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Sample records for biochemical evolution ii

  1. Biochemical evolution II: origin of life in tubular microstructures on weathered feldspar surfaces.

    Science.gov (United States)

    Parsons, I; Lee, M R; Smith, J V

    1998-12-22

    Mineral surfaces were important during the emergence of life on Earth because the assembly of the necessary complex biomolecules by random collisions in dilute aqueous solutions is implausible. Most silicate mineral surfaces are hydrophilic and organophobic and unsuitable for catalytic reactions, but some silica-rich surfaces of partly dealuminated feldspars and zeolites are organophilic and potentially catalytic. Weathered alkali feldspar crystals from granitic rocks at Shap, north west England, contain abundant tubular etch pits, typically 0.4-0.6 microm wide, forming an orthogonal honeycomb network in a surface zone 50 microm thick, with 2-3 x 10(6) intersections per mm2 of crystal surface. Surviving metamorphic rocks demonstrate that granites and acidic surface water were present on the Earth's surface by approximately 3.8 Ga. By analogy with Shap granite, honeycombed feldspar has considerable potential as a natural catalytic surface for the start of biochemical evolution. Biomolecules should have become available by catalysis of amino acids, etc. The honeycomb would have provided access to various mineral inclusions in the feldspar, particularly apatite and oxides, which contain phosphorus and transition metals necessary for energetic life. The organized environment would have protected complex molecules from dispersion into dilute solutions, from hydrolysis, and from UV radiation. Sub-micrometer tubes in the honeycomb might have acted as rudimentary cell walls for proto-organisms, which ultimately evolved a lipid lid giving further shelter from the hostile outside environment. A lid would finally have become a complete cell wall permitting detachment and flotation in primordial "soup." Etch features on weathered alkali feldspar from Shap match the shape of overlying soil bacteria.

  2. THE SYNTHESIS OF HEMOPROTEIDS IN THE LIGHT OF BIOCHEMICAL EVOLUTION,

    Science.gov (United States)

    the light of biochemical evolution , hemoproteids - resp. the porphyrin compounds they are based upon - must have existed on earth as early as... the CO2-assimilation, which means that the porphyrin catalyse of oxydative metabolism consequently derived from the second period of the early atmosphere. This aspect is discussed. (Author)...biological organisms with oxydative metabolism occurred. Since the primitive early atmosphere was followed by a CO2-containing

  3. Evolution of holometabola insect digestive systems: physiological and biochemical aspects

    Directory of Open Access Journals (Sweden)

    Walter R. Terra

    1987-01-01

    Full Text Available This review takes into account primarily the work done in our laboratory with insects from the major Holometabola orders. Only the most significant data for each insect will be presented and a proposal on the evolution of Holometabola insect digstive systems will be advanced.

  4. Mutation and biochemical analysis in carnitine palmitoyltransferase type II (CPT II) deficiency

    DEFF Research Database (Denmark)

    Olpin, S E; Afifi, A; Clark, S

    2003-01-01

    Carnitine palmitoyltransferase type II (CPT II) deficiency has three basic phenotypes, late-onset muscular (mild), infantile/juvenile hepatic (intermediate) and severe neonatal. We have measured fatty acid oxidation and CPT II activity and performed mutation studies in 24 symptomatic patients......, the implication being that they may significantly influence the manifestation of clinical disease and could therefore potentially be considered as a susceptibility variants. Among myopathic individuals, males comprised 88% of patients, suggesting increased susceptibility to clinical disease. A small number...

  5. 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

  6. Diversity of bile salts in fish and amphibians: evolution of a complex biochemical pathway.

    Science.gov (United States)

    Hagey, Lee R; Møller, Peter R; Hofmann, Alan F; Krasowski, Matthew D

    2010-01-01

    Bile salts are the major end metabolites of cholesterol and are also important in lipid and protein digestion, as well as shaping of the gut microflora. Previous studies had demonstrated variation of bile salt structures across vertebrate species. We greatly extend prior surveys of bile salt variation in fish and amphibians, particularly in analysis of the biliary bile salts of Agnatha and Chondrichthyes. While there is significant structural variation of bile salts across all fish orders, bile salt profiles are generally stable within orders of fish and do not correlate with differences in diet. This large data set allowed us to infer evolutionary changes in the bile salt synthetic pathway. The hypothesized ancestral bile salt synthetic pathway, likely exemplified in extant hagfish, is simpler and much shorter than the pathway of most teleost fish and terrestrial vertebrates. Thus, the bile salt synthetic pathway has become longer and more complex throughout vertebrate evolution. Analysis of the evolution of bile salt synthetic pathways provides a rich model system for the molecular evolution of a complex biochemical pathway in vertebrates.

  7. Sublethal effects of an organophosphorus insecticide (RPR-II) on biochemical parameters of tilapia, Oreochromis mossambicus.

    Science.gov (United States)

    Venkateswara Rao, J

    2006-08-01

    The effect of exposure to sublethal concentrations (0.017 mg L(-1), 1/10 of LC50) of the novel organophosphate (OP) insecticide, 2-butenoic acid-3-(diethoxyphosphinothioyl) methyl ester (RPR-II) on biochemical parameters in Oreochromis mossambicus was studied during exposure for 3, 7, 15, 30 and its recovery response after seven days. Acetylcholinesterase (AChE) activity of brain, gill and muscle was inhibited by 67%, 77% and 73% respectively on day-30. The plasma and kidney alanine aminotransferase (AlaAT), and aspartate aminotransferase (AspAT) activity increased, while decreases were observed in gill and liver. Increases in acid phosphatase (AcP), and alkaline phosphatase (AP) activities were observed in plasma, gill, and kidney, and reductions of 20% and 61% in liver AcP and AP, respectively. Depletion of glycogen was observed in all tissues, an indication of typical stress related response of the fish with pesticide. Lactate dehydrogenase (LDH) activity decreased in liver and muscle, indicating tissue damage but a significant increase in LDH activity in gill and brain was observed. Depletion of glutathione (GSH) was observed in all tissues, thereby enhancing lipid peroxidation resulting in cell damage. The induction in hepatic glutathione-S-transferase (GST) levels indicates protection against the toxicity of xenobiotic-induced lipid peroxidation. There was a significant recovery in the above biochemical parameters, in all tissues of fish after a recovery period of seven days. These results revealed that the OP insecticide RPR-II is highly toxic and affects the intermediary metabolism of O. mossambicus.

  8. Comparison of biochemical and immunochemical properties of myosin II in taeniid parasites.

    Science.gov (United States)

    Cruz-Rivera, M; Reyes-Torres, A; Reynoso-Ducoing, O; Flisser, A; Ambrosio, J R

    2006-07-01

    Type II myosins are highly conserved proteins, though differences have been observed among organisms, mainly in the filamentous region. Myosin isoforms have been identified in Taenia solium, a helminth parasite of public health importance in many developing countries. These isoforms are probably associated with the physiological requirements of each developmental stage of the parasite. In this paper we extend the characterization of myosin to several other Taenia species. Type II myosins were purified from the larvae (cysticerci) of Taenia solium, T. taeniaeformis and T. crassiceps and the adult stages of T. solium, T. taeniaeformis and T. saginata. Rabbit polyclonal antibodies against some of these myosins were specific at high dilutions but cross-reacted at low dilutions. ATPase activity was evaluated and kinetic values were calculated for each myosin. Homologous actin-myosin interactions increased both the affinity of myosin for ATP and the hydrolysis rate. The results indicate immunological and biochemical differences among taeniid myosins. This variability suggests that different isoforms are found not only in different taeniid species but also at different developmental stages. Further characterization of myosin isoforms should include determination of their amino acid composition.

  9. Biochemical markers of type II collagen breakdown and synthesis are positioned at specific sites in human osteoarthritic knee cartilage

    DEFF Research Database (Denmark)

    Jensen, Anne-Christine Bay; Levin Andersen, Thomas; Charni-Ben Tabassi, N;

    2007-01-01

    as for type IIA N propeptide (PIIANP), a biochemical marker reflecting synthesis of type IIA collagen. RESULTS: Helix-II and CTX-II were detected in areas where collagen damage was reported previously, most frequently around chondrocytes, but also frequently in regions not previously investigated......OBJECTIVE: To investigate whether type II collagen turnover markers used for osteoarthritis (OA) activity evaluation in body fluids can be detected at the level of specific histological features of OA cartilage tissue, as well as how they relate with each other at this level. METHODS: Adjacent...... sections were obtained from full-depth cartilage biopsies from 32 OA knees. Immunohistochemistry was performed for Helix-II and CTX-II, which are type II collagen fragments originating from the triple helix and the telopeptide region, respectively, and believed to reflect distinct breakdown events, as well...

  10. Quantifying the uncertainties of chemical evolution studies. II. Stellar yields

    CERN Document Server

    Romano, D; Tosi, M; Matteucci, F

    2010-01-01

    This is the second paper of a series which aims at quantifying the uncertainties in chemical evolution model predictions related to the underlying model assumptions. Specifically, it deals with the uncertainties due to the choice of the stellar yields. We adopt a widely used model for the chemical evolution of the Galaxy and test the effects of changing the stellar nucleosynthesis prescriptions on the predicted evolution of several chemical species. We find that, except for a handful of elements whose nucleosynthesis in stars is well understood by now, large uncertainties still affect the model predictions. This is especially true for the majority of the iron-peak elements, but also for much more abundant species such as carbon and nitrogen. The main causes of the mismatch we find among the outputs of different models assuming different stellar yields and among model predictions and observations are: (i) the adopted location of the mass cut in models of type II supernova explosions; (ii) the adopted strength ...

  11. The Kinematic Evolution of Strong MgII Absorbers

    CERN Document Server

    Mshar, Andrew C; Lynch, Ryan S; Churchill, Chris; Kim, Tae-Sun

    2007-01-01

    We consider the evolution of strong (W_r(2796) > 0.3A) MgII absorbers, most of which are closely related to luminous galaxies. Using 20 high resolution quasar spectra from the VLT/UVES public archive, we examine 33 strong MgII absorbers in the redshift range 0.3 < z < 2.5. We compare and supplement this sample with 23 strong MgII absorbers at 0.4 < z < 1.4 observed previously with HIRES/Keck. We find that neither equivalent width nor kinematic spread (the optical depth weighted second moment of velocity) of MgII2796 evolve. However, the kinematic spread is sensitive to the highest velocity component, and therefore not as sensitive to additional weak components at intermediate velocities relative to the profile center. The fraction of absorbing pixels within the full velocity range of the system does show a trend of decreasing with decreasing redshift. Most high redshift systems (14/20) exhibit absorption over the entire system velocity range, which differs from the result for low redshift systems ...

  12. THE EVOLUTION OF SOME BIOCHEMICAL PARAMETERS IN THE HONEYBEES’ HAEMOLYMPH (A. M. CARPATHICA COLLECTED IN THE INACTIVE SEASON

    Directory of Open Access Journals (Sweden)

    AGRIPINA SAPCALIU

    2013-12-01

    Full Text Available The biochemical analyses of the blood are largely used for the routine diagnosis and especially for the metabolic survey in farm animals. These facts conduct us to the idea that similar analyses, applied on honeybee hemolymph, could be used IN monitoring the healthy state of honeybee colonies. The present studies represent preliminary researches, which aimed to investigate the variability of the main biochemical parameters in the hemolymph of the healthy honeybees (Apis mellifera in inactive season. The researches were carried out on honeybee samples collected from 5 honeybee colonies belonging to a breeding apiary of the Institute for Beekeeping Research and Development from Bucharest. In order to perform the biochemical analyses, the honeybees samples, consisting in 50 individuals on sample (10 individuals/colony were randomly collected and their haemolimph collected, at different time intervals, in inactive season (fall-winter. Totally, there were collected 250 haemolyph samples in a 2 years interval and the following 21 biochemical parameters were analysed: GLU, HDL-c, ALP, T-cho, Tprot, Alb., BUN, LDH, CPK,, Mg, IP, GGT, GOT, GPT, Ca, Cre,, Amy, T–BIL, TG, UA.. The test was carried out after the collection and processing of the samples using the SPOTCHEM EZSP4430, equipment with dry kits, the slides technique, respectively .During the 2nd part of the inactive season, the values of most biochemical parameters increase in different proportions, their levels being maintained also in the first part of the active seasons (April, May, June.The values obtained for the main studied biochemical parameters in the haemolymph of the healthy honeybees collected from honeybee colonies kept in natural conditions show a highly variable evolution in the two consecutive years of experiments during the inactive season.

  13. Molecular evolution of the RNA polymerase II CTD.

    Science.gov (United States)

    Chapman, Rob D; Heidemann, Martin; Hintermair, Corinna; Eick, Dirk

    2008-06-01

    In higher eukaryotes, an unusual C-terminal domain (CTD) is crucial to the function of RNA polymerase II in transcription. The CTD consists of multiple heptapeptide repeats; differences in the number of repeats between organisms and their degree of conservation have intrigued researchers for two decades. Here, we review the evolution of the CTD at the molecular level. Several primitive motifs have been integrated into compound heptads that can be readily amplified. The selection of phosphorylatable residues in the heptad repeat provided the opportunity for advanced gene regulation in eukaryotes. Current findings suggest that the CTD should be considered as a collection of continuous overlapping motifs as opposed to a specific functional unit defined by a heptad.

  14. River water quality model no. 1 (RWQM1): II. Biochemical process equations

    DEFF Research Database (Denmark)

    Reichert, P.; Borchardt, D.; Henze, Mogens;

    2001-01-01

    In this paper, biochemical process equations are presented as a basis for water quality modelling in rivers under aerobic and anoxic conditions. These equations are not new, but they summarise parts of the development over the past 75 years. The primary goals of the presentation are to stimulate...... communication among modellers and field-oriented researchers of river water quality and of wastewater treatment, to facilitate practical application of river water quality modelling, and to encourage the use of elemental mass balances for the derivation of stoichiometric coefficients of biochemical...

  15. Aging as Evolution-Facilitating Program and a Biochemical Approach to Switch It Off

    Science.gov (United States)

    Skulachev, Vladimir P.

    A concept is presented considering aging of living organisms as a final step of their ontogenetic program. It is assumed that such an aging program was invented by biological evolution to facilitate the evolutionary process. Indications are summarized suggesting that controlled production of toxic forms of oxygen (so called reactive oxygen species) by respiring intracellular organelles (mitochondria) is an obligatory component of the aging program. First results of a research project devoted to an attempt to interrupt aging program by antioxidants specifically addressed to mitochondria have been described. Within the framework of the project, antioxidants of a new type (SkQ) were synthesized. SkQs are composed of (i) plastoquinone (an antioxidant moiety), (ii) a penetrating cation, and (iii) a decane or pentane linker. Using planar bilayer phospholipid membranes, we selected SkQ derivatives of the highest penetrability, namely plastoquinonyl decyl triphenylphosphonium (SkQ1), plastoquinonyl decyl rhodamine 19 (SkQR1), and methylplastoquinonyl decyl triphenylphosphonium (SkQ3). Anti- and prooxidant properties of these substances and also of ubiquinonyl-decyl-triphenylphosphonium (MitoQ) were tested in isolated mitochondria. Micromolar concentrations of cationic quinones are found to be very strong prooxidants, but in the lower (sub-micromolar) concentrations they display antioxidant activity which decreases in the series SkQ1 = SkQR1 > SkQ3 > MitoQ. Thus, the window between the anti- and prooxidant effects is the smallest for MitoQ and the largest for SkQ1 and SkQR1. SkQ1 is rapidly reduced by complex III of the mitochondrial respiratory chain, i.e. it is a rechargeable antioxidant. Extremely low concentrations of SkQ1 and SkQR1 completely arrest the H2O2-induced apoptosis in human fibroblasts and HeLa cells (for SkQ1, C 1/2 = 8 · 10-9M). Higher concentrations of SkQ1 are required to block necrosis initiated by reactive oxygen species (ROS). In mice, SkQ1

  16. Novel shape evolution in exotic Ni isotopes and Type II shell evolution

    CERN Document Server

    Tsunoda, Y; Shimizu, N; Honma, M; Utsuno, Y

    2013-01-01

    The shapes of neutron-rich exotic Ni isotopes are studied. Large-scale shell model calculations are performed by advanced Monte Carlo Shell Model (MCSM) for the $pf$-$g_{9/2}$-$d_{5/2}$ model space. Experimental energy levels are reproduced well by a single fixed Hamiltonian. Intrinsic shapes are analyzed for MCSM eigenstates. Intriguing interplays among spherical, oblate, prolate and gamma-unstable shapes are seen including shape fluctuations, $E$(5)-like situation, the magicity of doubly-magic $^{56,68,78}$Ni, and the coexistence of spherical and strongly deformed shapes. Regarding the last point, strong deformation and shell-gap reduction can take place simultaneously, while the latter occurs through the mechanism called Type II shell evolution driven by changes of configurations within the same nucleus and the tensor force.

  17. Modular evolution of glutathione peroxidase genes in association with different biochemical properties of their encoded proteins in invertebrate animals

    Directory of Open Access Journals (Sweden)

    Zo Young-Gun

    2009-04-01

    Full Text Available Abstract Background Phospholipid hydroperoxide glutathione peroxidases (PHGPx, the most abundant isoforms of GPx families, interfere directly with hydroperoxidation of lipids. Biochemical properties of these proteins vary along with their donor organisms, which has complicated the phylogenetic classification of diverse PHGPx-like proteins. Despite efforts for comprehensive analyses, the evolutionary aspects of GPx genes in invertebrates remain largely unknown. Results We isolated GPx homologs via in silico screening of genomic and/or expressed sequence tag databases of eukaryotic organisms including protostomian species. Genes showing strong similarity to the mammalian PHGPx genes were commonly found in all genomes examined. GPx3- and GPx7-like genes were additionally detected from nematodes and platyhelminths, respectively. The overall distribution of the PHGPx-like proteins with different biochemical properties was biased across taxa; selenium- and glutathione (GSH-dependent proteins were exclusively detected in platyhelminth and deuterostomian species, whereas selenium-independent and thioredoxin (Trx-dependent enzymes were isolated in the other taxa. In comparison of genomic organization, the GSH-dependent PHGPx genes showed a conserved architectural pattern, while their Trx-dependent counterparts displayed complex exon-intron structures. A codon for the resolving Cys engaged in reductant binding was found to be substituted in a series of genes. Selection pressure to maintain the selenocysteine codon in GSH-dependent genes also appeared to be relaxed during their evolution. With the dichotomized fashion in genomic organizations, a highly polytomic topology of their phylogenetic trees implied that the GPx genes have multiple evolutionary intermediate forms. Conclusion Comparative analysis of invertebrate GPx genes provides informative evidence to support the modular pathways of GPx evolution, which have been accompanied with sporadic

  18. How to be good at being a virus : Biochemical constraints of viral life-history evolution

    NARCIS (Netherlands)

    Berngruber, Thomas

    2008-01-01

    Viral reproduction depends on a careful balance of the viral life-cycle in time and magnitude. Maintenance of this balance is granted by the regulation of viral protein production and protein interactions. Viral evolution therefore hinges on the possibilities to optimize these protein interactions.

  19. Bacterial Bolsheviks: PS II and the Evolution of the Oxygenic Revolution

    Science.gov (United States)

    Kopp, R. E.; Kirschvink, J. L.; Newman, D. K.; Nash, C. Z.; Hilburn, I. A.

    2003-12-01

    After the rise of life itself, the most radical transformation of Earth's biogeochemical cycles was the transition from an anoxic to an oxic world. Though various studies have suggested O2 made its first bulk appearance in the atmosphere some time between 3.8 and 2.1 Ga, virtually all analyses agree the production of large quantities of free O2 was triggered by the evolution of oxygenic photosynthesis. We suggest the oldest strong geological evidence for O2 is the 2.22 Ga Kalahari Mn member of the Hotazel BIF (1), as in the oceans only free O2 can oxidize soluble Mn(II) into insoluble Mn(IV). Some have argued, however, that oxygenic cyanobacteria had originated by 2.7 Ga. The ˜500 Myr "gap" has often been interpreted as the timescale for gradual evolutionary improvement of the O2-generating system. Biochemical and genomic analyses of photosynthetic bacteria indicate that photosystems I and II, which operate together in cyanobacteria, had a long history of parallel development. Green sulfur bacteria and heliobacteria use PS-II, while green non-sulfur and purple bacteria use PS-I; none can use H2O as an electron donor. Recent genetic analyses show lateral gene transfer was rampant among photosynthetic lineages (2). Moreover, extant cyanobacteria shut down PS-II in the presence of an alternative electron donor like H2S. This suggests PS-I and PS-II came together with their functions intact. Hence, most `debugging' of the two systems predates their merger in the ancestor of modern cyanobacteria. The time interval between the lateral transfer events and the evolution of oxygenic photosynthesis could thus have been geologically short. We suggest the ˜500 Myr "gap" may result from misinterpretations. The presence of oxygenic photosynthesis is uncertain before the deposition of the Hotazel formation, in the aftermath of the Makganyene glaciation (1). A simple model of nutrient and reductant fluxes argues that, once triggered, the oxygenation of a reducing surface

  20. Insights into the molecular evolution of HslU ATPase through biochemical and mutational analyses.

    Directory of Open Access Journals (Sweden)

    Kwang Hoon Sung

    Full Text Available The ATP-dependent HslVU complexes are found in all three biological kingdoms. A single HslV protease exists in each species of prokaryotes, archaea, and eukaryotes, but two HslUs (HslU1 and HslU2 are present in the mitochondria of eukaryotes. Previously, a tyrosine residue at the C-terminal tail of HslU2 has been identified as a key determinant of HslV activation in Trypanosoma brucei and a phenylalanine at the equivalent position to E. coli HslU is found in T. brucei HslU1. Unexpectedly, we found that an F441Y mutation in HslU enhanced the peptidase and caseinolytic activity of HslV in E. coli but it showed partially reduced ATPase and SulA degradation activity. Previously, only the C-terminal tail of HslU has been the focus of HslV activation studies. However, the Pro315 residue interacting with Phe441 in free HslU has also been found to be critical for HslV activation. Hence, our current biochemical analyses explore the importance of the loop region just before Pro315 for HslVU complex functionality. The proline and phenylalanine pair in prokaryotic HslU was replaced with the threonine and tyrosine pair from the functional eukaryotic HslU2. Sequence comparisons between multiple HslUs from three different biological kingdoms in combination with biochemical analysis of E. coli mutants have uncovered important new insights into the molecular evolutionary pathway of HslU.

  1. Molecular and biochemical studies of the evolution, infection and transmission of insect bunyaviruses.

    Science.gov (United States)

    Bishop, D H; Beaty, B J

    1988-10-31

    Members of the Bunyaviridae family of RNA viruses (bunyaviruses, hantaviruses, nairoviruses, phleboviruses and uukuviruses) have been studied at the molecular and genetic level to understand the basis of their evolution and infection in vertebrate and invertebrate (arthropod) hosts. With the exception of the hantaviruses, these viruses infect and are transmitted by a variety of blood-sucking arthropods (mosquitoes, phlebotomines, gnats, ticks, etc.). The viruses are responsible for infection of various vertebrate species, occasionally causing human disease, morbidity and mortality (e.g. Rift Valley fever, Crimean-Congo haemorrhagic fever, Korean haemorrhagic fever). Genetic and molecular analyses of bunyaviruses have established the coding assignments of the three viral RNA species and documented which viral gene products determine host range and virulence. Ecological studies, with molecular techniques, have provided evidence for bunyavirus evolution in nature through genetic drift (involving the accumulation of point mutations) and shift (RNA-segment reassortment).

