1. Partially ionized plasmas here and everywhere; 2. Multifluid description of partially ionized plasmas; 3. Equilibrium of partially ionized plasmas; 4. Waves in partially ionized plasmas; 5. Advanced topics in partially ionized plasmas; 6. Research problems in partially ionized plasmas; Supplementary matter; Index.

  18. Fast Plasma from a Coaxial Gun

    International Nuclear Information System (INIS)

    The coaxial gun in use here is a source or two different plasmas produced by separate mechanisms. Abundant slow (∼107 cm/sec) deuterium plasma is produced directly by the j x B interaction of the radial plasma current and the magnetic field of the feed current along the centre electrode. The current disturbance moves through the injected gas toward the gun muzzle at ∼2.5 x 107 cm/sec, storing energy behind it in magnetic field and plasma motion. The gun, with its stored energy, functions as a high power low impedance electrical generator to drive into the vacuum beyond the gun muzzle a jet of current which is the source of the fast plasma (∼5 x 1017 deuterons, ∼108 cm/sec). The current jet and the plasma it produces are the subjects of these experiments. The mechanism of acceleration is complicated and imperfectly understood, but considerable insight has been gained by an extensive series of experiments, using as diagnostics the following: external diamagnetic pickup loops, intra vacuo Rogowsky loops, electric probes, external capacitive pickup electrodes, magnetic and electrostatic particle deflection analysis, spectroscopy, target light photography, time of flight with and without a guide field, d-d neutrons from the plasma volume and other methods. The picture which emerges is one of a complicated magneto-electric process taking place in front of the gun muzzle. The acceleration process depends on low gas density there as contrasted'with high density inside the gun. The fast plasma is largely derived from gas adsorbed on the electrodes. This makes necessary a clean vacuum so as to avoid contamination with highly ionized fast impurity ions (C5+, 108 cm/sec). Electrode material evaporates but appears not to be a serious contaminant because it comes late. The high voltage actually accelerating the ions is associated with the rapid expansion into vacuum of a magnetic flux volume around the jet. Fast plasma is emitted in a narrow conical distribution with an

  19. Applied plasma physics

    International Nuclear Information System (INIS)

    Applied Plasma Physics is a major sub-organizational unit of the MFE Program. It includes Fusion Plasma Theory and Experimental Plasma Research. The Fusion Plasma Theory group has the responsibility for developing theoretical-computational models in the general areas of plasma properties, equilibrium, stability, transport, and atomic physics. This group has responsibility for giving guidance to the mirror experimental program. There is a formal division of the group into theory and computational; however, in this report the efforts of the two areas are not separated since many projects have contributions from members of both. Under the Experimental Plasma Research Program, we are developing the intense, pulsed neutral-beam source (IPINS) for the generation of a reversed-field configuration on 2XIIB. We are also studying the feasibility of utilizing certain neutron-detection techniques as plasma diagnostics in the next generation of thermonuclear experiments

  20. Laminar Plasma Dynamos

    CERN Document Server

    Wang, Z; Barnes, C W; Barnes, D C; Wang, Zhehui; Pariev, Vladimir I.; Barnes, Cris W.; Barnes, Daniel C.

    2002-01-01

    A new kind of dynamo utilizing flowing laboratory plasmas has been identified. Conversion of plasma kinetic energy to magnetic energy is verified numerically by kinematic dynamo simulations for magnetic Reynolds numbers above 210. As opposed to intrinsically-turbulent liquid-sodium dynamos, the proposed plasma dynamos correspond to laminar flow topology. Modest plasma parameters, 1-20 eV temperatures, 10^{19}-10^{20} m^{-3} densities in 0.3-1.0 m scale-lengths driven by velocities on the order of the Alfven Critical Ionization Velocity (CIV), self-consistently satisfy the conditions needed for the magnetic field amplication. Growth rates for the plasma dynamos are obtained numerically with different geometry and magnetic Reynolds numbers. Magnetic-field-free coaxial plasma guns can be used to sustain the plasma flow and the dynamo.

  1. Plasma polymerization by Softplasma

    DEFF Research Database (Denmark)

    Jiang, J.; Wu, Zhenning; Benter, Maike;

    2008-01-01

    In the late 19th century, the first depositions - known today as plasma polymers, were reported. In the last century, more and more research has been put into plasma polymers. Many different deposition systems have been developed. [1, 2] Shi F. F. broadly classified them into internal electrode......, external electrode, and electrodeless microwave or high frequency reactors. [3] Softplasma™ is an internal electrode plasma setup powered by low frequenc~ gower supply. It was developed in late 90s for surface treatment of silicone rubber. [ ]- 5] It is a low pressure, low electron density, 3D homogenous...... plasma. In this study, we are presenting the surface modification"pf polymers by plasma polymerization using Softplasma™. Softplasma™ can be used for two major types of polymerization: polymerization of vinyl monomers, where plasma acts as initiator; chemical vapour deposition, where plasma acts...

  2. Arc Plasma Torch Modeling

    CERN Document Server

    Trelles, J P; Vardelle, A; Heberlein, J V R

    2013-01-01

    Arc plasma torches are the primary components of various industrial thermal plasma processes involving plasma spraying, metal cutting and welding, thermal plasma CVD, metal melting and remelting, waste treatment and gas production. They are relatively simple devices whose operation implies intricate thermal, chemical, electrical, and fluid dynamics phenomena. Modeling may be used as a means to better understand the physical processes involved in their operation. This paper presents an overview of the main aspects involved in the modeling of DC arc plasma torches: the mathematical models including thermodynamic and chemical non-equilibrium models, turbulent and radiative transport, thermodynamic and transport property calculation, boundary conditions and arc reattachment models. It focuses on the conventional plasma torches used for plasma spraying that include a hot-cathode and a nozzle anode.

  3. Applied plasma physics

    International Nuclear Information System (INIS)

    Applied Plasma Physics is a major sub-organizational unit of the MFE Porgram. It includes Fusion Plasma Theory and Experimental Plasma Research. Fusion Plasma Theory has the responsibility for developing theoretical-computational models in the general areas of plasma properties, equilibrium, stability, transport, and atomic physics. This group has responsibility for giving guidance to the mirror experimental program. There is a formal division of the group into theory and computational; however, in this report the efforts of the two areas are not separated since many projects have contributions from members of both. Under Experimental Plasma Research, we are developing the intense, pulsed ion-neutral source (IPINS) for the generation of a reversed-field configuration on 2XIIB. We are also studying the feasibility of utilizing certain neutron-detection techniques as plasma diagnostics in the next generation of thermonuclear experiments

  4. Applied plasma physics

    International Nuclear Information System (INIS)

    Applied Plasma Physics is a major sub-organizational unit of the Magnetic Fusion Energy (MFE) Program. It includes Fusion Plasma Theory and Experimental Plasma Research. The Fusion Plasma Theory group has the responsibility for developing theoretical-computational models in the general areas of plasma properties, equilibrium, stability, transport, and atomic physics. This group has responsibility for giving guidance to the mirror experimental program. There is a formal division of the group into theory and computational; however, in this report the efforts of the two areas are not separated since many projects have contributions from members of both. Under the Experimental Plasma Research Program we are developing a neutral-beam source, the intense, pulsed ion-neutral source (IPINS), for the generation of a reversed-field configuration on 2XIIB. We are also studying the feasibility of using certain neutron-detection techniques as plasma diagnostics in the next generation of thermonuclear experiments

  5. Seasonal Abundance of Aphids and Aphidophagous Insects in Pecan

    Directory of Open Access Journals (Sweden)

    Ghulam Abbas

    2012-12-01

    Full Text Available Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006–2011 from full leaf expansion in May to leaf fall in October in “Desirable” variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one time and black pecan aphids exceeded the recommended treatment levels three times over the six seasons. Increases in aphidophagous insect abundance coincided with aphid outbreaks in five of the six seasons. Among aphidophagous insects Harmonia axyridis and Olla v-nigrum were frequently collected in both the tree canopy and at the ground level, whereas, Coccinella septempunctata, Hippodamia convergens were rarely found in the tree canopy and commonly found at the ground level. Green lacewing abundance was higher in the ground level than in the tree canopy. Brown lacewings were more abundant in the tree canopy than at the ground level. Dolichopodid and syrphid fly abundance, at the ground level increased during peak aphid abundance in the tree canopy. Application of an aqueous solution of fermenting molasses to the pecan foliage during an aphid outbreak significantly increased the abundance of ladybeetles and lacewings and significantly reduced the abundance of yellow pecan, blackmargined and black pecan aphids.

  6. Seasonal Abundance of Aphids and Aphidophagous Insects in Pecan.

    Science.gov (United States)

    Dutcher, James D; Karar, Haider; Abbas, Ghulam

    2012-01-01

    Seasonal occurrence of aphids and aphidophagous insects was monitored for six years (2006-2011) from full leaf expansion in May to leaf fall in October in "Desirable" variety pecan trees that were not treated with insecticides. Aphid outbreaks occurred two times per season, once in the spring and again in the late summer. Yellow pecan and blackmargined aphids exceeded the recommended treatment thresholds one time and black pecan aphids exceeded the recommended treatment levels three times over the six seasons. Increases in aphidophagous insect abundance coincided with aphid outbreaks in five of the six seasons. Among aphidophagous insects Harmonia axyridis and Olla v-nigrum were frequently collected in both the tree canopy and at the ground level, whereas, Coccinella septempunctata, Hippodamia convergens were rarely found in the tree canopy and commonly found at the ground level. Green lacewing abundance was higher in the ground level than in the tree canopy. Brown lacewings were more abundant in the tree canopy than at the ground level. Dolichopodid and syrphid fly abundance, at the ground level increased during peak aphid abundance in the tree canopy. Application of an aqueous solution of fermenting molasses to the pecan foliage during an aphid outbreak significantly increased the abundance of ladybeetles and lacewings and significantly reduced the abundance of yellow pecan, blackmargined and black pecan aphids. PMID:26466738

  7. Stellar abundances in the solar neighborhood: The Hypatia Catalog

    Energy Technology Data Exchange (ETDEWEB)

    Hinkel, Natalie R.; Timmes, F.X.; Young, Patrick A.; Pagano, Michael D. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Turnbull, Margaret C. [Global Science Institute, P.O. Box 252, Antigo, WI 54409 (United States)

    2014-09-01

    We compile spectroscopic abundance data from 84 literature sources for 50 elements across 3058 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. We evaluate the variability of the spread in abundance measurements reported for the same star by different surveys. We also explore the likely association of the star within the Galactic disk, the corresponding observation and abundance determination methods for all catalogs in Hypatia, the influence of specific catalogs on the overall abundance trends, and the effect of normalizing all abundances to the same solar scale. The resulting stellar abundance determinations in the Hypatia Catalog are analyzed only for thin-disk stars with observations that are consistent between literature sources. As a result of our large data set, we find that the stars in the solar neighborhood may reveal an asymmetric abundance distribution, such that a [Fe/H]-rich group near the midplane is deficient in Mg, Si, S, Ca, Sc II, Cr II, and Ni as compared to stars farther from the plane. The Hypatia Catalog has a wide number of applications, including exoplanet hosts, thick- and thin-disk stars, and stars with different kinematic properties.

  8. Geographical range and local abundance of tree species in China.

    Directory of Open Access Journals (Sweden)

    Haibao Ren

    Full Text Available Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1 whether locally abundant species tend to be geographically widespread; 2 whether species are more abundant towards their range-centers; and 3 how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20-25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km(2, and >90% of 651 species had ranges >10(5 km(2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species' abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges.

  9. Metal abundance range in the Draco dwarf galaxy

    International Nuclear Information System (INIS)

    The multichannel scanner of the Hale telescope was used to measure the spectral flux distributions of 23 red giants in the Draco system over the range lambda lambda 3240 to 7620. The memberships of these stars in Draco were checked by use of the spectral scans, and for 17 of them the observations are of sufficient quality that estimates of metal abundance can be made. The scans of the Draco stars resemble in every way the scans of red giants in globular clusters. Large differences are seen among the scans of the Draco stars, which are due to a range in Fe/H. The distribution over metal abundance was found from the abundance estimates; its half-width corresponds to an abundance range of a factor of 2.7. The mean metal abundance [Fe/H] = -1.86 +- 0.09, which is larger than the abundance of M92. This result does not support the previous claims that Draco is more metal poor than the most metal-deficient globular clusters. The implications of these results for the interpetations of Draco's color--magnitude diagram and variable star population are discussed. The chemical evolution of Draco was modeled with simple models that assume mass loss and prompt initial enrichment. These models provide adequate fits to the observed abundance distribution, and suggest that the proto-Draco was initially approx. 100 times more massive than Draco is today. 10 figures, 2 tables

  10. Beryllium Abundances in Stars of One-Solar-Mass

    CERN Document Server

    Boesgaard, Ann Merchant

    2008-01-01

    We have determined Be abundances in 50 F and G dwarfs in the mass range of 0.9 $\\leq$ M$_\\odot$ $\\leq$ 1.1 as determined by Lambert & Reddy. The effective temperatures are 5600 to 6400 K and metallicities from $-$0.65 to +0.11. The spectra were taken primarily with Keck I + HIRES. The Be abundances were found via spectral synthesis of Be II lines near 3130 \\AA. The Be abundances were investigated as a function of age, temperature, metallicity and Li abundance in this narrow mass range. Even though our stars are similar in mass, they show a range in Be abundances of a factor of $>$40. We find that [Be/Fe] has no dependence on temperature, but does show a spread of a factor of 6 at a given temperature. The reality of the spread is shown by two identical stars which differ from each other by a factor of two only in their abundances of Li and Be. Our thin-disk-star sample fits the trend between Be abundance and [Fe/H] found for halo and thick disk stars, extending it to about 4 orders of magnitude in the two ...

  11. Abundance analysis of the outer halo globular cluster Palomar 14

    CERN Document Server

    Caliskan, S; Grebel, K E

    2011-01-01

    We determine the elemental abundances of nine red giant stars belonging to Palomar 14 (Pal 14). Pal 14 is an outer halo globular cluster (GC) at a distance of \\sim 70 kpc. Our abundance analysis is based on high-resolution spectra and one-dimensional stellar model atmospheres.We derived the abundances for the iron peak elements Sc, V, Cr, Mn, Co, Ni, the {\\alpha}-elements O, Mg, Si, Ca, Ti, the light odd element Na, and the neutron-capture elements Y, Zr, Ba, La, Ce, Nd, Eu, Dy, and Cu. Our data do not permit us to investigate light element (i.e., O to Mg) abundance variations. The neutron-capture elements show an r-process signature. We compare our measurements with the abundance ratios of inner and other outer halo GCs, halo field stars, GCs of recognized extragalactic origin, and stars in dwarf spheroidal galaxies (dSphs). The abundance pattern of Pal 14 is almost identical to those of Pal 3 and Pal 4, the next distant members of the outer halo GC population after Pal 14. The abundance pattern of Pal 14 is...

  12. Model reduction for stochastic chemical systems with abundant species

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stephen; Cianci, Claudia; Grima, Ramon [School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH93JR, Scotland (United Kingdom)

    2015-12-07

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  13. Geographical Range and Local Abundance of Tree Species in China

    Science.gov (United States)

    Ren, Haibao; Condit, Richard; Chen, Bin; Mi, Xiangcheng; Cao, Min; Ye, Wanhui; Hao, Zhanqing; Ma, Keping

    2013-01-01

    Most studies on the geographical distribution of species have utilized a few well-known taxa in Europe and North America, with little research in China and its wide range of climate and forest types. We assembled large datasets to quantify the geographic ranges of tree species in China and to test several biogeographic hypotheses: 1) whether locally abundant species tend to be geographically widespread; 2) whether species are more abundant towards their range-centers; and 3) how abundances are correlated between sites. Local abundances of 651 species were derived from four tree plots of 20–25 ha where all individuals ≥1 cm in stem diameter were mapped and identified taxonomically. Range sizes of these species across China were then estimated from over 460,000 geo-referenced records; a Bayesian approach was used, allowing careful measures of error of each range estimate. The log-transformed range sizes had a bell-shaped distribution with a median of 703,000 km2, and >90% of 651 species had ranges >105 km2. There was no relationship between local abundance and range size, and no evidence for species being more abundant towards their range-centers. Finally, species’ abundances were positively correlated between sites. The widespread nature of most tree species in China suggests few are vulnerable to global extinction, and there is no indication of the double-peril that would result if rare species also had narrow ranges. PMID:24130772

  14. Model reduction for stochastic chemical systems with abundant species

    Science.gov (United States)

    Smith, Stephen; Cianci, Claudia; Grima, Ramon

    2015-12-01

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  15. Relative nuclei abundance inside the International Space Station

    Science.gov (United States)

    Larsson, Oscar

    2012-07-01

    The Sileye3/Alteino experiment was first operational on-board the International Space Station, ISS, 27 April 2002. From 2006 through 2009 it was activated for long duration measurements of relative particle abundance as part of the ESA ALTCRISS project. Measuring the relative abundance of different nuclei species inside the ISS gives important clues as to how the known cosmic ray spectrum outside the space station changes when traversing the hull, i.e. giving indications as to how the hadronic interactions in the hull gives rise to changes in the expected radiation environment for the astronauts, which is of great interest for risk assessments for future long duration deep space missions. In our work the relative abundance for nuclei species with energies above ≃ 60 MeV/n and 5 ≤ Z ≤ 26 are presented for different places and detector orientations inside the ISS, also with and without shielding of the detector. What can be seen when comparing with the relative abundance of nuclei in the cosmic rays, is a significant difference in abundance for odd Z nuclei, whereas even numbered are in better agreement. Odd Z nuclei are much more abundant inside the ISS. This is an update from our previous report with increased statistics and with relative abundance on more nuclei.

  16. Arcetri Spectral Code for Thin Plasmas

    Science.gov (United States)

    Landi, E.; Landini, M.

    2010-07-01

    The Arcetri spectral code allows to evaluate the spectrum of the radiation emitted by hot and optically thin plasmas in the spectral range 1 - 2000 Angstroms. The database has been updated including atomic data and radiative and collisional rates to calculate level population and line emissivities for a number of ions of the minor elements; a critical compilation of the electron collision excitation for these elements has been performed. The present version of the program includes the CHIANTI database for the most abundant elements, the minor elements data, and Fe III atomic model, radiative and collisional data.

  17. The Arcetri spectral code for thin plasmas

    Science.gov (United States)

    Landi, E.; Landini, M.

    1998-12-01

    The Arcetri spectral code allows to evaluate the spectrum of the radiation emitted by hot and optically thin plasmas in the spectral range 1 - 2000 Angstroms. The database has been updated including atomic data and radiative and collisional rates to calculate level population and line emissivities for a number of ions of the minor elements; a critical compilation of the electron collision excitation for these elements has been performed. The present version of the program includes the CHIANTI database for the most abundant elements, the minor elements data, and Fe III atomic model, radiative and collisional data.

  18. Emission lines from hot astrophysical plasmas

    Science.gov (United States)

    Raymond, John C.

    The spectral lines which dominate the X-ray emission of hot, optically thin astrophysical plasmas reflect the elemental abundances, temperature distribution, and other physical parameters of the emitting gas. The accuracy and level of detail with which these parameters can be inferred are limited by the measurement uncertainties and uncertainties in atomic rates used to compute the model spectrum. This paper discusses the relative importance and the likely uncertainties in the various atomic rates and the likely uncertainties in the overall ionization balance and spectral line emissivities predicted by the computer codes currently used to fit X-ray spectral data.

  19. How ants drop out: ant abundance on tropical mountains.

    Directory of Open Access Journals (Sweden)

    John T Longino

    Full Text Available In tropical wet forests, ants are a large proportion of the animal biomass, but the factors determining abundance are not well understood. We characterized ant abundance in the litter layer of 41 mature wet forest sites spread throughout Central America (Chiapas, Guatemala, Honduras, Nicaragua, and Costa Rica and examined the impact of elevation (as a proxy for temperature and community species richness. Sites were intentionally chosen to minimize variation in precipitation and seasonality. From sea level to 1500 m ant abundance very gradually declined, community richness declined more rapidly than abundance, and the local frequency of the locally most common species increased. These results suggest that within this elevational zone, density compensation is acting, maintaining high ant abundance as richness declines. In contrast, in sites above 1500 m, ant abundance dropped abruptly to much lower levels. Among these high montane sites, community richness explained much more of the variation in abundance than elevation, and there was no evidence of density compensation. The relative stability of abundance below 1500 m may be caused by opposing effects of temperature on productivity and metabolism. Lower temperatures may decrease productivity and thus the amount of food available for consumers, but slower metabolisms of consumers may allow maintenance of higher biomass at lower resource supply rates. Ant communities at these lower elevations may be highly interactive, the result of continuous habitat presence over geological time. High montane sites may be ephemeral in geological time, resulting in non-interactive communities dominated by historical and stochastic processes. Abundance in these sites may be determined by the number of species that manage to colonize and/or avoid extinction on mountaintops.

  20. Plasmas for medicine

    Science.gov (United States)

    von Woedtke, Th.; Reuter, S.; Masur, K.; Weltmann, K.-D.

    2013-09-01

    Plasma medicine is an innovative and emerging field combining plasma physics, life science and clinical medicine. In a more general perspective, medical application of physical plasma can be subdivided into two principal approaches. (i) “Indirect” use of plasma-based or plasma-supplemented techniques to treat surfaces, materials or devices to realize specific qualities for subsequent special medical applications, and (ii) application of physical plasma on or in the human (or animal) body to realize therapeutic effects based on direct interaction of plasma with living tissue. The field of plasma applications for the treatment of medical materials or devices is intensively researched and partially well established for several years. However, plasma medicine in the sense of its actual definition as a new field of research focuses on the use of plasma technology in the treatment of living cells, tissues, and organs. Therefore, the aim of the new research field of plasma medicine is the exploitation of a much more differentiated interaction of specific plasma components with specific structural as well as functional elements or functionalities of living cells. This interaction can possibly lead either to stimulation or inhibition of cellular function and be finally used for therapeutic purposes. During recent years a broad spectrum of different plasma sources with various names dedicated for biomedical applications has been reported. So far, research activities were mainly focused on barrier discharges and plasma jets working at atmospheric pressure. Most efforts to realize plasma application directly on or in the human (or animal) body for medical purposes is concentrated on the broad field of dermatology including wound healing, but also includes cancer treatment, endoscopy, or dentistry. Despite the fact that the field of plasma medicine is very young and until now mostly in an empirical stage of development yet, there are first indicators of its enormous

  1. Nonlinear Plasma Wave in Magnetized Plasmas

    CERN Document Server

    Bulanov, Sergei V; Kando, Masaki; Koga, James K; Hosokai, Tomonao; Zhidkov, Alexei G; Kodama, Ryosuke

    2013-01-01

    Nonlinear axisymmetric cylindrical plasma oscillations in magnetized collisionless plasmas are a model for the electron fluid collapse on the axis behind an ultrashort relativisically intense laser pulse exciting a plasma wake wave. We present an analytical description of the strongly nonlinear oscillations showing that the magnetic field prevents closing of the cavity formed behind the laser pulse. This effect is demonstrated with 3D PIC simulations of the laser-plasma interaction. An analysis of the betatron oscillations of fast electrons in the presence of the magnetic field reveals a characteristic "Four-Ray Star" pattern which has been observed in the image of the electron bunch in experiments [T. Hosokai, et al., Phys. Rev. Lett. 97, 075004 (2006)].