  2. Improved Differential Evolution Algorithm for Parameter Estimation to Improve the Production of Biochemical Pathway

    Directory of Open Access Journals (Sweden)

    Chuii Khim Chong

    2012-06-01

    Full Text Available This paper introduces an improved Differential Evolution algorithm (IDE which aims at improving its performance in estimating the relevant parameters for metabolic pathway data to simulate glycolysis pathway for yeast. Metabolic pathway data are expected to be of significant help in the development of efficient tools in kinetic modeling and parameter estimation platforms. Many computation algorithms face obstacles due to the noisy data and difficulty of the system in estimating myriad of parameters, and require longer computational time to estimate the relevant parameters. The proposed algorithm (IDE in this paper is a hybrid of a Differential Evolution algorithm (DE and a Kalman Filter (KF. The outcome of IDE is proven to be superior than Genetic Algorithm (GA and DE. The results of IDE from experiments show estimated optimal kinetic parameters values, shorter computation time and increased accuracy for simulated results compared with other estimation algorithms

  3. Biochemical and phenotypic abnormalities in kynurenine aminotransferase II-deficient mice.

    Science.gov (United States)

    Yu, Ping; Di Prospero, Nicholas A; Sapko, Michael T; Cai, Tao; Chen, Amy; Melendez-Ferro, Miguel; Du, Fu; Whetsell, William O; Guidetti, Paolo; Schwarcz, Robert; Tagle, Danilo A

    2004-08-01

    Kynurenic acid (KYNA) can act as an endogenous modulator of excitatory neurotransmission and has been implicated in the pathogenesis of several neurological and psychiatric diseases. To evaluate its role in the brain, we disrupted the murine gene for kynurenine aminotransferase II (KAT II), the principal enzyme responsible for the synthesis of KYNA in the rat brain. mKat-2(-/-) mice showed no detectable KAT II mRNA or protein. Total brain KAT activity and KYNA levels were reduced during the first month but returned to normal levels thereafter. In contrast, liver KAT activity and KYNA levels in mKat-2(-/-) mice were decreased by >90% throughout life, though no hepatic abnormalities were observed histologically. KYNA-associated metabolites kynurenine, 3-hydroxykynurenine, and quinolinic acid were unchanged in the brain and liver of knockout mice. mKat-2(-/-) mice began to manifest hyperactivity and abnormal motor coordination at 2 weeks of age but were indistinguishable from wild type after 1 month of age. Golgi staining of cortical and striatal neurons revealed enlarged dendritic spines and a significant increase in spine density in 3-week-old mKat-2(-/-) mice but not in 2-month-old animals. Our results show that gene targeting of mKat-2 in mice leads to early and transitory decreases in brain KAT activity and KYNA levels with commensurate behavioral and neuropathological changes and suggest that compensatory changes or ontogenic expression of another isoform may account for the normalization of KYNA levels in the adult mKat-2(-/-) brain.

  4. Isolation of plasma and nuclear membranes of thymocytes. II. Biochemical composition.

    Science.gov (United States)

    Monneron, A; d'Alayer, J

    1978-04-01

    Thymocyte plasma and nuclear membranes obtained by the procedure described in the accompanying paper were analyzed for their biochemical composition. Plasma membranes were very rich in phospholipid, cholesterol, sialic aicd; they did not contain nucleic acids. In comparison, nuclear membranes had a lower phospholipid to protein ratio and contained much less sialic acid and cholesterol. 50% of the cellular cholesterol and of the membrane-bound sialic acid were found in the plasma membranes, 14% in the nuclear membranes. Live cells were labeled with 131I, and the acid-insoluble radioactivity was followed in the subfractions. A good correlation with the distribution and enrichment of plasma membrane market-enzymes was obtained. Label enrichment was about 50-fold in the two lightest of the three plasma membrane fractions. 60% of the label was contained in the plasma membranes, only 4% in the nuclear membranes. Cross-contamination of these two types of membranes was thus negligible. Sodium dodecyl sulfate-gel electrophoresis revealed three different patterns specific for, respectively, plasma membranes, the microsomal-mitochondrial fraction, and nuclear membranes. Each pattern was characterized by a set of proteins and glycoproteins, among which high molecular weight glycoproteins could be considered as marker-proteins of, respectively, 280,000, 260,000, and 230,000 daltons. 131I-labeling of live cells tagged with a very high specific activity three glycoproteins of mol wt 280,000, 200,000, and 135,000 daltons. Nuclear membranes prepared from labeled isolated nuclei had a set of labeled proteins completely different from plasma membranes.

  5. [Changes in platelet concentrates from dogs due to storage. II. Biochemical changes in concentrate plasma].

    Science.gov (United States)

    Klein, A; Adamik, A; Mischke, R

    1999-08-01

    Platelet concentrate (PC) obtained from dogs with an automatic cell separator was stored in C4-cell separation sets with low gasdiffusionable Polyvinylchlorid (PVC) storage containers or in C4L-sets developed for storage with high gasdiffusionable Polyolefin(PO) containers, respectively. PC were stored for 10 days under permanent agitation at 22 degrees C (C4/22 degrees C, n = 10; C4L/22 degrees C, n = 11) or at 4 degrees C (C4L/4 degrees C, n = 6), respectively. Measurements were carried out directly after production of the PC, after 6 hours and then daily during the 10-day storage period. In the second part of this paper the results of pH, the concentration of bicarbonate, glucose, lactate and potassium ions as well as the activity of lactate dehydrogenase (LDH) are presented. The varying duration and intensity of the energy metabolism of the platelets and different part of glycolysis became obvious by the consumption of glucose and production of lactate, which differed significantly between the different storage conditions. Resulting from this, the mean pH decreased under the limit prescribed for human PC (pH = 6.3) already after a storage period of 3 days due to the slight capacity of gas diffusion in PVC-containers (C4/22 degrees C). In the PO-containers the pH fell below this limit at 22 degrees C (C4L/22 degrees C) after a storage period of 5 days and at 4 degrees C (C4L/4 degrees C) after 10 days. The latter reflects the high gas diffusion capacity of the PO-containers and the decreased metabolism activity at 4 degrees C. The increase of activity of LDH and of the concentration of potassium ions, which are localized in the cytosol of platelets, depended also on the different storage conditions and, thereby, reflected the different rapidity of increasing membrane permeability or the destruction of the cell membrane, respectively. The results of this study nearly are in agreement with the changes of platelet function shown in part I. Biochemical changes occur

  6. The evolution of increased competitive ability, innate competitive advantages, and novel biochemical weapons act in concert for a tropical invader.

    Science.gov (United States)

    Qin, Rui-Min; Zheng, Yu-Long; Valiente-Banuet, Alfonso; Callaway, Ragan M; Barclay, Gregor F; Pereyra, Carlos Silva; Feng, Yu-Long

    2013-02-01

    There are many non-mutually exclusive mechanisms for exotic invasions but few studies have concurrently tested more than one hypothesis for the same species. Here, we tested the evolution of increased competitive ability (EICA) hypothesis in two common garden experiments in which Chromolaena odorata plants originating from native and nonnative ranges were grown in competition with natives from each range, and the novel weapons hypothesis in laboratory experiments with leachates from C. odorata. Compared with conspecifics originating from the native range, C. odorata plants from the nonnative range were stronger competitors at high nutrient concentrations in the nonnative range in China and experienced far more herbivore damage in the native range in Mexico. In both China and Mexico, C. odorata was more suppressed by species native to Mexico than by species native to China. Species native to China were much more inhibited by leaf extracts from C. odorata than species from Mexico, and this difference in allelopathic effects may provide a possible explanation for the biogeographic differences in competitive ability. Our results indicate that EICA, innate competitive advantages, and novel biochemical weapons may act in concert to promote invasion by C. odorata, and emphasize the importance of exploring multiple, non-mutually exclusive mechanisms for invasions.

  7. Detection of Extended He II Reionization in the Temperature Evolution of the Intergalactic Medium

    CERN Document Server

    Becker, George D; Haehnelt, Martin G; Sargent, Wallace L W

    2010-01-01

    We present new measurements of the temperature of the intergalactic medium (IGM) derived from the Lyman-alpha forest over 2.0 ~12000 K at z ~ 2.8. This increase is not consistent with the monotonic decline in T0 expected in the absence of He II reionization. We therefore interpret the observed rise in temperature as evidence of He II reionization beginning at z >~ 4.4. The evolution of T0 is consistent with an end to He II reionization at z ~ 3, as suggested by opacity measurements of the He II Lyman-alpha forest, although the redshift at which T0 peaks will depend somewhat on the evolution of th e temperature-density relation. These new temperature measurements suggest that the heat input due to the reionization of He II dominates the thermal balance of the IGM over an extended period with Delta_z >~ 1.

  8. Evolution of science II: Insights into working of Nature

    CERN Document Server

    Vahia, M N

    2016-01-01

    We attempt to provide a comprehensive model of evolution of science across millennia taking into account the contributions of other intellectual traditions, cultural value system and increasing in sophistication of humans in their study of nature. We also briefly discuss the role of technology and its interplay in the evolution of science. We identify five primary approaches to the study of nature, namely ad hoc formulations, religious approach, pragmatic approach, axiomatic approach and the logic based approach. Each of these approaches have had their prime periods and have contributed significantly to human understanding of nature and have also overlapped within a society. Each approach has had a central role over human evolution at some stage. We surmise that the currently dominant axiomatic method will reach its limits due to complexity of the system and may never be fully formalised. We suggest that the future progress of science will more be a logic based approach where experimentation and simulations r...

  9. Association analysis of urotensin II gene (UTS2 and flanking regions with biochemical parameters related to insulin resistance.

    Directory of Open Access Journals (Sweden)

    María E Sáez

    Full Text Available BACKGROUND: Urotensin II (UII is a potent vasoconstrictor peptide, which signals through a G-protein coupled receptor (GPCR known as GPR14 or urotensin receptor (UTR. UII exerts a broad spectrum of actions in several systems such as vascular cell, heart muscle or pancreas, where it inhibits insulin release. OBJECTIVE: Given the reported role of UII in insulin secretion, we have performed a genetic association analysis of the UTS2 gene and flanking regions with biochemical parameters related to insulin resistance (fasting glucose, glucose 2 hours after a glucose overload, fasting insulin and insulin resistance estimated as HOMA. RESULTS AND CONCLUSIONS: We have identified several polymorphisms associated with the analysed clinical traits, not only at the UTS2 gene, but also in thePER3 gene, located upstream from UTS2. Our results are compatible with a role for UII in glucose homeostasis and diabetes although we cannot rule out the possibility that PER3 gene may underlie the reported associations.

  10. Thermodynamic evolution of the cosmological baryonic gas II. Galaxy formation

    CERN Document Server

    Alimi, J M

    2004-01-01

    The problem of galaxy formation and its dependence on thermodynamic properties is addressed by using Eulerian hydrodynamic numerical simulations of large scale structure formation. Global galaxy properties are explored in simulations including gravitation, shock heating and cooling processes, and following self-consistently the chemical evolution of a primordial composition hydrogen-helium plasma without assuming collisional ionization equilibrium. The galaxy formation model is mainly based on the identification of converging dense cold gas regions. We show that the evolution at low redshift of the observed cosmic star formation rate density is reproduced, and that the galaxy-like object mass function is dominated by low-mass objects. The galaxy mass functions are well described by a two power-law Schechter function whose parameters are in good agreement with observational fits of the galaxy luminosity function. The high-mass end of the galaxy mass function includes objects formed at early epochs and residing...

  11. Animal lectins as self/non-self recognition molecules. Biochemical and genetic approaches to understanding their biological roles and evolution.

    Science.gov (United States)

    Vasta, G R; Ahmed, H; Fink, N E; Elola, M T; Marsh, A G; Snowden, A; Odom, E W

    1994-04-15

    In recent years, the significant contributions from molecular research studies on animal lectins have elucidated structural aspects and provided clues not only to their evolution but also to their multiple biological functions. The experimental evidence has suggested that distinct, and probably unrelated, groups of molecules are included under the term "lectin." Within the invertebrate taxa, major groups of lectins can be identified: One group would include lectins that show significant homology to membrane-integrated or soluble vertebrate C-type lectins. The second would include those beta-galactosyl-specific lectins homologous to the S-type vertebrate lectins. The third group would be constituted by lectins that show homology to vertebrate pentraxins that exhibit lectin-like properties, such as C-reactive protein and serum amyloid P. Finally, there are examples that do not exhibit similarities to any of the aforementioned categories. Moreover, the vast majority of invertebrate lectins described so far cannot yet be placed in one or another group because of the lack of information regarding their primary structure. (See Table 1.) Animal lectins do not express a recombinatorial diversity like that of antibodies, but a limited diversity in recognition capabilities would be accomplished by the occurrence of multiple lectins with distinct specificities, the presence of more than one binding site, specific for different carbohydrates in a single molecule, and by certain "flexibility" of the binding sites that would allow the recognition of a range of structurally related carbohydrates. In order to identify the lectins' "natural" ligands, we have investigated the interactions between those proteins and the putative endogenous or exogenous glycosylated substances or cells that may be relevant to their biological function. Results from these studies, together with information on the biochemical properties of invertebrate and vertebrate lectins, including their structural

  12. Properties of Star Clusters - II: Scale Height Evolution of Clusters

    CERN Document Server

    Buckner, Anne S M

    2014-01-01

    Until now it has been impossible to observationally measure how star cluster scale height evolves beyond 1Gyr as only small samples have been available. Here we establish a novel method to determine the scale height of a cluster sample using modelled distributions and Kolmogorov-Smirnov tests. This allows us to determine the scale height with a 25% accuracy for samples of 38 clusters or more. We apply our method to investigate the temporal evolution of cluster scale height, using homogeneously selected sub-samples of Kharchenko et al. (MWSC), Dias et al. (DAML02), WEBDA, and Froebrich et al. (FSR). We identify a linear relationship between scale height and log(age/yr) of clusters, considerably different from field stars. The scale height increases from about 40pc at 1Myr to 75pc at 1Gyr, most likely due to internal evolution and external scattering events. After 1Gyr, there is a marked change of the behaviour, with the scale height linearly increasing with log(age/yr) to about 550pc at 3.5Gyr. The most likely...

  13. Adaptation of a Cyanobacterium to a Biochemically Rich Environment in Experimental Evolution as an Initial Step toward a Chloroplast-Like State

    Science.gov (United States)

    Suzuki, Shingo; Miyazaki, Mikako; Takikawa, Go; Sakurai, Takahiro; Kashiwagi, Akiko; Sueyoshi, Makoto; Matsumoto, Yusuke; Kiuchi, Ayako; Mori, Kotaro; Yomo, Tetsuya

    2014-01-01

    Chloroplasts originated from cyanobacteria through endosymbiosis. The original cyanobacterial endosymbiont evolved to adapt to the biochemically rich intracellular environment of the host cell while maintaining its photosynthetic function; however, no such process has been experimentally demonstrated. Here, we show the adaptation of a model cyanobacterium, Synechocystis sp. PCC 6803, to a biochemically rich environment by experimental evolution. Synechocystis sp. PCC 6803 does not grow in a biochemically rich, chemically defined medium because several amino acids are toxic to the cells at approximately 1 mM. We cultured the cyanobacteria in media with the toxic amino acids at 0.1 mM, then serially transferred the culture, gradually increasing the concentration of the toxic amino acids. The cells evolved to show approximately the same specific growth rate in media with 0 and 1 mM of the toxic amino acid in approximately 84 generations and evolved to grow faster in the media with 1 mM than in the media with 0 mM in approximately 181 generations. We did not detect a statistically significant decrease in the autotrophic growth of the evolved strain in an inorganic medium, indicating the maintenance of the photosynthetic function. Whole-genome resequencing revealed changes in the genes related to the cell membrane and the carboxysome. Moreover, we quantitatively analyzed the evolutionary changes by using simple mathematical models, which evaluated the evolution as an increase in the half-maximal inhibitory concentration (IC50) and estimated quantitative characteristics of the evolutionary process. Our results clearly demonstrate not only the potential of a model cyanobacterium to adapt to a biochemically rich environment without a significant decrease in photosynthetic function but also the properties of its evolutionary process, which sheds light of the evolution of chloroplasts at the initial stage. PMID:24874568

  14. Dynamical evolution of star forming regions - II. Basic kinematics

    CERN Document Server

    Parker, Richard J

    2016-01-01

    We follow the dynamical evolution of young star-forming regions with a wide range of initial conditions and examine how the radial velocity dispersion, $\\sigma$, evolves over time. We compare this velocity dispersion to the theoretically expected value for the velocity dispersion if a region were in virial equilibrium, $\\sigma_{\\rm vir}$ and thus assess the virial state ($\\sigma / \\sigma_{\\rm vir}$) of these systems. We find that in regions that are initially subvirial, or in global virial equilibrium but subvirial on local scales, the system relaxes to virial equilibrium within several million years, or roughly 25 - 50 crossing times, according to the measured virial ratio. However, the measured velocity dispersion, $\\sigma$, appears to be a bad diagnostic of the current virial state of these systems as it suggests that they become supervirial when compared to the velocity dispersion estimated from the virial mass, $\\sigma_{\\rm vir}$. We suggest that this discrepancy is caused by the fact that the regions ar...

  15. Structure and evolution of low-mass Population II stars

    Science.gov (United States)

    Montalbán, J.; D'Antona, F.; Mazzitelli, I.

    2000-08-01

    The focus of the present paper is on the detailed description of the internal structures of low mass, population II stars, to clarify some issues about these stellar models and, mainly, their present reliability for observational comparisons. We then explore 1) the role of the local convective model; 2) the differences between "grey" and "non grey" models, and between models in which the photospheric boundary conditions are set at different optical depths (τph = 3 or 100); 3) the role of the equation of state (EoS), both in the atmospheric models and in the interior. One of the major conclusions of the paper is a cautionary note about the usage of the additive volume law in EoS calculations. The dependence of the HR diagram locations and mass luminosity relations on metal and helium content are also discussed. A few comparisons with globular cluster stars show that: 1) general consistency of distance scales and morphologies in the HR diagram is found, when comparing ground based measurements in the Johnson B and V bands and observations in the HST bands; 2) a discrepancy between models and observations may exist for more metal rich clusters; 3) the plausible hypothesis that the mass function in the globular cluster NGC 6397 behaves smoothly until the lower limit of the main sequence poses constraints on the mass-luminosity relation at the lowest end of the main sequence. The evolutionary tracks are available at the WEB location http://www.mporzio.astro.it.

  16. H II Regions and Protosolar Abundances in Galactic Chemical Evolution

    Directory of Open Access Journals (Sweden)

    L. Carigi

    2011-01-01

    Full Text Available Presentamos modelos de evolución química del disco galáctico con diferentes rendimientos dependientes de Z. Encontramos que una tasa moderada de pérdida de masa en estrellas masivas de metalicidad solar produce un excelente ajuste con los gradientes de C/H y C/O del disco de la Galaxia. El mejor modelo reproduce: las abundancias de H, He, C y O derivadas de líneas de recombinación en M17, las abundancias protosolares y las relaciones C/O-O/H, C/Fe-Fe/H y O/Fe-Fe/H derivadas de estrellas de la vecindad solar. La concordancia del modelo con las abundancias protosolares implica que el Sol se originó a una distancia galactocéntrica similar a la actual. El modelo para r = 3 kpc implica que una fracción de las estrellas en la dirección del bulbo se formó en el disco interno. Nuestro modelo reproduce la relación C/O-O/H derivada de regiones H II extragalácticas en galaxias espirales.

  17. Begetting machinery IIEvolutionärer Algorithmus und technische Evolution

    Directory of Open Access Journals (Sweden)

    Rothenhäusler, Andie

    2011-10-01

    Full Text Available In the 1970s and 1980s two new approaches to an evolutionary explanation of technology emerged: While a new generation of sociobiologists increasingly started to view animal and human artifacts as an ,extended phenotype’ of humankind historians and sociologists of technology found in an evolutionary genesis of technology a third way between technological determinism and a social construction of technology. This evolution of technology seemed able to explain multi-causal coherences in the genesis of technology applicably by using allegedly simple rules.

  18. Origin and Dynamical Evolution of Neptune Trojans - II: Long Term Evolution

    CERN Document Server

    Lykawka, Patryk Sofia; Jones, Barrie W; Mukai, Tadashi

    2010-01-01

    We present results examining the fate of the Trojan clouds produced in our previous work. We find that the stability of Neptunian Trojans seems to be strongly correlated to their initial post-migration orbital elements, with those objects that survive as Trojans for billions of years displaying negligible orbital evolution. The great majority of these survivors began the integrations with small eccentricities (e 20{\\deg}. Dynamical integrations of the currently observed Trojans show that five out of the seven are dynamically stable on 4 Gyr timescales, while 2001 QR322, exhibits significant dynamical instability. The seventh Trojan object, 2008 LC18, has such large orbital uncertainties that only future studies will be able to determine its stability.

  19. Precious Metals in SDSS Quasar Spectra II: Tracking the Evolution of Strong, 0.4 < z < 2.3 MgII Absorbers with Thousands of Systems

    CERN Document Server

    Seyffert, Eduardo N; Simcoe, Robert A; O'Meara, John M; Kao, Melodie M; Prochaska, J Xavier

    2013-01-01

    We have performed an analysis of over 34,000 MgII doublets at 0.36 2.3, while the W_r >= 1 \\AA absorber line density grew, dN_MgII/dX, by roughly 45%. Finally, we explore the different evolution of various absorber populations---damped Lyman-alpha absorbers, Lyman-limit systems, strong CIV absorbers, and strong and weaker MgII systems---across cosmic time (0 < z < 6).

  20. Cosmological Evolution of Supermassive Black Holes. II. Evidence for Downsizing of Spin Evolution

    CERN Document Server

    Li, Yan-Rong; Ho, Luis C

    2012-01-01

    The spin is an important but poorly constrained parameter for describing supermassive black holes (SMBHs). Using the continuity equation of SMBH number density, we explicitly obtain the mass-dependent cosmological evolution of the radiative efficiency for accretion, which serves as a proxy for SMBH spin. Our calculations make use of the SMBH mass function of active and inactive galaxies (derived in the first paper of this series), the bolometric luminosity function of active galactic nuclei (AGNs), corrected for the contribution from Compton-thick sources, and the observed Eddington ratio distribution. We find that the radiative efficiency generally increases with increasing black hole mass at high redshifts (z>~1), roughly as \\eta \\propto M_bh^0.5, while the trend reverses at lower redshifts, such that the highest efficiencies are attained by the lowest mass black holes. Black holes with M_bh>~10^8.5M_sun maintain radiative efficiencies as high as \\eta~0.3-0.4 at high redshifts, near the maximum for rapidly ...