  2. Carbon abundances and isotope ratios in 70 bright M giants

    International Nuclear Information System (INIS)

    Approximate carbon abundances and 12C/13C isotope ratios are obtained for 70 M giant stars from intermediate-resolution spectrophotometry of the CO bands near 2.3 μm. A low mean carbon abundance ([C/H]=-0.64±0.29) is obtained, suggesting that standard mixing is insufficient to explain atmospheric abundances in M giants. HR 8795 appears to be exceptionally carbon deficient, and is worthy of further study as a possible weak G-band star descendant. (author)

  3. Carbon abundances and isotope ratios in 70 bright M giants

    Energy Technology Data Exchange (ETDEWEB)

    Lazaro, C. (Inst. de Astrofisica de Canarias, Tenerife (Spain)); Lynas-Gray, A.E. (University Coll., London (UK). Dept. of Physics and Astronomy); Clegg, R.E.S. (Royal Greenwich Observatory, Cambridge (UK)); Mountain, C.M.; Zadrozny, A. (Imperial Coll. of Science and Technology, London (UK))

    1991-03-01

    Approximate carbon abundances and {sup 12}C/{sup 13}C isotope ratios are obtained for 70 M giant stars from intermediate-resolution spectrophotometry of the CO bands near 2.3 {mu}m. A low mean carbon abundance ((C/H)=-0.64+-0.29) is obtained, suggesting that standard mixing is insufficient to explain atmospheric abundances in M giants. HR 8795 appears to be exceptionally carbon deficient, and is worthy of further study as a possible weak G-band star descendant. (author).

  4. The determination of electron abundances in interstellar clouds

    Science.gov (United States)

    Wootten, A.; Snell, R.; Glassgold, A. E.

    1979-01-01

    An independent method is proposed for the determination of electron abundances in dense clouds based upon the abundance ratio of HCO(+) and CO. The method is derived from a simple application of gas phase ion molecule interstellar chemistry. It is noted that unlike the fractionation of deuterated molecules, it applies to warm as well as to cool clouds. The method is illustrated with the results of the recent abundance survey of Wooten et al. (1978). Finally, it is shown that in cases where deuterium enhancement is measured, an upper limit can be obtained for the cosmic ray ionization rate.

  5. Bacterioplankton abundance and production in Indian Ocean Regions

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.; Fernandes, V.; Rodrigues, V.V.; Paul, J.T.; Gauns, M.

    ]. These studies highlight that both bacterioplank- ton abundance and production within different regions of the IO vary seasonally. These studies are useful to note that the bacterial abundance and production are low during north- east monsoon (NEM) (December... for elucidating pelagic food-web dynamics in different regions of the IO. In view of this, a comparative account of abundance and productivity of the Hbac between seasons, regions, and depths (upper 120 m) of the IO is pro- vided in this chapter. 2. STUDY AREA...

  6. Nitrogen and oxygen abundances in the Local Universe

    OpenAIRE

    Vincenzo, Fiorenzo; Belfiore, Francesco; MAIOLINO, Roberto; Matteucci, Francesca; Ventura, Paolo

    2016-01-01

    We present chemical evolution models aimed at reproducing the observed (N/O) vs. (O/H) abundance pattern of star forming galaxies in the Local Universe. We derive gas-phase abundances from SDSS spectroscopy and a complementary sample of low-metallicity dwarf galaxies, making use of a consistent set of abundance calibrations. This collection of data clearly confirms the existence of a plateau in the (N/O) ratio at very low metallicity, followed by an increase of this ratio up to high values as...

  7. A Photometric Method for estimating CNO Abundances in Globular Clusters

    CERN Document Server

    Peat, David; Peat, David; Butler, Raymond

    2002-01-01

    Stromgren indices v and b are combined with broad-band index I, and a new index p, the short wavelength half of the v band, to estimate CN 4215A molecular absorption in a sample of stars in M22. The results have been used to estimate carbon and nitrogen abundances and suggest groups of stars within this cluster, each with a characteristic nitrogen abundance, but with a range of carbon abundances. The results suggest the possibility of stars consisting of material which has undergone CNO recycling two or three times. The method can be subsequently used for other globular clusters.

  8. Ecological niche structure and rangewide abundance patterns of species

    Science.gov (United States)

    Martínez-Meyer, Enrique; Díaz-Porras, Daniel; Peterson, A. Townsend; Yáñez-Arenas, Carlos

    2013-01-01

    Spatial abundance patterns across species' ranges have attracted intense attention in macroecology and biogeography. One key hypothesis has been that abundance declines with geographical distance from the range centre, but tests of this idea have shown that the effect may occur indeed only in a minority of cases. We explore an alternative hypothesis: that species' abundances decline with distance from the centroid of the species' habitable conditions in environmental space (the ecological niche). We demonstrate consistent negative abundance–ecological distance relationships across all 11 species analysed (turtles to wolves), and that relationships in environmental space are consistently stronger than relationships in geographical space. PMID:23134784

  9. Galactic abundances as a relic neutrino detection scheme

    DEFF Research Database (Denmark)

    Riis, Anna Sejersen; Thomas Zinner, Nikolaj; Hannestad, Steen

    2011-01-01

    to see the effect of NCB processes as a slightly eschewed abundance ratio of selected beta-decaying nuclei. First, the candidates must be chosen so that both the mother and daughter nuclei have a lifetime comparable to that of the Milky Way or the signal could be easily washed out by additional decays...... for 187-Re and 138-La and find that one needs abundance measurements with 24 digit precision in order to detect the effect of relic neutrinos. Or alternatively an enhancement of of the relic neutrino density by a factor of $10^{15}$ to produce an effect within the current abundance measurement precision....

  10. Identification and role of plasma membrane aquaporin in maize root

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Using antiserum against expressed aquaporin fusion protein, GST-RD28, the distribution of aquaporin in the plasma membrane of maize root protoplasts has been examined under confocal laser scanning microscopy by indirect fluorescence staining. Results indicate that there are abundant aquaporins in maize roots, which are distributed in plasma membrane unevenly. Western blotting analysis of total protein solubilized from maize root plasma membrane shows that antiserum against GST-RD28 can cross-react with one protein around 55 ku. Another 28 ku protein can also be detected when the concentration of SDS and DTT in SDS-PAGE sample buffer is increased. The 55 and 28 ku proteins may be dimeric and monomeric of aquaporin respectively. Functional experiments show that aquaporin blocker HgCl2 and aquaporin antiserum can suppress the swelling of maize root protoplasts in hypotonic solution, indicating that aquaporin in plasma membrane of protoplast facilitates rapid transmembrane water flow.

  11. Magnetospheric plasma waves

    International Nuclear Information System (INIS)

    A brief history of plasma wave observations in the Earth's magnetosphere is recounted and a classification of the identified plasma wave phenomena is presented. The existence of plasma waves is discussed in terms of the characteristic frequencies of the plasma, the energetic particle populations and the proposed generation mechanisms. Examples are given for which plasmas waves have provided information about the plasma parameters and particle characteristics once a reasonable theory has been developed. Observational evidence and arguments by analogy to the observed Earth plasma wave processes are used to identify plasma waves that may be significant in other planetary magnetospheres. The similarities between the observed characteristics of the terrestrial kilometric radiation and radio bursts from Jupiter, Saturn and possibly Uranus are stressed. Important scientific problems concerning plasma wave processes in the solar system and beyond are identified and discussed. Models for solar flares, flare star radio outbursts and pulsars include elements which are also common to the models for magnetospheric radio bursts. Finally, a listing of the research and development in terms of instruments, missions, laboratory experiments, theory and computer simulations needed to make meaningful progress on the outstanding scientific problems of plasma wave research is given. (Auth.)

  12. Whooping Crane Winter Abundance Survey Protocol Aransas National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This protocol is primarily designed to provide a mechanism for monitoring trends in whooping crane abundance on their wintering grounds along the Texas gulf coast....

  13. Impact of stochastic gas motions on galaxy cluster abundance profiles

    CERN Document Server

    Rebusco, P; Böhringer, H; Forman, W

    2005-01-01

    The impact of stochastic gas motions on the metal distribution in cluster core is evaluated. Peaked abundance profiles are a characteristic feature of clusters with cool cores and abundance peaks are likely associated with the brightest cluster galaxies (BCGs) which dwell in cluster cores. The width of the abundance peaks is however significantly broader than the BCG light distribution, suggesting that some gas motions are transporting metals originating from within the BCG. Assuming that this process can be treated as diffusive and using the brightest X-ray cluster A426 (Perseus) as an example, we estimate that a diffusion coefficient of the order of $2 10^{29} {\\rm cm^2 s^{-1}}$ is needed to explain the width of the observed abundance profiles. Much lower (higher) diffusion coefficients would result in too peaked (too shallow) profiles. Such diffusion could be produced by stochastic gas motions and our analysis provides constraints on the product of their characteristic velocity and their spatial coherence ...

  14. Trek and ECCO: Abundance measurements of ultraheavy galactic cosmic rays

    International Nuclear Information System (INIS)

    Using the Trek detector, we have measured the abundances of the heaviest elements (with Z>70) in the galactic cosmic rays with sufficient charge resolution to resolve the even-Z elements. We find that the abundance of Pb compared to Pt is ∼3 times lower than the value expected from the most widely-held class of models of the origin of galactic cosmic ray nuclei, that is, origination in a partially ionized medium with solar-like composition. The low abundance of Pb is, however, consistent with the interstellar gas and dust model of Meyer, Drury and Ellison, and with a source enriched in r-process material, proposed by Binns et al. A high-resolution, high-statistics measurement of the abundances of the individual actinides would distinguish between these models. This is the goal of ECCO, the Extremely Heavy Cosmic-ray Composition Observer, which we plan to deploy on the International Space Station

  15. The Helium abundance problem and non-minimally coupled quintessence

    OpenAIRE

    Chen, Xuelei

    2000-01-01

    There is a tension between observed Helium abundance and the prediction of the standard Big Bang Nucleosynthesis. We show that non-minimally quintessence model may help to reduce this tension between theory and observation.

  16. Relative Abundance of Breeding Birds in the Dismal Swamp 1982

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — To obtain an idea of the relative abundance of breeding birds in the predominant mixed swamp hardwoods forest of the Dismal Swamp in southeastern Virginia, a...

  17. Solar models with new low-metal abundances

    CERN Document Server

    Yang, Wuming

    2016-01-01

    In the last decade, the photospheric abundances of the Sun had been revised several times by many observers. The standard solar models (SSM) constructed with the new low-metal abundances disagree with helioseismic results and detected neutrino fluxes. The solar model problem has been puzzled some stellar physicists for more than ten years. Rotation, enhanced diffusion, convection overshoot, and magnetic fields are used to reconcile the new abundances with helioseismology. The \\textbf{too} low-helium \\textbf{subsurface abundance} in enhanced diffusion models can be improved by the mixing caused by rotation and magnetic fields. The problem of the depth of the convective zone in rotating models can be resolved by convection overshoot. Consequently the Asplund-Grevesse-Sauval rotation model including overshooting (AGSR) reproduces the seismically inferred sound-speed and density profiles, and the convection zone depth as well as the Grevesse and Sauval (GS98) model computed before. But this model fails to reprodu...

  18. Abundance of bacterial and diatom fouling on various surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi

    Abundance of bacterial and diatom fouling on aluminium, fibreglass and stainless steel were studied from Dona Paula waters of the Zuari Estuary. Both these forms were reversibly attached in large numbers to surfaces during the initial 24 hr...

  19. Fundamental constraints on the abundances of chemotaxis proteins

    CERN Document Server

    Bitbol, Anne-Florence

    2015-01-01

    Flagellated bacteria, such as Escherichia coli, perform directed motion in gradients of concentration of attractants and repellents in a process called chemotaxis. The E. coli chemotaxis signaling pathway is a model for signal transduction, but it has unique features. We demonstrate that the need for fast signaling necessitates high abundances of the proteins involved in this pathway. We show that further constraints on the abundances of chemotaxis proteins arise from the requirements of self-assembly, both of flagellar motors and of chemoreceptor arrays. All these constraints are specific to chemotaxis, and published data confirm that chemotaxis proteins tend to be more highly expressed than their homologs in other pathways. Employing a chemotaxis pathway model, we show that the gain of the pathway at the level of the response regulator CheY increases with overall chemotaxis protein abundances. This may explain why, at least in one E. coli strain, the abundance of all chemotaxis proteins is higher in media w...

  20. Relative abundance of desert tortoises on the Nevada Test Site

    International Nuclear Information System (INIS)

    Seven hundred fifty-nine transects having a total length of 1,191 km were walked during 1981--1986 to determine the distribution and relative abundance of desert tortoises (Gopherus agassizii) on the Nevada Test Site (NTS). The abundance of tortoises on NTS was low to very low relative to other populations in the Mojave Desert. Sign of tortoises was found from 880 to 1,570 m elevation and was more abundant above 1,200 m than has been reported previously for Nevada. Tortoises were more abundant on NTS on the upper alluvial fans and slopes of mountains than in valley bottoms. They also were more common on or near limestone and dolomite mountains than on mountains of volcanic origin

  1. THE ATOMIC WEIGHTS COMMISSION AND ISOTOPIC ABUNDANCE RATIO DETERMINATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    HOLDEN, N.E.

    2005-08-07

    Following Thomson's discovery of stable isotopes in non-radioactive chemical elements, the derivation of atomic weight values from mass spectrometric measurements of isotopic abundance ratios moved very slowly. Forty years later, only 3 1/2 % of the recommended values were based on mass spectrometric measurements and only 38% in the first half century. It might be noted that two chemical elements (tellurium and mercury) are still based on chemical measurements, where the atomic weight value calculated from the relative isotopic abundance measurement either agrees with the value from the chemical measurement or the atomic weight value calculated from the relative isotopic abundance measurement falls within the uncertainty of the chemical measurement of the atomic weight. Of the 19 chemical elements, whose atomic weight is based on non-corrected relative isotopic abundance measurements, five of these are two isotope systems (indium, iridium, lanthanum, lutetium and tantalum) and one is a three-isotope system (oxygen).

  2. Unit scale abundance and habitat data - Calawah River Riverscape Study

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The objective of this study was to identify the patterns of juvenile salmonid distribution and relative abundance in relation to habitat correlates. It is the first...

  3. A Comparison of Stellar Elemental Abundance Techniques and Measurements

    CERN Document Server

    Hinkel, Natalie R; Pagano, Michael D; Desch, Steven J; Anbar, Ariel D; Adibekyan, Vardan; Blanco-Cuaresma, Sergi; Carlberg, Joleen K; Mena, Elisa Delgado; Liu, Fan; Nordlander, Thomas; Sousa, Sergio G; Korn, Andreas; Gruyters, Pieter; Heiter, Ulrike; Jofre, Paula; Santos, Nuno C; Soubiran, Caroline

    2016-01-01

    Stellar elemental abundances are important for understanding the fundamental properties of a star or stellar group, such as age and evolutionary history, as well as the composition of an orbiting planet. However, as abundance measurement techniques have progressed, there has been little standardization between individual methods and their comparisons. As a result, different stellar abundance procedures determine measurements that vary beyond quoted error for the same elements within the same stars (Hinkel et al. 2014). The purpose of this paper is to better understand the systematic variations between methods and offer recommendations for producing more accurate results in the future. We have invited a number of participants from around the world (Australia, Portugal, Sweden, Switzerland, and USA) to calculate ten element abundances (C, O, Na, Mg, Al, Si, Fe, Ni, Ba, and Eu) using the same stellar spectra for four stars (HD361, HD10700, HD121504, HD202206). Each group produced measurements for each of the sta...

  4. Abundance of Asymmetric Dark Matter in Brane World Cosmology

    Science.gov (United States)

    Abdusattar, Haximjan; Iminniyaz, Hoernisa

    2016-09-01

    Relic abundance of asymmetric Dark Matter particles in brane world cosmological scenario is investigated in this article. Hubble expansion rate is enhanced in brane world cosmology and it affects the relic abundance of asymmetric Dark Matter particles. We analyze how the relic abundance of asymmetric Dark Matter is changed in this model. We show that in such kind of nonstandard cosmological scenario, indirect detection of asymmetric Dark Matter is possible if the cross section is small enough which let the anti-particle abundance kept in the same amount with the particle. We show the indirect detection signal constraints can be used to such model only when the cross section and the 5-dimensional Planck mass scale are in appropriate values. Supported by the National Natural Science Foundation of China under Grant No. 11365022

  5. Seabird abundance and behavior on Cape Peirce, Alaska, 1985

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers the seabird abundance and behavior on Cape Peirce on Togiak National Wildlife Refuge. Methods and results are discussed. Species covered include...

  6. Investigating Detailed Abundance Patterns in the Hyades Cluster

    Science.gov (United States)

    Williams, Drake; Schuler, Simon C.

    2016-01-01

    We have derived the paramters and abundances of up to 17 elements for seven stars within the Hyades open star cluster, through an analysis of high-resolution, high signal-to-noise ratio spectra obtained via the Harlan J. Smith 2.7 m telescope and the 2dcoude cross-dispersed echelle spectrometer at the McDonald Observatory. Four of the stars are solar-type dwarves while three giants were also analyzed to better calculate an overall metallicity of the entire cluster. In addition, we investigated whether there are differences in various stellar abundance trends across the open cluster. Here we present the results of our abundance analysis and stellar parameter derivations of the seven stars and discuss the implications of stellar abundance patterns across star clusters. We acknowledge support provided by grant NNX12AD19G to S.C.S. from the National Aeronautics and Space Administration as part of the Kepler Participating Scientist Program.

  7. Are Classification Criteria for IgG4-RD Now Possible? The Concept of IgG4-Related Disease and Proposal of Comprehensive Diagnostic Criteria in Japan

    Directory of Open Access Journals (Sweden)

    Kazuichi Okazaki

    2012-01-01

    Full Text Available Recent studies suggest simultaneous or metachronous lesions in multiorgans characterized by elevated serum levels of IgG4 and abundant infiltration of IgG4-positive plasma cells with various degrees of fibrosis. Two Japanese research committees for IgG4-RD, one from fibrosclerosis (Okazaki team and the other from lymph proliferation (Umehara team supported by the “Research Program for Intractable Disease” of the Ministry of Health, Labor, and Welfare of Japan, have agreed with the unified nomenclature as “IgG4-RD” and proposed the comprehensive diagnostic criteria (CDC for IgG4-RD. Validation of the CDC demonstrated satisfactory sensitivity for the practical use of general physicians and nonspecialists but low sensitivity in the organs to be difficult in taking biopsy specimens such as type1 autoimmune pancreatitis (IgG4-related AIP, compared with IgG4-related sialadenitis/dacryoadenitis (Mikulicz's disease and IgG4-related kidney disease. Although the diagnostic criteria covering all IgG4-RD are hard to be established, combination with the CDC and organ-specific diagnostic criteria should improve sensitivity.

  8. Protein abundance profiling of the Escherichia coli cytosol

    Directory of Open Access Journals (Sweden)

    Mann Matthias

    2008-02-01

    Full Text Available Abstract Background Knowledge about the abundance of molecular components is an important prerequisite for building quantitative predictive models of cellular behavior. Proteins are central components of these models, since they carry out most of the fundamental processes in the cell. Thus far, protein concentrations have been difficult to measure on a large scale, but proteomic technologies have now advanced to a stage where this information becomes readily accessible. Results Here, we describe an experimental scheme to maximize the coverage of proteins identified by mass spectrometry of a complex biological sample. Using a combination of LC-MS/MS approaches with protein and peptide fractionation steps we identified 1103 proteins from the cytosolic fraction of the Escherichia coli strain MC4100. A measure of abundance is presented for each of the identified proteins, based on the recently developed emPAI approach which takes into account the number of sequenced peptides per protein. The values of abundance are within a broad range and accurately reflect independently measured copy numbers per cell. As expected, the most abundant proteins were those involved in protein synthesis, most notably ribosomal proteins. Proteins involved in energy metabolism as well as those with binding function were also found in high copy number while proteins annotated with the terms metabolism, transcription, transport, and cellular organization were rare. The barrel-sandwich fold was found to be the structural fold with the highest abundance. Highly abundant proteins are predicted to be less prone to aggregation based on their length, pI values, and occurrence patterns of hydrophobic stretches. We also find that abundant proteins tend to be predominantly essential. Additionally we observe a significant correlation between protein and mRNA abundance in E. coli cells. Conclusion Abundance measurements for more than 1000 E. coli proteins presented in this work

  9. Urban Warming Drives Insect Pest Abundance on Street Trees

    OpenAIRE

    Meineke, Emily K.; Robert R Dunn; Sexton, Joseph O.; Frank, Steven D.

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within c...

  10. Regularity underlies erratic population abundances in marine ecosystems

    OpenAIRE

    Sun, Jie; Cornelius, Sean P.; Janssen, John; Gray, Kimberly A.; Motter, Adilson E.

    2015-01-01

    The abundance of a species' population in an ecosystem is rarely stationary, often exhibiting large fluctuations over time. Using historical data on marine species, we show that the year-to-year fluctuations of population growth rate obey a well-defined double-exponential (Laplace) distribution. This striking regularity allows us to devise a stochastic model despite seemingly irregular variations in population abundances. The model identifies the effect of reduced growth at low population den...

  11. Literature survey of isotopic abundance data for 1987-1989

    Energy Technology Data Exchange (ETDEWEB)

    Holden, N.E. (Brookhaven National Lab., Upton, NY (USA))

    1989-08-09

    I have compiled all of the data on isotopic abundance measurements and their variation in nature for the time period since the last General Assembly. Most of the data deals with the variations in the abundances as given by per mil deviations from some standard. As such, they are not of major interest to the Atomic Weights Commission. However, there were some measurements which are of general interest in this list.

  12. The Open Cluster Chemical Abundances from Spanish Observatories survey (OCCASO)

    CERN Document Server

    Carrera, R; Balaguer-Núñez, L; Jordi, C; Pancino, E; Allende-Prieto, C; Blanco-Cuaresma, S; Mártinez-Vázquez, C E; Murabito, S; del Pino, A; Aparicio, A; Gallart, C; Recio-Blanco, A

    2014-01-01

    We present the motivation, design and current status of the Open Cluster Chemical Abundances from Spanish Observatories survey (OCCASO). Using the high resolution spectroscopic facilities available at Spanish observatories, OCCASO will derive chemical abundances in a sample of 20 to 25 open clusters older than 0.5 Gyr. This sample will be used to study in detail the formation and evolution of the Galactic disc using open clusters as tracers.

  13. An Extension of the Abundancy Index to Certain Quadratic Rings

    OpenAIRE

    Defant, Colin

    2015-01-01

    We begin by introducing an extension of the traditional abundancy index to imaginary quadratic rings with unique factorization. After showing that many of the properties of the traditional abundancy index continue to hold in our extended form, we investigate what we call $n$-powerfully solitary numbers in these rings. This definition serves to extend the concept of solitary numbers, which have been defined and studied in the integers. We end with some open questions and a conjecture.