  1. Cosmological Evolution of Supermassive Black Holes. II. Evidence for Downsizing of Spin Evolution

    Science.gov (United States)

    Li, Yan-Rong; Wang, Jian-Min; Ho, Luis C.

    2012-04-01

    The spin is an important but poorly constrained parameter for describing supermassive black holes (SMBHs). Using the continuity equation of SMBH number density, we explicitly obtain the mass-dependent cosmological evolution of the radiative efficiency for accretion, which serves as a proxy for SMBH spin. Our calculations make use of the SMBH mass function of active and inactive galaxies (derived in the first paper of this series), the bolometric luminosity function of active galactic nuclei (AGNs), corrected for the contribution from Compton-thick sources, and the observed Eddington ratio distribution. We find that the radiative efficiency generally increases with increasing black hole mass at high redshifts (z >~ 1), roughly as ηvpropM 0.5 •, while the trend reverses at lower redshifts, such that the highest efficiencies are attained by the lowest mass black holes. Black holes with M • >~ 108.5 M ⊙ maintain radiative efficiencies as high as η ≈ 0.3-0.4 at high redshifts, near the maximum for rapidly spinning systems, but their efficiencies drop dramatically (by an order of magnitude) by z ≈ 0. The pattern for lower mass holes is somewhat more complicated but qualitatively similar. Assuming that the standard accretion disk model applies, we suggest that the accretion history of SMBHs and their accompanying spins evolves in two distinct regimes: an early phase of prolonged accretion, plausibly driven by major mergers, during which the black hole spins up, then switching to a period of random, episodic accretion, governed by minor mergers and internal secular processes, during which the hole spins down. The transition epoch depends on mass, mirroring other evidence for "cosmic downsizing" in the AGN population; it occurs at z ≈ 2 for high-mass black holes and somewhat later, at z ≈ 1, for lower mass systems.

  2. Rapid molecular evolution across amniotes of the IIS/TOR network.

    Science.gov (United States)

    McGaugh, Suzanne E; Bronikowski, Anne M; Kuo, Chih-Horng; Reding, Dawn M; Addis, Elizabeth A; Flagel, Lex E; Janzen, Fredric J; Schwartz, Tonia S

    2015-06-02

    The insulin/insulin-like signaling and target of rapamycin (IIS/TOR) network regulates lifespan and reproduction, as well as metabolic diseases, cancer, and aging. Despite its vital role in health, comparative analyses of IIS/TOR have been limited to invertebrates and mammals. We conducted an extensive evolutionary analysis of the IIS/TOR network across 66 amniotes with 18 newly generated transcriptomes from nonavian reptiles and additional available genomes/transcriptomes. We uncovered rapid and extensive molecular evolution between reptiles (including birds) and mammals: (i) the IIS/TOR network, including the critical nodes insulin receptor substrate (IRS) and phosphatidylinositol 3-kinase (PI3K), exhibit divergent evolutionary rates between reptiles and mammals; (ii) compared with a proxy for the rest of the genome, genes of the IIS/TOR extracellular network exhibit exceptionally fast evolutionary rates; and (iii) signatures of positive selection and coevolution of the extracellular network suggest reptile- and mammal-specific interactions between members of the network. In reptiles, positively selected sites cluster on the binding surfaces of insulin-like growth factor 1 (IGF1), IGF1 receptor (IGF1R), and insulin receptor (INSR); whereas in mammals, positively selected sites clustered on the IGF2 binding surface, suggesting that these hormone-receptor binding affinities are targets of positive selection. Further, contrary to reports that IGF2R binds IGF2 only in marsupial and placental mammals, we found positively selected sites clustered on the hormone binding surface of reptile IGF2R that suggest that IGF2R binds to IGF hormones in diverse taxa and may have evolved in reptiles. These data suggest that key IIS/TOR paralogs have sub- or neofunctionalized between mammals and reptiles and that this network may underlie fundamental life history and physiological differences between these amniote sister clades.

  3. Estimation of oxygen evolution by marine phytoplankton from measurement of the efficiency of Photosystem II electron flow.

    NARCIS (Netherlands)

    Geel, C.; Versluis, W.; Snel, J.F.H.

    1997-01-01

    The relation between photosynthetic oxygen evolution and Photosystem II electron transport was investigated for the marine algae t Phaeodactylum tricornutum, Dunaliella tertiolecta, Tetraselmis sp., t Isochrysis sp. and t Rhodomonas sp.. The rate of Photosystem II electron transport was estimated fr

  4. Fluctuating helical asymmetry and morphology of snails (Gastropoda in divergent microhabitats at 'Evolution Canyons I and II,' Israel.

    Directory of Open Access Journals (Sweden)

    Shmuel Raz

    Full Text Available BACKGROUND: Developmental instability of shelled gastropods is measured as deviations from a perfect equiangular (logarithmic spiral. We studied six species of gastropods at 'Evolution Canyons I and II' in Carmel and the Galilee Mountains, Israel, respectively. The xeric, south-facing, 'African' slopes and the mesic, north-facing, 'European' slopes have dramatically different microclimates and plant communities. Moreover, 'Evolution Canyon II' receives more rainfall than 'Evolution Canyon I.' METHODOLOGY/PRINCIPAL FINDINGS: We examined fluctuating asymmetry, rate of whorl expansion, shell height, and number of rotations of the body suture in six species of terrestrial snails from the two 'Evolution Canyons.' The xeric 'African' slope should be more stressful to land snails than the 'European' slope, and 'Evolution Canyon I' should be more stressful than 'Evolution Canyon II.' Only Eopolita protensa jebusitica showed marginally significant differences in fluctuating helical asymmetry between the two slopes. Contrary to expectations, asymmetry was marginally greater on the 'European' slope. Shells of Levantina spiriplana caesareana at 'Evolution Canyon I,' were smaller and more asymmetric than those at 'Evolution Canyon II.' Moreover, shell height and number of rotations of the suture were greater on the north-facing slopes of both canyons. CONCLUSIONS/SIGNIFICANCE: Our data is consistent with a trade-off between drought resistance and thermoregulation in snails; Levantina was significantly smaller on the 'African' slope, for increasing surface area and thermoregulation, while Eopolita was larger on the 'African' slope, for reducing water evaporation. In addition, 'Evolution Canyon I' was more stressful than Evolution Canyon II' for Levantina.

  5. Azide as a competitor of chloride in oxygen evolution by Photosystem II.

    Science.gov (United States)

    Haddy, A; Hatchell, J A; Kimel, R A; Thomas, R

    1999-05-11

    Oxygen evolution by higher plants requires chloride, which binds to a site associated with the oxygen-evolving complex of photosystem II (PSII). In this study, the inhibitory effect of the anion azide was characterized using steady state measurements of oxygen evolution activity in PSII-enriched thylakoid membranes. N3- (7.8 mM) inhibited O2 evolution activity by 50% when a standard buffer containing chloride was used. By considering Cl- as the substrate in O2 evolution assays, we found azide to be primarily competitive with Cl- with an inhibitor dissociation constant Ki of about 0.6 mM. An uncompetitive component with a Ki ' of 11 mM was also found. Removal of the 17 and 23 kDa polypeptides resulted in a decrease in each inhibition constant. A pH dependence study of O2 evolution activity showed that the pH maximum became narrower and shifted to a higher pH in the presence of azide. Analysis of the data indicated that an acidic residue defined the low side of the pH maximum with an apparent pKa of 6.7 in the presence of azide compared with 5.5 for the control. A basic residue was also affected, exhibiting an apparent pKa of 7.1 compared with a value of 7.6 for the control. This result can be explained by a simple model in which azide binding to the chloride site moves negative charge of the anion away from the basic residue and toward the acidic residue relative to chloride. As a competitor of chloride, azide may provide an interesting probe of the oxygen-evolving complex in future studies.

  6. Evolution of the biochemical profile of children treated or undergoing treatment for moderate or severe stunting: consequences of metabolic programming?

    Directory of Open Access Journals (Sweden)

    Jullyana F.R. Alves

    2014-07-01

    Full Text Available OBJECTIVE: to evaluate changes in the biochemical profile of children treated or being treated for moderate or severe stunting in a nutrition recovery and education center. METHODS: this was a retrospective longitudinal study of 263 children treated at this center between August of 2008 to August of 2011, aged 1 to 6 years, diagnosed with moderate (z-score of height-for-age [HAZ] < -2 or severe stunting (HAZ < -3. Data were collected on socioeconomic conditions, dietary habits, and biochemical changes, as well as height according to age. RESULTS: the nutritional intervention showed an increase in HAZ of children with moderate (0.51 ± 0.4, p = 0.001 and severe (0.91 ± 0.7, p = 0.001 stunting during the monitoring. Increased levels of insulin-like growth factor 1 (IGF-1 (initial: 71.7 ng/dL; final: 90.4 ng/dL; p = 0.01 were also observed, as well as a reduction in triglycerides (TG in both severely (initial: 91.8 mg/dL; final: 79.1 mg/dL; p = 0.01 and in moderately malnourished children (initial: 109.2 mg/dL; final 88.7 mg/dL; p = 0.01, and a significant increase in high-density lipoprotein cholesterol HDL-C only in the third year of intervention (initial: 31.4 mg/dL; final: 42.2 mg/dL. The values of total cholesterol (TC and low-density lipoprotein cholesterol (LDL-C levels remained high throughout the treatment (initial: 165.1 mg/dL; final: 163.5 mg/dL and initial: 109.0 mg/dL; final: 107.3 mg/dL, respectively. CONCLUSION: the nutritional treatment for children with short stature was effective in reducing stunting and improving TG and HDL-C after three years of intervention. However, the levels of LDL-C and TC remained high even in treated children. It is therefore speculated that these changes may result from metabolic programming due to malnutrition.

  7. Cobalt(II Coordination Compounds of Ethyl 4-Methyl-5-Imidazolecarboxylate: Chemical and Biochemical Characterization on Photosynthesis and Seed Germination

    Directory of Open Access Journals (Sweden)

    Beatriz King-Díaz

    2005-01-01

    chloroplasts. Seed germination and seedling growth of the monocotyledonous species Lolium multiflorum and Triticum aestivum and the dicotyledonous species Trifolium alexandrinum and Physalis ixocarpa were also assayed under the effect of the compounds and salts. The results showed that cobalt(II salts and their emizco coordination compounds inhibit photosynthetic electron flow and ATP-synthesis, behaving as Hill reaction inhibitors. Coordination compounds are more potent inhibitors than the salts. It was found that the salts target is at the b6f level while the complexes targets are at QB(D1-protein and b6f level. The QB inhibition site was confirmed by variable chlorophyll a fluorescence yield. On the other hand, emizco inhibits seed germination, root and shoot development, in both weed and crop species. Cobalt(II coordination compounds are the most effective photosynthesis inhibitors, but they are less potent than emizco in germination and seedling growth, while the metal salts are the least active of all.

  8. World War II, tantalum, and the evolution of modern cranioplasty technique.

    Science.gov (United States)

    Flanigan, Patrick; Kshettry, Varun R; Benzel, Edward C

    2014-04-01

    Cranioplasty is a unique procedure with a rich history. Since ancient times, a diverse array of materials from coconut shells to gold plates has been used for the repair of cranial defects. More recently, World War II greatly increased the demand for cranioplasty procedures and renewed interest in the search for a suitable synthetic material for cranioprostheses. Experimental evidence revealed that tantalum was biologically inert to acid and oxidative stresses. In fact, the observation that tantalum did not absorb acid resulted in the metal being named after Tantalus, the Greek mythological figure who was condemned to a pool of water in the Underworld that would recede when he tried to take a drink. In clinical use, malleability facilitated a single-stage cosmetic repair of cranial defects. Tantalum became the preferred cranioplasty material for more than 1000 procedures performed during World War II. In fact, its use was rapidly adopted in the civilian population. During World War II and the heyday of tantalum cranioplasty, there was a rapid evolution in prosthesis implantation and fixation techniques significantly shaping how cranioplasties are performed today. Several years after the war, acrylic emerged as the cranioplasty material of choice. It had several clear advantages over its metallic counterparts. Titanium, which was less radiopaque and had a more optimal thermal conductivity profile (less thermally conductive), eventually supplanted tantalum as the most common metallic cranioplasty material. While tantalum cranioplasty was popular for only a decade, it represented a significant breakthrough in synthetic cranioplasty. The experiences of wartime neurosurgeons with tantalum cranioplasty played a pivotal role in the evolution of modern cranioplasty techniques and ultimately led to a heightened understanding of the necessary attributes of an ideal synthetic cranioplasty material. Indeed, the history of tantalum cranioplasty serves as a model for innovative

  9. Diversity, mobility, and structural and functional evolution of group II introns carrying an unusual 3' extension

    Directory of Open Access Journals (Sweden)

    Tourasse Nicolas J

    2011-12-01

    Full Text Available Abstract Background Group II introns are widespread genetic elements endowed with a dual functionality. They are catalytic RNAs (ribozymes that are able of self-splicing and they are also mobile retroelements that can invade genomic DNA. The group II intron RNA secondary structure is typically made up of six domains. However, a number of unusual group II introns carrying a unique extension of 53-56 nucleotides at the 3' end have been identified previously in bacteria of the Bacillus cereus group. Methods In the present study, we conducted combined sequence comparisons and phylogenetic analyses of introns, host gene, plasmid and chromosome of host strains in order to gain insights into mobility, dispersal, and evolution of the unusual introns and their extension. We also performed in vitro mutational and kinetic experiments to investigate possible functional features related to the extension. Results We report the identification of novel copies of group II introns carrying a 3' extension including the first two copies in bacteria not belonging to the B. cereus group, Bacillus pseudofirmus OF4 and Bacillus sp. 2_A_57_CT2, an uncharacterized species phylogenetically close to B. firmus. Interestingly, the B. pseudofirmus intron has a longer extension of 70 bases. From sequence comparisons and phylogenetic analyses, several possible separate events of mobility involving the atypical introns could be identified, including both retrohoming and retrotransposition events. In addition, identical extensions were found in introns that otherwise exhibit little sequence conservation in the rest of their structures, with the exception of the conserved and catalytically critical domains V and VI, suggesting either separate acquisition of the extra segment by different group II introns or a strong selection pressure acting on the extension. Furthermore, we show by in vitro splicing experiments that the 3' extension affects the splicing properties differently in

  10. Biochemical and molecular dynamic simulation analysis of a weak coiled coil association between kinesin-II stalks.

    Directory of Open Access Journals (Sweden)

    Harinath Doodhi

    Full Text Available DEFINITION: Kinesin-2 refers to the family of motor proteins represented by conserved, heterotrimeric kinesin-II and homodimeric Osm3/Kif17 class of motors. BACKGROUND: Kinesin-II, a microtubule-based anterograde motor, is composed of three different conserved subunits, named KLP64D, KLP68D and DmKAP in Drosophila. Although previous reports indicated that coiled coil interaction between the middle segments of two dissimilar motor subunits established the heterodimer, the molecular basis of the association is still unknown. METHODOLOGY/PRINCIPAL FINDINGS: Here, we present a detailed heterodimeric association model of the KLP64D/68D stalk supported by extensive experimental analysis and molecular dynamic simulations. We find that KLP64D stalk is unstable, but forms a weak coiled coil heteroduplex with the KLP68D stalk when coexpressed in bacteria. Local instabilities, relative affinities between the C-terminal stalk segments, and dynamic long-range interactions along the stalks specify the heterodimerization. Thermal unfolding studies and independent simulations further suggest that interactions between the C-terminal stalk fragments are comparatively stable, whereas the N-terminal stalk reversibly unfolds at ambient temperature. CONCLUSIONS/SIGNIFICANCE: Results obtained in this study suggest that coiled coil interaction between the C-terminal stalks of kinesin-II motor subunits is held together through a few hydrophobic and charged interactions. The N-terminal stalk segments are flexible and could uncoil reversibly during a motor walk. This supports the requirement for a flexible coiled coil association between the motor subunits, and its role in motor function needs to be elucidated.

  11. First Measurement of Collectivity of Coexisting Shapes based on Type II Shell Evolution: The Case of $^{96}$Zr

    CERN Document Server

    Kremer, C; Bassauer, S; Hilcker, M; Krugmann, A; von Neumann-Cosel, P; Otsuka, T; Pietralla, N; Ponomarev, V Yu; Shimizu, N; Singer, M; Steinhilber, G; Togashi, T; Tsunoda, Y; Werner, V; Zweidinger, M

    2016-01-01

    Background: Type II shell evolution has recently been identified as a microscopic cause for nuclear shape coexistence. Purpose: Establish a low-lying rotational band in 96-Zr. Methods: High-resolution inelastic electron scattering and a relative analysis of transition strengths are used. Results: The B(E2; 0_1^+ -> 2_2^+) value is measured and electromagnetic decay strengths of the secdond 2^+ state are deduced. Conclusions: Shape coexistence is established for 96-Zr. Type II shell evolution provides a systematic and quantitative mechanism to understand deformation at low excitation energies.

  12. 3D-MHD simulations of the evolution of magnetic fields in FR II radio sources

    CERN Document Server

    Huarte-Espinosa, Martin; Alexander, Paul

    2010-01-01

    3D-MHD numerical simulations of bipolar, hypersonic, weakly magnetized jets and synthetic synchrotron observations are presented to study the structure and evolution of magnetic fields in FR II radio sources. The magnetic field setup in the jet is initially random. The power of the jets as well as the observational viewing angle are investigated. We find that synthetic polarization maps agree with observations and show that magnetic fields inside the sources are shaped by the jets' backflow. Polarimetry statistics correlates with time, the viewing angle and the jet-to-ambient density contrast. The magnetic structure inside thin elongated sources is more uniform than for ones with fatter cocoons. Jets increase the magnetic energy in cocoons, in proportion to the jet velocity. Both, filaments in synthetic emission maps and 3D magnetic power spectra suggest that turbulence develops in evolved sources.

  13. Measurement of antioxidant activity and antioxidant compounds under versatile extraction conditions: II. The immuno-biochemical antioxidant properties of black sour cherry (Prunus cerasus) extracts.

    Science.gov (United States)

    Haddad, John J; Ghadieh, Rana M; Hasan, Hiba A; Nakhal, Yasmine K; Hanbali, Lama B

    2013-01-01

    Retrospectively, we have measured the antioxidant activity and a variety of antioxidant compounds under versatile extraction conditions of sweet cherry (Prunus avium) extracts. Further in this study, in order to understand the biochemical constituents and antioxidant activities of a variety of extracts of black sour cherries (P. cerasus), a related species, antioxidant compounds, including L-ascorbic acid (vitamin C), phenols, flavonoids, and anthocyanins, and the total antioxidant activity were simultaneously measured under varying extraction conditions (mild heating and brief microwave exposure) for: i) whole juice extracts (WJE), ii) methanol-extracted juice (MEJ), iii) ddH2O-extracted pomace (dPOM), and iv) methanol-extracted pomace (mPOM). The antioxidant activity for WJE was substantially increased with mild and prolonged exposure to either heating or microwave, such that the % inhibition against 2,2-diphenyl-1-bspicrylhydrazyl (DPPH) followed a positive correlation (heating, 5-20 min.; microwave, 1-2 min.), insignificant with MEJ and dPOM, whereas with mPOM there was sharp downregulation. L-Ascorbic acid content was not affected with mild to prolonged heating or microwave exposure (WEJ and mPOM), except a mild increase with MEJ and dPOM. Similarly, total phenols assessed showed no significant variations, as compared with control extracts, except a mild decrease with exposure for mPOM. In a manner similar to L-ascorbic acid, total flavonoid content was increased under varying conditions for WEJ and MEJ, and slightly decreased for dPOM and mPOM. On the other hand, anthocyanins showed differential variations with exposure (up- and downregulation). Assessment of extraction means as compared with WJE revealed sharp increase in the antioxidant activity for MEJ, dPOM and mPOM, significant increase in L-ascorbic acid, total phenol, and flavonoid contents for MEJ, dPOM and mPOM, and mild decrease in anthocyanin contents for MEJ, dPOM, and mPOM. These results

  14. Interaction of polyamines with proteins of photosystem II: Cation binding and photosynthetic oxygen evolution

    Science.gov (United States)

    Beauchemin, R.; Harnois, J.; Rouillon, R.; Tajmir-Riahi, H. A.; Carpentier, R.

    2007-05-01

    Polyamines are organic cations that function in diverse physiological processes that share as a common thread a close relationship to cell proliferation and growth. Polyamines also affect photosynthetic oxygen evolution and therefore, this study was designed to investigate the interaction of 1,3-diaminopropane, 1,4-diaminobutane (putrescine), and 1,5-diaminopentane (cadaverine) cations with proteins of photosystem II (PSII) using PSII-enriched submembrane fractions with diamine concentrations between 0.01 and 20 mM. Fourier transformed infrared (FTIR) difference spectroscopy with its self-deconvolution and second derivative resolution enhancement, as well as curve-fitting procedures were applied in order to determine the diamine binding mode, the protein conformational changes, and the structural properties of diamine-protein complexes. Spectroscopic evidence showed that diamines interact with proteins (H-bonding) through polypeptide C dbnd O groups with no major perturbations of protein secondary structure. At very low diamine concentration (0.01 mM), no inhibition of oxygen-evolution occurred, while at higher diamine content (5-10 mM), 100% inhibition was observed. Chorophyll fluorescence measurements demonstrated that the inhibition mainly affects the oxygen evolving complex of PSII. Comparisons of the effects of these dipositive organic cations with divalent metal cations on one hand and with polyvalent spermine and spermidine on the other hand, show major alterations of the protein secondary structure as positive charge increases.

  15. Cosmological evolution of the Fanaroff-Riley type II source population

    CERN Document Server

    Wang, Y

    2008-01-01

    By combining a model for the evolution of the radio luminosity of an individual source with the radio luminosity function, we perform a multi-dimensional Monte-Carlo simulation to investigate the cosmological evolution of the Fanaroff-Riley Class II radio galaxy population by generating large artificial samples. The properties of FRII sources are required to evolve with redshift in the artificial samples to fit the observations. Either the maximum jet age or the maximum density of the jet environment or both evolve with redshift. We also study the distribution of FRII source properties as a function of redshift. From currently available data we can not constrain the shape of the distribution of environment density or age, but jet power is found to follow a power-law distribution with an exponent of approximately -2. This power-law slope does not change with redshift out to z=0.6. We also find the distribution of the pressure in the lobes of FRII sources to evolve with redshift up to $z\\sim1.2$.

  16. A Survey of MgII Absorption at 2 < z < 6 with Magellan / FIRE: I: Sample and Evolution of the MgII Frequency

    CERN Document Server

    Matejek, Michael S

    2012-01-01

    We present initial results from the first systematic survey for MgII quasar absorption lines at z > 2.5. Using infrared spectra of 46 high-redshift quasars, we discovered 111 MgII systems over a path covering 1.9 5, with a maximum of z = 5.33 - the most distant MgII system now known. The comoving MgII line density for weaker systems (Wr < 1.0A) is statistically consistent with no evolution from z = 0.4 to z = 5.5, while that for stronger systems increases three-fold until z \\sim 3 before declining again towards higher redshifts. The equivalent width distribution, which fits an exponential, reflects this evolution by flattening as z approaches 3 before steepening again. The rise and fall of the strong absorbers suggests a connection to the star formation rate density, as though they trace galactic outflows or other byproducts of star formation. The weaker systems' lack of evolution does not fit within this interpretation, but may be reproduced by extrapolating low redshift scaling relations between host ga...

  17. Three Dimensional Structure and Time Evolution of a Transition Region Explosive Event Observed in He II

    Science.gov (United States)

    Fox, J. L.; Kankelborg, C. C.; Thomas, R. J.; Longcope, D.

    2007-12-01

    Transition Region Explosive Events (TREEs) have been observed with slit spectrographs since at least 1975, most commonly in lines of C IV (1548A,1550A) and Si IV (1393A, 1402A). We report what we believe to be the first observation of a TREE in He II 304A. With the MOSES sounding rocket, a novel type of imaging spectrograph, we are able to see the spatial and spectral structure of the event. It consists of a bright core expelling two jets, oppositely directed but not collinear, which curve away from the axis of the core. The jets have both line-of-sight and sky-plane motion. The core is a region of high non-thermal doppler broadening, characteristic of TREEs. It is possible to resolve the core broadening into red and blue line-of-sight components. MOSES captured approximately 150 sec of time evolution before the rocket flight ended. We see the beginning (core activation) and middle (jet ejection), but not the end. It is clear from our data-set that TREEs in He II 304A are much less common than observed in other wavelengths.

  18. A prescription and fast code for the long-term evolution of star clusters - II. Unbalanced and core evolution

    NARCIS (Netherlands)

    M. Gieles; P.E.R. Alexander; H.J.G.L.M. Lamers; H. Baumgardt

    2013-01-01

    We introduce version two of the fast star cluster evolution code Evolve Me A Cluster of StarS (emacss). The first version (Alexander and Gieles) assumed that cluster evolution is balanced for the majority of the life cycle, meaning that the rate of energy generation in the core of the cluster equals

  19. A prescription and fast code for the long-term evolution of star clusters - II. Unbalanced and core evolution

    NARCIS (Netherlands)

    M. Gieles; P.E.R. Alexander; H.J.G.L.M. Lamers; H. Baumgardt

    2014-01-01

    We introduce version two of the fast star cluster evolution code Evolve Me A Cluster of StarS (emacss). The first version (Alexander and Gieles) assumed that cluster evolution is balanced for the majority of the life cycle, meaning that the rate of energy generation in the core of the cluster equals

  20. Purification and partial biochemical characterization of a membrane-bound type II-like α-glucosidase from the yeast morphotype of Sporothrix schenckii.

    Science.gov (United States)

    Torres-Rodríguez, Blanca I; Flores-Berrout, Karina; Villagómez-Castro, Julio C; López-Romero, Everardo

    2012-02-01

    The early steps of glycoprotein biosynthesis involve processing of the N-glycan core by endoplasmic reticulum α-glucosidases I and II which sequentially trim the outermost α1,2-linked and the two more internal α1,3-linked glucose units, respectively. We have demonstrated the presence of some components of the enzymic machinery required for glycoprotein synthesis in Sporothrix schenckii, the etiological agent of human and animal sporotrichosis. However, information on this process is still very limited. Here, a distribution analysis of α-glucosidase revealed that 38 and 50% of total enzyme activity were present in a soluble and in a mixed membrane fraction, respectively. From the latter, the enzyme was solubilized, purified to apparent homogeneity and biochemically characterized. Analysis of the enzyme by denaturing electrophoresis and size exclusion chromatography revealed molecular masses of 75.4 and 152.7 kDa, respectively, suggesting a homodimeric structure. Purified α-glucosidase cleaved the fluorogenic substrate 4-methylumbelliferyl-α-D: -glucopyranoside with high affinity as judged from K(m) and V(max) values of 0.3 μM and 250 nmol of MU/min/mg protein, respectively. Analysis of linkage specificity using a number of glucose α-disaccharides as substrates demonstrated a clear preference of the enzyme for nigerose, an α1,3-linked disaccharide, over other substrates such as kojibiose (α1,2), trehalose (α1,1) and isomaltose (α1,6). Use of selective inhibitors of processing α-glucosidases such as 1-deoxynojirimycin, castanospermine and australine provided further evidence of the possible type of α-glucosidase. Accordingly, 1-deoxynojirimycin, a more specific inhibitor of α-glucosidase II than I, was a stronger inhibitor of hydrolysis of 4-methylumbelliferyl-α-D: -glucopyranoside and nigerose than castanospermine, a preferential inhibitor of α-glucosidase I. Inhibition of hydrolysis of kojibiose and maltose by 1-deoxynojirimycin and

  1. The growth of galactic bulges through mergers in LCDM haloes revisited. II. Morphological mix evolution

    CERN Document Server

    Avila-Reese, Vladimir; Lacerna, Ivan

    2013-01-01

    The mass aggregation and merger histories of present-day distinct haloes selected from the cosmological Millennium Simulations I and II are mapped into stellar mass aggregation and galaxy merger histories of central galaxies by using empirical stellar-to-halo and stellar-to-gas mass relations. The growth of bulges driven by the galaxy mergers/interactions is calculated using analytical recipes. The predicted bulge demographics at redshift z~0 is consistent with observations (Zavala+2012). Here we present the evolution of the morphological mix (traced by the bulge-to-total mass ratio, B/T) as a function of mass up to z=3. This mix remains qualitatively the same up to z~1: B/T0.45 at large masses. At z>1, the fractions of disc-dominated and bulgeless galaxies increase strongly, and by z~2 the era of pure disc galaxies is reached. Bulge-dominated galaxies acquire such a morphology, and most of their mass, following a downsizing trend. Since our results are consistent with several recent observational studies of ...

  2. Type II shell evolution in A=70 isobars from the N≥40 island of inversion

    Directory of Open Access Journals (Sweden)

    A.I. Morales

    2017-02-01

    Full Text Available The level structures of 70Co and 70Ni, populated from the β decay of 70Fe, have been investigated using β-delayed γ-ray spectroscopy following in-flight fission of a 238U beam. The experimental results are compared to Monte-Carlo Shell-Model calculations including the pf+g9/2+d5/2 orbitals. The strong population of a (1+ state at 274 keV in 70Co is at variance with the expected excitation energy of ∼1 MeV from near spherical single-particle estimates. This observation indicates a dominance of prolate-deformed intruder configurations in the low-lying levels, which coexist with the normal near spherical states. It is shown that the β decay of the neutron-rich A=70 isobars from the new island of inversion to the Z=28 closed-shell regime progresses in accordance with a newly reported type of shell evolution, the so-called Type II, which involves many particle-hole excitations across energy gaps.

  3. Rapid Evolution of the Photosystem II Electronic Structure during Water Splitting

    CERN Document Server

    Davis, Katherine M; Palenik, Mark; Yan, Lifen; Purohit, Vatsal; Robison, Gregory; Kosheleva, Irina; Henning, Robert W; Seidler, Gerald T; Pushkar, Yulia

    2015-01-01

    Photosynthetic water oxidation is a fundamental process that sustains the biosphere. A Mn$_{4}$Ca cluster embedded in the photosystem II protein environment is responsible for the production of atmospheric oxygen. Here, time-resolved x-ray emission spectroscopy (XES) was used to observe the process of oxygen formation in real time. These experiments reveal that the oxygen evolution step, initiated by three sequential laser flashes, is accompanied by rapid (within 50 $\\mu$s) changes to the Mn K$\\beta$ XES spectrum. However, no oxidation of the Mn$_{4}$Ca core above the all Mn$^{\\text{IV}}$ state was detected to precede O-O bond formation. A new mechanism featuring Mn$^{\\text{IV}}$=O formation in the S$_{3}$ state is proposed to explain the spectroscopic results. This chemical formulation is consistent with the unique reactivity of the S$_{3}$ state and explains facilitation of the following S$_{3}$ to S$_{0}$ transition, resolving in part the kinetic limitations associated with O-O bond formation. In the propo...

  4. Type II shell evolution in A = 70 isobars from the N ≥ 40 island of inversion

    Science.gov (United States)

    Morales, A. I.; Benzoni, G.; Watanabe, H.; Tsunoda, Y.; Otsuka, T.; Nishimura, S.; Browne, F.; Daido, R.; Doornenbal, P.; Fang, Y.; Lorusso, G.; Patel, Z.; Rice, S.; Sinclair, L.; Söderström, P.-A.; Sumikama, T.; Wu, J.; Xu, Z. Y.; Yagi, A.; Yokoyama, R.; Baba, H.; Avigo, R.; Bello Garrote, F. L.; Blasi, N.; Bracco, A.; Camera, F.; Ceruti, S.; Crespi, F. C. L.; de Angelis, G.; Delattre, M.-C.; Dombradi, Zs.; Gottardo, A.; Isobe, T.; Kojouharov, I.; Kurz, N.; Kuti, I.; Matsui, K.; Melon, B.; Mengoni, D.; Miyazaki, T.; Modamio-Hoybjor, V.; Momiyama, S.; Napoli, D. R.; Niikura, M.; Orlandi, R.; Sakurai, H.; Sahin, E.; Sohler, D.; Schaffner, H.; Taniuchi, R.; Taprogge, J.; Vajta, Zs.; Valiente-Dobón, J. J.; Wieland, O.; Yalcinkaya, M.

    2017-02-01

    The level structures of 70Co and 70Ni, populated from the β decay of 70Fe, have been investigated using β-delayed γ-ray spectroscopy following in-flight fission of a 238U beam. The experimental results are compared to Monte-Carlo Shell-Model calculations including the pf +g9/2 +d5/2 orbitals. The strong population of a (1+) state at 274 keV in 70Co is at variance with the expected excitation energy of ∼1 MeV from near spherical single-particle estimates. This observation indicates a dominance of prolate-deformed intruder configurations in the low-lying levels, which coexist with the normal near spherical states. It is shown that the β decay of the neutron-rich A = 70 isobars from the new island of inversion to the Z = 28 closed-shell regime progresses in accordance with a newly reported type of shell evolution, the so-called Type II, which involves many particle-hole excitations across energy gaps.

  5. A prescription and fast code for the long-term evolution of star clusters II: unbalanced and core evolution

    CERN Document Server

    Gieles, Mark; Lamers, Henny; Baumgardt, Holger

    2013-01-01

    We introduce version two of the fast star cluster evolution code Evolve Me A Cluster of StarS (EMACSS). The first version (Alexander & Gieles) assumed that cluster evolution is balanced for the majority of the life-cycle, meaning that the rate of energy generation in the core of the cluster equals the diffusion rate of energy by two-body relaxation, which makes the code suitable for modelling clusters in weak tidal fields. In this new version we extend the model to include an unbalanced phase of evolution to describe the pre-collapse evolution and the accompanying escape rate such that clusters in strong tidal fields can also be modelled. We also add a prescription for the evolution of the core radius and density and a related cluster concentration parameter. The model simultaneously solves a series of first-order ordinary differential equations for the rate of change of the core radius, half-mass radius and the number of member stars N. About two thousand integration steps in time are required to solve f...

  6. Sequencing of Sipuleucel-T and Androgen Deprivation Therapy in Men with Hormone-Sensitive Biochemically Recurrent Prostate Cancer: A Phase II Randomized Trial.

    Science.gov (United States)

    Antonarakis, Emmanuel S; Kibel, Adam S; Yu, Evan Y; Karsh, Lawrence I; Elfiky, Aymen; Shore, Neal D; Vogelzang, Nicholas J; Corman, John M; Millard, Frederick E; Maher, Johnathan C; Chang, Nancy N; DeVries, Todd; Sheikh, Nadeem A; Drake, Charles G

    2016-11-10

    Purpose: STAND, a randomized, phase II, open-label trial (NCT01431391), assessed sequencing of sipuleucel-T (an autologous cellular immunotherapy) with androgen deprivation therapy (ADT) in biochemically recurrent prostate cancer (BRPC) patients at high risk for metastasis.Experimental Design: Men with BRPC following prostatectomy and/or radiotherapy, a PSA doubling time ≤12 months, and no metastasis were enrolled. Patients were randomized (34/arm) to sipuleucel-T followed by ADT (started 2 weeks after sipuleucel-T completion), or ADT followed by sipuleucel-T (started 12 weeks after ADT initiation); ADT continued for 12 months in both arms. The primary endpoint was PA2024-specific T-cell response [enzyme-linked immunospot (ELISPOT)] over time.Results: PA2024-specific ELISPOT responses over time were similar between groups, except at week 6, where responses were higher with sipuleucel-T→ADT versus ADT→sipuleucel-T (P = 0.013). PA2024-specific T-cell proliferation responses, averaged across time points, were approximately 2-fold higher with sipuleucel-T→ADT versus ADT→sipuleucel-T (P = 0.001). PA2024-specific cellular and humoral responses and prostatic acid phosphatase-specific humoral responses increased significantly versus baseline (P Sipuleucel-T with ADT was generally well tolerated.Conclusions: Sipuleucel-T→ADT appears to induce greater antitumor immune responses than the reverse sequence. These results warrant further investigation to determine whether this sequence leads to improved clinical outcomes, as well as the independent contribution of ADT alone in terms of immune activation. Clin Cancer Res; 1-9. ©2016 AACR.

  7. Precious metals in SDSS quasar spectra. II. Tracking the evolution of strong, 0.4 < z < 2.3 Mg II absorbers with thousands of systems

    Energy Technology Data Exchange (ETDEWEB)

    Seyffert, Eduardo N.; Simcoe, Robert A. [Department of Physics, MIT, 77 Massachusetts Avenue, 37-664D, Cambridge, MA 02139 (United States); Cooksey, Kathy L. [MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37-685, Cambridge, MA 02139 (United States); O' Meara, John M. [Department of Chemistry and Physics, Saint Michael' s College, One Winooski Park, Colchester, VT 05439 (United States); Kao, Melodie M. [Caltech, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Prochaska, J. Xavier, E-mail: enseyff@mit.edu, E-mail: simcoe@space.mit.edu, E-mail: kcooksey@space.mit.edu, E-mail: jomeara@smcvt.edu, E-mail: mkao@caltech.edu, E-mail: xavier@ucolick.org [Department of Astronomy and UCO/Lick Observatory, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States)

    2013-12-20

    We have performed an analysis of over 34,000 Mg II doublets at 0.36 < z < 2.29 in Sloan Digital Sky Survey (SDSS) Data Release 7 quasar spectra; the catalog, advanced data products, and tools for analysis are publicly available. The catalog was divided into 14 small redshift bins with roughly 2500 doublets in each and from Monte Carlo simulations, we estimate 50% completeness at rest equivalent width W {sub r} ≈ 0.8 Å. The equivalent width frequency distribution is described well by an exponential model at all redshifts, and the distribution becomes flatter with increasing redshift, i.e., there are more strong systems relative to weak ones. Direct comparison with previous SDSS Mg II surveys reveals that we recover at least 70% of the doublets in these other catalogs, in addition to detecting thousands of new systems. We discuss how these surveys came by their different results, which qualitatively agree but because of the very small uncertainties, differ by a statistically significant amount. The estimated physical cross section of Mg II-absorbing galaxy halos increased approximately threefold from z = 0.4 to z = 2.3, while the W {sub r} ≥ 1 Å absorber line density, dN{sub MgII}/dX, grew by roughly 45%. Finally, we explore the different evolution of various absorber populations—damped Lyα absorbers, Lyman limit systems, strong C IV absorbers, and strong and weaker Mg II systems—across cosmic time (0 < z < 6).

  8. Probing the Evolution of Massive Young Stellar Objects using Weak Class II 6.7GHz Methanol Maser Emission

    Science.gov (United States)

    Ludwig, Bethany Ann; Cunningham, Nichol

    2017-01-01

    We present results from an investigation of class II 6.7GHz methanol masers towards four Massive Young Stellar Objects (MYSOs). The sources, selected from the Red MSX Source (RMS) Survey (Lumsden et al. 2013), were previously understood to be non-detections for class II methanol maser emission in the methanol multi-beam (MMB) Survey (Caswell et al. 2010.) Class II methanol masers are a well-known sign post of massive star forming regions and may be utilized to probe their relatively poorly understood formation. It is possible that these non-detections are simply weak masers that are potentially associated with a younger evolutionary phase of MYSOs as hypothesized by Olmi et al. (2014). The sources were chosen to sample various stages of evolution, having similar 21 to 8 micron flux ratios and bolometric luminosities as other MYSOs with previous class II methanol maser detections. We observed all 4 MYSOs with ATCA (~2" resolution) at 10 times deeper sensitivity than previously obtained with the MMB survey and have a spectral resolution of 0.087kms^-1 . The raw data is reduced using the program Miriad (Sault, R. J., et al., 1995) and deconvolutioned using the program CASA (McMullin, J. P., et al. 2007.) We determine one of the four observed MYSOs is harboring a weak class II methanol maser. We discuss the possibility of sensitivity limitations on the remaining sources as well as environmental and evolutionary differences between the sources.

  9. Evolution of stellar collision products in open clusters : II. A grid of low-mass collisions

    NARCIS (Netherlands)

    Glebbeek, E.; Pols, O.R.

    2008-01-01

    In a companion paper we studied the detailed evolution of stellar collision products that occurred in an N-body simulation of the old open cluster M 67 and compared our detailed models to simple prescriptions. In this paper we extend this work by studying the evolution of the collision products in o

  10. Molecular evolution of glutamine synthetase II: Phylogenetic evidence of a non-endosymbiotic gene transfer event early in plant evolution

    Directory of Open Access Journals (Sweden)

    Tartar Aurélien

    2010-06-01

    a cytosolic function. GSIIB sequences were absent in vascular plants where the duplication of GSIIE replaced the function of GSIIB. Conclusions Phylogenetic evidence suggests GSIIB in Chloroplastida evolved by HGT, possibly after the divergence of the primary endosymbiotic lineages. Thus while multiple GS isoenzymes are common among members of the Chloroplastida, the isoenzymes may have evolved via different evolutionary processes. The acquisition of essential enzymes by HGT may provide rapid changes in biochemical capacity and therefore be favored by natural selection.

  11. Ultracold fermions in real or fictitious magnetic fields: BCS-BEC evolution and type-I-type-II transition

    OpenAIRE

    Iskin, Menderes

    2011-01-01

    PHYSICAL REVIEW A 83, 045602 (2011) Ultracold fermions in real or fictitious magnetic fields: BCS-BEC evolution and type-I–type-II transition M. Iskin1 and C. A. R. S´a de Melo2 1Department of Physics, Koc¸ University, Rumelifeneri Yolu, TR-34450 Sariyer, Istanbul, Turkey 2School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA (Received 11 March 2010; published 26 April 2011) We study ultracold neutral fermion superfluids in the presence of fictit...

  12. Characterization and evolution of MHC class II B genes in Galápagos marine iguanas (Amblyrhynchus cristatus).

    Science.gov (United States)

    Glaberman, Scott; Moreno, Maria A; Caccone, Adalgisa

    2009-08-01

    Major histocompatibility complex (MHC) class II molecules play a key role in the adaptive immune system of vertebrates. Class II B genes appear to evolve in a very different manner in mammals and birds. Orthology is commonly observed among mammal loci, while genes tend to cluster phylogenetically within bird species. Here we present class II B data from a representative of another major group of amniotes, the squamates (i.e. lizards, snakes, amphisbaenians), with the ultimate goal of placing mammalian and avian MHC evolution into a broader context. In this study, eight class II B cDNA sequences were obtained from the Galápagos marine iguana (Amblyrhynchus cristatus) which were divided into five locus groups, Amcr-DAB1 through -DAB5, based on similarities along most of the coding and noncoding portions of the transcribed gene. All marine iguana sequences were monophyletic with respect to class II genes from other vertebrates indicating that they originated from a common ancestral locus after squamates split from other reptiles. The beta-1 domain, which is involved in antigen binding, exhibited signatures of positive selection as well as interlocus gene conversion in both long and short tracts-a pattern also observed in birds and fish, but not in mammals. On the other hand, the beta-2 domain was divergent between gene groups, which is characteristic of mammals. Based on these results, we preliminarily show that squamate class II B genes have been shaped by a unique blend of evolutionary forces that have been observed in differing degrees in other vertebrates.

  13. Comparing equivalent thermal, high pressure and pulsed electric field processes for mild pasteurization of orange juice: Part II: Impact on specific chemical and biochemical quality parameters

    NARCIS (Netherlands)

    Vervoort, L.; Plancken, van der I.; Grauwet, T.; Timmermans, R.A.H.; Mastwijk, H.C.; Matser, A.M.; Hendrickx, M.E.; Loey, van A.

    2011-01-01

    The impact of thermal, high pressure (HP) and pulsed electric field (PEF) processing for mild pasteurization of orange juice was compared on a fair basis, using processing conditions leading to an equivalent degree of microbial inactivation. Examining the effect on specific chemical and biochemical

  14. Fast evolution of the retroprocessed mitochondrial rps3 gene in Conifer II and further evidence for the phylogeny of gymnosperms.

    Science.gov (United States)

    Ran, Jin-Hua; Gao, Hui; Wang, Xiao-Quan

    2010-01-01

    The popular view that plant mitochondrial genome evolves slowly in sequence has been recently challenged by the extraordinarily high substitution rates of mtDNA documented mainly from several angiosperm genera, but high substitution rate acceleration accompanied with great length variation has been very rarely reported in plant mitochondrial genes. Here, we studied evolution of the mitochondrial rps3 gene that encodes the ribosomal small subunit protein 3 and found a dramatically high variation in both length and sequence of an exon region of it in Conifer II. A sequence comparison between cDNA and genomic DNA showed that there are no RNA editing sites in the Conifer II rps3 gene. Southern blotting analyses of the total DNA and mtDNA, together with the real-time PCR analysis, showed that rps3 exists as a single mitochondrial locus in gymnosperms. It is very likely that the Conifer II rps3 gene has experienced retroprocessing, i.e., the re-integration of its cDNA into the mitochondrial genome, followed by an evolutionary acceleration due to the intron loss. In addition, the phylogenetic analysis of rps3 supports the sister relationship between conifers and Gnetales. In particular, the monophyly of conifer II is strongly supported by the shared loss of two rps3 introns. Our results also indicate that the mitochondrial gene tree would be affected in topology when the "edited" paralogs are analyzed together with their genomic sequences.