  14. Beryllium, Lithium and Oxygen Abundances in F-type Stars

    CERN Document Server

    García-López, R J; Pérez de Taoro, M R; Casares, C; Rasilla, J L; Rebolo, R; Allende-Prieto, C

    1997-01-01

    Beryllium and oxygen abundances have been derived in a sample of F-type field stars for which lithium abundances had been measured previously, with the aim of obtaining observational constraints to discriminate between the different mixing mechanisms proposed. Mixing associated with the transport of angular momentum in the stellar interior and internal gravity waves within the framework of rotating evolutionary models, appear to be promising ways to explain the observations.

  15. Zooplankton composition and abundance in Mida Creek, Kenya

    OpenAIRE

    Osore, M.K.W.; Mwaluma, J.M.; FIERS, F; Daro, M.H.

    2004-01-01

    In order to determine the resident assemblages of zooplankton in Mida Creek, Kenya, a survey was conducted from May 1996 to Apr. 1997 for which we studied their seasonal composition, abundance, and distribution. Twenty-seven major zooplankton taxa were identified. The order Copepoda was the most abundant taxon dominated mainly by the genera Acartia, Paracalanus, Labidocera, Temora, Centropages, and Calanopia. Other common zooplankton taxa included the Medusae, Ctenophora, Brachyura larvae, an...

  16. The Open Cluster Chemical Abundances from Spanish Observatories Survey (OCCASO)

    Science.gov (United States)

    Carrera, R.; Casamiquela, L.; Balaguer-Núñez, L.; Jordi, C.; Pancino, E.; Allende-Prieto, C.; Blanco-Cuaresma, S.; Martínez-Vázquez, C. E.; Murabito, S.; del Pino, A.; Aparicio, A.; Gallart, C.; Recio-Blanco, A.

    2016-10-01

    We present the motivation, design and current status of the Open Cluster Chemical Abundances from Spanish Observatories survey (OCCASO). Using the high resolution spectroscopic facilities available at Spanish observatories, OCCASO will derive chemical abundances in a sample of 20 to 25 OCs older than 0.5 Gyr. This sample will be used to study in detail the formation and evolution of the Galactic disk using OCs as tracers.

  17. The First-Integral Method and Abundant Explicit Exact Solutions to the Zakharov Equations

    Directory of Open Access Journals (Sweden)

    Yadong Shang

    2012-01-01

    Full Text Available This paper is concerned with the system of Zakharov equations which involves the interactions between Langmuir and ion-acoustic waves in plasma. Abundant explicit and exact solutions of the system of Zakharov equations are derived uniformly by using the first integral method. These exact solutions are include that of the solitary wave solutions of bell-type for n and E, the solitary wave solutions of kink-type for E and bell-type for n, the singular traveling wave solutions, periodic wave solutions of triangle functions, Jacobi elliptic function doubly periodic solutions, and Weierstrass elliptic function doubly periodic wave solutions. The results obtained confirm that the first integral method is an efficient technique for analytic treatment of a wide variety of nonlinear systems of partial differential equations.

  18. Nontoxic and abundant copper zinc tin sulfide nanocrystals for potential high-temperature thermoelectric energy harvesting.

    Science.gov (United States)

    Yang, Haoran; Jauregui, Luis A; Zhang, Genqiang; Chen, Yong P; Wu, Yue

    2012-02-01

    Improving energy/fuel efficiency by converting waste heat into electricity using thermoelectric materials is of great interest due to its simplicity and reliability. However, many thermoelectric materials are composed of either toxic or scarce elements. Here, we report the experimental realization of using nontoxic and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS nanocrystals can be synthesized in large quantities from solution phase reaction and compressed into robust bulk pellets through spark plasma sintering and hot press while still maintaining nanoscale grain size inside. Electrical and thermal measurements have been performed from 300 to 700 K to understand the electron and phonon transports. Extra copper doping during the nanocrystal synthesis introduces a significant improvement in the performance. PMID:22214524

  19. The Detectability of Neon Fluorescence and Measurement of the Solar Photospheric Neon Abundance

    CERN Document Server

    Drake, Jeremy J

    2007-01-01

    Monte Carlo calculations of the Ne K$\\alpha$ line fluoresced by coronal x-rays and emitted near the temperature minimum region of the solar atmosphere have been employed to investigate the use of this feature to measure directly the solar photospheric Ne abundance. Though very weak, comparison with spectral line databases indicates that at plasma temperatures typical of the quiet Sun and cool active regions ($\\leq 2\\times 10^6$ K) the line is isolated and unblended. A canonical solar chemical composition yields an equivalent width of $\\sim 6$ m\\AA (0.3 eV) when observed at heliocentric angles $\\sim 0$. For a 1 arcmin field of view, photon fluxes at Earth are of order 0.2 ph s$^{-1}$ for the quiet Sun, rendering the Ne K$\\alpha$ fluorescent line a quite feasible means for determining the solar photospheric Ne content.

  20. Nontoxic and abundant copper zinc tin sulfide nanocrystals for potential high-temperature thermoelectric energy harvesting.

    Science.gov (United States)

    Yang, Haoran; Jauregui, Luis A; Zhang, Genqiang; Chen, Yong P; Wu, Yue

    2012-02-01

    Improving energy/fuel efficiency by converting waste heat into electricity using thermoelectric materials is of great interest due to its simplicity and reliability. However, many thermoelectric materials are composed of either toxic or scarce elements. Here, we report the experimental realization of using nontoxic and abundant copper zinc tin sulfide (CZTS) nanocrystals for potential thermoelectric applications. The CZTS nanocrystals can be synthesized in large quantities from solution phase reaction and compressed into robust bulk pellets through spark plasma sintering and hot press while still maintaining nanoscale grain size inside. Electrical and thermal measurements have been performed from 300 to 700 K to understand the electron and phonon transports. Extra copper doping during the nanocrystal synthesis introduces a significant improvement in the performance.

  1. Ruthenium and hafnium abundances in giant and dwarf barium stars

    CERN Document Server

    Allen, D M

    2007-01-01

    We present abundances for Ru and Hf, compare them to abundances of other heavy elements, and discuss the problems found in determining Ru and Hf abundances with laboratory gf-values in the spectra of barium stars. We determined Ru and Hf abundances in a sample of giant and dwarf barium stars, by the spectral synthesis of two RuI (4080.574A and 4757.856A) and two HfII (4080.437A and 4093.155A) transitions. The stellar spectra were observed with FEROS/ESO, and the stellar atmospheric parameters lie in the range 4300 < Teff/K < 6500, -1.2 < [Fe/H] <= 0 and 1.4 <= log g < 4.6. The HfII 4080A and the RuI 4758A observed transitions result in a unreasonably high solar abundance, given certain known uncertainties, when fitted with laboratory gf-values. For these two transitions we determined empirical gf-values by fitting the observed line profiles of the spectra of the Sun and Arcturus. For the sample stars, this procedure resulted in a good agreement of Ru and Hf abundances given by the two availa...

  2. Chemical abundances from planetary nebulae in local spiral galaxies

    CERN Document Server

    Richer, M G

    2015-01-01

    While the chemical abudances observed in bright planetary nebulae in local spiral galaxies are less varied than their counterparts in dwarfs, they provide new insight. Their helium abundances are typically enriched by less than 50\\% compared to the primordial abundance. Nitrogen abundances always show some level of secondary enrichment, but the absolute enrichment is not extreme. In particular, type I PNe are rare among the bright PNe in local spirals. The oxygen and neon abundances are very well correlated and follow the relation between these abundances observed in star-forming galaxies, implying that either the progenitor stars of these PNe modify neither abundance substantially or that they modify both to maintain the ratio (not predicted by theory). According to theory, these results imply that the progenitor stars of bright PNe in local spirals have masses of about $2\\,\\mathrm M_{\\odot}$ or less. If so, the progenitors of these PNe have substantial lifetimes that allow us to use them to study the recent...

  3. CHROMOSPHERIC MODELS AND THE OXYGEN ABUNDANCE IN GIANT STARS

    Energy Technology Data Exchange (ETDEWEB)

    Dupree, A. K.; Avrett, E. H.; Kurucz, R. L., E-mail: dupree@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2016-04-10

    Realistic stellar atmospheric models of two typical metal-poor giant stars in Omega Centauri, which include a chromosphere (CHR), influence the formation of optical lines of O i: the forbidden lines (λ6300, λ6363) and the infrared triplet (λλ7771−7775). One-dimensional semi-empirical non-local thermodynamic equilibrium (LTE) models are constructed based on observed Balmer lines. A full non-LTE formulation is applied for evaluating the line strengths of O i, including photoionization by the Lyman continuum and photoexcitation by Lyα and Lyβ. Chromospheric models (CHR) yield forbidden oxygen transitions that are stronger than those in radiative/convective equilibrium (RCE) models. The triplet oxygen lines from high levels also appear stronger than those produced in an RCE model. The inferred oxygen abundance from realistic CHR models for these two stars is decreased by factors of ∼3 as compared to values derived from RCE models. A lower oxygen abundance suggests that intermediate-mass AGB stars contribute to the observed abundance pattern in globular clusters. A change in the oxygen abundance of metal-poor field giants could affect models of deep mixing episodes on the red giant branch. Changes in the oxygen abundance can impact other abundance determinations that are critical to astrophysics, including chemical tagging techniques and galactic chemical evolution.

  4. On ribosome load, codon bias and protein abundance.

    Directory of Open Access Journals (Sweden)

    Stefan Klumpp

    Full Text Available Different codons encoding the same amino acid are not used equally in protein-coding sequences. In bacteria, there is a bias towards codons with high translation rates. This bias is most pronounced in highly expressed proteins, but a recent study of synthetic GFP-coding sequences did not find a correlation between codon usage and GFP expression, suggesting that such correlation in natural sequences is not a simple property of translational mechanisms. Here, we investigate the effect of evolutionary forces on codon usage. The relation between codon bias and protein abundance is quantitatively analyzed based on the hypothesis that codon bias evolved to ensure the efficient usage of ribosomes, a precious commodity for fast growing cells. An explicit fitness landscape is formulated based on bacterial growth laws to relate protein abundance and ribosomal load. The model leads to a quantitative relation between codon bias and protein abundance, which accounts for a substantial part of the observed bias for E. coli. Moreover, by providing an evolutionary link, the ribosome load model resolves the apparent conflict between the observed relation of protein abundance and codon bias in natural sequences and the lack of such dependence in a synthetic gfp library. Finally, we show that the relation between codon usage and protein abundance can be used to predict protein abundance from genomic sequence data alone without adjustable parameters.

  5. Chromospheric Models and the Oxygen Abundance in Giant Stars

    Science.gov (United States)

    Dupree, A. K.; Avrett, E. H.; Kurucz, R. L.

    2016-04-01

    Realistic stellar atmospheric models of two typical metal-poor giant stars in Omega Centauri, which include a chromosphere (CHR), influence the formation of optical lines of O i: the forbidden lines (λ6300, λ6363) and the infrared triplet (λλ7771-7775). One-dimensional semi-empirical non-local thermodynamic equilibrium (LTE) models are constructed based on observed Balmer lines. A full non-LTE formulation is applied for evaluating the line strengths of O i, including photoionization by the Lyman continuum and photoexcitation by Lyα and Lyβ. Chromospheric models (CHR) yield forbidden oxygen transitions that are stronger than those in radiative/convective equilibrium (RCE) models. The triplet oxygen lines from high levels also appear stronger than those produced in an RCE model. The inferred oxygen abundance from realistic CHR models for these two stars is decreased by factors of ˜3 as compared to values derived from RCE models. A lower oxygen abundance suggests that intermediate-mass AGB stars contribute to the observed abundance pattern in globular clusters. A change in the oxygen abundance of metal-poor field giants could affect models of deep mixing episodes on the red giant branch. Changes in the oxygen abundance can impact other abundance determinations that are critical to astrophysics, including chemical tagging techniques and galactic chemical evolution.

  6. The Solar Flare Sulphur Abundance from RESIK Observations

    CERN Document Server

    Sylwester, J; Phillips, K J H; Kuznetsov, V D

    2012-01-01

    The RESIK instrument on {\\em CORONAS-F} spacecraft observed several sulphur X-ray lines in three of its four channels covering the wavelength range 3.8-6.1 \\AA\\ during solar flares. The fluxes are analyzed to give the sulphur abundance. Data are chosen for when the instrument parameters were optimized. The measured fluxes of the \\ion{S}{15} $1s^2-1s4p$ ($w4$) line at 4.089 \\AA\\ gives $A({\\rm S}) = 7.16 \\pm 0.17$ (abundances on a logarithmic scale with $A({\\rm H}) = 12$) which we consider to be the most reliable. Estimates from other lines range from 7.13 to 7.24. The preferred S abundance estimate is very close to recent photospheric abundance estimates and to quiet-Sun solar wind and meteoritic abundances. This implies no fractionation of sulphur by processes tending to enhance the coronal abundance from the photospheric that depend on the first ionization potential (FIP), or that sulphur, though its FIP has an intermediate value of 10.36 eV, acts like a "high-FIP" element.

  7. Global abundance of planktonic heterotrophic protists in the deep ocean.

    Science.gov (United States)

    Pernice, Massimo C; Forn, Irene; Gomes, Ana; Lara, Elena; Alonso-Sáez, Laura; Arrieta, Jesus M; del Carmen Garcia, Francisca; Hernando-Morales, Victor; MacKenzie, Roy; Mestre, Mireia; Sintes, Eva; Teira, Eva; Valencia, Joaquin; Varela, Marta M; Vaqué, Dolors; Duarte, Carlos M; Gasol, Josep M; Massana, Ramon

    2015-03-01

    The dark ocean is one of the largest biomes on Earth, with critical roles in organic matter remineralization and global carbon sequestration. Despite its recognized importance, little is known about some key microbial players, such as the community of heterotrophic protists (HP), which are likely the main consumers of prokaryotic biomass. To investigate this microbial component at a global scale, we determined their abundance and biomass in deepwater column samples from the Malaspina 2010 circumnavigation using a combination of epifluorescence microscopy and flow cytometry. HP were ubiquitously found at all depths investigated down to 4000 m. HP abundances decreased with depth, from an average of 72±19 cells ml(-1) in mesopelagic waters down to 11±1 cells ml(-1) in bathypelagic waters, whereas their total biomass decreased from 280±46 to 50±14 pg C ml(-1). The parameters that better explained the variance of HP abundance were depth and prokaryote abundance, and to lesser extent oxygen concentration. The generally good correlation with prokaryotic abundance suggested active grazing of HP on prokaryotes. On a finer scale, the prokaryote:HP abundance ratio varied at a regional scale, and sites with the highest ratios exhibited a larger contribution of fungi molecular signal. Our study is a step forward towards determining the relationship between HP and their environment, unveiling their importance as players in the dark ocean's microbial food web.

  8. Divertor plasma detachment

    Science.gov (United States)

    Krasheninnikov, S. I.; Kukushkin, A. S.; Pshenov, A. A.

    2016-05-01

    Regime with the plasma detached from the divertor targets (detached divertor regime) is a natural continuation of the high recycling conditions to higher density and stronger impurity radiation loss. Both the theoretical considerations and experimental data show clearly that the increase of the impurity radiation loss and volumetric plasma recombination causes the rollover of the plasma flux to the target when the density increases, which is the manifestation of detachment. Plasma-neutral friction (neutral viscosity effects), although important for the sustainment of high density/pressure plasma upstream and providing the conditions for efficient recombination and power loss, is not directly involved in the reduction of the plasma flux to the targets. The stability of detachment is also discussed.

  9. What is a plasma?

    Energy Technology Data Exchange (ETDEWEB)

    Intrator, Thomas P. [Los Alamos National Laboratory

    2012-08-30

    This introduction will define the plasma fourth state of matter, where we find plasmas on earth and beyond, and why they are useful. There are applications to many consumer items, fusion energy, scientific devices, satellite communications, semiconductor processing, spacecraft propulsion, and more. Since 99% of our observable universe is ionized gas, plasma physics determines many important features of astrophysics, space physics, and magnetosphere physics in our solar system. We describe some plasma characteristics, examples in nature, some useful applications, how to create plasmas. A brief introduction to the theoretical framework includes the connection between kinetic and fluid descriptions, quasi neutrality, Debye shielding, ambipolar electric fields, some plasma waves. Hands-on demonstrations follow. More complete explanations will follow next week.

  10. Introduction to Complex Plasmas

    CERN Document Server

    Bonitz, Michael; Ludwig, Patrick

    2010-01-01

    Complex plasmas differ from traditional plasmas in many ways: these are low-temperature high pressure systems containing nanometer to micrometer size particles which may be highly charged and strongly interacting. The particles may be chemically reacting or be in contact with solid surfaces, and the electrons may show quantum behaviour. These interesting properties have led to many applications of complex plasmas in technology, medicine and science. Yet complex plasmas are extremely complicated, both experimentally and theoretically, and require a variety of new approaches which go beyond standard plasma physics courses. This book fills this gap presenting an introduction to theory, experiment and computer simulation in this field. Based on tutorial lectures at a very successful recent Summer Institute, the presentation is ideally suited for graduate students, plasma physicists and experienced undergraduates.

  11. A Model of Calculating Radiative Opacities of Hot Dense Plasmas Based on the Density-Functional Theory

    OpenAIRE

    Kiyokawa, Shuji

    2014-01-01

    We determine the radiative opacity of plasmas in a local thermal equilibrium (LTE) by time-dependent density-functional theory (TDDFT) including autoionization resonances, where the photoabsorption cross section is calculated for an ion embedded in the plasma using the detailed configuration accounting (DCA) method. The abundance of ion with integer occupation numbers is determined by means of the finite temperature density-functional theory (FTDFT). For an Al plasma of temperature T=20 eV an...

  12. Two steps towards the realization of fusion: New plasma configurations in the TCV tokamak and its ongoing upgrades

    OpenAIRE

    Martin Yves; Duval Basil P.; Karpushov Alexander N.; Labit Benoit; Reimerdes Holger

    2014-01-01

    To realise the potential of fusion as an abundant energy source, several challenges remain. The TCV tokamak, featuring high shaping capability and a flexible heating system, is strongly contributing to solving these challenges. A fundamental challenge remains in controlling heat exhaust from the plasma. ITER's currently foreseen operational regime implies heat flows to the plasma facing materials that are not compatible with a commercial fusion reactor. TCV has demonstrated alternative plasma...

  13. Space plasma physics research

    Science.gov (United States)

    Comfort, Richard H.; Horwitz, James L.

    1993-01-01

    During the course of this grant, work was performed on a variety of topics and there were a number of significant accomplishments. A summary of these accomplishments is included. The topics studied include empirical model data base, data reduction for archiving, semikinetic modeling of low energy plasma in the inner terrestrial magnetosphere and ionosphere, O(+) outflows, equatorial plasma trough, and plasma wave ray-tracing studies. A list of publications and presentations which have resulted from this research is also included.

  14. Temperature of the Source Plasma for Impulsive Solar Energetic Particles

    CERN Document Server

    Reames, Donald V; Kahler, Stephen W

    2015-01-01

    The steep power-law dependence of element abundance enhancements on the mass-to-charge ratios [A/Q] of the ions in impulsive solar energetic-particle (SEP) events causes these enhancements to reflect the temperature-dependent pattern of Q of the ions in the source plasma. We searched for SEP events from coronal plasma that is hotter or cooler than the limited region of 2.5 - 3.2 MK previously found to dominate 111 impulsive SEP events. Fifteen new events were found, four (three) originated in 2-MK (4-MK) plasma, but none from outside this temperature range. Although the impulsive SEP events are strongly associated with flares, this result indicates that these ions are not accelerated from flare-heated plasma, which can often exceed 10 MK. Evidently the ions of 2 - 20 MeV/amu that we observe in space are accelerated from active-region plasma on open magnetic-field lines near the flare, but not from the closed loops of the flare. The power-law dependence of the abundance enhancements on A/Q of the ions is expec...

  15. Nonlinear Physics of Plasmas

    CERN Document Server

    Kono, Mitsuo

    2010-01-01

    A nonlinearity is one of the most important notions in modern physics. A plasma is rich in nonlinearities and provides a variety of behaviors inherent to instabilities, coherent wave structures and turbulence. The book covers the basic concepts and mathematical methods, necessary to comprehend nonlinear problems widely encountered in contemporary plasmas, but also in other fields of physics and current research on self-organized structures and magnetized plasma turbulence. The analyses make use of strongly nonlinear models solved by analytical techniques backed by extensive simulations and available experiments. The text is written for senior undergraduates, graduate students, lecturers and researchers in laboratory, space and fusion plasmas.

  16. Physics of Plasmas

    CERN Document Server

    Woods, Leslie Colin

    2003-01-01

    A short, self-sufficient introduction to the physics of plasma for beginners as well as researchers in a number of fields. The author looks at the dynamics and stability of magnetoplasma and discusses wave and transport in this medium. He also looks at such applications as fusion research using magnetic confinement of Deuterium plasma, solar physics with its plasma loops reaching high into the corona, sunspots and solar wind, engineering applications to metallurgy, MHD direct generation of electricity, and railguns, finally touching on the relatively new and difficult subject of dusty plasmas.

  17. Plasma membrane ATPases

    DEFF Research Database (Denmark)

    Palmgren, Michael Broberg; Bækgaard, Lone; Lopez Marques, Rosa Laura;

    2011-01-01

    The plasma membrane separates the cellular contents from the surrounding environment. Nutrients must enter through the plasma membrane in order to reach the cell interior, and toxic metabolites and several ions leave the cell by traveling across the same barrier. Biological pumps in the plasma...... membrane include ABC transporters, vacuolar (V-type) H+ pumps, and P-type pumps. These pumps all utilize ATP as a fuel for energizing pumping. This review focuses on the physiological roles of plasma membrane P-type pumps, as they represent the major ATP hydrolytic activity in this membrane....

  18. Plasma processing for VLSI

    CERN Document Server

    Einspruch, Norman G

    1984-01-01

    VLSI Electronics: Microstructure Science, Volume 8: Plasma Processing for VLSI (Very Large Scale Integration) discusses the utilization of plasmas for general semiconductor processing. It also includes expositions on advanced deposition of materials for metallization, lithographic methods that use plasmas as exposure sources and for multiple resist patterning, and device structures made possible by anisotropic etching.This volume is divided into four sections. It begins with the history of plasma processing, a discussion of some of the early developments and trends for VLSI. The second section

  19. Tornado plasma theory

    International Nuclear Information System (INIS)

    The formation mechanism and plasma theory of tornado are proposed. Tornado is considered as a gas discharge. Electrical fields, currents, electromagnetic forces and velocities fields have been obtained

  20. Princeton Plasma Physics Laboratory

    International Nuclear Information System (INIS)

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990

  1. Princeton Plasma Physics Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This report discusses the following topics: principal parameters achieved in experimental devices fiscal year 1990; tokamak fusion test reactor; compact ignition tokamak; Princeton beta experiment- modification; current drive experiment-upgrade; international collaboration; x-ray laser studies; spacecraft glow experiment; plasma processing: deposition and etching of thin films; theoretical studies; tokamak modeling; international thermonuclear experimental reactor; engineering department; project planning and safety office; quality assurance and reliability; technology transfer; administrative operations; PPPL patent invention disclosures for fiscal year 1990; graduate education; plasma physics; graduate education: plasma science and technology; science education program; and Princeton Plasma Physics Laboratory reports fiscal year 1990.