  15. The HETDEX Pilot Survey. IV. The Evolution of [O II] Emitting Galaxies from z ~ 0.5 to z ~ 0

    CERN Document Server

    Ciardullo, Robin; Adams, Joshua J; Blanc, Guillermo A; Gebhardt, Karl; Finkelstein, Steven L; Jogee, Shardha; Hill, Gary J; Drory, Niv; Hopp, Ulrich; Schneider, Donald P; Zeimann, Gregory R; Dalton, Gavin B

    2013-01-01

    We present an analysis of the luminosities and equivalent widths of the 284 z < 0.56 [O II]-emitting galaxies found in the 169 square arcmin pilot survey for the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX). By combining emission-line fluxes obtained from the Mitchell spectrograph on the McDonald 2.7-m telescope with deep broadband photometry from archival data, we derive each galaxy's de-reddened [O II] 3727 luminosity and calculate its total star formation rate. We show that over the last ~5 Gyr of cosmic time there has been substantial evolution in the [O II] emission-line luminosity function, with L* decreasing by ~0.6 +/-0.2 dex in the observed function, and by ~0.9 +/-0.2 dex in the de-reddened relation. Accompanying this decline is a significant shift in the distribution of [O II] equivalent widths, with the fraction of high equivalent-width emitters declining dramatically with time. Overall, the data imply that the relative intensity of star formation within galaxies has decreased over th...

  16. The Radio and Optical Luminosity Evolution of Quasars II - The SDSS Sample

    Energy Technology Data Exchange (ETDEWEB)

    Singal, J.; Petrosian, V.; Stawarz, L.; Lawrence, A.

    2012-12-28

    We determine the radio and optical luminosity evolutions and the true distribution of the radio loudness parameter R, defined as the ratio of the radio to optical luminosity, for a set of more than 5000 quasars combining SDSS optical and FIRST radio data. We apply the method of Efron and Petrosian to access the intrinsic distribution parameters, taking into account the truncations and correlations inherent in the data. We find that the population exhibits strong positive evolution with redshift in both wavebands, with somewhat greater radio evolution than optical. With the luminosity evolutions accounted for, we determine the density evolutions and local radio and optical luminosity functions. The intrinsic distribution of the radio loudness parameter R is found to be quite different than the observed one, and is smooth with no evidence of a bi-modality in radio loudness. The results we find are in general agreement with the previous analysis of Singal et al., 2011 which used POSS-I optical and FIRST radio data.

  17. Three-dimensional magnetohydrodynamic simulations of the evolution of magnetic fields in Fanaroff-Riley class II radio sources

    CERN Document Server

    Huarte-Espinosa, Martin; Alexander, Paul

    2011-01-01

    Radio observations of Fanaroff-Riley class II sources often show correlations between the synchrotron emission and the linear-polarimetric distributions. Magnetic position vectors seem to align with the projected emission of both the radio jets and the sources' edges. Using statistics we study such relation as well as its unknown time evolution via synthetic polarisation maps of model FR II sources formed in 3D-MHD numerical simulations of bipolar, hypersonic and weakly magnetised jets. The magnetic field is initially random with a Kolmogorov power spectrum, everywhere. We investigate the structure and evolution of magnetic fields in the sources as a function of the power of jets and the observational viewing angle. Our synthetic polarisation maps agree with observations, showing B-field vectors which are predominantly aligned with the jet axis, and show that magnetic fields inside sources are shaped by the jets' backflow. Polarimetry is found to correlate with time, the viewing angle and the jet-to-ambient d...

  18. Second-order corrections to mean-field evolution of weakly interacting Bosons, II

    CERN Document Server

    Grillakis, M; Margetis, D

    2010-01-01

    We study the evolution of a N-body weakly interacting system of Bosons. Our work forms an extension of our previous paper I, in which we derived a second-order correction to a mean-field evolution law for coherent states in the presence of small interaction potential. Here, we remove the assumption of smallness of the interaction potential and prove global existence of solutions to the equation for the second-order correction. This implies an improved Fock-space estimate for our approximation of the N-body state.

  19. Impact of river overflowing on trace element contamination of volcanic soils in south Italy: Part II. Soil biological and biochemical properties in relation to trace element speciation

    Energy Technology Data Exchange (ETDEWEB)

    D' Ascoli, R. [Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli, via Vivaldi 43, 81100 Caserta (Italy)]. E-mail: rosaria.dascoli@unina2.it; Rao, M.A. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: maria.rao@unina.it; Adamo, P. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: adamo@unina.it; Renella, G. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita degli Studi di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy)]. E-mail: giancarlo.renella@unifi.it; Landi, L. [Dipartimento di Scienza del Suolo e Nutrizione della Pianta, Universita degli Studi di Firenze, P.le delle Cascine 28, 50144 Firenze (Italy)]. E-mail: loretta.landi@unifi.it; Rutigliano, F.A. [Dipartimento di Scienze Ambientali, Seconda Universita degli Studi di Napoli, via Vivaldi 43, 81100 Caserta (Italy)]. E-mail: floraa.rutigliano@unina2.it; Terribile, F. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: terribil@unina.it; Gianfreda, L. [Dipartimento di Scienze del Suolo, della Pianta e dell' Ambiente, Universita degli Studi di Napoli Federico II, Via Universita 100, 80055 Portici (Italy)]. E-mail: liliana.gianfreda@unina.it

    2006-11-15

    The effect of heavy metal contamination on biological and biochemical properties of Italian volcanic soils was evaluated in a multidisciplinary study, involving pedoenvironmental, micromorphological, physical, chemical, biological and biochemical analyses. Soils affected by recurring river overflowing, with Cr(III)-contaminated water and sediments, and a non-flooded control soil were analysed for microbial biomass, total and active fungal mycelium, enzyme activities (i.e., FDA hydrolase, dehydrogenase, {beta}-glucosidase, urease, arylsulphatase, acid phosphatase) and bacterial diversity (DGGE characterisation). Biological and biochemical data were related with both total and selected fractions of Cr and Cu (the latter deriving from agricultural chemical products) as well as with total and extractable organic C. The growth and activity of soil microbial community were influenced by soil organic C content rather than Cu or Cr contents. In fact, positive correlations between all studied parameters and organic C content were found. On the contrary, negative correlations were observed only between total fungal mycelium, dehydrogenase, arylsulphatase and acid phosphatase activities and only one Cr fraction (the soluble, exchangeable and carbonate bound). However, total Cr content negatively affected the eubacterial diversity but it did not determine changes in soil activity, probably because of the redundancy of functions within species of soil microbial community. On the other hand, expressing biological and biochemical parameters per unit of total organic C, Cu pollution negatively influenced microbial biomass, fungal mycelium and several enzyme activities, confirming soil organic matter is able to mask the negative effects of Cu on microbial community. - In studied soils organic C content resulted the principal factor influencing growth and activity of microbial community, with Cu and Cr contents having a lower relevance.

  20. The role of OH in the chemical evolution of protoplanetary disks : II. Gas-rich environments

    NARCIS (Netherlands)

    Chaparro-Molano, German; Kamp, I.

    2012-01-01

    Context. We present a method for including gas extinction of cosmic-ray-generated UV photons in chemical models of the midplane of protoplanetary disks, focusing on its implications on ice formation and chemical evolution. Aims. Our goal is to improve on chemical models by treating cosmic rays, the

  1. Evolution of stellar collision products in open clusters. II. A grid of low-mass collisions

    CERN Document Server

    Glebbeek, E

    2008-01-01

    In a companion paper we studied the detailed evolution of stellar collision products that occurred in an $N$-body simulation of the old open cluster M67 and compared our detailed models to simple prescriptions. In this paper we extend this work by studying the evolution of the collision products in open clusters as a function of mass and age of the progenitor stars. We calculated a grid of head-on collisions covering the section of parameter space relevant for collisions in open clusters. We create detailed models of the merger remnants using an entropy-sorting algorithm and follow their subsequent evolution during the initial contraction phase, through the main sequence and up to the giant branch with our detailed stellar evolution code. We compare the location of our models in a colour-magnitude diagram to the observed blue straggler population of the old open clusters M67 and NGC 188 and find that they cover the observed blue straggler region of both clusters. For M67, collisions need to have taken place r...

  2. Application of Gas Dynamical Friction for Planetesimals. II. Evolution of Binary Planetesimals

    Science.gov (United States)

    Grishin, Evgeni; Perets, Hagai B.

    2016-04-01

    One of the first stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs long before the dispersal of most of the gas from the protoplanetary disk. At this stage gas-planetesimal interactions play a key role in the dynamical evolution of single intermediate-mass planetesimals (mp ˜ 1021-1025 g) through gas dynamical friction (GDF). A significant fraction of all solar system planetesimals (asteroids and Kuiper-belt objects) are known to be binary planetesimals (BPs). Here, we explore the effects of GDF on the evolution of BPs embedded in a gaseous disk using an N-body code with a fiducial external force accounting for GDF. We find that GDF can induce binary mergers on timescales shorter than the disk lifetime for masses above mp ≳ 1022 g at 1 au, independent of the binary initial separation and eccentricity. Such mergers can affect the structure of merger-formed planetesimals, and the GDF-induced binary inspiral can play a role in the evolution of the planetesimal disk. In addition, binaries on eccentric orbits around the star may evolve in the supersonic regime, where the torque reverses and the binary expands, which would enhance the cross section for planetesimal encounters with the binary. Highly inclined binaries with small mass ratios, evolve due to the combined effects of Kozai-Lidov (KL) cycles with GDF which lead to chaotic evolution. Prograde binaries go through semi-regular KL evolution, while retrograde binaries frequently flip their inclination and ˜50% of them are destroyed.

  3. APPLICATION OF GAS DYNAMICAL FRICTION FOR PLANETESIMALS. II. EVOLUTION OF BINARY PLANETESIMALS

    Energy Technology Data Exchange (ETDEWEB)

    Grishin, Evgeni; Perets, Hagai B. [Physics Department, Technion—Israel Institute of Technology, Haifa, 3200003 (Israel)

    2016-04-01

    One of the first stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs long before the dispersal of most of the gas from the protoplanetary disk. At this stage gas–planetesimal interactions play a key role in the dynamical evolution of single intermediate-mass planetesimals (m{sub p} ∼ 10{sup 21}–10{sup 25} g) through gas dynamical friction (GDF). A significant fraction of all solar system planetesimals (asteroids and Kuiper-belt objects) are known to be binary planetesimals (BPs). Here, we explore the effects of GDF on the evolution of BPs embedded in a gaseous disk using an N-body code with a fiducial external force accounting for GDF. We find that GDF can induce binary mergers on timescales shorter than the disk lifetime for masses above m{sub p} ≳ 10{sup 22} g at 1 au, independent of the binary initial separation and eccentricity. Such mergers can affect the structure of merger-formed planetesimals, and the GDF-induced binary inspiral can play a role in the evolution of the planetesimal disk. In addition, binaries on eccentric orbits around the star may evolve in the supersonic regime, where the torque reverses and the binary expands, which would enhance the cross section for planetesimal encounters with the binary. Highly inclined binaries with small mass ratios, evolve due to the combined effects of Kozai–Lidov (KL) cycles with GDF which lead to chaotic evolution. Prograde binaries go through semi-regular KL evolution, while retrograde binaries frequently flip their inclination and ∼50% of them are destroyed.

  4. Modes of salmonid MHC class I and II evolution differ from the primate paradigm

    NARCIS (Netherlands)

    Shum, B.P.; Guethlein, L.; Flodin, L.R.; Adkison, M.A.; Hedrick, R.P.; Nehring, R.B.; Stet, R.J.M.; Secombes, C.; Parham, P.

    2001-01-01

    Rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta) represent two salmonid genera separated for 15-20 million years. cDNA sequences were determined for the classical MHC class I heavy chain gene UBA and the MHC class II β-chain gene DAB from 15 rainbow and 10 brown trout. Both genes a

  5. Catalytic Oxygen Evolution by a Bioinorganic Model of the Photosystem II Oxygen-Evolving Complex

    Science.gov (United States)

    Howard, Derrick L.; Tinoco, Arthur D.; Brudvig, Gary W.; Vrettos, John S.; Allen, Bertha Connie

    2005-01-01

    Bioinorganic models of the manganese Mn4 cluster are important not only as aids in understanding the structure and function of the oxygen-evolving complex (OEC), but also in developing artificial water-oxidation catalysts. The mechanism of water oxidation by photosystem II (PSII) is thought to involve the formation of a high-valent terminal Mn-oxo…

  6. Oceanographic profile biochemical measurements collected using a net from the ARLIS II (ARCTIC RESEARCH LABORATORY ICE STATION) in the Arctic in 1964 (NCEI Accession 0000978)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Thirty-nine plankton samples were collected at the Drift Station "Arlis II" at the north of Greenland in the Arctic Ocean during the period from June to December,...

  7. Astrocladistics: a phylogenetic analysis of galaxy evolution II. Formation and diversification of galaxies

    CERN Document Server

    Fraix-Burnet, D; Choler, P; Verhamme, A; Fraix-Burnet, Didier; Douzery, Emmanuel J.P.; Choler, Philippe; Verhamme, Anne

    2006-01-01

    This series of papers is intended to evaluate astrocladistics in reconstructing phylogenies of galaxies. The objective of this second paper is to formalize the concept of galaxy formation and to identify the processes of diversification. We show that galaxy diversity can be expected to organize itself in a hierarchy. In order to better understand the role of mergers, we have selected a sample of 43 galaxies from the GALICS database built from simulations with a hybrid model for galaxy formation studies. These simulated galaxies, described by 119 characters and considered as representing still undefined classes, have experienced different numbers of merger events during evolution. Our cladistic analysis yields a robust tree that proves the existence of a hierarchy. Mergers, like interactions (not taken into account in the GALICS simulations), are probably a strong driver for galaxy diversification. Our result shows that mergers participate in a branching type of evolution, but do not seem to play the role of a...

  8. Formation and Evolution of the Dust in Galaxies. II. The Solar Neighbourhood

    CERN Document Server

    Piovan, L; Merlin, E; Grassi, T; Tantalo, R; Buonomo, U; Cassarà, L P

    2011-01-01

    Over the past decade a new generation of chemical models have included the dust in the treatment of the ISM. This major accomplishment has been spurred by the growing amounts of data on the highly obscured high-z Universe and the intriguing local properties of the Solar Neighbourhood (SoNE). We present here a new model able to simulate the formation and evolution of dust in the ISM. The model follows the evolution of 16 elemental species, with particular attention to those that are simultaneously present in form of gas and dust, e.g. C, N, O, Mg, Si, S, Ca and Fe. In this study we focus on the SoNe and the MW Disk as a whole which are considered as laboratories to test the physical ingredients governing the dust evolution. Infall of primordial gas, birth and death of stars, radial flows of matter between contiguous shells, presence of a central bar, star-dust emission by SNae and AGB stars, dust destruction and accretion are taken into account. The model reproduces the local depletion of the elements in the g...

  9. Evolution of Binary Stars in Multiple-Population Globular Clusters - II. Compact Binaries

    CERN Document Server

    Hong, Jongsuk; Sollima, Antonio; McMillan, Stephen L W; D'Antona, Franca; D'Ercole, Annibale

    2016-01-01

    We present the results of a survey of N-body simulations aimed at exploring the evolution of compact binaries in multiple-population globular clusters.We show that as a consequence of the initial differences in the structural properties of the first-generation (FG) and the second-generation (SG) populations and the effects of dynamical processes on binary stars, the SG binary fraction decreases more rapidly than that of the FG population. The difference between the FG and SG binary fraction is qualitatively similar to but quantitatively smaller than that found for wider binaries in our previous investigations.The evolution of the radial variation of the binary fraction is driven by the interplay between binary segregation, ionization and ejection. Ionization and ejection counteract in part the effects of mass segregation but for compact binaries the effects of segregation dominate and the inner binary fraction increases during the cluster evolution. We explore the variation of the difference between the FG an...

  10. VLT\\/UVES Abundances in Four Nearby Dwarf Spheroidal Galaxies II. Implications for Understanding Galaxy Evolution

    CERN Document Server

    Tolstoy, E; Shetrone, M; Primas, F; Hill, V; Szeifert, A K T; Tolstoy, Eline

    2003-01-01

    We have used UVES on VLT-UT2 to take spectra of 15 individual red giant stars in the centers of four nearby dwarf spheroidal galaxies: Sculptor, Fornax, Carina and Leo I. We measure the abundance variations of numerous elements in these low mass stars with a range of ages (1-15Gyr old). This means that we can effectively measure the chemical evolution of these galaxies WITH TIME. Our results show a significant spread in metallicity with age, but an overall trend consistent with what might be expected from a closed (or perhaps leaky) box chemical evolution scenario over the last 10-15Gyr. We notice that each of these galaxies show broadly similar abundance patterns for all elements measured. This suggests a fairly uniform progression of chemical evolution with time, despite quite a large range of star formation histories. It seems likely that these galaxies had similar initial conditions, and evolve in a similar manner with star formation occurring at a uniformly low rate, even if at different times. With our ...

  11. Effects of chloroquine on the adrenocortical function. II. Histological, histochemical and biochemical changes in the suprarenal gland of rats on long-term administration of chloroquine.

    Science.gov (United States)

    Grundmann, M; Bayer, A

    1976-01-01

    White female Wistar rats were used in order to study the influence of long-term oral application of 7-chloro-4-(4-diethylamino-1-methylbutylamino) quinoline (chloroquine) in doses of 30, 40 and 80 mg of base/kg upon the suprarenal gland. Histological, histochemical and biochemical findings give evidence of adrenocortical activation induced by chloroquine at all dose levels tested. The differences between the signs of adrenocortical activation as observed after the various doses were only those of quantity and time onset. The results indicate that the stimulation of the suprarenal cortex produced by repeated administration of chloroquine is not solely a manifestation of toxic action of chloroquine.

  12. The Mitochondrial Genome of Conus textile, coxI-coxII Intergenic Sequences and Conoidean Evolution

    OpenAIRE

    2007-01-01

    The cone snails belong to the superfamily Conoidea, comprising ∼10,000 venomous marine gastropods. We determined the complete mitochondrial DNA sequence of Conus textile. The gene order is identical in Conus textile, Lophiotoma cerithiformis (another Conoidean gastropod), and the neogastropod Ilyanassa obsoleta, (not in the superfamily Conoidea). However, the intergenic interval between the coxI/coxII genes, was much longer in C. textile (165 bp) than in any other previously analyzed gastropo...

  13. ON THE TEMPORAL EVOLUTION OF THE DISK COUNTERPART OF TYPE II SPICULES IN THE QUIET SUN

    Energy Technology Data Exchange (ETDEWEB)

    Sekse, D. H.; Rouppe van der Voort, L. [Institute of Theoretical Astrophysics, University of Oslo, P.O. Box 1029, Blindern, N-0315 Oslo (Norway); De Pontieu, B. [Lockheed Martin Solar and Astrophysics Lab, Org. A021S, Bldg. 252, 3251 Hanover Street, Palo Alto, CA 94304 (United States)

    2013-02-20

    The newly established type II spicule has been speculated to provide enough hot plasma to play an important role in the mass loading and heating of the solar corona. With the identification of rapid blueshifted excursions (RBEs) as the on-disk counterpart of type II spicules we have analyzed three different high-quality timeseries with the CRisp Imaging SpectroPolarimeter (CRISP) at the Swedish Solar Telescope on La Palma and subjected to an automated detection routine to detect a large number of RBEs for statistical purposes. Our observations are of a quiet-Sun region at disk center and we find lower Doppler velocities, 15-40 km s{sup -1}, and Doppler widths, 2-15 km s{sup -1}, of RBEs than in earlier coronal hole studies, 30-50 km s{sup -1} and 7-23 km s{sup -1}, respectively. In addition, we examine the spatial dependence of Doppler velocities and widths along the RBE axis and conclude that there is no clear trend to this over the field of view or in individual RBEs in the quiet Sun at disk center. These differences with previous coronal hole studies are attributed to the more varying magnetic field configuration in quiet-Sun conditions. Using an extremely high-cadence data set has allowed us to improve greatly on the determination of lifetimes of RBEs, which we find to range from 5 to 60 s with an average lifetime of 30 s, as well as the transverse motions in RBEs, with transverse velocities up to 55 km s{sup -1} and averaging 12 km s{sup -1}. Furthermore, our measurements of the recurrence rates of RBEs provide important new constraints on coronal heating by spicules. We also see many examples of a sinusoidal wave pattern in the transverse motion of RBEs with periods averaging 54 s and amplitudes from 21.5 to 129 km which agrees well with previous studies of wave motion in spicules at the limb. We interpret the appearance of RBEs over their full length within a few seconds as the result of a combination of three kinds of motions as is earlier reported for

  14. Clustering of galaxies in a hierarchical universe - II. Evolution to high redshift

    Science.gov (United States)

    Kauffmann, Guinevere; Colberg, Jörg M.; Diaferio, Antonaldo; White, Simon D. M.

    1999-08-01

    In hierarchical cosmologies the evolution of galaxy clustering depends both on cosmological quantities such as Omega, Lambda and P(k), which determine how collapsed structures - dark matter haloes - form and evolve, and on the physical processes - cooling, star formation, radiative and hydrodynamic feedback - which drive the formation of galaxies within these merging haloes. In this paper we combine dissipationless cosmological N-body simulations and semi-analytic models of galaxy formation in order to study how these two aspects interact. We focus on the differences in clustering predicted for galaxies of differing luminosity, colour, morphology and star formation rate, and on what these differences can teach us about the galaxy formation process. We show that a `dip' in the amplitude of galaxy correlations between z=0 and z=1 can be an important diagnostic. Such a dip occurs in low-density CDM models, because structure forms early, and dark matter haloes of mass ~10^12M_solar, containing galaxies with luminosities ~L_*, are unbiased tracers of the dark matter over this redshift range; their clustering amplitude then evolves similarly to that of the dark matter. At higher redshifts, bright galaxies become strongly biased and the clustering amplitude increases again. In high density models, structure forms late, and bias evolves much more rapidly. As a result, the clustering amplitude of L_* galaxies remains constant from z=0 to z=1. The strength of these effects is sensitive to sample selection. The dip becomes weaker for galaxies with lower star formation rates, redder colours, higher luminosities and earlier morphological types. We explain why this is the case, and how it is related to the variation with redshift of the abundance and environment of the observed galaxies. We also show that the relative peculiar velocities of galaxies are biased low in our models, but that this effect is never very strong. Studies of clustering evolution as a function of galaxy

  15. Time-evolution of quantum systems via a complex nonlinear Riccati equation. II. Dissipative systems

    Science.gov (United States)

    Cruz, Hans; Schuch, Dieter; Castaños, Octavio; Rosas-Ortiz, Oscar

    2016-10-01

    In our former contribution (Cruz et al., 2015), we have shown the sensitivity to the choice of initial conditions in the evolution of Gaussian wave packets via the nonlinear Riccati equation. The formalism developed in the previous work is extended to effective approaches for the description of dissipative quantum systems. By means of simple examples we show the effects of the environment on the quantum uncertainties, correlation function, quantum energy contribution and tunnelling currents. We prove that the environmental parameter γ is strongly related with the sensitivity to the choice of initial conditions.