  2. New Strong Line Abundance Diagnostics for \\HII Regions: Effects of $\\kappa$-Distributed Electron Energies and New Atomic Data

    CERN Document Server

    Dopita, Michael A; Nicholls, David C; Kewley, Lisa J; Vogt, Frédéric P A

    2013-01-01

    Recently, \\citet{Nicholls12}, inspired by \\emph{in situ} observations of solar system astrophysical plasmas, suggested that the electrons in \\HII regions are characterised by a $\\kappa$-distribution of electron energies rather than by a simple Maxwell-Boltzmann distribution. Here we have collected together the new atomic data within a modified photoionisation code to explore the effects of both the new atomic data and the $\\kappa$-distribution on the strong-line techniques used to determine chemical abundances in \\HII regions. By comparing the recombination temperatures ($T_{\\rm rec}$) with the forbidden line temperatures ($T_{\\rm FL}$) we conclude that $ \\kappa \\sim 20$. While representing only a mild deviation from equilibrium, this is sufficient to strongly influence abundances determined using methods which depend on measurements of the electron temperature from forbidden lines. We present a number of new emission line ratio diagnostics which cleanly separate the two parameters determining the optical spe...

  3. A search for stars of very low metal abundance. VI. Detailed abundances of 313 metal-poor stars

    Energy Technology Data Exchange (ETDEWEB)

    Roederer, Ian U.; Preston, George W.; Thompson, Ian B.; Shectman, Stephen A.; Burley, Gregory S.; Kelson, Daniel D. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Sneden, Christopher, E-mail: iur@umich.edu [Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712 (United States)

    2014-06-01

    We present radial velocities, equivalent widths, model atmosphere parameters, and abundances or upper limits for 53 species of 48 elements derived from high resolution optical spectroscopy of 313 metal-poor stars. A majority of these stars were selected from the metal-poor candidates of the HK Survey of Beers, Preston, and Shectman. We derive detailed abundances for 61% of these stars for the first time. Spectra were obtained during a 10 yr observing campaign using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan Telescopes at Las Campanas Observatory, the Robert G. Tull Coudé Spectrograph on the Harlan J. Smith Telescope at McDonald Observatory, and the High Resolution Spectrograph on the Hobby-Eberly Telescope at McDonald Observatory. We perform a standard LTE abundance analysis using MARCS model atmospheres, and we apply line-by-line statistical corrections to minimize systematic abundance differences arising when different sets of lines are available for analysis. We identify several abundance correlations with effective temperature. A comparison with previous abundance analyses reveals significant differences in stellar parameters, which we investigate in detail. Our metallicities are, on average, lower by ≈0.25 dex for red giants and ≈0.04 dex for subgiants. Our sample contains 19 stars with [Fe/H] ≤–3.5, 84 stars with [Fe/H] ≤–3.0, and 210 stars with [Fe/H] ≤–2.5. Detailed abundances are presented here or elsewhere for 91% of the 209 stars with [Fe/H] ≤–2.5 as estimated from medium resolution spectroscopy by Beers, Preston, and Shectman. We will discuss the interpretation of these abundances in subsequent papers.

  4. Highly Ionized Potassium Lines in Solar X-ray Spectra and the Abundance of Potassium

    CERN Document Server

    Sylwester, J; Phillips, K J H; Kuznetsov, V D

    2010-01-01

    The abundance of potassium is derived from X-ray lines observed during flares by the RESIK instrument on the solar mission CORONAS-F between 3.53 A and 3.57 A. The lines include those emitted by He-like K and Li-like K dielectronic satellites, which have been synthesized using the CHIANTI atomic code and newly calculated atomic data. There is good agreement of observed and synthesized spectra, and the theoretical behavior of the spectra with varying temperature estimated from the ratio of the two GOES channels is correctly predicted. The observed fluxes of the He-like K resonance line per unit emission measure gives log A(K) = 5.86 (on a scale log A(H) = 12), with a total range of a factor 2.9. This is higher than photospheric abundance estimates by a factor 5.5, a slightly greater enhancement than for other elements with first ionization potential (FIP) less than about 10 eV. There is, then, the possibility that enrichment of low-FIP elements in coronal plasmas depends weakly on the value of the FIP which fo...

  5. Urban warming drives insect pest abundance on street trees.

    Science.gov (United States)

    Meineke, Emily K; Dunn, Robert R; Sexton, Joseph O; Frank, Steven D

    2013-01-01

    Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer. PMID:23544087

  6. Change in avian abundance predicted from regional forest inventory data

    Science.gov (United States)

    Twedt, Daniel J.; Tirpak, John M.; Jones-Farrand, D. Todd; Thompson, Frank R., III; Uihlein, William B.; Fitzgerald, Jane A.

    2010-01-01

    An inability to predict population response to future habitat projections is a shortcoming in bird conservation planning. We sought to predict avian response to projections of future forest conditions that were developed from nationwide forest surveys within the Forest Inventory and Analysis (FIA) program. To accomplish this, we evaluated the historical relationship between silvicolous bird populations and FIA-derived forest conditions within 25 ecoregions that comprise the southeastern United States. We aggregated forest area by forest ownership, forest type, and tree size-class categories in county-based ecoregions for 5 time periods spanning 1963-2008. We assessed the relationship of forest data with contemporaneous indices of abundance for 24 silvicolous bird species that were obtained from Breeding Bird Surveys. Relationships between bird abundance and forest inventory data for 18 species were deemed sufficient as predictive models. We used these empirically derived relationships between regional forest conditions and bird populations to predict relative changes in abundance of these species within ecoregions that are anticipated to coincide with projected changes in forest variables through 2040. Predicted abundances of these 18 species are expected to remain relatively stable in over a quarter (27%) of the ecoregions. However, change in forest area and redistribution of forest types will likely result in changed abundance of some species within many ecosystems. For example, abundances of 11 species, including pine warbler (Dendroica pinus), brown-headed nuthatch (Sitta pusilla), and chuckwills- widow (Caprimulgus carolinensis), are projected to increase within more ecoregions than ecoregions where they will decrease. For 6 other species, such as blue-winged warbler (Vermivora pinus), Carolina wren (Thryothorus ludovicianus), and indigo bunting (Passerina cyanea), we projected abundances will decrease within more ecoregions than ecoregions where they will

  7. Urban warming drives insect pest abundance on street trees.

    Directory of Open Access Journals (Sweden)

    Emily K Meineke

    Full Text Available Cities profoundly alter biological communities, favoring some species over others, though the mechanisms that govern these changes are largely unknown. Herbivorous arthropod pests are often more abundant in urban than in rural areas, and urban outbreaks have been attributed to reduced control by predators and parasitoids and to increased susceptibility of stressed urban plants. These hypotheses, however, leave many outbreaks unexplained and fail to predict variation in pest abundance within cities. Here we show that the abundance of a common insect pest is positively related to temperature even when controlling for other habitat characteristics. The scale insect Parthenolecanium quercifex was 13 times more abundant on willow oak trees in the hottest parts of Raleigh, NC, in the southeastern United States, than in cooler areas, though parasitism rates were similar. We further separated the effects of heat from those of natural enemies and plant quality in a greenhouse reciprocal transplant experiment. P. quercifex collected from hot urban trees became more abundant in hot greenhouses than in cool greenhouses, whereas the abundance of P. quercifex collected from cooler urban trees remained low in hot and cool greenhouses. Parthenolecanium quercifex living in urban hot spots succeed with warming, and they do so because some demes have either acclimatized or adapted to high temperatures. Our results provide the first evidence that heat can be a key driver of insect pest outbreaks on urban trees. Since urban warming is similar in magnitude to global warming predicted in the next 50 years, pest abundance on city trees may foreshadow widespread outbreaks as natural forests also grow warmer.

  8. Abundance of Hepatic Transporters in Caucasians: A Meta-Analysis.

    Science.gov (United States)

    Burt, Howard J; Riedmaier, Arian Emami; Harwood, Matthew D; Crewe, H Kim; Gill, Katherine L; Neuhoff, Sibylle

    2016-10-01

    This study aimed to derive quantitative abundance values for key hepatic transporters suitable for in vitro-in vivo extrapolation within a physiologically based pharmacokinetic modeling framework. A meta-analysis was performed whereby data on abundance measurements, sample preparation methods, and donor demography were collated from the literature. To define values for a healthy Caucasian population, a subdatabase was created whereby exclusion criteria were applied to remove samples from non-Caucasian individuals, those with underlying disease, or those with subcellular fractions other than crude membrane. Where a clinically relevant active genotype was known, only samples from individuals with an extensive transporter phenotype were included. Authors were contacted directly when additional information was required. After removing duplicated samples, the weighted mean, geometric mean, standard deviation, coefficient of variation, and between-study homogeneity of transporter abundances were determined. From the complete database containing 24 transporters, suitable abundance data were available for 11 hepatic transporters from nine studies after exclusion criteria were applied. Organic anion transporting polypeptides OATP1B1 and OATP1B3 showed the highest population abundance in healthy adult Caucasians. For several transporters, the variability in abundance was reduced significantly once the exclusion criteria were applied. The highest variability was observed for OATP1B3 > OATP1B1 > multidrug resistance protein 2 > multidrug resistance gene 1. No relationship was found between transporter expression and donor age. To our knowledge, this study provides the first in-depth analysis of current quantitative abundance data for a wide range of hepatic transporters, with the aim of using these data for in vitro-in vivo extrapolation, and highlights the significance of investigating the background of tissue(s) used in quantitative transporter proteomic studies. Similar

  9. Is abundance a species attribute? An example with haematophagous ectoparasites.

    Science.gov (United States)

    Krasnov, Boris R; Shenbrot, Georgy I; Khokhlova, Irina S; Poulin, Robert

    2006-11-01

    Population density is a fundamental property of a species and yet it varies among populations of the same species. The variation comes from the interplay between intrinsic features of a species that tend to produce repeatable density values across all populations of the same species and extrinsic environmental factors that differ among localities and thus tend to produce spatial variation in density. Is inter-population variation in density too large for density to be considered a true species character? We addressed this question using data on abundance (number of parasites per individual host, i.e. equivalent to density) of fleas ectoparasitic on small mammals. The data included samples of 548 flea populations, representing 145 flea species and obtained from 48 different geographical regions. Abundances of the same flea species on the same host species, but in different regions, were more similar to each other than expected by chance, and varied significantly among flea species, with 46% of the variation among samples accounted by differences between flea species. Thus, estimates of abundance are repeatable within the same flea species. The same repeatability was also observed, but to a lesser extent, across flea genera, tribes and subfamilies. Independently of the identity of the flea species, abundance values recorded on the same host species, or in the same geographical region, also showed significant statistical repeatability, though not nearly as strong as that associated with abundance values from the same flea species. There were also no strong indications that regional differences in abiotic variables were an important determinant of variation in abundance of a given flea species on a given host species. Abundance thus appears to be a true species trait in fleas, although it varies somewhat within bounds set by species-specific life history traits. PMID:16896773

  10. Pharmacological zinc and phytase supplementation enhance metallothionein mRNA abundance and protein concentration in newly weaned pigs.

    Science.gov (United States)

    Martínez, Michelle M; Hill, Gretchen M; Link, Jane E; Raney, Nancy E; Tempelman, Robert J; Ernst, Catherine W

    2004-03-01

    The swine industry feeds pharmacological zinc (Zn) to newly weaned pigs to improve health. Because most swine diets are plant-based with a high phytic acid content, we hypothesized that adding phytase to diets could reduce the amount of Zn required to obtain beneficial responses. The role of metallothionein (MT) in Zn homeostasis could be important in this positive response. Thus, the goal of this study was to investigate the effect of dietary Zn and phytase on relative MT mRNA abundance and protein concentration in newly weaned pigs. Diets containing adequate (150 mg Zn/kg) or pharmacological concentrations of Zn (1000 or 2000 mg Zn/kg), as zinc oxide, with or without phytase [0, 500 phytase units (FTU)/kg, Natuphos, BASF] were fed in a 3 x 2 factorial design. Plasma and tissue minerals were measured in pigs killed after 14 d of dietary intervention. Hepatic and renal relative MT mRNA abundance and protein were greater (P pigs fed 1000 mg Zn/kg with phytase, or 2000 mg Zn/kg with or without phytase vs. the remaining treatments. Intestinal mucosa MT mRNA abundance and protein were greater (P pigs fed 2000 mg Zn/kg with phytase than in pigs fed 2000 mg Zn/kg alone or 1000 mg Zn/kg with phytase. Pigs fed 1000 mg Zn/kg plus phytase or 2000 mg Zn/kg with or without phytase had higher plasma, hepatic, and renal Zn than those fed the adequate Zn diets or 1000 mg Zn/kg. We conclude that feeding 1000 mg Zn/kg with phytase enhances MT mRNA abundance and protein and Zn absorption to the same degree as 2000 mg Zn/kg with and without phytase. PMID:14988443

  11. Plasma Physics An Introduction to Laboratory, Space, and Fusion Plasmas

    CERN Document Server

    Piel, Alexander

    2010-01-01

    Plasma Physics gives a comprehensive introduction to the basic processes in plasmas and demonstrates that the same fundamental concepts describe cold gas-discharge plasmas, space plasmas, and hot fusion plasmas. Starting from particle drifts in magnetic fields, the principles of magnetic confinement fusion are explained and compared with laser fusion. Collective processes are discussed in terms of plasma waves and instabilities. The concepts of plasma description by magnetohydrodynamics, kinetic theory, and particle simulation are stepwise introduced. Space charge effects in sheath regions, double layers and plasma diodes are given the necessary attention. The new fundamental mechanisms of dusty plasmas are explored and integrated into the framework of conventional plasmas. The book concludes with a brief introduction to plasma discharges. Written by an internationally renowned researcher in experimental plasma physics, the text keeps the mathematical apparatus simple and emphasizes the underlying concepts. T...

  12. New aerial survey and hierarchical model to estimate manatee abundance

    Science.gov (United States)

    Langimm, Cahterine A.; Dorazio, Robert M.; Stith, Bradley M.; Doyle, Terry J.

    2011-01-01

    Monitoring the response of endangered and protected species to hydrological restoration is a major component of the adaptive management framework of the Comprehensive Everglades Restoration Plan. The endangered Florida manatee (Trichechus manatus latirostris) lives at the marine-freshwater interface in southwest Florida and is likely to be affected by hydrologic restoration. To provide managers with prerestoration information on distribution and abundance for postrestoration comparison, we developed and implemented a new aerial survey design and hierarchical statistical model to estimate and map abundance of manatees as a function of patch-specific habitat characteristics, indicative of manatee requirements for offshore forage (seagrass), inland fresh drinking water, and warm-water winter refuge. We estimated the number of groups of manatees from dual-observer counts and estimated the number of individuals within groups by removal sampling. Our model is unique in that we jointly analyzed group and individual counts using assumptions that allow probabilities of group detection to depend on group size. Ours is the first analysis of manatee aerial surveys to model spatial and temporal abundance of manatees in association with habitat type while accounting for imperfect detection. We conducted the study in the Ten Thousand Islands area of southwestern Florida, USA, which was expected to be affected by the Picayune Strand Restoration Project to restore hydrology altered for a failed real-estate development. We conducted 11 surveys in 2006, spanning the cold, dry season and warm, wet season. To examine short-term and seasonal changes in distribution we flew paired surveys 1–2 days apart within a given month during the year. Manatees were sparsely distributed across the landscape in small groups. Probability of detection of a group increased with group size; the magnitude of the relationship between group size and detection probability varied among surveys. Probability

  13. [Effects of sewage discharge on abundance and biomass of meiofauna].

    Science.gov (United States)

    Huang, De-Ming; Liu, Xiao-Shou; Lin, Ming-Xian; Chen, Huai-Pu; Wei, Lian-Ming; Huang, Xin; Zhang, Zhi-Nan

    2014-10-01

    In order to elucidate the effects of sewage discharge on abundance and biomass of meio- fauna, a seasonal survey was carried out on meiofauna at stations with different distances to a sewage outlet in the middle intertidal zone of No. 1 bathing beach in Huiquan Bay, Qingdao in spring (April), summer (August), autumn (October) and winter (December), 2011. The results showed that the annual average meiofaunal abundance was (1859.9 ± 705.1) ind · 10 cm(-2), with higher values of (2444.9 ± 1220.5) ind · 10 cm(-2) at Station S2 (20 m to the sewage outlet) and (2492.2 ± 1839.9) ind · 10 cm(-2) at Station S3 (40 m to the sewage outlet), while the lowest value of (327.9 ± 183.2) ind · 10 cm(-2) was observed at Station S1 (0 m to the sewage outlet) in terms of horizontal distribution. The annual average biomass was (1513.4 ± 372.7) μg · 10 cm(-2). Meiofaunal abundance and biomass varied seasonally with the highest values in spring and the lowest values in summer. A total of 11 meiofaunal groups were identified, including nematodes, copepods, polychaetes, oligochaetes, tardigrades, halacaroideans, planarians, ostracods, isopods, crustacean nauplii and others. Free-living marine nematodes were the dominant group constituting 83. 1% of the total abundance, followed by benthic copepods, accounting for 12. 8% of the total abundance. In terms of vertical distribution, most of the meiofauna concentrated in the top 0-2 cm, and the meiofauna abundance decreased with increasing the sediment depth. Meiofauna was also noted to migrate deeper into the sediment in the winter. Pearson correlation analysis showed that meiofaunal abundance and biomass had highly significant negative correlations with sediment median particle diameter and organic matter content. In addition, tourism-induced activities affected meiofaunal abundance and distribution. A comparison with historical data from similar studies was carried out, and the applicability of the ratio of abundance of nematodes

  14. Analysis and modeling of scale-invariance in plankton abundance

    CERN Document Server

    Pelletier, J D

    1996-01-01

    The power spectrum, $S$, of horizontal transects of plankton abundance are often observed to have a power-law dependence on wavenumber, $k$, with exponent close to $-2$: $S(k)\\propto k^{-2}$ over a wide range of scales. I present power spectral analyses of aircraft lidar measurements of phytoplankton abundance from scales of 1 to 100 km. A power spectrum $S(k)\\propto k^{-2}$ is obtained. As a model for this observation, I consider a stochastic growth equation where the rate of change of plankton abundance is determined by turbulent mixing, modeled as a diffusion process in two dimensions, and exponential growth with a stochastically variable net growth rate representing a fluctuating environment. The model predicts a lognormal distribution of abundance and a power spectrum of horizontal transects $S(k)\\propto k^{-1.8}$, close to the observed spectrum. The model equation predicts that the power spectrum of variations in abundance in time at a point in space is $S(f)\\propto f^{-1.5}$ (where $f$ is the frequency...

  15. Correlation between lithium abundances and ages of solar twin stars

    CERN Document Server

    Carlos, Marilia; Melendez, Jorge

    2016-01-01

    We want to determine the lithium abundances of solar twin stars as a function of stellar age to provide constraints for stellar evolutions models and to investigate whether there is a connection between low Li abundance and the occurrence of planets. For a sample of 21 solar twins observed with the HARPS spectrograph at high spectral resolution (R~115.000) and very high signal-to-noise ratio (600 < S/N < 2400), precise lithium abundances were obtained by spectral synthesis of the LiI 6707.8 A line and compared to stellar ages, masses, and metallicities determined from a spectroscopic analysis of the same set of HARPS spectra. We show that for the large majority of the solar twins there is a strong correlation between lithium abundance and stellar age. As the age increases from 1 to 9 Gyr, the Li abundance decreases by a factor of ~ 50. The relation agrees fairly well with predictions from non-standard stellar evolution models of Li destruction at the bottom of the upper convection zone. Two stars deviat...

  16. Carbon and Oxygen abundances across the Hertzsprung gap

    CERN Document Server

    Adamczak, Jens

    2014-01-01

    We derived atmospheric parameters and spectroscopic abundances for C and O for a large sample of stars located in the Hertzsprung gap in the Hertzsprung-Russell Diagram in order to detect chemical peculiarities and get a comprehensive overview of the population of stars in this evolutionary state. We have observed and analyzed high resolution spectra (R = 60 000) of 188 stars in the mass range 2 - 5 Msun with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory including 28 stars previously identified as Am/Ap stars. We find that the C and O abundances of the majority of stars in the Hertzsprung gap are in accordance with abundances derived for local lower mass dwarfs but detect expected peculiarities for the Am/Ap stars. The C and O abundances of stars with Teff < 6500 K are slightly lower than for the hotter objects but the C/O ratio is constant in the analyzed temperature domain. No indication of an alteration of the C and O abundances of the stars by mixing during the evolution across the He...

  17. Stellar chemical abundances: in pursuit of the highest achievable precision

    Energy Technology Data Exchange (ETDEWEB)

    Bedell, Megan; Bean, Jacob L. [Department of Astronomy and Astrophysics, University of Chicago, 5640 S. Ellis Avenue, Chicago, IL 60637 (United States); Meléndez, Jorge; Leite, Paulo [Departamento de Astronomia do IAG/USP, Universidade de São Paulo, Rua do Matão 1226, Cidade Universitária, São Paulo, SP 05508-900 (Brazil); Ramírez, Ivan [McDonald Observatory and Department of Astronomy, University of Texas at Austin, Austin, TX 78712-1206 (United States); Asplund, Martin, E-mail: mbedell@oddjob.uchicago.edu [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT 2611 (Australia)

    2014-11-01

    The achievable level of precision on photospheric abundances of stars is a major limiting factor on investigations of exoplanet host star characteristics, the chemical histories of star clusters, and the evolution of the Milky Way and other galaxies. While model-induced errors can be minimized through the differential analysis of spectrally similar stars, the maximum achievable precision of this technique has been debated. As a test, we derive differential abundances of 19 elements from high-quality asteroid-reflected solar spectra taken using a variety of instruments and conditions. We treat the solar spectra as being from unknown stars and use the resulting differential abundances, which are expected to be zero, as a diagnostic of the error in our measurements. Our results indicate that the relative resolution of the target and reference spectra is a major consideration, with use of different instruments to obtain the two spectra leading to errors up to 0.04 dex. Use of the same instrument at different epochs for the two spectra has a much smaller effect (∼0.007 dex). The asteroid used to obtain the solar standard also has a negligible effect (∼0.006 dex). Assuming that systematic errors from the stellar model atmospheres have been minimized, as in the case of solar twins, we confirm that differential chemical abundances can be obtained at sub-0.01 dex precision with due care in the observations, data reduction, and abundance analysis.

  18. Sulfur and zinc abundances of red giant stars

    CERN Document Server

    Takeda, Yoichi; Harakawa, Hiroki; Sato, Bun'ei

    2016-01-01

    Sulfur and zinc are chemically volatile elements, which play significant roles as depletion-free tracers in studying galactic chemical evolution. However, regarding red giants having evolved off the main sequence, reliable abundance determinations of S and Zn seem to be difficult despite that a few studies have been reported so far. Given this situation, we tried to establish the abundances of these elements for an extensive sample of 239 field GK giants (-0.8 < [Fe/H] < +0.2), by applying the spectrum-fitting technique to S I 8694-5, S I 6757, and Zn I 6362 lines and by taking into account the non-LTE effect. Besides, similar abundance analysis was done for 160 FGK dwarfs to be used for comparison. The non-LTE corrections for the S and Zn abundances derived from these lines turned out < 0.1(-0.2) dex for most cases and not very significant. It revealed that the S I 6757 feature is more reliable as an abundance indicator than S I 8694-5 for the case of red giants, because the latter suffers blending ...

  19. Enhanced Abundances in Spiral Galaxies of the Pegasus I Cluster

    CERN Document Server

    Robertson, Paul; Blanc, Guillermo A

    2011-01-01

    We study the influence of cluster environment on the chemical evolution of spiral galaxies in the Pegasus I cluster. We determine the gas-phase heavy element abundances of six galaxies in Pegasus derived from H II region spectra obtained from integral-field spectroscopy. These abundances are analyzed in the context of Virgo, whose spirals are known to show increasing interstellar metallicity as a function of H I deficiency. The galaxies in the Pegasus cluster, despite its lower density and velocity dispersion, also display gas loss due to ISM-ICM interaction, albeit to a lesser degree. Based on the abundances of 3 H I deficient spirals and 2 H I normal spirals, we observe a heavy element abundance offset of +0.13\\pm0.07 dex for the H I deficient galaxies. This abundance differential is consistent with the differential observed in Virgo for galaxies with a similar H I deficiency, and we observe a correlation between log(O/H) and the H I deficiency parameter DEF for the two clusters analyzed together. Our resul...

  20. New Radial Abundance Gradients for NGC 628 and NGC 2403

    CERN Document Server

    Berg, Danielle A; Garnett, Donald R; Croxall, Kevin V; Marble, Andrew R; Smith, J D; Gordon, Karl; Kennicutt, Robert C

    2013-01-01

    Motived by recent ISM studies, we present high quality MMT and Gemini spectroscopic observations of H II regions in the nearby spiral galaxies NGC 628 and NGC 2403 in order to measure their chemical abundance gradients. Using long-slit and multi-object mask optical spectroscopy, we obtained measurements of the temperature sensitive auroral lines [O III] {\\lambda}4363 and/or [N II] {\\lambda}5755 at a strength of 4{\\sigma} or greater in 11 H II regions in NGC 628 and 7 regions in NGC 2403. These observations allow us, for the first time, to derive an oxygen abundance gradient in NGC 628 based solely on "direct" oxygen abundances of H II regions: 12 + log(O/H) = (8.43+/-0.03) + (-0.017+/-0.002) x Rg (dex/kpc), with a dispersion in log(O/H) of {\\sigma} = 0.10 dex, from 14 regions with a radial coverage of ~2-19 kpc. This is a significantly shallower slope than found by previous "strong-line" abundance studies. In NGC 2403, we derive an oxygen abundance gradient of 12 + log(O/H) = (8.48+/-0.04) + (-0.032+/-0.007) ...

  1. Generalized estimators of avian abundance from count survey data

    Directory of Open Access Journals (Sweden)

    Royle, J. A.

    2004-01-01

    Full Text Available I consider modeling avian abundance from spatially referenced bird count data collected according to common protocols such as capture-recapture, multiple observer, removal sampling and simple point counts. Small sample sizes and large numbers of parameters have motivated many analyses that disregard the spatial indexing of the data, and thus do not provide an adequate treatment of spatial structure. I describe a general framework for modeling spatially replicated data that regards local abundance as a random process, motivated by the view that the set of spatially referenced local populations (at the sample locations constitute a metapopulation. Under this view, attention can be focused on developing a model for the variation in local abundance independent of the sampling protocol being considered. The metapopulation model structure, when combined with the data generating model, define a simple hierarchical model that can be analyzed using conventional methods. The proposed modeling framework is completely general in the sense that broad classes of metapopulation models may be considered, site level covariates on detection and abundance may be considered, and estimates of abundance and related quantities may be obtained for sample locations, groups of locations, unsampled locations. Two brief examples are given, the first involving simple point counts, and the second based on temporary removal counts. Extension of these models to open systems is briefly discussed.

  2. Influence of edge on predator prey distribution and abundance

    Science.gov (United States)

    Ferguson, Steven H.

    2004-03-01

    I investigated the effect of spatial configuration on distribution and abundance of invertebrate trophic groups by counting soil arthropods under boxes (21 × 9.5 cm) arranged in six different patterns that varied in the amount of edge (137-305 cm). I predicted fewer individuals from the consumer trophic group (Collembola) in box groups with greater amount of edge. This prediction was based on the assumption that predators (mites, ants, spiders, centipedes) select edge during foraging and thereby reduce abundance of the less mobile consumer group under box patterns with greater edge. Consumer abundance (Collembola) was not correlated with amount of edge. Among the predator groups, mite, ant and centipede abundance related to the amount of edge of box groups. However, in contrast to predictions, abundance of these predators was negatively correlated with amount of edge in box patterns. All Collembola predators, with the exception of ants, were less clumped in distribution than Collembola. The results are inconsistent with the view that predators used box edges to predate the less mobile consumer trophic group. Alternative explanations for the spatial patterns other than predator-prey relations include (1) a negative relationship between edge and moisture, (2) a positive relationship between edge and detritus decomposition (i.e. mycelium as food for the consumer group), and (3) a negative relationship between edge and the interstices between adjacent boxes. Landscape patterns likely affect microclimate, food, and predator-prey relations and, therefore, future experimental designs need to control these factors individually to distinguish among alternative hypotheses.

  3. Elemental abundances variations in plume and interplume regions

    Science.gov (United States)

    Guennou, Chloé; Savin, Daniel; Hahn, Michael

    2016-07-01

    Plumes are relatively bright, narrow structures in coronal holes that extend along open magnetic field lines far out into the corona. Extensive coronal measurements show abundances anomalies in the solar corona, in which elements with a low first ionization potential (FIP) Remote sensing spectroscopic measurements show that interplume regions have a photospheric composition. In contrast, the elemental composition of plume material is still unclear, previous spectroscopic measurements have reached contradictory results as to whether the elemental abundances in plumes are the same as or different from interplume regions. In this work, we measured the FIP bias, i.e. the ratio of coronal to photospheric abundances, in both interplumes and plumes using Hinode/Extreme Ultraviolet Imaging Spectrometer (EIS) data. Using spectral line intensities and Differential Emission Measure analysis, we assess the chemical composition of plumes and interplumes over an ~24 hour period in March, 2007. We find that some plumes do show different elemental abundances relative to interplumes. Moreover, the abundance anomaly in plumes is time dependent. If previous studies observed plumes at different stages in their evolution, this time dependence may explain the lack of consistency among previous results. Our work on plume and interplume elemental composition may also enable in situ measurements to answer the longstanding question of whether plumes contribute to the fast solar wind, which originates from coronal holes.

  4. Study on the Abundance Discrepancy Problem in the Magellanic Clouds

    CERN Document Server

    Cipriano, L Toribio San; Domínguez-Guzmán, G; García-Rojas, J

    2016-01-01

    We present chemical abundances of carbon (C) and oxygen (O) in the Large and Small Magellanic Clouds from deep and high-quality optical spectra of HII regions. The data have been taken using the Ultraviolet-Visual Echelle Spectrograph at the 8.2-m Very Large Telescope with the goal of detecting the faint CII and OII recombination lines. For all the objects of the sample, we determine C^2+ abundances from recombination lines and O^2+ abundances from recombination lines and collisionally excited lines. In addition, we calculate the abundance discrepancy factors (ADFs) for O^2+ and C^2+, as well as the O/H, C/H and C/O ratios. We study the behaviour of the ADF comparing the values obtained in the Magellanic Clouds with those obtained for other HII regions in different galaxies. We also compare the nebular and stellar abundances in two regions of the sample. Finally, we discuss the chemical evolution of the MCs through the O/H, C/H and C/O radial gradients and the changes of the C/O ratio as a function of O/H.

  5. Beryllium abundances in stars with planets:Extending the sample

    CERN Document Server

    Gálvez-Ortiz, M C; Hernández, J I González; Israelian, G; Santos, N C; Rebolo, R; Ecuvillon, A

    2011-01-01

    Context: Chemical abundances of light elements as beryllium in planet-host stars allow us to study the planet formation scenarios and/or investigate possible surface pollution processes. Aims: We present here an extension of previous beryllium abundance studies. The complete sample consists of 70 stars hosting planets and 30 stars without known planetary companions. The aim of this paper is to further assess the trends found in previous studies with less number of objects. This will provide more information on the processes of depletion and mixing of light elements in the interior of late type stars, and will provide possible explanations for the abundance differences between stars that host planets and "single" stars. Methods: Using high resolution UVES spectra, we measure beryllium abundances of 26 stars that host planets and 1 "single" star mainly using the \\lambda 3131.065 A Be II line, by fitting synthetic spectra to the observational data. We also compile beryllium abundance measurements of 44 stars hos...

  6. Neutron-Capture Element Abundances in Magellanic Cloud Planetary Nebulae

    CERN Document Server

    Mashburn, A L; Madonna, S; Dinerstein, H L; Roederer, I U; Geballe, T

    2016-01-01

    We present near-infrared spectra of ten planetary nebulae (PNe) in the Large and Small Magellanic Clouds (LMC and SMC), acquired with the FIRE and GNIRS spectrometers on the 6.5-m Baade and 8.1-m Gemini South Telescopes, respectively. We detect Se and/or Kr emission lines in eight of these objects, the first detections of n-capture elements in Magellanic Cloud PNe. Our abundance analysis shows large s-process enrichments of Kr (0.6-1.3 dex) in the six PNe in which it was detected, and Se is enriched by 0.5-0.9 dex in five objects. We also estimate upper limits to Rb and Cd abundances in these objects. Our abundance results for the LMC are consistent with the hypothesis that PNe with 2--3 M$_{\\odot}$ progenitors dominate the bright end of the PN luminosity function in young gas-rich galaxies. We find no significant correlations between s-process enrichments and other elemental abundances, central star temperature, or progenitor mass, though this is likely due to our small sample size. We determine S abundances...

  7. Effect of disjunct size distributions on foraminiferal species abundance determinations

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R.E.; Liddell, W.D.

    1988-02-01

    Studies of foraminiferal distribution and abundance have typically employed a procedure (standard method) that entails counting approximately 300 specimens from a size range greater than some specified minimum (commonly 63 or 125 ..mu..m). This method fails to take into account that foraminifera may be found only within certain size fractions, either because of species specific size ranges or taphonomic processes (sorting, transport, abrasion). Use of a modified counting procedure (sieve method) takes into account foraminiferal size distributions. The sieve method uses counts of up to 300 specimens in each sand-size fraction (0.125-0.25, 0.25-0.5, 0.5-1, 1-2 mm) of each sample. Counts are then totaled for each sample (up to 1200 specimens per site) and used in determination of species abundances for each site. The sieve method has been of considerable utility in recognition of a foraminiferal bathymetric zonation preserved in sediment assemblages from fringing reef environments at Discovery Bay, north Jamaica. Well-documented reef zones (based on corals and physiography) are clearly defined in Q-mode cluster analysis (UPGMA) of species abundances determined using the sieve method. In contrast, individual fore reef zones are not recognized in cluster analysis of foraminiferal species abundances based on the standard method, nor by cluster analysis of species abundances within individual size fractions.

  8. EDITORIAL: Plasma jets and plasma bullets Plasma jets and plasma bullets

    Science.gov (United States)

    Kong, M. G.; Ganguly, B. N.; Hicks, R. F.

    2012-06-01

    Plasma plumes, or plasma jets, belong to a large family of gas discharges whereby the discharge plasma is extended beyond the plasma generation region into the surrounding ambience, either by a field (e.g. electromagnetic, convective gas flow, or shock wave) or a gradient of a directionless physical quantity (e.g. particle density, pressure, or temperature). This physical extension of a plasma plume gives rise to a strong interaction with its surrounding environment, and the interaction alters the properties of both the plasma and the environment, often in a nonlinear and dynamic fashion. The plasma is therefore not confined by defined physical walls, thus extending opportunities for material treatment applications as well as bringing in new challenges in science and technology associated with complex open-boundary problems. Some of the most common examples may be found in dense plasmas with very high dissipation of externally supplied energy (e.g. in electrical, optical or thermal forms) and often in or close to thermal equilibrium. For these dense plasmas, their characteristics are determined predominantly by strong physical forces of different fields, such as electrical, magnetic, thermal, shock wave, and their nonlinear interactions [1]. Common to these dense plasma plumes are significant macroscopic plasma movement and considerable decomposition of solid materials (e.g. vaporization). Their applications are numerous and include detection of elemental traces, synthesis of high-temperature materials and welding, laser--plasma interactions, and relativistic jets in particle accelerators and in space [2]-[4]. Scientific challenges in the understanding of plasma jets are exciting and multidisciplinary, involving interweaving transitions of all four states of matter, and their technological applications are wide-ranging and growing rapidly. Using the Web of Science database, a search for journal papers on non-fusion plasma jets reveals that a long initial phase up

  9. Atoms in dense plasmas

    International Nuclear Information System (INIS)

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs

  10. Waves in unmagnetized plasma

    International Nuclear Information System (INIS)

    A review of linear and weakly non-linear theory of electron waves, ion waves and electromagnetic waves in plasmas is presented. The author restricts the discussion to an infinitely extended, homogeneous and isotropic plasma, not affected by external fields and described by Vlasov's and Maxwell's equations. (Auth.)

  11. Plasma technology directory

    International Nuclear Information System (INIS)

    The Plasma Technology Directory has two main goals: (1) promote, coordinate, and share plasma technology experience and equipment within the Department of Energy; and (2) facilitate technology transfer to the commercial sector where appropriate. Personnel are averaged first by Laboratory and next by technology area. The technology areas are accelerators, cleaning and etching deposition, diagnostics, and modeling

  12. Plasma technology directory

    Science.gov (United States)

    Ward, Pamela P.; Dybwad, Gay L.

    1995-03-01

    The Plasma Technology Directory has two main goals: (1) promote, coordinate, and share plasma technology experience and equipment within the Department of Energy; and (2) facilitate technology transfer to the commercial sector where appropriate. Personnel are averaged first by Laboratory and next by technology area. The technology areas are accelerators, cleaning and etching deposition, diagnostics, and modeling.

  13. Modelling of Complex Plasmas

    NARCIS (Netherlands)

    Akdim, M.R. (Mohamed Reda)

    2003-01-01

    Nowadays plasmas are used for various applications such as the fabrication of silicon solar cells, integrated circuits, coatings and dental cleaning. In the case of a processing plasma, e.g. for the fabrication of amorphous silicon solar cells, a mixture of silane and hydrogen gas is injected in a r

  14. Plasma etching an introduction

    CERN Document Server

    Manos, Dennis M

    1989-01-01

    Plasma etching plays an essential role in microelectronic circuit manufacturing. Suitable for researchers, process engineers, and graduate students, this book introduces the basic physics and chemistry of electrical discharges and relates them to plasma etching mechanisms. Throughout the volume the authors offer practical examples of process chemistry, equipment design, and production methods.

  15. Atoms in dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    More, R.M.

    1986-01-01

    Recent experiments with high-power pulsed lasers have strongly encouraged the development of improved theoretical understanding of highly charged ions in a dense plasma environment. This work examines the theory of dense plasmas with emphasis on general rules which govern matter at extreme high temperature and density. 106 refs., 23 figs.

  16. Microphysics of cosmic plasmas

    CERN Document Server

    Bykov, Andrei; Cargill, Peter; Dendy, Richard; Wit, Thierry; Raymond, John

    2014-01-01

    This title presents a review of the detailed aspects of the physical processes that underlie the observed properties, structures and dynamics of cosmic plasmas. An assessment of the status of understanding of microscale processes in all astrophysical collisionless plasmas is provided. The topics discussed include  turbulence in astrophysical and solar system plasmas as a phenomenological description of their dynamic properties on all scales; observational, theoretical and modelling aspects of collisionless magnetic reconnection; the formation and dynamics of shock waves; and a review and assessment of microprocesses, such as the hierarchy of plasma instabilities, non-local and non-diffusive transport processes and ionisation and radiation processes.  In addition, some of the lessons that have been learned from the extensive existing knowledge of laboratory plasmas as applied to astrophysical problems are also covered.   This volume is aimed at graduate students and researchers active in the areas of cosmi...

  17. Plasma kinetic theory

    CERN Document Server

    Swanson, Donald Gary

    2008-01-01

    Developed from the lectures of a leading expert in plasma wave research, Plasma Kinetic Theory provides the essential material for an introductory course on plasma physics as well as the basis for a more advanced course on kinetic theory. Exploring various wave phenomena in plasmas, it offers wide-ranging coverage of the field. After introducing basic kinetic equations and the Lenard–Balescu equation, the book covers the important Vlasov–Maxwell equations. The solutions of these equations in linear and quasilinear approximations comprise the majority of kinetic theory. Another main topic in kinetic theory is to assess the effects of collisions or correlations in waves. The author discusses the effects of collisions in magnetized plasma and calculates the different transport coefficients, such as pressure tensor, viscosity, and thermal diffusion, that depend on collisions. With worked examples and problem sets that enable sound comprehension, this text presents a detailed, mathematical approach to app...

  18. Solar system plasma waves

    Science.gov (United States)

    Gurnett, Donald A.

    1995-01-01

    An overview is given of spacecraft observations of plasma waves in the solar system. In situ measurements of plasma phenomena have now been obtained at all of the planets except Mercury and Pluto, and in the interplanetary medium at heliocentric radial distances ranging from 0.29 to 58 AU. To illustrate the range of phenomena involved, we discuss plasma waves in three regions of physical interest: (1) planetary radiation belts, (2) planetary auroral acceleration regions and (3) the solar wind. In each region we describe examples of plasma waves that are of some importance, either due to the role they play in determining the physical properties of the plasma, or to the unique mechanism involved in their generation.

  19. Basic plasma physics

    CERN Document Server

    Ghosh, Basudev

    2014-01-01

    Basic Plasma Physics is designed to serve as an introductory compact textbook for advanced undergraduate, postgraduate and research students taking plasma physics as one of their subject of study for the first time. It covers the current syllabus of plasma physics offered by the most universities and technical institutions. The book requires no background in plasma physics but only elementary knowledge of basic physics and mathematics. Emphasis has been given on the analytical approach. Topics are developed from first principle so that the students can learn through self-study. One chapter has been devoted to describe some practical aspects of plasma physics. Each chapter contains a good number of solved and unsolved problems and a variety of review questions, mostly taken from recent examination papers. Some classroom experiments described in the book will surely help students as well as instructors.

  20. Helical plasma thruster

    Energy Technology Data Exchange (ETDEWEB)

    Beklemishev, A. D., E-mail: bekl@bk.ru [Budker Institute of Nuclear Physics SB RAS, Novosibirsk (Russian Federation)

    2015-10-15

    A new scheme of plasma thruster is proposed. It is based on axial acceleration of rotating magnetized plasmas in magnetic field with helical corrugation. The idea is that the propellant ionization zone can be placed into the local magnetic well, so that initially the ions are trapped. The E × B rotation is provided by an applied radial electric field that makes the setup similar to a magnetron discharge. Then, from the rotating plasma viewpoint, the magnetic wells of the helically corrugated field look like axially moving mirror traps. Specific shaping of the corrugation can allow continuous acceleration of trapped plasma ions along the magnetic field by diamagnetic forces. The accelerated propellant is expelled through the expanding field of magnetic nozzle. By features of the acceleration principle, the helical plasma thruster may operate at high energy densities but requires a rather high axial magnetic field, which places it in the same class as the VASIMR{sup ®} rocket engine.

  1. Wakes in inhomogeneous plasmas

    CERN Document Server

    Kompaneets, Roman; Nosenko, Vladimir; Morfill, Gregor E

    2014-01-01

    The Debye shielding of a charge immersed in a flowing plasma is an old classic problem in plasma physics. It has been given renewed attention in the last two decades in view of experiments with complex plasmas, where charged dust particles are often levitated in a region with strong ion flow. Efforts to describe the shielding of the dust particles in such conditions have been focused on the homogeneous plasma approximation, which ignores the substantial inhomogeneity of the levitation region. We address the role of the plasma inhomogeneity by rigorously calculating the point charge potential in the collisionless Bohm sheath. We demonstrate that the inhomogeneity can dramatically modify the wake, making it non-oscillatory and weaker.

  2. Innovations in plasma sensors

    Science.gov (United States)

    Zurbuchen, Thomas H.; Gershman, Daniel J.

    2016-04-01

    During the history of space exploration, ever improving instruments have continued to enable new measurements and discoveries. Focusing on plasma sensors, we examine the processes by which such new instrument innovations have occurred over the past decades. Due to risk intolerance prevalent in many NASA space missions, innovations in plasma instrumentation occur primarily when heritage systems fail to meet science requirements, functional requirements as part of its space platform, or design constraints. We will review such innovation triggers in the context of the design literature and with the help of two case studies, the Fast Imaging Plasma Spectrometer on MErcury Surface, Space ENvironment, GEochemistry, and Ranging and the Fast Plasma Investigation on Magnetosphere Multiscale. We will then discuss the anticipated needs for new plasma instrument innovations to enable the science program of the next decade.

  3. Department of Plasma Dynamics

    International Nuclear Information System (INIS)

    The gas flow in high temperatures with regard to intensive heat transfer and chemical processes was investigated. The influence of flow rate of stabilizing gas on the electron concentration in plasma torch jet was studied. The microwave measurements of plasma parameters in middle pressure range and the time resolved measurements of the electron energy distribution in unstable plasma were carried out. A simple phase-sensitive microwave reflectometer for plasma diagnostics has been used for measuring the electron density in a positive column of glow discharge plasma in noble gases. The independance between energy conversion and charge distribution in the slender EGD channel was investigated. The discontinuities in electrogasdynamics were studied. (S.B.)

  4. Stochastic acceleration and charge change of helium ions in the solar flare plasma.

    Science.gov (United States)

    Kartavykh, Yu. Yu.; Ostryakov, V. M.; Stepanov, I. Yu.; Yoshimori, M.

    1998-10-01

    In order to explain the energy spectra and abundances of the He+ and He++ solar flare ions measured in some works, the authors calculated the behavior of these ions in solar plasma, taking into account both their stochastic acceleration by Alfvén waves and the possibility of charge exchange with the surrounding plasma. The results agree with the experiments if the plasma in the regions where acceleration takes place has a concentration and temperature on the order of N = 2×107 cm-3 and T = 6.31×104K, respectively. Recent observations of solar flares onboard the Yohkoh satellite have demonstrated that it is apparently impractical to expect the existence of such rarefied and low-temperature plasma in the flare loops. The calculations indicate that the high abundance of He+ is most likely due to its nonsolar origin. Some possibilities of enrichment of energetic particle fluxes by He+ ions are briefly discussed.