  16. Interacting Binaries with Eccentric Orbits II. Secular Orbital Evolution Due To Non-Conservative Mass Transfer

    CERN Document Server

    Sepinsky, J F; Kalogera, V; Rasio, F A

    2009-01-01

    We investigate the secular evolution of the orbital semi-major axis and eccentricity due to mass transfer in eccentric binaries, allowing for both mass and angular momentum loss from the system. Adopting a delta function mass transfer rate at the periastron of the binary orbit, we find that, depending on the initial binary properties at the onset of mass transfer, the orbital semi-major axis and eccentricity can either increase or decrease at a rate linearly proportional to the magnitude of the mass transfer rate at periastron. The range of initial binary mass ratios and eccentricities that leads to increasing orbital semi-major axes and eccentricities broadens with increasing degrees of mass loss from the system and narrows with increasing orbital angular momentum loss from the binary. Comparison with tidal evolution timescales shows that the usual assumption of rapid circularization at the onset of mass transfer in eccentric binaries is not justified, irrespective of the degree of systemic mass and angular ...

  17. The effect of intermediate mass close binaries on the chemical evolution of Globular Clusters II

    CERN Document Server

    Mennekens, N; De Greve, J P

    2013-01-01

    The chemical processes during the Asymptotic Giant Branch (AGB) evolution of intermediate mass single stars predict most of the observations of the different populations in Globular Clusters although some important issues still need to be further clarified. In particular, to reproduce the observed anticorrelations of Na-O and Al-Mg, chemically enriched gas lost during the AGB phase of intermediate mass single stars must be mixed with matter with a pristine chemical composition. The source of this matter is still a matter of debate. Furthermore, observations reveal that a significant fraction of the intermediate mass and massive stars are born as components of close binaries. We will investigate the effects of binaries on the chemical evolution of Globular Clusters and on the origin of matter with a pristine chemical composition that is needed for the single star AGB scenario to work. We use a population synthesis code that accounts for binary physics in order to estimate the amount and the composition of the ...

  18. Application of Gas Dynamical Friction for Planetesimals: II. Evolution of Binary Planetesimals

    CERN Document Server

    Grishin, Evgeni

    2015-01-01

    One of first the stages of planet formation is the growth of small planetesimals and their accumulation into large planetesimals and planetary embryos. This early stage occurs much before the dispersal of most of the gas from the protoplanetary disk. At this stage gas-planetesimal interactions play a key role in the dynamical evolution of \\emph{single} intermediate-mass planetesimals ($m_{p}\\sim10^{21}-10^{25}g$) \\emph{through gas dynamical friction} (GDF). A significant fraction of all Solar system planetesimals (asteroids and Kuiper-belt objects) are known to be binary planetesimals (BPs). Here, we explore the effects of GDF on the evolution of \\emph{binary} planetesimals embedded in a gaseous disk using an N-body code with a fiducial external force accounting for GDF. We find that GDF can induce binary mergers on timescales shorter than the disk lifetime for masses above $m_{p}\\gtrsim10^{22}g$ at 1AU, independent of the binary initial separation and eccentricity. Such mergers can affect the structure of me...

  19. Evolution of Prolate Molecular Clouds at Hii Boundaries: II. Formation of BRCs of asymmetrical morphology

    CERN Document Server

    Kinnear, T M; White, G J; Sugitani, K; Goodwin, S

    2015-01-01

    A systematic investigation on the evolution of a prolate cloud at an Hii boundary is conducted using Smoothed Particle Hydrodynamics (SPH) in order to understand the mechanism for a variety of irregular morphological structures found at the boundaries of various Hii regions. The prolate molecular clouds in this investigation are set with their semi-major axes at inclinations between 0 and 90 degrees to a plane parallel ionizing radiation flux. A set of 4 parameters, the number density n, the ratio of major to minor axis gamma, the inclination angle phi and the incident flux F_EUV, are used to define the initial state of the simulated clouds. The dependence of the evolution of a prolate cloud under Radiation Driven Implosion (RDI) on each of the four parameters is investigated. It is found that: i) in addition to the well studied standard type A, B or C Bright Rimmed Clouds (BRCs), many other types such as asymmetrical BRCs, filamentary structures and irregular horse-head structures could also be developed at ...

  20. Spectral Energy Distributions of Type 1 AGN in XMM-COSMOS Survey II - Shape Evolution

    CERN Document Server

    Hao, Heng; Civano, Francesca; Zamorani, Gianni; Ho, Luis C; Comastri, Andrea; Bongiorno, Angela; Merloni, Andrea; Brusa, Marcella; Trump, Jonathan R; Salvato, Mara; Impey, Chris D; Koekemoer, Anton M; Lanzuisi, Giorgio; Celotti, Annalisa; Jahnke, Knud; Vignali, Cristian; Silverman, John D; Urry, C Megan; Schawinski, Kevin; Capak, Peter

    2012-01-01

    The near-infrared to optical-ultraviolet (0.1 -- 10 $\\mu m$) spectral energy distribution (SED) shapes of 407 X-ray-selected radio-quiet type 1 AGN in the wide-field "Cosmic Evolution Survey" (COSMOS) have been studied for signs of evolution. For a sub-sample of 200 radio-quiet quasars with black hole mass estimation and host galaxy correction, we study the mean SEDs as a function of a broad range of redshift, bolometric luminosity, black hole mass and Eddington ratio, and compare them with the Elvis et al. (1994, E94) type 1 AGN mean SED. The mean SEDs in each bin are very similar to each other, showing no evidence of dependence on any of the analyzed parameters. We also checked the SED dispersion as a function of these four parameters, and found no significant dependance. The dispersion of the XMM-COSMOS SEDs is generally larger than E94 SED dispersion in the ultraviolet, which might be largely due to the broader "window function" for COSMOS quasars, and the X-ray based selection technique.

  1. Chemical evolution in the early phases of massive star formation II: Deuteration

    CERN Document Server

    Gerner, Th; Beuther, H; Semenov, D; Linz, H; Abertsson, T; Henning, Th

    2015-01-01

    The chemical evolution in high-mass star-forming regions is still poorly constrained. Studying the evolution of deuterated molecules allows to differentiate between subsequent stages of high-mass star formation regions due to the strong temperature dependence of deuterium isotopic fractionation. We observed a sample of 59 sources including 19 infrared dark clouds, 20 high-mass protostellar objects, 11 hot molecular cores and 9 ultra-compact HII regions in the (3-2) transitions of the four deuterated molecules, DCN, DNC, DCO+ and N2D+ as well as their non-deuterated counterpart. The overall detection fraction of DCN, DNC and DCO+ is high and exceeds 50% for most of the stages. N2D+ was only detected in a few infrared dark clouds and high-mass protostellar objects. It can be related to problems in the bandpass at the frequency of the transition and to low abundances in the more evolved, warmer stages. We find median D/H ratios of ~0.02 for DCN, ~0.005 for DNC, ~0.0025 for DCO+ and ~0.02 for N2D+. While the D/H ...

  2. Improved angular momentum evolution model for solar-like stars II. Exploring the mass dependence

    CERN Document Server

    Gallet, Florian

    2015-01-01

    We developed angular momentum evolution models for 0.5 and 0.8 $M_{\\odot}$ stars. The parametric models include a new wind braking law based on recent numerical simulations of magnetised stellar winds, specific dynamo and mass-loss rate prescriptions, as well as core/envelope decoupling. We compare model predictions to the distributions of rotational periods measured for low mass stars belonging to star forming regions and young open clusters. Furthermore, we explore the mass dependence of model parameters by comparing these new models to the solar-mass models we developed earlier. Rotational evolution models are computed for slow, median, and fast rotators at each stellar mass. The models reproduce reasonably well the rotational behaviour of low-mass stars between 1~Myr and 8-10~Gyr, including pre-main sequence to zero-age main sequence spin up, prompt zero-age main sequence spin down, and early-main sequence convergence of the surface rotation rates. Fast rotators are found to have systematically shorter di...

  3. Introduction: CRevolution 2: origin and evolution of the Colorado River System II

    Science.gov (United States)

    Karlstrom, Karl E.; Beard, L. Sue; House, Kyle; Young, Richard A.; Aslan, Andres; Billingsley, George; Pederson, Joel

    2012-01-01

    A 2010 Colorado River symposium held in Flagstaff, Arizona, in May 2010, had 70 participants who engaged in intense debate about the origin and evolution of the Colorado River system. This symposium, built on two previous decadal scientific meetings, focused on forging scientific consensus where possible, while also articulating continued controversies regarding the Cenozoic evolution of the Colorado River System and the landscapes of the Colorado Plateau–Rocky Mountain region that it drains. New developments involved hypotheses that Neogene mantle flow is driving plateau tilting and differential uplift, with consensus that multidisciplinary studies involving differential incision studies and additional geochronology and thermochronology are needed to test the relative importance of tectonic and geomorphic forcings in shaping the spectacular landscapes of the Colorado Plateau region. In addition to the scientific goals, the meeting participants emphasized the iconic status of Grand Canyon for geosciences, and the importance of good communication between the research community, the geoscience education/interpretation community, the public, and the media. Building on a century-long tradition, this region still provides a globally important natural laboratory for studies of the interactions of erosion and tectonism in the shaping landscape of elevated plateaus.

  4. TiO2/ZnS/CdS Nanocomposite for Hydrogen Evolution and Orange II Dye Degradation

    Directory of Open Access Journals (Sweden)

    Václav Štengl

    2011-01-01

    Full Text Available TiO2/ZnS/CdS composites for photocatalytic hydrogen production from water were prepared by homogeneous hydrolysis of aqueous solutions mixture of TiOSO4, ZnSO4, and CdSO4 with thioacetamide. Hydrogen evolution was observed in the presence of palladium and platinum nanoparticles deposited on TiO2/ZnS/CdS composites. The morphology was obtained by scanning electron microscopy, the nitrogen adsorption-desorption was used for determination of surface area (BET and porosity. The method of UV-VIS diffuse reflectance spectroscopy was employed to estimate band-gap energies of prepared TiO2/ZnS/CdS nano-composites. The photocatalytic activity of the prepared samples were assessed by photocatalytic decomposition of Orange II dye in an aqueous slurry under UV irradiation at 365 nm wavelength and visible light up to 400 nm wavelength. Doped titanium dioxide by the CdS increased band-gap energy and doping with ZnS increased photocatalytic activity. The best photocatalytic activity for H2 evolution shows sample named TiZnCd7 on surface deposited with palladium, which contains 20.21% TiO2, 78.5% ZnS, and 1.29% CdS.

  5. Self-consistent evolution of gas and cosmic rays in Cygnus A and similar FR II classic double radio sources

    CERN Document Server

    Mathews, William G

    2010-01-01

    In Cygnus A and other classical FR II double radio sources, powerful opposing jets from the cores of halo-centered galaxies drive out into the surrounding cluster gas, forming hotspots of shocked and compressed cluster gas at the jet extremities. The moving hotspots are sandwiched between two shocks. An inner-facing shock receives momentum and cosmic rays from the jet and creates additional cosmic rays that form a radio lobe elongated along the jet axis. An outer-facing bow shock moves directly into the undisturbed group or cluster gas, creating a cocoon of shocked gas enclosing the radio lobe. We describe computations that follow the self-consistent dynamical evolution of the shocked cluster gas and the relativistic synchrotron-emitting gas inside the lobes. Relativistic and non-relativistic components exchange momentum by interacting with small magnetic fields having dynamically negligible energy densities. The evolution of Cygnus A is governed almost entirely by cosmic ray energy flowing from the hotspots....

  6. Uncovering Additional Clues to Galaxy Evolution. II. The Environmental Impact of the Virgo Cluster on the Evolution of Dwarf Irregular Galaxies

    CERN Document Server

    Lee, H; Richer, M G; Lee, Henry; Call, Marshall L. Mc; Richer, Michael G.

    2003-01-01

    The impact of the cluster environment on the evolution of dwarf galaxies is investigated by comparing the properties of a sample of dwarf irregulars (dIs) in the Virgo Cluster with a control sample of nearby ("field") dIs having oxygen abundances derived from [O III]4363 measurements and measured distances from resolved stellar constituents. Spectroscopic data are obtained for H II regions in 11 Virgo dIs distributed in the central and outer regions of the cluster. To ensure that oxygen abundances are derived in a homogeneous manner, oxygen abundances for field and Virgo dIs are computed using the bright-line method and compared with abundances directly obtained from [O III]4363, where available. They are found to agree to within about 0.2 dex with no systematic offset. At a given optical luminosity, there is no systematic difference in oxygen abundance between the sample of Virgo dIs and the sample of nearby dIs. However, five of the eleven Virgo dIs exhibit much lower baryonic gas fractions than field dIs a...

  7. Atomic data for Zn II - Improving Spectral Diagnostics of Chemical Evolution in High-redshift Galaxies

    CERN Document Server

    Kisielius, Romas; Ferland, Gary J; Bogdanovich, Pavel; Som, Debopam; Lykins, Matt L

    2015-01-01

    Damped Lyman-alpha (DLA) and sub-DLA absorbers in quasar spectra provide the most sensitive tools for measuring element abundances of distant galaxies. Estimation of abundances from absorption lines depends sensitively on the accuracy of the atomic data used. We have started a project to produce new atomic spectroscopic parameters for optical/UV spectral lines using state-of-the-art computer codes employing very broad configuration interaction basis. Here we report our results for Zn II, an ion used widely in studies of the interstellar medium (ISM) as well as DLA/sub-DLAs. We report new calculations of many energy levels of Zn II, and the line strengths of the resulting radiative transitions. Our calculations use the configuration interaction approach within a numerical Hartree-Fock framework. We use both non-relativistic and quasi-relativistic one-electron radial orbitals. We have incorporated the results of these atomic calculations into the plasma simulation code Cloudy, and applied them to a lab plasma a...

  8. Atomic data for S II - Toward Better Diagnostics of Chemical Evolution in High-redshift Galaxies

    CERN Document Server

    Kisielius, Romas; Ferland, Gary J; Bogdanovich, Pavel; Lykins, Matt L

    2013-01-01

    Absorption-line spectroscopy is a powerful tool used to estimate element abundances in the nearby as well as distant universe. The accuracy of the abundances thus derived is, naturally, limited by the accuracy of the atomic data assumed for the spectral lines. We have recently started a project to perform the new extensive atomic data calculations used for optical/UV spectral lines in the plasma modeling code Cloudy using state-of-the-art quantal calculations. Here we demonstrate our approach by focussing on S II, an ion used to estimate metallicities for Milky Way interstellar clouds as well as distant damped Lyman-alpha (DLA) and sub-DLA absorber galaxies detected in the spectra of quasars and gamma-ray bursts (GRBs). We report new extensive calculations of a large number of energy levels of S II, and the line strengths of the resulting radiative transitions. Our calculations are based on the configuration interaction approach within a numerical Hartree-Fock framework, and utilize both non-ralativistic and ...

  9. Instability of wormholes supported by a ghost scalar field: II. Nonlinear evolution

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J A; Guzman, F S; Sarbach, O [Instituto de Fisica y Matematicas, Universidad Michoacana de San Nicolas de Hidalgo, Edificio C-3, Cd. Universitaria, A P 2-82, 58040 Morelia, Michoacan (Mexico)

    2009-01-07

    We analyze the nonlinear evolution of spherically symmetric wormhole solutions coupled to a massless ghost scalar field using numerical methods. In a previous article, we have shown that static wormholes with these properties are unstable with respect to linear perturbations. Here, we show that depending on the initial perturbation the wormholes either expand or decay to a Schwarzschild black hole. We estimate the time scale of the expanding solutions and those collapsing to a black hole, and show that they are consistent in the regime of small perturbations with those predicted from perturbation theory. In the collapsing case, we also present a systematic study of the final black hole horizon and discuss the possibility for a luminous signal to travel from one universe to the other and back before the black hole forms. In the expanding case, the wormholes seem to undergo an exponential expansion, at least during the run time of our simulations.

  10. Evolution of self-gravitating magnetized disks. II- Interaction between MHD turbulence and gravitational instabilities

    CERN Document Server

    Fromang, S; Terquem, C; De Villiers, J P; Fromang, Sebastien; Balbus, Steven A.; Terquem, Caroline; Villiers, Jean-Pierre De

    2004-01-01

    We present 3D magnetohydrodynamic (MHD) numerical simulations of the evolution of self--gravitating and weakly magnetized disks with an adiabatic equation of state. Such disks are subject to the development of both the magnetorotational and gravitational instabilities, which transport angular momentum outward. As in previous studies, our hydrodynamical simulations show the growth of strong m=2 spiral structure. This spiral disturbance drives matter toward the central object and disappears when the Toomre parameter Q has increased well above unity. When a weak magnetic field is present as well, the magnetorotational instability grows and leads to turbulence. In that case, the strength of the gravitational stress tensor is lowered by a factor of about~2 compared to the hydrodynamical run and oscillates periodically, reaching very small values at its minimum. We attribute this behavior to the presence of a second spiral mode with higher pattern speed than the one which dominates in the hydrodynamical simulations...

  11. Dynamics of magnetic flux tubes in close binary stars II. Nonlinear evolution and surface distributions

    CERN Document Server

    Holzwarth, V R

    2003-01-01

    Observations of magnetically active close binaries with orbital periods of a few days reveal the existence of starspots at preferred longitudes (with respect to the direction of the companion star). We numerically investigate the non-linear dynamics and evolution of magnetic flux tubes in the convection zoneof a fast-rotating component of a close binary system and explore whether the tidal effects are able to generate non-uniformities in the surface distribution of erupting flux tubes. Assuming a synchronised system with a rotation period of two days and consisting of two solar-type components, both the tidal force and the deviation of the stellar structure from spherical shape are considered in lowest-order perturbation theory. The magnetic field is initially stored in the form of toroidal magnetic flux rings within the stably stratified overshoot region beneath the convection zone. Once the field has grown sufficiently strong, instabilities initiate the formation of rising flux loops, which rise through the...

  12. Galaxy evolution in cosmological simulations with outflows - II. Metallicities and gas fractions

    Science.gov (United States)

    Davé, Romeel; Finlator, Kristian; Oppenheimer, Benjamin D.

    2011-09-01

    We use cosmological hydrodynamic simulations to investigate how inflows, star formation and outflows govern the gaseous and metal content of galaxies within a hierarchical structure formation context. In our simulations, galaxy metallicities are established by a balance between inflows and outflows as governed by the mass outflow rate, implying that the mass-metallicity relation reflects how the outflow rate varies with stellar mass. Gas content, meanwhile, is set by a competition between inflow into and gas consumption within the interstellar medium, the latter being governed by the star formation law, while the former is impacted by both wind recycling and preventive feedback. Stochastic variations in the inflow rate move galaxies off the equilibrium mass-metallicity and mass-gas fraction relations in a manner correlated with the star formation rate, and the scatter is set by the time-scale to re-equilibrate. The evolution of both relations from z= 3 → 0 is slow, as individual galaxies tend to evolve mostly along the relations. Gas fractions at a given stellar mass slowly decrease with time because the cosmic inflow rate diminishes faster than the consumption rate, while metallicities slowly increase as infalling gas becomes more enriched. Observations from z˜ 3 → 0 are better matched by simulations employing momentum-driven wind scalings rather than constant wind speeds, but all models predict too low gas fractions at low masses and too high metallicities at high masses. All our models reproduce observed second-parameter trends of the mass-metallicity relation with the star formation rate and environment, indicating that these are a consequence of equilibrium and not feedback. Overall, the analytical framework of our equilibrium scenario broadly captures the relevant physics establishing the galaxy gas and metal content in simulations, which suggests that the cycle of baryonic inflows and outflows centrally governs the cosmic evolution of these properties

  13. Genetic structure and evolution of the Vps25 family, a yeast ESCRT-II component

    Directory of Open Access Journals (Sweden)

    Slater Ruth

    2006-08-01

    Full Text Available Abstract Background Vps25p is the product of yeast gene VPS25 and is found in an endosomal sorting complex required for transport (ESCRT-II, along with Vps22p and Vps36p. This complex is essential for sorting of ubiquitinated biosynthetic and endosomal cargoes into endosomes. Results We found that VPS25 is a highly conserved and widely expressed eukaryotic gene, with single orthologs in chromalveolate, excavate, amoebozoan, plant, fungal and metazoan species. Two paralogs were found in Trichomonas vaginalis. An ortholog was strikingly absent from the Encephalitozoon cuniculi genome. Intron positions were analyzed in VPS25 from 36 species. We found evidence for five ancestral VPS25 introns, intron loss, and single instances of intron gain (a Paramecium species and intron slippage (Theileria species. Processed pseudogenes were identified in four mammalian genomes, with a notable absence in the mouse genome. Two retropseudogenes were found in the chimpanzee genome, one more recently inserted, and one evolving from a common primate ancestor. The amino acid sequences of 119 Vps25 orthologs are aligned, compared with the known secondary structure of yeast Vps25p, and used to carry out phylogenetic analysis. Residues in two amino-terminal PPXY motifs (motif I and II, involved in dimerization of Vps25p and interaction with Vps22p and Vps36p, were closely, but not absolutely conserved. Specifically, motif I was absent in Vps25 homologs of chromalveolates, euglenozoa, and diplomonads. A highly conserved carboxy-terminal lysine was identified, which suggests Vps25 is ubiquitinated. Arginine-83 of yeast Vps25p involved in Vps22p interaction was highly, but not absolutely, conserved. Human tissue expression analysis showed universal expression. Conclusion We have identified 119 orthologs of yeast Vps25p. Expression of mammalian VPS25 in a wide range of tissues, and the presence in a broad range of eukaryotic species, indicates a basic role in eukaryotic cell

  14. Prevalence and evolution of core photosystem II genes in marine cyanobacterial viruses and their hosts.

    Directory of Open Access Journals (Sweden)

    Matthew B Sullivan

    2006-07-01

    Full Text Available Cyanophages (cyanobacterial viruses are important agents of horizontal gene transfer among marine cyanobacteria, the numerically dominant photosynthetic organisms in the oceans. Some cyanophage genomes carry and express host-like photosynthesis genes, presumably to augment the host photosynthetic machinery during infection. To study the prevalence and evolutionary dynamics of this phenomenon, 33 cultured cyanophages of known family and host range and viral DNA from field samples were screened for the presence of two core photosystem reaction center genes, psbA and psbD. Combining this expanded dataset with published data for nine other cyanophages, we found that 88% of the phage genomes contain psbA, and 50% contain both psbA and psbD. The psbA gene was found in all myoviruses and Prochlorococcus podoviruses, but could not be amplified from Prochlorococcus siphoviruses or Synechococcus podoviruses. Nearly all of the phages that encoded both psbA and psbD had broad host ranges. We speculate that the presence or absence of psbA in a phage genome may be determined by the length of the latent period of infection. Whether it also carries psbD may reflect constraints on coupling of viral- and host-encoded PsbA-PsbD in the photosynthetic reaction center across divergent hosts. Phylogenetic clustering patterns of these genes from cultured phages suggest that whole genes have been transferred from host to phage in a discrete number of events over the course of evolution (four for psbA, and two for psbD, followed by horizontal and vertical transfer between cyanophages. Clustering patterns of psbA and psbD from Synechococcus cells were inconsistent with other molecular phylogenetic markers, suggesting genetic exchanges involving Synechococcus lineages. Signatures of intragenic recombination, detected within the cyanophage gene pool as well as between hosts and phages in both directions, support this hypothesis. The analysis of cyanophage psbA and psb

  15. Patterns of evolution of MHC class II genes of crows (Corvus suggest trans-species polymorphism

    Directory of Open Access Journals (Sweden)

    John A. Eimes

    2015-03-01

    Full Text Available A distinguishing characteristic of genes that code for the major histocompatibility complex (MHC is that alleles often share more similarity between, rather than within species. There are two likely mechanisms that can explain this pattern: convergent evolution and trans-species polymorphism (TSP, in which ancient allelic lineages are maintained by balancing selection and retained by descendant species. Distinguishing between these two mechanisms has major implications in how we view adaptation of immune genes. In this study we analyzed exon 2 of the MHC class IIB in three passerine bird species in the genus Corvus: jungle crows (Corvus macrorhynchos japonensis American crows (C. brachyrhynchos and carrion crows (C. corone orientalis. Carrion crows and American crows are recently diverged, but allopatric, sister species, whereas carrion crows and jungle crows are more distantly related but sympatric species, and possibly share pathogens linked to MHC IIB polymorphisms. These patterns of evolutionary divergence and current geographic ranges enabled us to test for trans-species polymorphism and convergent evolution of the MHC IIB in crows. Phylogenetic reconstructions of MHC IIB sequences revealed several well supported interspecific clusters containing all three species, and there was no biased clustering of variants among the sympatric carrion crows and jungle crows. The topologies of phylogenetic trees constructed from putatively selected sites were remarkably different than those constructed from putatively neutral sites. In addition, trees constructed using non-synonymous substitutions from a continuous fragment of exon 2 had more, and generally more inclusive, supported interspecific MHC IIB variant clusters than those constructed from the same fragment using synonymous substitutions. These phylogenetic patterns suggest that recombination, especially gene conversion, has partially erased the signal of allelic ancestry in these species. While

  16. Simultaneous Effect of Resistance Training and Portulace Oleraceal Supplementation on Some Biochemical Markers of Bone Dynamics in Women with Type II Diabetes

    Directory of Open Access Journals (Sweden)

    Shokufe Ziadloo (MSc

    2016-06-01

    Full Text Available Background and Objective: Osteoporosis is one of the complications of diabetes. The aim of this study was to determine the impact of resistance training along with Portulaca oleracea supplementation on OPG and NFκB levels (bone markers in women with type II diabetes. Methods: Overall, 28 women with type II diabetes (44 to 60 years old were randomly and equally assigned into four groups (supplement, training, training-supplement and control. An eight-week resistance training program (three one-hour sessions per week with one repetition maximum was performed using three types of bands with different resistances, at 40-50% intensity and 50-70% maximum heart rate. P. oleracea seeds were supplemented daily (7.5 grams mixed in yogurt for eight weeks. The data was analyzed using descriptive statistics, paired t-test and ANOVA. Results: After 8 weeks, OPG and NFκB levels in the three groups of supplement, training and training-supplement increased and decreased, respectively. The highest change in both variables was observed in the training-supplement group. Moreover, the level of these two variables in the training-supplement group had significant difference with the controls and other groups (P=0.000. Conclusion: As a non-pharmacological therapeutic approach, the regular resistance training and P. oleracea supplementation can increase bone formation markers and reduce bone resorption in women with type II diabetes.