  5. Elemental abundances of intermediate age open cluster NGC 3680

    CERN Document Server

    Mitschang, A W; Zucker, D B

    2012-01-01

    We present a new abundance analysis of the intermediate age Galactic open cluster NGC 3680, based on high resolution, high signal-to-noise VLT/UVES spectroscopic data. Several element abundances are presented for this cluster for the first time, but most notably we derive abundances for the light and heavy s-process elements Y, Ba, La, and Nd. The serendipitous measurement of the rare-earth r-process element Gd is also reported. This cluster exhibits a significant enhancement of Na in giants as compared to dwarfs, which may be a proxy for an O to Na anti-correlation as observed in Galactic globular clusters but not open clusters. We also observe a step-like enhancement of heavy s-process elements towards higher atomic number, contrary to expectations from AGB nucleosynthesis models, suggesting that the r-process played a significant role in the generation of both La and Nd in this cluster

  6. O, Na, Ba and Eu abundance patterns in open clusters

    CERN Document Server

    MacLean, B T; Lattanzio, J

    2014-01-01

    Open clusters are historically regarded as single-aged stellar populations representative of star formation within the Galactic disk. Recent literature has questioned this view, based on discrepant Na abundances relative to the field, and concerns about the longevity of bound clusters contributing to a selection bias: perhaps long-lived open clusters are chemically different to the star formation events that contributed to the Galactic disk. We explore a large sample of high resolution Na, O, Ba & Eu abundances from the literature, homogenized as much as reasonable including accounting for NLTE effects, variations in analysis and choice of spectral lines. Compared to a template globular cluster and representative field stars, we find no significant abundance trends, confirming that the process producing the Na-O anti-correlation in globular clusters is not present in open clusters. Furthermore, previously reported Na-enhancement of open clusters is found to be an artefact of NLTE effects, with the open cl...

  7. Oxygen Abundance Methods in SDSS: View from Modern Statistics

    Indian Academy of Sciences (India)

    Fei Shi; Gang Zhao; James Wicker

    2010-09-01

    Our purpose is to find which is the most reliable one among various oxygen abundance determination methods. We will test the validity of several different oxygen abundance determination methods using methods of modern statistics. These methods include Bayesian analysis and information scoring. We will analyze a sample of ∼ 6000 HII galaxies from the Sloan Digital Sky Survey (SDSS) spectroscopic observations data release four. All methods that we used drew the same conclusion that the method is a more reliable oxygen abundance determination method than the Bayesian metallicity method under the existing telescope ability. The ratios of the likelihoods between the different kinds of methods tell us that the , , and 32 methods are consistent with each other because the and 32 methods are calibrated by method. The Bayesian and 23 methods are consistent with each other because both are calibrated by a galaxy model. In either case, the 2 method is an unreliable method.

  8. Resolving microbial membership using Abundance and Variability In Taxonomy ('AVIT ).

    Science.gov (United States)

    Chakrabarti, Anirikh; Siddharth, Jay; Lauber, Christian L; Membrez, Mathieu; Betrisey, Bertrand; Loyer, Carole; Chou, Chieh Jason; Pataky, Zoltan; Golay, Alain; Parkinson, Scott J

    2016-01-01

    Development of NGS has revolutionized the analysis in microbial ecology contributing to our deeper understanding of microbiota in health and disease. However, the quality, quantity and confidence of summarized taxonomic abundances are in need of further scrutiny due to sample dependent and independent effects. In this article we introduce 'AVIT (Abundance and Variability In Taxonomy), an unbiased method to enrich for assigned members of microbial communities. As opposed to using a priori thresholds, 'AVIT uses inherent abundance and variability of taxa in a dataset to determine the inclusion or rejection of each taxa for further downstream analysis. Using in-vitro and in-vivo studies, we benchmarked performance and parameterized 'AVIT to establish a framework for investigating the dynamic range of microbial community membership in clinically relevant scenarios. PMID:27530237

  9. La and Eu Abundances in Metal-poor Halo Stars

    Science.gov (United States)

    Cardillo, Harrison; Burris, Debra L.

    2016-01-01

    Elements with atomic number greater than Z=26 (the Iron Peak) cannot be formed through fusion in a star's core; the majority of these elements are produced through one of two neutron-capture processes. Early in the history of the Galaxy, the rapid neutron-capture process (r-process) is believed to be responsible for the production of elements Z=56 and beyond. These elements require at least one generation of stars to have completed their life cycle in order to be synthesized. Therefore, if we observe the heavy metal abundances in what are called Population II stars (metal-poor stars), then we can begin to make inferences about the chemistry of the earliest stars in the Galaxy. To contribute to this picture of the early universe, the Lanthanum and Europium abundances of low-metallicity stars will be measured and trends in these abundances based on comparisons to existing related literature will be sought.

  10. Ammonia abundance in the coma of Halley's Comet

    International Nuclear Information System (INIS)

    Consideration is given to recent work by Allen et al. (1987) which suggests that the value of the ratio of the abundance of the atomic masses 19 to 18 observed in situ in the inner coma of Comet Halley is incompatible with a pure H2O nucleus and requires an NH3 abundance of 1-2 percent. The present authors discuss possible ways of explaining the radial profile of r = 19/18, which deemphasizes the presence of NH3. It is shown that the observed value of the 19/18 mass ratio in the inner coma does not necessarily imply the existence of a significant abundance of NH3. An elevated UV flux, for which there is circumstantial evidence, could produce the same effect. 21 references

  11. An MCMC determination of the primordial helium abundance

    CERN Document Server

    Aver, Erik; Skillman, Evan D

    2011-01-01

    Spectroscopic observations of the chemical abundances in metal-poor H II regions provide an independent method for estimating the primordial helium abundance. H II regions are described by several physical parameters such as electron density, electron temperature, and reddening, in addition to y, the ratio of helium to hydrogen. It had been customary to estimate or determine self-consistently these parameters to calculate y. Frequentist analyses of the parameter space have been shown to be successful in these determinations, and Markov Chain Monte Carlo (MCMC) techniques have proven to be very efficient in sampling this parameter space. Nevertheless, accurate determination of the primordial helium abundance from observations of H II regions is constrained by both systematic and statistical uncertainties. In an attempt to better reduce the latter, and better characterize the former, we apply MCMC methods to the large dataset recently compiled by Izotov, Thuan, & Stasinska (2007). To improve the reliability...

  12. Relative species abundance of replicator dynamics with sparse interactions

    CERN Document Server

    Obuchi, Tomoyuki; Tokita, Kei

    2016-01-01

    A theory of relative species abundance on sparsely-connected networks is presented by investigating the replicator dynamics with symmetric interactions. Sparseness of a network involves difficulty in analyzing the fixed points of the equation, and we avoid this problem by treating large self interaction $u$, which allows us to construct a perturbative expansion. Based on this perturbation, we find that the nature of the interactions is directly connected to the abundance distribution, and some characteristic behaviors, such as multiple peaks in the abundance distribution and all species coexistence at moderate values of $u$, are discovered in a wide class of the distribution of the interactions. The all species coexistence collapses at a critical value of $u$, $u_c$, and this collapsing is regarded as a phase transition. To get more quantitative information, we also construct a non-perturbative theory on random graphs based on techniques of statistical mechanics. The result shows those characteristic behavior...

  13. The abundance of short proteins in the mammalian proteome.

    Directory of Open Access Journals (Sweden)

    Martin C Frith

    2006-04-01

    Full Text Available Short proteins play key roles in cell signalling and other processes, but their abundance in the mammalian proteome is unknown. Current catalogues of mammalian proteins exhibit an artefactual discontinuity at a length of 100 aa, so that protein abundance peaks just above this length and falls off sharply below it. To clarify the abundance of short proteins, we identify proteins in the FANTOM collection of mouse cDNAs by analysing synonymous and non-synonymous substitutions with the computer program CRITICA. This analysis confirms that there is no real discontinuity at length 100. Roughly 10% of mouse proteins are shorter than 100 aa, although the majority of these are variants of proteins longer than 100 aa. We identify many novel short proteins, including a "dark matter" subset containing ones that lack detectable homology to other known proteins. Translation assays confirm that some of these novel proteins can be translated and localised to the secretory pathway.

  14. Accurate Enthalpies of Formation of Astromolecules: Energy, Stability and Abundance

    CERN Document Server

    Etim, Emmanuel E

    2016-01-01

    Accurate enthalpies of formation are reported for known and potential astromolecules using high level ab initio quantum chemical calculations. A total of 130 molecules comprising of 31 isomeric groups and 24 cyanide/isocyanide pairs with atoms ranging from 3 to 12 have been considered. The results show an interesting, surprisingly not well explored, relationship between energy, stability and abundance (ESA) existing among these molecules. Among the isomeric species, isomers with lower enthalpies of formation are more easily observed in the interstellar medium compared to their counterparts with higher enthalpies of formation. Available data in literature confirm the high abundance of the most stable isomer over other isomers in the different groups considered. Potential for interstellar hydrogen bonding accounts for the few exceptions observed. Thus, in general, it suffices to say that the interstellar abundances of related species are directly proportional to their stabilities. The immediate consequences of ...

  15. The abundant world: Paul Feyerabend's metaphysics of science.

    Science.gov (United States)

    Brown, Matthew J

    2016-06-01

    The goal of this paper is to provide an interpretation of Feyerabend's metaphysics of science as found in late works like Conquest of Abundance and Tyranny of Science. Feyerabend's late metaphysics consists of an attempt to criticize and provide a systematic alternative to traditional scientific realism, a package of views he sometimes referred to as "scientific materialism." Scientific materialism is objectionable not only on metaphysical grounds, nor because it provides a poor ground for understanding science, but because it implies problematic claims about the epistemic and cultural authority of science, claims incompatible with situating science properly in democratic societies. I show how Feyerabend's metaphysical view, which I call "the abundant world" or "abundant realism," constitute a sophisticated and challenging form of ontological pluralism that makes interesting connections with contemporary philosophy of science and issues of the political and policy role of science in a democratic society. PMID:27269274

  16. Revised element abundances for WC-type central stars

    CERN Document Server

    Todt, H; Hamann, W -R

    2007-01-01

    According to previous spectral analyses of Wolf-Rayet type central stars, late [WC] subtypes show systematically higher carbon-to-helium abundance ratios than early [WC] subtypes. If this were true, it would rule out that these stars form an evolutionary sequence. However, due to the different parameter domains and diagnostic lines, one might suspect systematic errors being the source of this discrepancy. In an ongoing project we are therefore checking the [WC] analyses by means of the last generation of non-LTE models for expanding stellar atmospheres which account for line-blanketing and wind clumping. So far, the abundance discrepancy is not resolved. Further element abundances (H, N, Fe) are determined and compared with evolutionary predictions.

  17. Diversity is maintained by seasonal variation in species abundance

    Science.gov (United States)

    2013-01-01

    Background Some of the most marked temporal fluctuations in species abundances are linked to seasons. In theory, multispecies assemblages can persist if species use shared resources at different times, thereby minimizing interspecific competition. However, there is scant empirical evidence supporting these predictions and, to the best of our knowledge, seasonal variation has never been explored in the context of fluctuation-mediated coexistence. Results Using an exceptionally well-documented estuarine fish assemblage, sampled monthly for over 30 years, we show that temporal shifts in species abundances underpin species coexistence. Species fall into distinct seasonal groups, within which spatial resource use is more heterogeneous than would be expected by chance at those times when competition for food is most intense. We also detect seasonal variation in the richness and evenness of the community, again linked to shifts in resource availability. Conclusions These results reveal that spatiotemporal shifts in community composition minimize competitive interactions and help stabilize total abundance. PMID:24007204

  18. The effects of He I 10830 on helium abundance determinations

    CERN Document Server

    Aver, Erik; Skillman, Evan D

    2015-01-01

    Observations of helium and hydrogen emission lines from metal-poor extragalactic H II regions provide an independent method for determining the primordial helium abundance, Y_p. Traditionally, the emission lines employed are in the visible wavelength range, and the number of suitable lines is limited. Furthermore, when using these lines, large systematic uncertainties in helium abundance determinations arise due to the degeneracy of physical parameters, such as temperature and density. Recently, Izotov, Thuan, & Guseva (2014) have pioneered adding the He 10830 infrared emission line in helium abundance determinations. The strong electron density dependence of He 10830 makes it ideal for better constraining density, potentially breaking the degeneracy with temperature. We revisit our analysis of the dataset published by Izotov, Thuan, & Stasinska (2007) and incorporate the newly available observations of He 10830 by scaling them using the observed-to-theoretical Paschen-gamma ratio. The solutions are b...

  19. Online monitoring of immunoaffinity-based depletion of high-abundance blood proteins by UV spectrophotometry using enhanced green fluorescence protein and FITC-labeled human serum albumin

    Directory of Open Access Journals (Sweden)

    Yu Hyeong

    2010-12-01

    Full Text Available Abstract Background The removal of high-abundance proteins from plasma is an efficient approach to investigating flow-through proteins for biomarker discovery studies. Most depletion methods are based on multiple immunoaffinity methods available commercially including LC columns and spin columns. Despite its usefulness, high-abundance depletion has an intrinsic problem, the sponge effect, which should be assessed during depletion experiments. Concurrently, the yield of depletion of high-abundance proteins must be monitored during the use of the depletion column. To date, there is no reasonable technique for measuring the recovery of flow-through proteins after depletion and assessing the capacity for capture of high-abundance proteins. Results In this study, we developed a method of measuring recovery yields of a multiple affinity removal system column easily and rapidly using enhanced green fluorescence protein as an indicator of flow-through proteins. Also, we monitored the capture efficiency through depletion of a high-abundance protein, albumin labeled with fluorescein isothiocyanate. Conclusion This simple method can be applied easily to common high-abundance protein depletion methods, effectively reducing experimental variations in biomarker discovery studies.

  20. Nonthermal plasma chemistry and physics

    CERN Document Server

    Meichsner, Jurgen; Schneider, Ralf; Wagner, Hans-Erich

    2013-01-01

    In addition to introducing the basics of plasma physics, Nonthermal Plasma Chemistry and Physics is a comprehensive presentation of recent developments in the rapidly growing field of nonthermal plasma chemistry. The book offers a detailed discussion of the fundamentals of plasma chemical reactions and modeling, nonthermal plasma sources, relevant diagnostic techniques, and selected applications.Elucidating interconnections and trends, the book focuses on basic principles and illustrations across a broad field of applications. Expert contributors address environmental aspects of plasma chemist

  1. Mangroves Enhance Reef Fish Abundance at the Caribbean Regional Scale.

    Directory of Open Access Journals (Sweden)

    Joseph E Serafy

    Full Text Available Several studies conducted at the scale of islands, or small sections of continental coastlines, have suggested that mangrove habitats serve to enhance fish abundances on coral reefs, mainly by providing nursery grounds for several ontogenetically-migrating species. However, evidence of such enhancement at a regional scale has not been reported, and recently, some researchers have questioned the mangrove-reef subsidy effect. In the present study, using two different regression approaches, we pursued two questions related to mangrove-reef connectivity at the Caribbean regional scale: (1 Are reef fish abundances limited by mangrove forest area?; and (2 Are mean reef fish abundances proportional to mangrove forest area after taking human population density and latitude into account? Specifically, we tested for Caribbean-wide mangrove forest area effects on the abundances of 12 reef fishes that have been previously characterized as "mangrove-dependent". Analyzed were data from an ongoing, long-term (20-year citizen-scientist fish monitoring program; coastal human population censuses; and several wetland forest information sources. Quantile regression results supported the notion that mangrove forest area limits the abundance of eight of the 12 fishes examined. Linear mixed-effects regression results, which considered potential human (fishing and habitat degradation and latitudinal influences, suggested that average reef fish densities of at least six of the 12 focal fishes were directly proportional to mangrove forest area. Recent work questioning the mangrove-reef fish subsidy effect likely reflects a failure to: (1 focus analyses on species that use mangroves as nurseries, (2 consider more than the mean fish abundance response to mangrove forest extent; and/or (3 quantitatively account for potentially confounding human impacts, such as fishing pressure and habitat degradation. Our study is the first to demonstrate at a large regional scale (i

  2. Relationships between sedimentary subseafloor microbial abundance and sedimentation rate

    Science.gov (United States)

    Kallmeyer, J.

    2015-12-01

    Cell count data for estimates of global subseafloor microbial abundance need to be simplified in order to be used for model calculations All models rely on regressions of cell counts vs. depth. Different strategies are being used for simplifying the data, e.g. averaging over highly variable data from different oceanic provinces or excluding individual datasets that cannot be described by a single regression. While providing global estimates, these models fail to identify the finer details of the controls on subseafloor microbial abundance. Most subseafloor microbes are heterotrophic and gain energy by degrading buried organic matter. Because sedimentation rate is usually positively correlated with primary productivity and organic matter flux to the seafloor, it determines how much organic matter is deposited on the sea floor and how fast it is buried and reaches greater depths. At the same depth, in environments with low sed. rates the organic matter is older, more degraded and supports less metabolic activity than in those with high sed. rates. As a result, sed. rates control penetration depth of oxygen and other electron acceptors. Oxygen penetration remains in the mm to cm range over most sed. rates and it only penetrates significantly deeper at very low rates of ca. 1 mm/kyr or less. However, microbial abundance correlates with sed. rate over a wider range. In order to take a more detailed look at the influence of sed. rate and therefore sediment age on cell abundance, ages and additional geochemical information were assigned to individual cell counts. The new dataset shows the strong influence of sed. rates or rather sediment age on microbial abundance, while oxygen concentrations seem to have only a minor influence. Using data from IODP drill sites that have moved from high to low productivity zones or vice versa helps to differentiate between different factors that control microbial cell abundance.

  3. Sulfur and zinc abundances of red giant stars†

    Science.gov (United States)

    Takeda, Yoichi; Omiya, Masashi; Harakawa, Hiroki; Sato, Bun'ei

    2016-10-01

    Sulfur and zinc are chemically volatile elements, which play significant roles as depletion-free tracers in studying galactic chemical evolution. However, regarding red giants having evolved off the main sequence, reliable abundance determinations of S and Zn seem to be difficult, despite the several studies that have been reported so far. Given this situation, we tried to establish the abundances of these elements for an extensive sample of 239 field GK giants ( - 0.8 ≲ [Fe/H] ≲ +0.2), by applying the spectrum-fitting technique to S I 8694-5, S I 6757, and Zn I 6362 lines and by taking into account the non-LTE effect. Besides, similar abundance analysis was done for 160 FGK dwarfs to be used for comparison. The non-LTE corrections for the S and Zn abundances derived from these lines turned out to be ≲ 0.1(-0.2) dex for most cases and not very significant. It revealed that the S I 6757 feature is more reliable as an abundance indicator than S I 8694-5 for the case of red giants, because the latter suffers blending of unidentified lines. The finally resulting [S/Fe]-[Fe/H] and [Zn/Fe]-[Fe/H] relations for GK giants were confirmed to be in good agreement with those for FGK dwarfs, indicating that S and Zn abundances of red giants are reliably determinable from the S I 6757 and Zn I 6362 lines. Accordingly, not only main-sequence stars but also evolved red giant stars are usable for tracing the chemical evolution history of S and Zn in the regime of disk metallicity by using these lines.

  4. The Iron Abundance of IOTA Herculis From Ultraviolet Iron Lines

    Science.gov (United States)

    Grigsby, J.; Mulliss, C.; Baer, G.

    1995-03-01

    We have obtained (Adelman 1992, 1993, private comunication) coadded, high-resolution IUE spectra of Iota Herculis (B3 IV) in both short wavelength (SWP) and long wavelength (LWP) regions. The spectra span the ultraviolet spectrum from 110 - 300 nm and have a SNR of roughly 30 -50; they are described in Adelman et. al. (1993, ApJ 419, 276). Abundance indicators were 54 lines of Fe II and 26 lines of Fe III whose atomic parameters have been measured in the laboratory. LTE synthetic spectra for comparison with observations were produced with the Kurucz model atmosphere and spectral synthesis codes ATLAS9/SYNTHE (Kurucz 1979, ApJS 40,1; Kurucz and Avrett 1981, SAO Special Report 391). Model parameters were chosen from the literature: effective temperature = 17500 K, log g =3.75, v sin i= 11 km/s, and turbulent velocity = 0 km/s. (Peters and Polidan 1985, in IAU Symposium 111, ed. D. S. Hayes et al. (Dordrecht: Reidel), 417). We determined the equivalent widths of the chosen lines by fitting gaussian profiles to the lines and by measuring the equivalent widths of the gaussians. We derived abundances by fitting a straight line to a plot of observed equivalent widths vs. synthetic equivalent widths; we adjusted the iron abundance of the models until a slope of unity was achieved. The abundances derived from the different ionization stages are in agreement: Fe II lines indicate an iron abundance that is 34 +15/-10% the solar value([Fe/H]=-0.47 +0.16-0.15dex), while from Fe III lines we obtain 34 +/- 10% ([Fe/H]=-0.47 +0.11/-0.15 dex). A search of the literature suggests that no previous investigations of this star's iron abundance have found agreement between the different ionization stages. We thank Saul Adelman for his generous assistance, and the Faculty Research Fund Board of Wittenberg University for support of this research.

  5. Dark Matter Relic Abundance and Light Sterile Neutrinos

    CERN Document Server

    Tang, Yi-Lei

    2016-01-01

    In this paper, we calculate the relic abundance of the dark matter particles when they can annihilate into sterile neutrinos with the mass $\\lesssim 100 \\text{ GeV}$ in a simple model. Unlike the usual standard calculations, the sterile neutrino may fall out of the thermal equilibrium with the thermal bath before the dark matter freezes out. In such case, if the Yukawa coupling between Higgs and sterile neutrino $y_N$ is small, this process gives rise to a larger $\\Omega_{\\text{DM}} h^2$ so we need a larger coupling between dark matter and the sterile neutrino for a correct relic abundance.

  6. Fe-peak element abundances in disk and halo stars

    CERN Document Server

    Bergemann, Maria

    2009-01-01

    At present none of Galactic chemical evolution (GCE) models provides a self-consistent description of observed trends for all iron-peak elements with metallicity simultaneously. The question is whether the discrepancy is due to deficiencies of GCE models, such as stellar yields, or due to erroneous spectroscopically-determined abundances of these elements in metal-poor stars. The present work aims at a critical reevaluation of the abundance trends for several odd and even-Z Fe-peak elements, which are important for understanding explosive nucleosynthesis in supernovae.

  7. HD 209621: Abundances of neutron-capture elements

    OpenAIRE

    Goswami, Aruna; Aoki, Wako

    2010-01-01

    High resolution spectra obtained from the Subaru Telescope High Dispersion Spectrograph have been used to update the stellar atmospheric parameters and metallicity of the star HD 209621. We have derived a metallicity of [Fe/H] = -1.93 for this star, and have found a large enhancement of carbon and of heavy elements, with respect to iron. Updates on the elemental abundances of four s-process elements (Y, Ce, Pr, Nd) along with the first estimates of abundances for a number of other heavy eleme...

  8. Asteroseismic estimate of helium abundance of 16 Cyg A, B

    Directory of Open Access Journals (Sweden)

    Verma Kuldeep

    2015-01-01

    Full Text Available The helium ionization zone in a star leaves a characteristic signature on its oscillation frequencies, which can be used to estimate the helium content in the envelope of the star. We use the oscillation frequencies of 16 Cyg A and B, obtained using 2.5 years of Kepler data, to estimate the envelope helium abundance of these stars. We find the envelope helium abundance to lie in the range 0.231–0.251 for 16 Cyg A and 0.218–0.266 for 16 Cyg B.

  9. Suppressing the QCD axion abundance by hidden monopoles

    Energy Technology Data Exchange (ETDEWEB)

    Kawasaki, Masahiro [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Takahashi, Fuminobu [Tokyo Univ., Miyagi (Japan). Dept. of Physics; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; Yamada, Masaki [Tokyo Univ., Chiba (Japan). Inst. for Cosmic Ray Research; Tokyo Univ., Chiba (Japan). Kavli IPMU (WPI), UTIAS; DESY Hamburg (Germany)

    2015-11-15

    We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 10{sup 12} GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei-Quinn symmetry is spontaneously broken after inflation.