  17. The role of OH in the chemical evolution of protoplanetary disks II. Gas-rich environments

    CERN Document Server

    Molano, Germán Chaparro

    2012-01-01

    Context. We present a method for including gas extinction of cosmic-ray-generated UV photons in chemical models of the midplane of protoplanetary disks, focusing on its implications on ice formation and chemical evolution. Aims. Our goal is to improve on chemical models by treating cosmic rays, the main source of ionization in the midplane of the disk, in a way that is consistent with current knowledge of the gas and grain environment present in those regions. We trace the effects of cosmic rays by identifying the main chemical reaction channels and also the main contributors to the gas opacity to cosmic-ray-induced UV photons. This information is crucial in implementing gas opacities for cosmic-ray-induced reactions in full 2D protoplanetary disk models. Methods. We considered time-dependent chemical models within the range 1-10 AU in the midplane of a T Tauri disk. The extinction of cosmic-ray-induced UV photons by gaseous species was included in the calculation of photorates at each timestep. We integrated...

  18. Galaxy Evolution in Cosmological Simulations with Outflows II: Metallicities and Gas Fractions

    CERN Document Server

    Davé, Romeel; Oppenheimer, Benjamin D

    2011-01-01

    We use cosmological hydrodynamic simulations to investigate how inflows, star formation, and outflows govern the the gaseous and metal content of galaxies. In our simulations, galaxy metallicities are established by a balance between inflows and outflows as governed by the mass outflow rate, implying that the mass-metallicity relation reflects how the outflow rate varies with stellar mass. Gas content is set by a competition between inflow into and gas consumption within the ISM, the latter being governed by the star formation law, while the former is impacted by both wind recycling and preventive feedback. Stochasticity in the inflow rate moves galaxies off the equilibrium mass-metallicity and mass-gas fraction relations in a manner correlated with the SFR, and the scatter is set by the timescale to re-equilibrate. The evolution of both relations from z=3-0 is slow, as individual galaxies tend to evolve mostly along the relations. Gas fractions at a given stellar mass slowly decrease with time because the co...

  19. Stellar Rotation in Young Clusters. II. Evolution of Stellar Rotation and Surface Helium Abundance

    CERN Document Server

    Huang, W

    2005-01-01

    We derive the effective temperatures and gravities of 461 OB stars in 19 young clusters by fitting the H-gamma profile in their spectra. We use synthetic model profiles for rotating stars to develop a method to estimate the polar gravity for these stars, which we argue is a useful indicator of their evolutionary status. We combine these results with projected rotational velocity measurements obtained in a previous paper on these same open clusters. We find that the more massive B-stars experience a spin down as predicted by the theories for the evolution of rotating stars. Furthermore, we find that the members of binary stars also experience a marked spin down with advanced evolutionary state due to tidal interactions. We also derive non-LTE-corrected helium abundances for most of the sample by fitting the He I 4026, 4387, 4471 lines. A large number of helium peculiar stars are found among cooler stars with Teff < 23000 K. The analysis of the high mass stars (8.5 solar masses < M < 16 solar masses) s...

  20. Spin Evolution of Accreting Young Stars. II. Effect of Accretion-Powered Stellar Winds

    CERN Document Server

    Matt, Sean P; Greene, Thomas P; Pudritz, Ralph E

    2011-01-01

    We present a model for the rotational evolution of a young, solar-mass star interacting magnetically with an accretion disk. As in a previous paper (Paper I), the model includes changes in the star's mass and radius as it descends the Hayashi track, a decreasing accretion rate, and a prescription for the angular momentum transfer between the star and disk. Paper I concluded that, for the relatively strong magnetic coupling expected in real systems, additional processes are necessary to explain the existence of slowly rotating pre-main-sequence stars. In the present paper, we extend the stellar spin model to include the effect of a spin-down torque that arises from an accretion-powered stellar wind. For a range of magnetic field strengths, accretion rates, initial spin rates, and mass outflow rates, the modeled stars exhibit rotation periods within the range of 1--10 days in the age range of 1--3 Myr. This range coincides with the bulk of the observed rotation periods, with the slow rotators corresponding to s...

  1. SPIN EVOLUTION OF ACCRETING YOUNG STARS. II. EFFECT OF ACCRETION-POWERED STELLAR WINDS

    Energy Technology Data Exchange (ETDEWEB)

    Matt, Sean P. [Laboratoire AIM Paris-Saclay, CEA/Irfu Universite Paris-Diderot CNRS/INSU, 91191 Gif-sur-Yvette (France); Pinzon, Giovanni [Observatorio Astronomico Nacional, Facultad de Ciencias, Universidad Nacional de Colombia, Bogota (Colombia); Greene, Thomas P. [NASA Ames Research Center, M.S. 245-6, Moffett Field, CA 94035-1000 (United States); Pudritz, Ralph E., E-mail: sean.matt@cea.fr, E-mail: thomas.p.greene@nasa.gov, E-mail: gapinzone@unal.edu.co, E-mail: pudritz@physics.mcmaster.ca [Physics and Astronomy Department, McMaster University, Hamilton, ON L8S 4M1 (Canada)

    2012-01-20

    We present a model for the rotational evolution of a young, solar-mass star interacting magnetically with an accretion disk. As in a previous paper (Paper I), the model includes changes in the star's mass and radius as it descends the Hayashi track, a decreasing accretion rate, and a prescription for the angular momentum transfer between the star and disk. Paper I concluded that, for the relatively strong magnetic coupling expected in real systems, additional processes are necessary to explain the existence of slowly rotating pre-main-sequence stars. In the present paper, we extend the stellar spin model to include the effect of a spin-down torque that arises from an accretion-powered stellar wind (APSW). For a range of magnetic field strengths, accretion rates, initial spin rates, and mass outflow rates, the modeled stars exhibit rotation periods within the range of 1-10 days in the age range of 1-3 Myr. This range coincides with the bulk of the observed rotation periods, with the slow rotators corresponding to stars with the lowest accretion rates, strongest magnetic fields, and/or highest stellar wind mass outflow rates. We also make a direct, quantitative comparison between the APSW scenario and the two types of disk-locking models (namely, the X-wind and Ghosh and Lamb type models) and identify some remaining theoretical issues for understanding young star spins.

  2. The longterm evolution of neutron star merger remnants II: radioactively powered transients

    CERN Document Server

    Grossman, Doron; Rosswog, Stephan; Piran, Tsvi

    2013-01-01

    We use 3D hydrodynamic simulations of the longterm evolution of neutron star merger ejecta to predict the light curves of electromagnetic transients that are powered by the decay of freshly produced r-process nuclei. For the dynamic ejecta that are launched by tidal and hydrodynamic interaction we adopt gray opacities of 10 cm$^2$/g, as suggested by recent studies. For our reference case of a 1.3-1.4 $m_\\odot$ merger we find a broad IR peak 2-4 days after the merger. The peak luminosity is $\\approx 2\\times 10^{40}$ erg/s for an average orientation, but increased by up to a factor of 4 for more favorable binary parameters and viewing angles. These signals are rather weak and hardly detectable within the large error box (~100 deg$^2$) of a GW trigger. A second electromagnetic transient results from neutrino-driven winds. These winds produce "weak" r-process material with 50

  3. Evolution, nucleosynthesis and yields of low mass AGB stars at different metallicities (II): the FRUITY database

    CERN Document Server

    Cristallo, Sergio; Straniero, Oscar; Gallino, Roberto; Dominguez, Inma; Abia, Carlos; DiRico, Gianluca; Quintini, Massimo; Bisterzo, Sara

    2011-01-01

    By using updated stellar low mass stars models, we can systematically investigate the nucleosynthesis processes occurring in AGB stars, when these objects experience recurrent thermal pulses and third dredge-up episodes. In this paper we present the database dedicated to the nucleosynthesis of AGB stars: the FRUITY (FRANEC Repository of Updated Isotopic Tables & Yields) database. An interactive web-based interface allows users to freely download the full (from H to Bi) isotopic composition, as it changes after each third dredge-up episode and the stellar yields the models produce. A first set of AGB models, having masses in the range 1.5 < M/Msun < 3.0 and metallicities 1e-3 < Z < 2e-2, is discussed here. For each model, a detailed description of the physical and the chemical evolution is provided. In particular, we illustrate the details of the s-process and we evaluate the theoretical uncertainties due to the parametrization adopted to model convection and mass loss. The resulting nucleosynt...

  4. Anthocyanins and their variation in red wines. II. Anthocyanin derived pigments and their color evolution.

    Science.gov (United States)

    He, Fei; Liang, Na-Na; Mu, Lin; Pan, Qiu-Hong; Wang, Jun; Reeves, Malcolm J; Duan, Chang-Qing

    2012-02-07

    Originating in the grapes, anthocyanins and their derivatives are the crucial pigments responsible for the red wine color. During wine maturation and aging, the concentration of monomeric anthocyanins declines constantly, while numerous more complex and stable anthocyanin derived pigments are formed, mainly including pyranoanthocyanins, polymeric anthocyanins produced from condensation between anthocyanin and/or flavan-3-ols directly or mediated by aldehydes. Correspondingly, their structural modifications result in a characteristic variation of color, from purple-red color in young red wines to brick-red hue of the aged. Because of the extreme complexity of chemical compounds involved, many investigations have been made using model solutions of know composition rather than wine. Thus, there is a large amount of research still required to obtain an overall perspective of the anthocyanin composition and its change with time in red wines. Future findings may well greatly revise our current interpretation of the color in red wines. This paper summarizes the most recent advances in the studies of the anthocyanins derived pigments in red wines, as well as their color evolution.

  5. On the evolution of the snow line in protoplanetary discs II: Analytic approximations

    CERN Document Server

    Martin, Rebecca G

    2013-01-01

    We examine the evolution of the snow line in a protoplanetary disc that contains a dead zone (a region of zero or low turbulence). The snow line is within a self-gravitating part of the dead zone, and we obtain a fully analytic solution for its radius. Our formula could prove useful for future observational attempts to characterise the demographics of planets outside the snow line. External sources such as comic rays or X-rays from the central star can ionise the disc surface layers and allow the magneto-rotational instability to drive turbulence there. We show that provided that the surface density in this layer is less than about 50 g/cm^2, the dead zone solution exists, after an initial outbursting phase, until the disc is dispersed by photoevaporation. We demonstrate that the snow line radius is significantly larger than that predicted by a fully turbulent disc model, and that in our own solar system it remains outside of the orbital radius of the Earth. Thus, the inclusion of a dead zone into a protoplan...

  6. Anthocyanins and Their Variation in Red Wines II. Anthocyanin Derived Pigments and Their Color Evolution

    Directory of Open Access Journals (Sweden)

    Chang-Qing Duan

    2012-02-01

    Full Text Available Originating in the grapes, anthocyanins and their derivatives are the crucial pigments responsible for the red wine color. During wine maturation and aging, the concentration of monomeric anthocyanins declines constantly, while numerous more complex and stable anthocyanin derived pigments are formed, mainly including pyranoanthocyanins, polymeric anthocyanins produced from condensation between anthocyanin and/or flavan-3-ols directly or mediated by aldehydes. Correspondingly, their structural modifications result in a characteristic variation of color, from purple-red color in young red wines to brick-red hue of the aged. Because of the extreme complexity of chemical compounds involved, many investigations have been made using model solutions of know composition rather than wine. Thus, there is a large amount of research still required to obtain an overall perspective of the anthocyanin composition and its change with time in red wines. Future findings may well greatly revise our current interpretation of the color in red wines. This paper summarizes the most recent advances in the studies of the anthocyanins derived pigments in red wines, as well as their color evolution.

  7. Full computation of massive AGB evolution. II. The role of mass loss and cross-sections

    CERN Document Server

    D'Antona, P V F

    2005-01-01

    In the course of a systematic exploration of the uncertainties associated to the input micro- and macro-physics in the modeling of the evolution of intermediate mass stars during their Asymptotic Giant Branch (AGB) phase, we focus on the role of the nuclear reactions rates and mass loss. We consider masses 3

  8. The perspective effects of various seed coating substances on rice seed variety Khao Dawk Mali 105 storability II: the case study of chemical and biochemical properties.

    Science.gov (United States)

    Thobunluepop, P; Pan-in, W; Pawelzik, E; Vearasilp, S

    2009-04-01

    The aim of this study was to investigate the effects of seed coating substances; chemical fungicide (CA) and biological fungicide polymers [chitosan-lignosulphonate polymer (CL) and eugenol incorporated into chitosan-lignosulphonate polymer (E+CL)] on chemical and biochemical changes of rice seeds cv. KDML 105, which have been studied during storage for 12 months. CA significantly affected the rice seed chemical properties and the associated seed deterioration. After 12 months storage, protein content decreased accompanied by declined of lipid content, increased free fatty acids and activated lipoxygenase enzyme. In the case of biological fungicide coated seeds, the antioxidative scavenging enzymes were ascorbate peroxidase and superoxide dismutase and a high antioxidant activity protected them. Moreover, the sugar content was positive correlated with seed germination and vigor. The biological coated seeds were found to maintain high sugar contents inside the seeds, which resulted high seed storability significantly. In contrast, under fungicide stress (CA), those compounds were lost that directly affected seed vigor during storage.

  9. The MassiveBlack-II Simulation: The Evolution of Halos and Galaxies to z~0

    CERN Document Server

    Khandai, Nishikanta; Croft, Rupert; Wilkins, Stephen M; Feng, Yu; Tucker, Evan; DeGraf, Colin; Liu, Mao-Sheng

    2014-01-01

    (Abridged for arXiv)We investigate the properties of halos, galaxies and blackholes to z=0 in the high resolution hydrodynamical simulation MassiveBlack-II (MBII) which evolves a LCDM cosmology in a comoving volume Vbox=100(Mpc/h)^3. MBII is the highest resolution simulation of this size which includes a self-consistent model for star formation, black hole accretion and associated feedback. We provide a simulation browser web application which enables interactive search and tagging of halos, subhalos and their properties and publicly release our galaxy catalogs. Our analysis of the halo mass function (MF) in MBII reveals that baryons have strong effects, with changes in the halo abundance of 20-35% below the knee of the MF (Mhalo =2. At z10^11 Msun) galaxies hosting bright AGNs make significant contributions to the GSMF. The quasar bolometric luminosity function is also largely consistent with observations. We note however that more efficient AGN feedback (beyond simple thermal coupling used here) is likely n...

  10. Photoinduced hydrogen evolution with new tetradentate cobalt(ii) complexes based on the TPMA ligand.

    Science.gov (United States)

    Natali, Mirco; Badetti, Elena; Deponti, Elisa; Gamberoni, Marta; Scaramuzzo, Francesca A; Sartorel, Andrea; Zonta, Cristiano

    2016-10-07

    Hydrogen production from water splitting is nowadays recognized as a target, fundamental reaction for the production of clean fuels. Indeed, tremendous efforts have been devoted towards the research of suitable catalysts capable of performing this reaction. With respect to heterogeneous systems, molecular catalysts such as metal complexes are amenable to chemical functionalization in order to fine tune the catalytic properties. In this paper a new class of tris(2-pyridylmethyl)-amine (TPMA) cobalt(ii) complexes (CoL0-4) has been synthesized and employed as hydrogen evolving catalysts under photochemical conditions taking advantage of Ru(bpy)3(2+) (where bpy is 2,2'-bipyridine) as a light-harvesting sensitizer and ascorbic acid as a sacrificial electron donor. Tuning of the photocatalytic activity has been attempted through the introduction of different substituents at the catalyst periphery rather than through a direct chemical modification of the chelating TPMA ligand. The results show that CoL0-4 behave as competent hydrogen evolving catalysts (HECs), although the effects played by the different substituents on the catalysis are relatively modest. Possible reasons supporting the observed behavior as well as possible improvements of the aforementioned tuning approach are discussed.

  11. The ATLAS transverse momentum trigger evolution at the LHC towards Run II

    CERN Document Server

    Strubig, Antonia; The ATLAS collaboration

    2015-01-01

    The missing transverse momentum triggers of the ATLAS experiment at the CERN Large Hadron Collider (LHC) are designed to select collision events with non-interacting particles passing through the detector. Such events provide an interesting probe for new physics interactions beyond the Standard Model, but also provide the basis for precise measurements of Standard Model parameters such as the Higgs couplings. The transverse momentum used in the trigger system is calculated from calorimeter-based global energy sums and supplemented with information from the muon detection system. The trigger operated successfully during the first running period of the LHC. With the start-up in 2015, the LHC is now operating at a higher centre-of-mass energy and increased luminosity, both making it challenging to improve on the Run I performance. A brief summary of the Run I performance studies will be presented, together with the Run II software and hardware-based improvements as well as some of the first results from the Run ...

  12. Unveiling The Sigma-Discrepancy II: Revisiting the Evolution of ULIRGs & The Origin of Quasars

    CERN Document Server

    Rothberg, Barry; Rodrigues, Myriam; Sanders, David B

    2013-01-01

    We present the first central velocity dispersions (sigma_o) measured from the 0.85 micron Calcium II Triplet (CaT) for 8 advanced (i.e. single nuclei) local (z < 0.15) Ultraluminous Infrared Galaxies (ULIRGs). First, these measurements are used to test the prediction that the "sigma-Discrepancy," in which the CaT sigma_o is systematically larger than the sigma_o obtained from the 1.6 or 2.3 micron stellar CO band-heads, extends to ULIRG luminosities. Next, we combine the CaT data with rest-frame I-band photometry obtained from archival Hubble Space Telescope data and the Sloan Digital Sky Survey (SDSS) to derive dynamical properties for the 8 ULIRGs. These are then compared to the dynamical properties of 9,255 elliptical galaxies from the SDSS within the same redshift volume and of a relatively nearby (z < 0.4) sample of 53 QSO host galaxies. A comparison is also made between the I-band and H-band dynamical properties of the ULIRGs. We find four key results: 1) the sigma-Discrepancy extends to ULIRG lum...

  13. Mg II Absorber Number Density at z~0.05 Implications for Omega_DLA Evolution

    CERN Document Server

    Churchill, C W

    2001-01-01

    [Abridged] A 147 quasar/AGN spectra, obtained with FOS/HST, have been searched for Mg II absorbers for 0 = 0.06, yielding dN/dz = 0.22(+0.12)(-0.09) for absorbers with W_r > 0.6 Ang. This is consistent with the value expected if these systems do not evolve from higher redshifts (z = 2.2). (2) No systems with W_r 0.2 galaxies. (3) Three systems are candidates for damped Lyman-alpha absorbers (DLAs). Based upon the results of Rao & Turnshek (2000, ApJS, 130, 1), this translates to dN/dz = 0.08(+0.09)(-0.05) for DLAs at z ~ 0. This would suggest that dN/dz for DLAs does not evolve from z = 4 to z = 0. However, because of the distribution of H I mass in 21-cm selected galaxies, the Rao & Turnshek finding that the cosmological H I mass density, Omega_DLA, decreases either rapidly from z = 0.5 to z = 0, or more gradually from z = 1.5, still holds.