  10. Suppressing the QCD axion abundance by hidden monopoles

    Directory of Open Access Journals (Sweden)

    Masahiro Kawasaki

    2016-02-01

    Full Text Available We study the Witten effect of hidden monopoles on the QCD axion dynamics, and show that its abundance as well as isocurvature perturbations can be significantly suppressed if there is a sufficient amount of hidden monopoles. When the hidden monopoles make up a significant fraction of dark matter, the Witten effect suppresses the abundance of axion with the decay constant smaller than 1012GeV. The cosmological domain wall problem of the QCD axion can also be avoided, relaxing the upper bound on the decay constant when the Peccei–Quinn symmetry is spontaneously broken after inflation.

  11. Distribution and abundance of West Greenland humpback whales ( Megaptera novaeangliae )

    DEFF Research Database (Denmark)

    Larsen, Finn; Hammond, P.S.

    2004-01-01

    Photo-identification surveys of humpback whales Megaptera novaeangliae were conducted at West Greenland during 1988-93, the last 2 years of which were part of the internationally coordinated humpback whale research programme YoNAH, with the primary aim of estimating abundance for the West Greenland...... effort. A total of 670 groups of humpback whales was encountered leading to the identification of 348 individual animals. Three areas of concentration were identified: an area off Nuuk; an area at c. 63degrees30'N; and an area off Frederikshab. Sequential Petersen capture-recapture estimates of abundance...

  12. How Does Abundant Display Space Support Data Analysis?

    DEFF Research Database (Denmark)

    Knudsen, Søren

    This thesis explores information visualizations on large, high-resolution touch displays for analysis of massive amounts of data. The ever increasing rate at which data is collected about everything from peoples’ health, over organisations expenditures, to scientific experiments, necessitates new...... data analysis techniques. Information visualizations on large, high-resolution touch displays is a promising answer to these needs, and provide abundant display space for people to make sense of data. However, little is known about how to tailor interactive visualizations to abundant display space or...

  13. Factors affecting Culicoides species composition and abundance in avian nests

    OpenAIRE

    Martínez de la Puente, Josué; Merino, Santiago; Tomás, Gustavo; Morales, Judith; Lobato, Elisa; Talavera, Salvador; Sarto i Monteys, V.

    2009-01-01

    Mechanisms affecting patterns of vector distribution among host individuals may influence the population and evol- utionary dynamics of vectors, hosts and the parasites transmitted. We studied the role of different factors affecting the species composition and abundance of Culicoides found in nests of the blue tit (Cyanistes caeruleus). We identified 1531 females and 2 males of 7 different Culicoides species in nests, with C. simulator being the most abundant species, followed by C. kibunensis, ...

  14. Bulk eutectic Cu–Ag alloys with abundant twin boundaries

    International Nuclear Information System (INIS)

    Abundant growth twin boundaries are found and characterized in two bulk eutectic Cu–Ag alloys that can be obtained conveniently. The statistical electron backscattering diffraction results show that both hetero-twin and cube-on-cube orientation relationships coexist in the eutectic Cu–Ag alloy. The tensile strength of the eutectic alloy increases with a decrease in the layer thickness of the Cu/Ag phase. This study provides a potential way to produce bulk eutectic Cu–Ag alloy with abundant twin boundaries that offers a combination of high strength and high ductility.

  15. Species abundance patterns : the problem of testing stochastic models

    OpenAIRE

    Bersier, Louis-Félix; Sugihara, George

    2009-01-01

    1. Tokeshi (1990) proposed a goodness-of-fit test to distinguish among a general class of stochastic species abundance models using field data. This test is a good first step, but it is impaired by some shortcomings: there is no adjustment for the number of species (the rejection rate increases with the number of species in a data set); the variance of the generated abundance distributions are not taken into account (data sets with higher variance than a model are not rejected). 2. We pro...

  16. Trace Element Abundance Measurements on Cosmic Dust Particles

    Science.gov (United States)

    Flynn, George

    1996-01-01

    The X-Ray Microprobe on beamline X-26A at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory was used to determine the abundances of elements from Cr through Sr in individual interplanetary dust particles (IDPs) collected from the Earth's stratosphere and the Scanning Transmission X-ray Microscope (STXM) on beamline X-1A at the NSLS was used to determine the carbon abundances and spatial distributions in IDPs. In addition, modeling was performed in an attempt to associate particular types of IDPs with specific types of parent bodies, and thus to infer the chemistry, mineralogy, and structural properties of those parent bodies.

  17. Flavour kinetics in an expanding quark-gluon plasma

    International Nuclear Information System (INIS)

    A phenomenological model for the expansion of a quark-gluon plasma is presented and applied to ultra-relativistic nucleus-nucleus collisions. The flavour kinetics is described by rate equations allowing the abundances of the different constituents of the system to be out of equilibrium. The basic constituents are the quarks and gluons in the plasma phase and hadrons in the hadronic phase. Besides ordinary kinetic processes within the two phases (inelastic collisions), we construct a model for the confinement mechanism which is based on the string phenomenology of hadronization. The latter aspect constitutes the novel and essential part of the paper. Abundances of the various hadrons have been calculated for a baryon poor and a baryon rich scenario. The results show that during the hadronization process, the original quark content is roughly doubled. The resulting hadron abundances are found to depend on the hadronization mechanism, while the subsequent hadronic reactions do not have a significant effect on the final hadronic abundances. We find a K-/π- ratio as much as a factor 6 larger than in panti p collisions. (orig.)

  18. Plasma Science Committee (PLSC)

    International Nuclear Information System (INIS)

    The Plasma Science Committee (PLSC) is a standing committee under the auspices of the Board on Physics and Astronomy, Commission on Physical Sciences, Mathematics, and Applications of the National Academy of Sciences--National Research Council. Plasma sciences represent a broad and diverse field. The PLSC has accepted the responsibility of monitoring the continuing development and assessing the general health of the field as whole. Although select advisory bodies have been created to address specific issues that affect plasma science, such as the Fusion Policy Advisory Committee (FPAC), the PLSC provides a focus for the plasma science community that is unique and essential. The membership of the PLSC is drawn from research laboratories in universities, industry, and government. Areas of expertise on the committee include accelerators and beams, space physics, astrophysics, computational physics and applied mathematics, fusion plasmas, fundamental experiments and theory, radiation sources, low temperature plasmas, and plasma-surface interactions. The PLSC is well prepared to respond to requests for studies on specific issues. This report discusses ion of the PLSC work

  19. Turbulent ion heating in TCV Tokamak plasmas

    International Nuclear Information System (INIS)

    charge exchange measurements, by doping the plasma with ion neutralisation targets injected with the diagnostic neutral beam (DNBI), were used to absolutely calibrate the NPA. Advanced modelling of the measured hydrogenic charge exchange spectra with the neutralisation and neutral transport codes KN1D and DOUBLE-TCV permitted a calculation of the absolute neutral density profiles of the plasma species.The energisation and the properties of fast ions were studied in dedicated, low density, cold ion, hot electron plasmas, resonantly heated at the second harmonic of the electron cyclotron frequency. The ion acceleration occurs on a characteristic timescale in the sub-millisecond range and comprises up to 20 % of the plasma ions. The number of fast ions nis and their effective temperature Tis are found to depend strongly on the bulk and suprathermal electron parameters, in particular Tis ≥ Teb (electron bulk) and nis ∼ vde (toroidal electron drift speed). The suprathermal electrons, abundantly generated in plasmas subjected to ECCD, are diagnosed with perpendicular and oblique viewing electron cyclotron emission (ECE) antennas and the measured frequency spectra are reconstructed with the relativistic ECE radiation balance code NOTEC-TCV. With steady-state ECRH and ECCD, the fast ion population reaches an equilibrium state. The spatial fast ion temperature profile is broad, of similar shape compared to the bulk ion temperature profile. The hottest suprathermal temperature observed is Tis ≥ 6 keV. Various potential ion acceleration mechanisms were examined for relevance in the TCV parameter range. The simultaneous wave-electron and wave-ion resonances of ion acoustic turbulence (IAT) show the best correlation with the available experimental knowledge. Ion acoustic waves are emitted by the weakly relativistic circulating electrons and are mainly Landau damped onto the ions. Destabilisation of IAT is markedly facilitated by the important degree of nonisothermicity Te/Ti

  20. Unexpected high plasma cobalamin

    DEFF Research Database (Denmark)

    Arendt, Johan F B; Nexo, Ebba

    2013-01-01

    It is well-established that more than 8% of patients examined for vitamin B12 deficiency unexpectedly have increased plasma levels of the vitamin, but so far there are no guidelines for the clinical interpretation of such findings. In this review, we summarise known associations between high plasma...... cobalamin binding proteins, transcobalamin and haptocorrin. Based on current knowledge, we suggest a strategy for the clinical interpretation of unexpected high plasma cobalamin. Since a number of the associated diseases are critical and life-threatening, the strategy promotes the concept of 'think...

  1. Plasma synthesis of nanopowders

    Energy Technology Data Exchange (ETDEWEB)

    Vollath, Dieter, E-mail: dieter.vollath@nanoconsulting.d [NanoConsulting (Germany)

    2008-12-15

    There is a huge variety of plasma processes for synthesis of nanoparticulate powders. They may be grouped with respect to operating temperature, which is the essential parameter with respect to the properties of the products. In view of industrial production, the highest degree of maturity is found in high temperature processes working under ambient pressure. For products, where well-defined properties are demanded, low temperature microwave plasma processes are best suited. Additionally, these processes allow coating of the produced particles, even with organic phases. Other processes where plasmas are involved, such as laser or flame processes coupled with electric fields have, to some extent, a high potential for development.

  2. Optical plasma microelectronic devices

    CERN Document Server

    Forati, Ebrahim; Dill, Thyler; Sievenpiper, Dan

    2015-01-01

    The semiconductor channel in conventional microelectronic devices was successfully replaced with an optically triggered gas plasma channel. The combination of DC and laser-induced gas ionizations controls the conductivity of the channel, enabling us to realize different electronic devices such as transistors, switches, modulators, etc. A special micro-scale metasurface was used to enhance the laser-gas interaction, as well as combining it with DC ionization properly. Optical plasma devices benefit form the advantages of plasma/vacuum electronic devices while preserving most of the integrablity of semiconductor based devices.

  3. Radiofrequency power in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This document includes the various communications that were presented at the 11th topical conference on radio frequency power in plasmas which took place in Palm Springs in May 1995. It includes current diffusion studies to assess the non-inductive current deposition profiles, experiments for plasma to reach quickly an equilibrium state, and modelling of electrons in plasma. Some comparison studies also reveal the efficiency of the Quasi-Optical Grill antenna for reactor applications. Finally, a scenario for efficient mode conversion heating in the ion cyclotron range of frequency is presented. Separate abstracts were prepared for the 6 papers in this volume. (TEC).

  4. Ambipolar diffusion in plasma

    International Nuclear Information System (INIS)

    Is this thesis, a numerical method for the solution of the linear diffusion equation for a plasma containing two types of ions, with the possibility of charge exchange, has been developed. It has been shown that the decay time of the electron and ion densities is much smaller than that in a plasma containing only a single type of ion. A non-linear diffusion equation, which includes the effects of an external electric field varying linearly in time, to describe a slightly ionized plasma has also been developed. It has been verified that the decay of the electron density in the presence of such an electric field is very slow. (author)

  5. Plasma for cancer treatment

    Science.gov (United States)

    Keidar, Michael

    2015-06-01

    Plasma medicine is a relatively new field that grew from research in application of low-temperature (or cold) atmospheric plasmas in bioengineering. One of the most promising applications of cold atmospheric plasma (CAP) is cancer therapy. Convincing evidence of CAP selectivity towards the cancer cells has been accumulated. This review summarizes the state of the art of this emerging field, presenting various aspects of CAP application in cancer such as the role of reactive species (reactive oxygen and nitrogen), cell cycle modification, in vivo application, CAP interaction with cancer cells in conjunction with nanoparticles, and computational oncology applied to CAP.

  6. Interaction of detritus with abundance of cyanobacteria and microalgae

    NARCIS (Netherlands)

    Gons, H.J.

    1995-01-01

    Detritus particles interact with phytoplankton growth through light attenuation and nutrient retention. A model is described for predicting abundance of cyanobacteria and microalgae in relation to the detritus dynamics in shallow lakes with varying phosphorus load. Steady-state P distribution among

  7. Abundances of 30 elements in 23 metal-poor stars

    CERN Document Server

    Johnson, J A

    2002-01-01

    We report the abundances of 30 elements in 23 metal-poor ([Fe/H] 0.10 dex, the relative abundances, especially between closely allied atoms such as the rare earth group, often show only small (<0.03 dex) changes. We found that some strong lines of FeI, MnI and CrI consistently gave lower abundances by ~0.2 dex, a number larger than the quoted errors in the gf values. After considering a model with depth-dependent microturbulent velocity and a model with hotter temperatures in the upper layers, we conclude that the latter did a better job of resolving the problem and agreeing with observational evidence for the structure of stars. The error analysis includes the effects of correlation of Teff, log g, and microturbulent velocity errors, which is crucial for certain element ratios, such as [Mg/Fe]. The abundances presented here are being analyzed and discussed in a separate series of papers.

  8. "Capture" Me if You Can: Estimating Abundance of Dolphin Populations

    Science.gov (United States)

    Thompson, Jessica; Curran, Mary Carla; Cox, Tara

    2016-01-01

    Animal populations are monitored over time to assess the effects of environmental disaster and disease, as well as the efficacy of laws designed to protect them. Determining the abundance of a species within a defined area is one method of monitoring a population. In "Capture" Me if You Can, middle school students will use data collected…

  9. Abundance analysis of s-process enhanced barium stars

    Science.gov (United States)

    Mahanta, Upakul; Karinkuzhi, Drisya; Goswami, Aruna; Duorah, Kalpana

    2016-08-01

    Detailed chemical composition studies of stars with enhanced abundances of neutron-capture elements can provide observational constraints for neutron-capture nucleosynthesis studies and clues for understanding their contribution to the Galactic chemical enrichment. We present abundance results from high-resolution spectral analyses of a sample of four chemically peculiar stars characterized by s-process enhancement. High-Resolution spectra (R ˜42000) of these objects spanning a wavelength range from 4000 to 6800 Å, are taken from the ELODIE archive. We have estimated the stellar atmospheric parameters, the effective temperature Teff, the surface gravity log g, and metallicity [Fe/H] from local thermodynamic equilibrium analysis using model atmospheres. We report estimates of elemental abundances for several neutron-capture elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. While HD 49641 and HD 58368 show [Ba/Fe] ≥ 1.16 the other two objects HD 119650 and HD 191010 are found to be mild barium stars with [Ba/Fe] ˜ 0.4. The derived abundances of the elements are interpreted on the basis of existing theories for understanding their origin and evolution.

  10. Big Bang Nucleosynthesis and the Observed Abundances of Light Elements

    OpenAIRE

    Hogan, Craig J.

    1996-01-01

    The predictions of Standard Big Bang Nucleosynthesis are summarized and compared with observations of abundances of helium in HII regions, deuterium in quasar absorbers, deuterium and helium-3 in the Galaxy, and lithium in metal-poor stars. It is concluded that the prospects are good for a precise test of the theory.

  11. Invasive lionfish reduce native fish abundance on a regional scale.

    Science.gov (United States)

    Ballew, Nicholas G; Bacheler, Nathan M; Kellison, G Todd; Schueller, Amy M

    2016-01-01

    Invasive lionfish pose an unprecedented threat to biodiversity and fisheries throughout Atlantic waters off of the southeastern United States, the Caribbean, and the Gulf of Mexico. Here, we employ a spatially replicated Before-After-Control-Impact analysis with temporal pairing to quantify for the first time the impact of the lionfish invasion on native fish abundance across a broad regional scale and over the entire duration of the lionfish invasion (1990-2014). Our results suggest that 1) lionfish-impacted areas off of the southeastern United States are most prevalent off-shore near the continental shelf-break but are also common near-shore and 2) in impacted areas, lionfish have reduced tomtate (a native forage fish) abundance by 45% since the invasion began. Tomtate served as a model native fish species in our analysis, and as such, it is likely that the lionfish invasion has had similar impacts on other species, some of which may be of economic importance. Barring the development of a control strategy that reverses the lionfish invasion, the abundance of lionfish in the Atlantic, Caribbean, and Gulf of Mexico will likely remain at or above current levels. Consequently, the effect of lionfish on native fish abundance will likely continue for the foreseeable future. PMID:27578096

  12. Terrestrial salamander abundance on reclaimed mountaintop removal mines

    Science.gov (United States)

    Wood, Petra Bohall; Williams, Jennifer M.

    2013-01-01

    Mountaintop removal mining, a large-scale disturbance affecting vegetation, soil structure, and topography, converts landscapes from mature forests to extensive grassland and shrubland habitats. We sampled salamanders using drift-fence arrays and coverboard transects on and near mountaintop removal mines in southern West Virginia, USA, during 2000–2002. We compared terrestrial salamander relative abundance and species richness of un-mined, intact forest with habitats on reclaimed mountaintop removal mines (reclaimed grassland, reclaimed shrubland, and fragmented forest). Salamanders within forests increased in relative abundance with increasing distance from reclaimed mine edge. Reclaimed grassland and shrubland habitats had lower relative abundance and species richness than forests. Characteristics of reclaimed habitats that likely contributed to lower salamander abundance included poor soils (dry, compacted, little organic matter, high rock content), reduced vertical structure of vegetation and little tree cover, and low litter and woody debris cover. Past research has shown that salamander populations reduced by clearcutting may rebound in 15–24 years. Time since disturbance was 7–28 years in reclaimed habitats on our study areas and salamander populations had not reached levels found in adjacent mature forests.

  13. Elemental Abundance Survey of The Galactic Thick Disk

    CERN Document Server

    Reddy, B E; Allende-Prieto, C; Reddy, Bacham E.; Lambert, David L.; Prieto, Carlos Allende

    2006-01-01

    [Abridged abstract] We have performed an abundance analysis for 176 F- and G- dwarfs of the Galactic thick disk component. Using accurate radial velocities combined with $Hipparcos$ astrometry, kinematics (U, V, and W) and Galactic orbital parameters were computed. We estimate the probability for a star to belong to the thin disk, the thick disk or the halo. Abundances of C, O, Na, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Ba, Ce, Nd, and Eu have been obtained. The abundances for thick disk stars are compared with those for thin disk members from Reddy et al. (2003). The ratios of $\\alpha$-elements (O, Mg, Si, Ca and Ti) to iron for thick disk disk stars show a clear enhancement compared to thin disk members in the range $-0.3 <$ [Fe/H] $ < -1.2$. There are also other elements -- Al, Sc, V, Co, and possibly Zn -- which show enhanced ratios to iron in the thick disk relative to the thin disk. The abundances of Na, Cr, Mn, Ni, and Cu (relative to Fe) are very similar for thin and thick dis...

  14. Generating potassium abundance variations in the Solar Nebula

    Science.gov (United States)

    Hubbard, Alexander

    2016-08-01

    An intriguing aspect of chondritic meteorites is that they are complementary: while their separate components have wildly varying abundances, bulk chondrites have nearly solar composition. This implies that the nearly solar reservoirs in which chondrites were born were in turn assembled from sub-reservoirs of differing compositions that birthed the different components. We focus on explaining the potassium abundance variations between chondrules even within a single chondrite, while maintaining the observed CI 41K to 39K ratios. This requires physically separating potassium and chondrules while the temperature is high enough for K to be in the gas phase. We examine several mechanisms which could drive the dust through gas and show that to do so locally would have required long (sub-orbital to many orbits) time scales; with shortest potassium depletion time-scales occurring in a scenario where chondrules formed high above the mid-plane and settled out of the evaporated potassium. While orbital time-scales are at odds with laboratory chondrule cooling rate estimates, any other model for the origin for the potassium abundance variation has to wrestle with the severe logistical difficulty of generating a plethora of correlated reservoirs which varied strongly in their potassium abundances, but not in their potassium isotope ratios.

  15. High-resolution abundance analysis of HD 140283

    CERN Document Server

    Siqueira-Mello, C; Barbuy, B; Spite, M; Spite, F; Korotin, S A

    2015-01-01

    HD 140283 is a reference subgiant that is metal poor and confirmed to be a very old star. The abundances of this type of old star can constrain the nature and nucleosynthesis processes that occurred in its (even older) progenitors. The present study may shed light on nucleosynthesis processes yielding heavy elements early in the Galaxy. A detailed abundance analysis of a high-quality spectrum is carried out, with the intent of providing a reference on stellar lines and abundances of a very old, metal-poor subgiant. We aim to derive abundances from most available and measurable spectral lines. The analysis is carried out using high-resolution (R = 81 000) and high signal-to-noise ratio (800 < S/N/pixel < 3400) spectrum, in the wavelength range 3700 - 10475, obtained with a seven-hour exposure time, using the ESPaDOnS at the CFHT. The calculations in LTE were performed with the OSMARCS 1D atmospheric model and the spectrum synthesis code Turbospectrum, while the analysis in NLTE is based on the MULTI code...

  16. Determining Boundaries between Abundance Biozones Using Minimal Equipment

    Directory of Open Access Journals (Sweden)

    Brent Wilson

    2010-01-01

    Full Text Available The areal extent of a biological community is usually determined using statistical techniques that only give reliable results where samples contain similar and high numbers of specimens. This paper presents a simple, inexpensive method for determining the geographical limits of biological communities applicable where adjacent samples contain widely differing numbers of specimens. The method is a development of SHE Analysis, which discerns boundaries between adjacent abundance biozones (ABs, an AB being an area with a distinct community structure. As originally conceived, SHEbi (SHE Analysis for the identification of Biozones commences with species' absolute abundances and works best with large samples of equal sizes. If the variance in (per sample is high, SHEbi may place AB boundaries in unexpected locations. A modification, based on proportional abundances, is developed here using species' proportional abundances (=/ for each sample where is the number of specimens in the ith species in the sample. For intertidal foraminifera from the Caroni Swamp, Trinidad, where , the number of specimens, fluctuates widely between samples, the modification (SHEbip gives ecologically more sensible results than does traditional SHEbi.

  17. Dilaton could affect abundance of dark matter particles

    CERN Multimedia

    2007-01-01

    "The amount of dark matter left over from the early universe may be less than previously believed. new research shows that the "relic abundance" of stable dark matter particles such as the neutralino may be reduced as compared to standard cosmology theories due to the effects of the "dilaton", a particle with zero spin in the gravitational sector of strings." (1 page)

  18. Monitoring the abundance of plastic debris in the marine environment

    NARCIS (Netherlands)

    Ryan, P.G.; Moore, C.J. C.J.; Franeker, van J.A.; Moloney, C.L.

    2009-01-01

    Plastic debris has significant environmental and economic impacts in marine systems. Monitoring is crucial to assess the efficacy of measures implemented to reduce the abundance of plastic debris, but it is complicated by large spatial and temporal heterogeneity in the amounts of plastic debris and

  19. Pastoral del Nino: Bringing the Abundant Life to Paraguayan Children

    Science.gov (United States)

    Austin, Ann Berghout; Aquino, Cyle; Burro, Elizabeth

    2007-01-01

    Pastoral del Nino is transforming children's lives in rural Paraguay. Part of Pastoral Social (Catholic Social Services), Pastoral del Nino's primary focus is to bring "vida en abundancia" (the abundant life) to families by ensuring that mothers survive childbirth and children reach their first birthdays. In addition, the organization promotes…

  20. Boom in boarfish abundance: insight from otolith analysis

    DEFF Research Database (Denmark)

    Coad, Julie Olivia; Hüssy, Karin

    2012-01-01

    The boarfish Capros aper is a pelagic shoaling species widely distributed along the Northeast Atlantic continental shelf. In recent years, this species has experienced a dramatic boom in abundance in the Bay of Biscay and Celtic Sea. This study aims at resolving the mechanisms responsible for thi...

  1. GASEOUS CO ABUNDANCE-AN EVOLUTIONARY TRACER FOR MOLECULAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Liu Tie; Wu Yuefang; Zhang Huawei, E-mail: liutiepku@gmail.com, E-mail: ywu@pku.edu.cn [Department of Astronomy, Peking University, Beijing 100871 (China)

    2013-09-20

    Planck cold clumps are among the most promising objects to investigate the initial conditions of the evolution of molecular clouds. In this work, by combing the dust emission data from the survey of the Planck satellite with the molecular data of {sup 12}CO/{sup 13}CO/C{sup 18}O (1-0) lines from observations with the Purple Mountain Observatory 13.7 m telescope, we investigate the CO abundance, CO depletion, and CO-to-H{sub 2} conversion factor of 674 clumps in the early cold cores sample. The median and mean values of the CO abundance are 0.89 Multiplication-Sign 10{sup -4} and 1.28 Multiplication-Sign 10{sup -4}, respectively. The mean and median of CO depletion factor are 1.7 and 0.9, respectively. The median value of X{sub CO-to-H{sub 2}} for the whole sample is 2.8 Multiplication-Sign 10{sup 20} cm{sup -2} K{sup -1} km{sup -1} s. The CO abundance, CO depletion factor, and CO-to-H{sub 2} conversion factor are strongly (anti-)correlated to other physical parameters (e.g., dust temperature, dust emissivity spectral index, column density, volume density, and luminosity-to-mass ratio). To conclude, the gaseous CO abundance can be used as an evolutionary tracer for molecular clouds.

  2. Chemical abundances of distant extremely metal-poor unevolved stars

    CERN Document Server

    Bonifacio, P; Caffau, E; Ludwig, H -G; Spite, M; Hernández, J I González; Behara, N T

    2012-01-01

    Aims: The purpose of our study is to determine the chemical composition of a sample of 16 candidate Extremely Metal-Poor (EMP) dwarf stars, extracted from the Sloan Digital Sky Survey (SDSS). There are two main purposes: in the first place to verify the reliability of the metallicity estimates derived from the SDSS spectra; in the second place to see if the abundance trends found for the brighter nearer stars studied previously also hold for this sample of fainter, more distant stars. Methods: We used the UVES at the VLT to obtain high-resolution spectra of the programme stars. The abundances were determined by an automatic analysis with the MyGIsFOS code, with the exception of lithium, for which the abundances were determined from the measured equivalent widths of the Li I resonance doublet. Results: All candidates are confirmed to be EMP stars, with [Fe/H]<= -3.0. The chemical composition of the sample of stars is similar to that of brighter and nearer samples. We measured the lithium abundance for 12 st...

  3. The abundance of (not just) dark matter haloes

    CERN Document Server

    Sawala, Till; Crain, Robert A; Jenkins, Adrian; Schaye, Joop; Theuns, Tom; Zavala, Jesus

    2012-01-01

    We study the effect of baryons on the abundance of structures and substructures in a Lambda-CDM cosmology, using a pair of high resolution cosmological simulations from the GIMIC project. Both simulations use identical initial conditions, but while one contains only dark matter, the other also includes baryons. We find that gas pressure, reionisation, supernova feedback, stripping, and truncated accretion systematically reduce the total mass and the abundance of structures below ~10^12 solar masses compared to the pure dark matter simulation. Taking this into account and adopting an appropriate detection threshold lowers the abundance of observed galaxies with maximum circular velocities below 100 km/s, significantly reducing the reported discrepancy between Lambda-CDM and the measured HI velocity function of the ALFALFA survey. We also show that the stellar-to-total mass ratios of galaxies with stellar masses of ~10^5 - 10^7 solar masses inferred from abundance matching of the (sub)halo mass function to the ...

  4. Light element abundances, galactic evolution, and the universal baryon density

    International Nuclear Information System (INIS)

    The present mean universal mean baryon density, rho/sub b/, is of particular interest because, in Friedmann cosmologies with no cosmological constant, it is this quantity together with the Hubble constant, H/sub o/, which determines the spatial curvature of the universe, i.e., whether it is open or closed. The most stringent upper limit to rho/sub b/ so far established comes from the present deuterium abundance. This paper proposes an alternative method to evaluate the range of permissible values of rho/sub b/. The method considers the abundance of both D and 7Li. By utilizing the abundance ratio of 7Li to D, the difficulty associated with the astration process can be essentially canceled from the problem. Further, this method is slightly more sensitive to rho/sub b/ than the method which uses the D abundance alone. The ratio of 7Li to D mass fractions is plotted as a function of the present baryon density for a background temperature of 2.80K. Results are tabulated; they indicate that rho/sub b/ is too small to close the universe by a factor of the order of 5. 1 figure, 1 table

  5. Accurate genome relative abundance estimation based on shotgun metagenomic reads.

    Directory of Open Access Journals (Sweden)

    Li C Xia

    Full Text Available Accurate estimation of microbial community composition based on metagenomic sequencing data is fundamental for subsequent metagenomics analysis. Prevalent estimation methods are mainly based on directly summarizing alignment results or its variants; often result in biased and/or unstable estimates. We have developed a unified probabilistic framework (named GRAMMy by explicitly modeling read assignment ambiguities, genome size biases and read distributions along the genomes. Maximum likelihood method is employed to compute Genome Relative Abundance of microbial communities using the Mixture Model theory (GRAMMy. GRAMMy has been demonstrated to give estimates that are accurate and robust across both simulated and real read benchmark datasets. We applied GRAMMy to a collection of 34 metagenomic read sets from four metagenomics projects and identified 99 frequent species (minimally 0.5% abundant in at least 50% of the data-sets in the human gut samples. Our results show substantial improvements over previous studies, such as adjusting the over-estimated abundance for Bacteroides species for human gut samples, by providing a new reference-based strategy for metagenomic sample comparisons. GRAMMy can be used flexibly with many read assignment tools (mapping, alignment or composition-based even with low-sensitivity mapping results from huge short-read datasets. It will be increasingly useful as an accurate and robust tool for abundance estimation with the growing size of read sets and the expanding database of reference genomes.

  6. Cross-scale interactions and the distribution-abundance relationship.

    Science.gov (United States)

    Werner, Earl E; Davis, Christopher J; Skelly, David K; Relyea, Rick A; Benard, Michael F; McCauley, Shannon J

    2014-01-01

    Positive interspecific relationships between local abundance and extent of regional distribution are among the most ubiquitous patterns in ecology. Although multiple hypotheses have been proposed, the mechanisms underlying distribution-abundance (d-a) relationships remain poorly understood. We examined the intra- and interspecific distribution-abundance relationships for a metacommunity of 13 amphibian species sampled for 15 consecutive years. Mean density of larvae in occupied ponds was positively related to number of ponds occupied by species; employing the fraction of ponds uniquely available to each species this same relationship sharply decelerates. The latter relationship suggested that more abundant species inhabited most available habitats annually, whereas rarer species were dispersal limited. We inferred the mechanisms responsible for this pattern based on the dynamics of one species, Pseudacris triseriata, which transitioned between a rare, narrowly distributed species to a common, widely distributed species and then back again. Both transitions were presaged by marked changes in mean local densities driven by climatic effects on habitat quality. We identified threshold densities separating these population regime shifts that differed with landscape configuration. Our data suggest that these transitions were caused by strong cross-scale interactions between local resource/niche processes and larger scale metapopulation processes. The patterns we observed have relevance for understanding the mechanisms of interspecific d-a relationships and critical thresholds associated with habitat fragmentation. PMID:24875899

  7. Chemical Abundance Analysis of Moving Group W11450 (Latham 1)

    CERN Document Server

    O'Connell, Julia E; Frinchaboy, Peter M

    2016-01-01

    We present elemental abundances for all seven stars in Moving Group W11450 (Latham 1) to determine if they may be chemically related. These stars appear to be both spatially and kinematically related, but no spectroscopic abundance analysis exists in literature. Abundances for eight elements were derived via equivalent width analyses of high resolution (R $\\sim$60,000), high signal-to-noise ratio ($\\langle$SNR$\\rangle\\sim$100) spectra obtained with the Otto Struve 2.1m telescope and Sandiford Echelle Spectrograph at McDonald Observatory. The large star-to-star scatter in metallicity, -0.55 $\\leq$ [Fe/H] $\\leq$ 0.06 dex ($\\sigma$= 0.25), implies these stars were not produced from the same chemically homogeneous molecular cloud, and are therefore not part of a remnant or open cluster as previously proposed. Prior to this analysis, it was suggested that two stars in the group, W11449 & W11450, are possible wide binaries. The candidate wide binary pair show similar chemical abundance patterns with not only ir...

  8. Variation of the subhalo abundance in dark matter halos

    CERN Document Server

    Ishiyama, Tomoaki; Makino, Junichiro

    2008-01-01

    We analyzed the statistics of subhalo abundance of galaxy-sized and giant-galaxy-sized halos formed in a high-resolution cosmological simulation of a 46.5Mpc cube with the uniform mass resolution of $10^6 M_{\\odot}$. We analyzed all halos with mass more than $1.5 \\times 10^{12}M_{\\odot}$ formed in this simulation box. The total number of halos was 125. We found that the subhalo abundance, measured by the number of subhalos with maximum rotation velocity larger than 10% of that of the parent halo, shows large halo-to-halo variations. The results of recent ultra-high-resolution runs fall within the variation of our samples. We found that the concentration parameter and the radius at the moment of the maximum expansion shows fairly tight correlation with the subhalo abundance. This correlation suggests that the variation of the subhalo abundance is at least partly due to the difference in the formation history. Halos formed earlier have smaller number of subhalos at present.

  9. Invasive lionfish reduce native fish abundance on a regional scale

    Science.gov (United States)

    Ballew, Nicholas G.; Bacheler, Nathan M.; Kellison, G. Todd; Schueller, Amy M.

    2016-01-01

    Invasive lionfish pose an unprecedented threat to biodiversity and fisheries throughout Atlantic waters off of the southeastern United States, the Caribbean, and the Gulf of Mexico. Here, we employ a spatially replicated Before-After-Control-Impact analysis with temporal pairing to quantify for the first time the impact of the lionfish invasion on native fish abundance across a broad regional scale and over the entire duration of the lionfish invasion (1990–2014). Our results suggest that 1) lionfish-impacted areas off of the southeastern United States are most prevalent off-shore near the continental shelf-break but are also common near-shore and 2) in impacted areas, lionfish have reduced tomtate (a native forage fish) abundance by 45% since the invasion began. Tomtate served as a model native fish species in our analysis, and as such, it is likely that the lionfish invasion has had similar impacts on other species, some of which may be of economic importance. Barring the development of a control strategy that reverses the lionfish invasion, the abundance of lionfish in the Atlantic, Caribbean, and Gulf of Mexico will likely remain at or above current levels. Consequently, the effect of lionfish on native fish abundance will likely continue for the foreseeable future. PMID:27578096

  10. Morphological change in Newfoundland caribou: Effects of abundance and climate

    Directory of Open Access Journals (Sweden)

    Shane P. Mahoney

    2011-04-01

    Full Text Available The demographic and environmental influences on large mammal morphology are central questions in ecology. We investigated the effects of population abundance and climate on body size and number of male antler points for the La Poile and Middle Ridge caribou (Rangifer tarandus, L. 1758 herds, Newfoundland, Canada. Across 40 years and 20-fold changes in abundance, adult males and females exhibited diminished stature as indicated by jawbone size (diastema and total mandible length and the number of antler points at the time of harvest. Associations between jawbone size and population abundance at birth were consistently negative for both herds, both sexes, and all age classes. Large-scale climate patterns, as measured by the North Atlantic Oscillation in the winter prior to birth, were also negatively associated with jawbone size. Declines in male antler size, as measured by the number of antler points, were not well predicted by either abundance or climate, suggesting other factors (e.g., current, rather than latent, foraging conditions may be involved. We conclude that these morphological changes indicate competition for food resources.

  11. Direct Oxygen Abundances for Low Luminosity LVL Galaxies

    CERN Document Server

    Berg, Danielle A; Marble, Andrew R; van Zee, Liese; Engelbracht, Charles W; Lee, Janice C; Kennicutt, Robert C; Jr.,; Calzetti, Daniela; Dale, Daniel A; Johnson, Benjamin D

    2012-01-01

    We present MMT spectroscopic observations of HII regions in 42 low luminosity galaxies in the LVL. For 31 galaxies, we measured the temperature sensitive [O III] line at a strength of 4 sigma or greater, and thus determine direct oxygen abundances. Our results provide the first direct estimates of oxygen abundance for 19 galaxies. Oxygen abundances were compared to B-band and 4.5 micron luminosities and stellar masses in order to characterize the luminosity-metallicity (L-Z) and mass-metallicity (M-Z) relationships at low-luminosity. We present and analyze a "Combined Select" sample composed of 38 objects (drawn from our parent sample and the literature) with direct oxygen abundances and reliable distance determinations (TRGB or Ceph). Consistent with previous studies, the B-band and 4.5 micron L-Z relationships were found to be 12+log(O/H)=(6.27+/-0.21)+(-0.11+/-0.01)M_B and 12+log(O/H)=(6.10+/-0.21)+(-0.10+/-0.01)M_[4.5] (sigma=0.15 and 0.14). For this sample, we derive a M-Z relationship of 12+log(O/H)=(5....

  12. A catalogue of helium abundance indicators from globular cluster photometry

    Science.gov (United States)

    Sandquist, Eric L.

    2000-04-01

    We present a survey of helium abundance indicators derived from a comprehensive study of globular cluster photometry in the literature. For each of the three indicators used, we conduct a thorough error analysis, and identify systematic errors in the computational procedures. For the population ratio RNHBNRGB, we find that there is no evidence of a trend with metallicity, although there appears to be real scatter in the values derived. Although this indicator is the one best able to provide useful absolute helium abundances, the mean value is Y~0.20, indicating the probable presence of additional systematic error. For the magnitude difference from the horizontal branch to the main sequence Δ and the RR Lyrae mass-luminosity exponent A, it is only possible to determine relative helium abundances reliably. This is due to continuing uncertainties in the absolute metallicity scale for Δ, and uncertainty in the RR Lyrae temperature scale for A. Both indicators imply that the helium abundance is approximately constant as a function of [Fe/H]. According to the A indicator, both Oosterhoff I and II group clusters have constant values independent of [Fe/H] and horizontal branch type. In addition, the two groups have slopes dlog/d[Fe/H] that are consistent with each other, but significantly smaller than the slope for the combined sample.

  13. Lead abundance in the uranium star CS 31082-001

    CERN Document Server

    Plez, B; Cayrel, R; Spite, M; Barbuy, B; Beers, T C; Bonifacio, P; Primas, F; Nordström, B

    2004-01-01

    In a previous paper we were able to measure the abundance of uranium and thorium in the very-metal poor halo giant BPS CS 31082-001, but only obtained an upper limit for the abundance of lead (Pb). We have got from ESO 17 hours of additional exposure on this star in order to secure a detection of the minimum amount of lead expected to be present in CS 31082-001, the amount arising from the decay of the original content of Th and U in the star. We report here this successful detection. We find an LTE abundance log(Pb/H)+12=-0.55 \\pm 0.15 dex, one dex below the upper limits given by other authors for the similar stars CS 22892-052 and BD +17d3248, also enhanced in r-process elements. From the observed present abundances of Th and U in the star, the expected amount of Pb produced by the decay of 232Th, and 238U alone, over 12-15 Gyr is -0.73\\pm 0.17 dex. The decay of 235U is more difficult to estimate, but is probably slightly below the contribution of 238U, making the contribution of the 3 actinides only slight...

  14. Abundance of eukaryotic microbes in the deep subtropical North Atlantic

    NARCIS (Netherlands)

    Morgan-Smith, D.; Herndl, G.J.; van Aken, H.M.; Bochdansky, A.B.

    2011-01-01

    The meso- and bathypelagic ocean comprises the largest habitat on earth, yet we know very little about the distribution and activity of protists in this environment. These small eukaryotes are responsible for controlling bacterial abundance in the surface ocean and are major players in the material

  15. Chemical Constraints on the Oxygen Abundances in Jupiter and Saturn

    CERN Document Server

    Wang, Dong

    2012-01-01

    We perform a comparative analysis of the chemical kinetics of CO and $\\rm PH_3$ in Jupiter and Saturn to assess the full set of constraints available on the troposphere water abundance in the two giant planets. For carbon monoxide we employ both a widely used CO kinetic scheme from Yung et al, and a newly identified CO chemical scheme from Visscher and Moses. For $\\rm PH_3$ chemical scheme, we use the same chemical scheme as in Visscher and Fegley. Yung's chemical scheme for CO yields a water enrichment of 0.95 - 23.0 times solar abundance on Jupiter, and an upper limit of 14.0 for Saturn. Visscher's chemical scheme in contrast produces a water enrichment of 0.24 - 2.6 times solar abundance in Jupiter, and for Saturn an upper limit for water enrichment of 8.0. From this scheme, which takes advantage of the most up-to-date kinetics, we preclude high water enrichments on Jupiter and Saturn, and show that the kinetics approach yields Jovian bulk abundance in which values of C/O elevated relative to solar are adm...

  16. The Arabian Sea: Physical environment, zooplankton and myctophid abundance

    Digital Repository Service at National Institute of Oceanography (India)

    Nair, K.K.C.; Madhupratap, M.; Gopalakrishnan, T.C.; Haridas, P.; Gauns, M.

    that there are considerable spatial and temporal variations in the area in primary productivity. Nonetheless, contrary to earlier thinking, it would seem that the mesozooplankton abundance in the Arabian Sea is fairly high in the mixed layer all through the year. This paradox...

  17. Red Supergiants as Cosmic Abundance Probes: The Magellanic Clouds

    CERN Document Server

    Davies, Ben; Gazak, Zach; Plez, Bertrand; Bergemann, Maria; Evans, Chris; Patrick, Lee

    2015-01-01

    Red Supergiants (RSGs) are cool (~4000K), highly luminous stars (L - 10^5 Lsun), and are among the brightest near-infrared (NIR) sources in star-forming galaxies. This makes them powerful probes of the properties of their host galaxies, such as kinematics and chemical abundances. We have developed a technique whereby metallicities of RSGs may be extracted from a narrow spectral window around 1{\\mu}m from only moderate resolution data. The method is therefore extremely efficient, allowing stars at large distances to be studied, and so has tremendous potential for extragalactic abundance work. Here, we present an abundance study of the Large and Small Magellanic Clouds (LMC and SMC respectively) using samples of 9-10 RSGs in each. We find average abundances for the two galaxies of [Z]LMC = -0.37 +/- 0.14 and [Z]SMC = -0.53 +/- 0.16 (with respect to a Solar metallicity of Zsun=0.012). These values are consistent with other studies of young stars in these galaxies, and though our result for the SMC may appear hig...

  18. Latitudinal patterns in the abundance of major marine bacterioplankton groups

    DEFF Research Database (Denmark)

    Wietz, Matthias; Gram, Lone; Jørgensen, Bo;

    2010-01-01

    saturation in colder oceans. On a global scale, Roseobacter and SAR86 were correlated with chlorophyll a. Linkages of environmental parameters with relative abundances were more complex, with e.g. Bacteroidetes being associated with chlorophyll a. The finding of differing communities in warmer and colder...

  19. Estimating abundance in the presence of species uncertainty

    Science.gov (United States)

    Chambert, Thierry A; Hossack, Blake R.; Fishback, LeeAnn; Davenport, Jon M.

    2016-01-01

    1.N-mixture models have become a popular method for estimating abundance of free-ranging animals that are not marked or identified individually. These models have been used on count data for single species that can be identified with certainty. However, co-occurring species often look similar during one or more life stages, making it difficult to assign species for all recorded captures. This uncertainty creates problems for estimating species-specific abundance and it can often limit life stages to which we can make inference. 2.We present a new extension of N-mixture models that accounts for species uncertainty. In addition to estimating site-specific abundances and detection probabilities, this model allows estimating probability of correct assignment of species identity. We implement this hierarchical model in a Bayesian framework and provide all code for running the model in BUGS-language programs. 3.We present an application of the model on count data from two sympatric freshwater fishes, the brook stickleback (Culaea inconstans) and the ninespine stickleback (Pungitius pungitius), ad illustrate implementation of covariate effects (habitat characteristics). In addition, we used a simulation study to validate the model and illustrate potential sample size issues. We also compared, for both real and simulated data, estimates provided by our model to those obtained by a simple N-mixture model when captures of unknown species identification were discarded. In the latter case, abundance estimates appeared highly biased and very imprecise, while our new model provided unbiased estimates with higher precision. 4.This extension of the N-mixture model should be useful for a wide variety of studies and taxa, as species uncertainty is a common issue. It should notably help improve investigation of abundance and vital rate characteristics of organisms’ early life stages, which are sometimes more difficult to identify than adults.

  20. Neutron-capture Element Abundances in Magellanic Cloud Planetary Nebulae

    Science.gov (United States)

    Mashburn, A. L.; Sterling, N. C.; Madonna, S.; Dinerstein, Harriet L.; Roederer, I. U.; Geballe, T. R.

    2016-11-01

    We present near-infrared spectra of 10 planetary nebulae (PNe) in the Large and Small Magellanic Clouds (LMC and SMC), acquired with the FIRE and GNIRS spectrometers on the 6.5 m Baade and 8.1 m Gemini South Telescopes, respectively. We detect Se and/or Kr emission lines in eight of these objects, the first detections of n-capture elements in Magellanic Cloud PNe. Our abundance analysis shows large s-process enrichments of Kr (0.6–1.3 dex) in the six PNe in which it was detected, and Se is enriched by 0.5–0.9 dex in five objects. We also estimate upper limits to Rb and Cd abundances in these objects. Our abundance results for the LMC are consistent with the hypothesis that PNe with 2–3 M ⊙ progenitors dominate the bright end of the PN luminosity function in young gas-rich galaxies. We find no significant correlations between s-process enrichments and other elemental abundances, central star temperature, or progenitor mass, though this is likely due to our small sample size. We determine S abundances from our spectra and find that [S/H] agrees with [Ar/H] to within 0.2 dex for most objects, but is lower than [O/H] by 0.2–0.4 dex in some PNe, possibly due to O enrichment via third dredge-up. Our results demonstrate that n-capture elements can be detected in PNe belonging to nearby galaxies with ground-based telescopes, allowing s-process enrichments to be studied in PN populations with well-determined distances. This paper includes data obtained with the 6.5-m Magellan Telescopes located at Las Campanas Observatory, Chile, and with the Gemini-South Telescope at Cerro Pachon, Chile.