  14. MOLECULAR EVOLUTION OF GLUTAMINE SYNTHETASE II AND III IN THE CHROMALVEOLATES(1).

    Science.gov (United States)

    Ghoshroy, Sohini; Robertson, Deborah L

    2012-06-01

    Glutamine synthetase (GS) is encoded by three distinct gene families (GSI, GSII, and GSIII) that are broadly distributed among the three domains of life. Previous studies established that GSII and GSIII isoenzymes were expressed in diatoms; however, less is known about the distribution and evolution of the gene families in other chromalveolate lineages. Thus, GSII cDNA sequences were isolated from three cryptophytes (Guillardia theta D. R. A. Hill et Wetherbee, Cryptomonas phaseolus Skuja, and Pyrenomonas helgolandii Santore), and GSIII was sequenced from G. theta. Red algal GSII sequences were obtained from Bangia atropurpurea (Mertens ex Roth) C. Agardh; Compsopogon caeruleus (Balbis ex C. Agardh) Mont.; Flintiella sanguinaria F. D. Ott and Porphyridium aerugineum Geitler; Rhodella violacea (Kornmann) Wehrmeyer and Dixoniella grisea (Geitler) J. L. Scott, S. T. Broadwater, B. D. Saunders, J. P. Thomas et P. W. Gabrielson; and Stylonema alsidii (Zanardini) K. M. Drew. In Bayesian inference and maximum-likelihood (ML) phylogenetic analyses, chromalveolate GSII sequences formed a weakly supported clade that nested among sequences from glaucophytes, red algae, green algae, and plants. Red algal GSII sequences formed two distinct clades. The largest clade contained representatives from the Cyanidiophytina and Rhodophytina and grouped with plants and green algae. The smaller clade (C. caeruleus, Porphyra yezoensis, and S. alsidii) nested within the chromalveolates, although its placement was unresolved. Chromalveolate GSIII sequences formed a well-supported clade in Bayesian and ML phylogenies, and mitochondrial transit peptides were identified in many of the sequences. There was strong support for a stramenopile-haptophyte-cryptophyte GSIII clade in which the cryptophyte sequence diverged from the deepest node. Overall, the evolutionary history of the GS gene families within the algae is complex with evidence for the presence of orthologous and paralogous sequences

  15. Simulations in evolution. II. Relative fitness and the propagation of mutants.

    Science.gov (United States)

    Testa, Bernard; Bojarski, Andrzej J

    2009-03-01

    In Neo-Darwinism, variation and natural selection are the two evolutionary mechanisms which propel biological evolution. Our previous article presented a histogram model [1] consisting in populations of individuals whose number changed under the influence of variation and/or fitness, the total population remaining constant. Individuals are classified into bins, and the content of each bin is calculated generation after generation by an Excel spreadsheet. Here, we apply the histogram model to a stable population with fitness F(1)=1.00 in which one or two fitter mutants emerge. In a first scenario, a single mutant emerged in the population whose fitness was greater than 1.00. The simulations ended when the original population was reduced to a single individual. The histogram model was validated by excellent agreement between its predictions and those of a classical continuous function (Eqn. 1) which predicts the number of generations needed for a favorable mutation to spread throughout a population. But in contrast to Eqn. 1, our histogram model is adaptable to more complex scenarios, as demonstrated here. In the second and third scenarios, the original population was present at time zero together with two mutants which differed from the original population by two higher and distinct fitness values. In the fourth scenario, the large original population was present at time zero together with one fitter mutant. After a number of generations, when the mutant offspring had multiplied, a second mutant was introduced whose fitness was even greater. The histogram model also allows Shannon entropy (SE) to be monitored continuously as the information content of the total population decreases or increases. The results of these simulations illustrate, in a graphically didactic manner, the influence of natural selection, operating through relative fitness, in the emergence and dominance of a fitter mutant.

  16. Evolution of Migmatitic Granulite Complexes: implications from Lapland Granulite Belt, Part II: isotopic dating

    Directory of Open Access Journals (Sweden)

    Pekka Tuisku

    2006-01-01

    Full Text Available The migmatitic metapelites of the Lapland granulite belt (LGB in the NE part of the Fennoscandian Shield represent an arc-related greywacke basin metamorphosed in the granulite facies. Detrital zircons from migmatitic metapelites are derived from 1.94 - 2.9 Ga old acid source rocks (U-Pb SIMS ages. The clustering of detrital zircon ages between 1.97 and 2.2 Ga is problematic, because abundant felsic crust of this age is absent in the shield. The metasediments are characterized by Sm-Nd model ages of ca. 2.3 Ga. A younger, 1905-1880 Ma population of homogeneous zircons was formed during regional metamorphism. The peak high-grade metamorphism took place at ~1900 Ma and the latest chronological record from subsequent decompression and cooling phase is from ca. 1870 Ma. The norite-enderbite series of the LGB represents arc-magmas, which were intruded into the metasediments at ~1920-1905 Ma ago according to zircon U-Pb ages and were probably an important heat source for metamorphism. Older, zoned zircon grains in a quartz norite vein, initial εNd values of 0 to +1 and the continuous spectrum of LILE enrichment in the enderbite-series probably reflect assimilation of metasediments by magmas. Monazite U-Pb ages of migmatitic metasediments in the range 1906-1910±3 Ma overlap the late stage of enderbite intrusion and growth of early metamorphic zircons. Garnet-whole rock Sm-Nd ages from leucosomes in the range 1880-1886±7 Ma are concurrent with the growth of the youngest metamorphic zircons and probably indicate the crystallization of leucosomes of the influence of a fluid liberated from them. Isotopic and petrologic data reveal that the evolution of Lapland Granulite belt from the erosion of source rocks to the generation of a sedimentary basin, its burial, metamorphism and exhumation took place within ca. 60 Ma.

  17. Biochemical and Spectroscopic Characterization of the Non-Heme Fe(II)- and 2-Oxoglutarate-Dependent Ethylene-Forming Enzyme from Pseudomonas syringae pv. phaseolicola PK2.

    Science.gov (United States)

    Martinez, Salette; Hausinger, Robert P

    2016-11-01

    The ethylene-forming enzyme (EFE) from Pseudomonas syringae pv. phaseolicola PK2 is a member of the mononuclear non-heme Fe(II)- and 2-oxoglutarate (2OG)-dependent oxygenase superfamily. This enzyme is reported to simultaneously catalyze the conversion of 2OG into ethylene and three CO2 molecules and the Cδ hydroxylation of l-arginine (l-Arg) while oxidatively decarboxylating 2OG to form succinate and carbon dioxide. A new plasmid construct for expression in recombinant Escherichia coli cells allowed for the purification of large amounts of EFE with activity greater than that previously recorded. A variety of assays were used to quantify and confirm the identity of the proposed products, including the first experimental demonstration of l-Δ(1)-pyrroline-5-carboxylate and guanidine derived from 5-hydroxyarginine. Selected l-Arg derivatives could induce ethylene formation without undergoing hydroxylation, demonstrating that ethylene production and l-Arg hydroxylation activities are not linked. Similarly, EFE utilizes the alternative α-keto acid 2-oxoadipate as a cosubstrate (forming glutaric acid) during the hydroxylation of l-Arg, with this reaction unlinked from ethylene formation. Kinetic constants were determined for both ethylene formation and l-Arg hydroxylation reactions. Anaerobic UV-visible difference spectra were used to monitor the binding of Fe(II) and substrates to the enzyme. On the basis of our results and what is generally known about EFE and Fe(II)- and 2OG-dependent oxygenases, an updated model for the reaction mechanism is presented.

  18. Evidence for transitional stages in the evolution of euglenid group II introns and twintrons in the Monomorphina aenigmatica plastid genome.

    Directory of Open Access Journals (Sweden)

    Jean-François Pombert

    Full Text Available BACKGROUND: Photosynthetic euglenids acquired their plastid by secondary endosymbiosis of a prasinophyte-like green alga. But unlike its prasinophyte counterparts, the plastid genome of the euglenid Euglena gracilis is riddled with introns that interrupt almost every protein-encoding gene. The atypical group II introns and twintrons (introns-within-introns found in the E. gracilis plastid have been hypothesized to have been acquired late in the evolution of euglenids, implying that massive numbers of introns may be lacking in other taxa. This late emergence was recently corroborated by the plastid genome sequences of the two basal euglenids, Eutreptiella gymnastica and Eutreptia viridis, which were found to contain fewer introns. METHODOLOGY/PRINCIPAL FINDINGS: To gain further insights into the proliferation of introns in euglenid plastids, we have characterized the complete plastid genome sequence of Monomorphina aenigmatica, a freshwater species occupying an intermediate phylogenetic position between early and late branching euglenids. The M. aenigmatica UTEX 1284 plastid genome (74,746 bp, 70.6% A+T, 87 genes contains 53 intron insertion sites, of which 41 were found to be shared with other euglenids including 12 of the 15 twintron insertion sites reported in E. gracilis. CONCLUSIONS: The pattern of insertion sites suggests an ongoing but uneven process of intron gain in the lineage, with perhaps a minimum of two bursts of rapid intron proliferation. We also identified several sites that represent intermediates in the process of twintron evolution, where the external intron is in place, but not the internal one, offering a glimpse into how these convoluted molecular contraptions originate.

  19. Biochemical, transcriptomic and proteomic analyses of digestion in the scorpion Tityus serrulatus: insights into function and evolution of digestion in an ancient arthropod.

    Science.gov (United States)

    Fuzita, Felipe J; Pinkse, Martijn W H; Patane, José S L; Juliano, Maria A; Verhaert, Peter D E M; Lopes, Adriana R

    2015-01-01

    Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

  20. Biochemical, transcriptomic and proteomic analyses of digestion in the scorpion Tityus serrulatus: insights into function and evolution of digestion in an ancient arthropod.

    Directory of Open Access Journals (Sweden)

    Felipe J Fuzita

    Full Text Available Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability, zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also

  1. Novel copper-based therapeutic agent for anti-inflammatory: synthesis, characterization, and biochemical activities of copper(II) complexes of hydroxyflavone Schiff bases.

    Science.gov (United States)

    Joseph, J; Nagashri, K

    2012-07-01

    Four hydroxyflavone derivatives have been synthesized with the aim of obtaining a good model of superoxide dismutase. Better to mimic the natural metalloenzyme, copper complexes have been designed. The Cu(II) complexes of general formulae, [CuL] where L = 5-hydroxyflavone-o-phenylenediamine (L¹H₂)/m-phenylenediamine (L²H₂) and 3-hydroxyflavone-o-phenylenediamine (L³H₂)/m-phenylenediamine (L⁴H₂) have been synthesized. The structural features have been determined from their analytical and spectral data. All the Cu(II) complexes exhibit square planar geometry. Redox behavior of copper complexes was studied and the present ligand systems stabilize the unusual oxidation state of the copper ion during electrolysis. The in vitro antimicrobial activities of the investigated compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Pseudomonas aeruginosa and fungal species Aspergillus niger, Rhizopus stolonifer, Aspergillus flavus, Rhizoctonia bataicola, and Candida albicans. Superoxide dismutase and anti-inflammatory activities of the copper complexes have also been measured and discussed.

  2. Evolution of thermally pulsing asymptotic giant branch stars - II. Dust production at varying metallicity

    Science.gov (United States)

    Nanni, Ambra; Bressan, Alessandro; Marigo, Paola; Girardi, Léo

    2013-09-01

    excess, determined by the complex interplay between mass-loss, third dredge-up and hot-bottom burning, or the homogeneous growth scheme should be revised. Finally, we analyse the differences in the total dust production of M-stars that arise from the use of the two approaches (i.e. with or without chemisputtering). We find that, in spite of the differences in the expected dust stratification, for a given set of TP-AGB models, the ejecta are only weakly sensitive to the specific assumption. This work also shows that the properties of TP-AGB circumstellar envelopes are important diagnostic tools that may be profitably added to the traditional calibrators for setting further constraints on this complex phase of stellar evolution.

  3. The evolution and explosion of massive Stars II: Explosive hydrodynamics and nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Woosley, S.E. [California Univ., Santa Cruz, CA (United States)]|[Lawrence Livermore National Lab., CA (United States); Weaver, T.A. [Lawrence Livermore National Lab., CA (United States)

    1995-08-30

    The nucleosynthetic yield of isotopes lighter than A = 66 (zinc) is determined for a grid of stellar masses and metallicities including stars of 11, 12, 13, 15, 18, 19, 20, 22, 25, 30, 35, and 40 M{sub {circle_dot}} and metallicities Z = 0, 10{sup {minus}4}, 0.01, 0.1, and 1 times solar (a slightly reduced mass grid is employed for non-solar metallicities). Altogether 78 different model supernova explosions are calculated. In each case nucleosynthesis has already been determined for 200 isotopes in each of 600 to 1200 zones of the presupernova star, including the effects of time dependent convection. Here each star is exploded using a piston to give a specified final kinetic energy at infinity (typically 1.2 {times} 10{sup 51} erg), and the explosive modifications to the nucleosynthesis, including the effects of neutrino irradiation, determined. A single value of the critical {sup 12}C({sub {alpha},{gamma}}){sup 16}O reaction rate corresponding to S(300 keV) = 170 keV barns is used in all calculations. The synthesis of each isotope is discussed along with its sensitivity to model parameters. In each case, the final mass of the collapsed remnant is also determined and often found not to correspond to the location of the piston (typically the edge of the iron core), but to a ``mass cut`` farther out. This mass cut is sensitive not only to the explosion energy, but also to the presupernova structure, stellar mass, and the metallicity. Unless the explosion mechanism, for unknown reasons, provides a much larger characteristic energy in more massive stars, it appears likely that stars larger than about 30 M{sub {center_dot}} will experience considerable reimplosion of heavy elements following the initial launch of a successful shock. While such explosions will produce a viable, bright Type II supernova light curve, lacking the radioactive tail, they will have dramatically reduced yields of heavy elements and may leave black hole remnants of up to 10 and more solar masses.

  4. The Unusual Temporal and Spectral Evolution of SN2011ht. II. Peculiar Type IIn or Impostor?

    Science.gov (United States)

    Humphreys, Roberta M.; Davidson, Kris; Jones, Terry J.; Pogge, R. W.; Grammer, Skyler H.; Prieto, José L.; Pritchard, T. A.

    2012-11-01

    SN2011ht has been described both as a true supernova (SN) and as an impostor. In this paper, we conclude that it does not match some basic expectations for a core-collapse event. We discuss SN2011ht's spectral evolution from a hot dense wind to a cool dense wind, followed by the post-plateau appearance of a faster low density wind during a rapid decline in luminosity. We identify a slow dense wind expanding at only 500-600 km s-1, present throughout the eruption. A faster wind speed V ~ 900 km s-1 occurred in a second phase of the outburst. There is no direct or significant evidence for any flow speed above 1000 km s-1 the broad asymmetric wings of Balmer emission lines in the hot wind phase were due to Thomson scattering, not bulk motion. We estimate a mass-loss rate of order 0.05 M ⊙ yr-1 during the hot dense wind phase of the event. The same calculations present difficulties for a hypothetical unseen SN blast wave. There is no evidence that the kinetic energy greatly exceeded the luminous energy, roughly 3 × 1049 erg so the radiative plus kinetic energy was small compared to a typical SN. We suggest that SN2011ht may have been a giant eruption driven by super-Eddington radiation pressure, perhaps beginning a few months before the discovery. A strongly non-spherical SN might also account for the data at the cost of more free parameters. Based on observations with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are: The University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University, and The Research Corporation, on behalf of The University of Notre Dame, University of Minnesota, and University of Virginia. Based also on observations obtained at the

  5. Non-noble metal graphene oxide-copper (II) ions hybrid electrodes for electrocatalytic hydrogen evolution reaction

    KAUST Repository

    Muralikrishna, S.

    2015-08-25

    Non-noble metal and inexpensive graphene oxide-copper (II) ions (GO-Cu2+) hybrid catalysts have been explored for the hydrogen evolution reaction (HER). We were able to tune the binding abilities of GO toward the Cu2+ ions and hence their catalytic properties by altering the pH. We have utilized the oxygen functional moieties such as carboxylate, epoxide, and hydroxyl groups on the edge and basal planes of the GO for binding the Cu2+ ions through dative bonds. The GO-Cu2+ hybrid materials were characterized by cyclic voltammetry in sodium acetate buffer solution. The morphology of the hybrid GO-Cu2+ was characterized by atomic force microscopy. The GO-Cu2+ hybrid electrodes show good electrocatalytic activity for HER with low overpotential in acidic solution. The Tafel slope for the GO-Cu2+ hybrid electrode implies that the primary discharge step is the rate determining step and HER proceed with Volmer step. © 2015 American Institute of Chemical Engineers Environ Prog.

  6. Cooperative cathode electrode and in situ deposited copper for subsequent enhanced Cd(II) removal and hydrogen evolution in bioelectrochemical systems.

    Science.gov (United States)

    Wang, Qiang; Huang, Liping; Pan, Yuzhen; Zhou, Peng; Quan, Xie; Logan, Bruce E; Chen, Hongbo

    2016-01-01

    Bioelectrochemical systems (BESs) were first operated in microbial fuel cell mode for recovering Cu(II), and then shifted to microbial electrolysis cells for Cd(II) reduction on the same cathodes of titanium sheet (TS), nickel foam (NF) or carbon cloth (CC). Cu(II) reduction was similar to all materials (4.79-4.88mg/Lh) whereas CC exhibited the best Cd(II) reduction (5.86±0.25mg/Lh) and hydrogen evolution (0.35±0.07m(3)/m(3)d), followed by TS (5.27±0.43mg/Lh and 0.15±0.02m(3)/m(3)d) and NF (4.96±0.48mg/Lh and 0.80±0.07m(3)/m(3)d). These values were higher than no copper controls by factors of 2.0 and 5.0 (TS), 4.2 and 2.0 (NF), and 1.8 and 7.0 (CC). These results demonstrated cooperative cathode electrode and in situ deposited copper for subsequent enhanced Cd(II) reduction and hydrogen production in BESs, providing an alternative approach for efficiently remediating Cu(II) and Cd(II) co-contamination with simultaneous hydrogen production.

  7. Biochemical adaptation to ocean acidification.

    Science.gov (United States)

    Stillman, Jonathon H; Paganini, Adam W

    2015-06-01

    The change in oceanic carbonate chemistry due to increased atmospheric PCO2  has caused pH to decline in marine surface waters, a phenomenon known as ocean acidification (OA). The effects of OA on organisms have been shown to be widespread among diverse taxa from a wide range of habitats. The majority of studies of organismal response to OA are in short-term exposures to future levels of PCO2 . From such studies, much information has been gathered on plastic responses organisms may make in the future that are beneficial or harmful to fitness. Relatively few studies have examined whether organisms can adapt to negative-fitness consequences of plastic responses to OA. We outline major approaches that have been used to study the adaptive potential for organisms to OA, which include comparative studies and experimental evolution. Organisms that inhabit a range of pH environments (e.g. pH gradients at volcanic CO2 seeps or in upwelling zones) have great potential for studies that identify adaptive shifts that have occurred through evolution. Comparative studies have advanced our understanding of adaptation to OA by linking whole-organism responses with cellular mechanisms. Such optimization of function provides a link between genetic variation and adaptive evolution in tuning optimal function of rate-limiting cellular processes in different pH conditions. For example, in experimental evolution studies of organisms with short generation times (e.g. phytoplankton), hundreds of generations of growth under future conditions has resulted in fixed differences in gene expression related to acid-base regulation. However, biochemical mechanisms for adaptive responses to OA have yet to be fully characterized, and are likely to be more complex than simply changes in gene expression or protein modification. Finally, we present a hypothesis regarding an unexplored area for biochemical adaptation to ocean acidification. In this hypothesis, proteins and membranes exposed to the

  8. Dynamic analysis of biochemical network using complex network method

    Directory of Open Access Journals (Sweden)

    Wang Shuqiang

    2015-01-01

    Full Text Available In this study, the stochastic biochemical reaction model is proposed based on the law of mass action and complex network theory. The dynamics of biochemical reaction system is presented as a set of non-linear differential equations and analyzed at the molecular-scale. Given the initial state and the evolution rules of the biochemical reaction system, the system can achieve homeostasis. Compared with random graph, the biochemical reaction network has larger information capacity and is more efficient in information transmission. This is consistent with theory of evolution.

  9. The population of planetary nebulae and H II regions in M 81. A study of radial metallicity gradients and chemical evolution

    Science.gov (United States)

    Stanghellini, L.; Magrini, L.; Villaver, E.; Galli, D.

    2010-10-01

    Context. M 81 is an ideal laboratory to investigate the galactic chemical and dynamical evolution through the study of its young and old stellar populations. Aims: We analyze the chemical abundances of planetary nebulae and H ii regions in the M 81 disk for insight on galactic evolution, and compare it with that of other galaxies, including the Milky Way. Methods: We acquired Hectospec/MMT spectra of 39 PNe and 20 H ii regions, with 33 spectra viable for temperature and abundance analysis. Our PN observations represent the first PN spectra in M 81 ever published, while several H ii region spectra have been published before, although without a direct electron temperature determination. We determine elemental abundances of helium, nitrogen, oxygen, neon, sulfur, and argon in PNe and H ii regions, and determine their averages and radial gradients. Results: The average O/H ratio of PNe compared to that of the H ii regions indicates a general oxygen enrichment in M 81 in the last ~10 Gyr. The PN metallicity gradient in the disk of M 81 is Δlog(O/H)/ΔRG = -0.055 ± 0.02 dex/kpc. Neon and sulfur in PNe have a radial distribution similar to that of oxygen, with similar gradient slopes. If we combine our H ii sample with the one in the literature we find a possible mild evolution of the gradient slope, with results consistent with gradient steepening with time. Additional spectroscopy is needed to confirm this trend. There are no type I PNe in our M 81 sample, consistently with the observation of only the brightest bins of the PNLF, the galaxy metallicity, and the evolution of post-AGB shells. Conclusions: Both the young and the old populations of M 81 disclose shallow but detectable negative radial metallicity gradient, which could be slightly steeper for the young population, thus not excluding a mild gradients steepening with the time since galaxy formation. During its evolution M 81 has been producing oxygen; its total oxygen enrichment exceeds that of other nearby

  10. Influence of different ruthenium(II) bipyridyl complex on the photocatalytic H{sub 2} evolution over TiO{sub 2} nanoparticles with mesostructures

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Tianyou [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China); Hubei Key Laboratory for Catalysis and Material Science, College of Chemistry and Material Science, South-Central University for Nationalities, Wuhan 430074 (China); Ke, Dingning; Cai, Ping; Dai, Ke; Ma, Liang; Zan, Ling [College of Chemistry and Molecular Science, Wuhan University, Wuhan 430072 (China)

    2008-05-15

    H{sub 2} production over dye-sensitized Pt/TiO{sub 2} nanoparticles with mesostructures (m-TiO{sub 2}) under visible light ({lambda} > 420 nm) was investigated by using methanol as electron donors. Experimental results indicate that three types of ruthenium(II) bipyridyl complex dyes (one binuclear Ru, two mononuclear Ru), which can be attached to Pt/m-TiO{sub 2} with different linkage modes, show different photosensitization effects due to their different coordination circumstances and physicochemical properties. The dye tightly linked with m-TiO{sub 2} has better durability but the lowest H{sub 2} evolution efficiency, whereas the loosely attached dyes possess higher H{sub 2} evolution efficiency and preferable durability. It seems that the dynamic equilibrium between the linkage of the ground state dye with TiO{sub 2} and the divorce of the oxidization state dye from the surfaces plays a crucial role in the photochemical behavior during the photocatalyst sensitization process. It is helpful to improve the H{sub 2} evolution efficiency by enhancing the electron injection and hindering the backward transfer. The binuclear Ru(II) dye shows a better photosensitization in comparison with mononuclear Ru(II) dyes due to its large molecular area, conjugation system, and ''antenna effect'', which, in turn, improve the visible light harvesting and electron transfer between the dye molecules and TiO{sub 2}. (author)

  11. Influence of the Mn(II) and CH 4 on the evolution of light induced radicals in chloroplasts

    Science.gov (United States)

    Trif, V.; Trif, Eleonora

    1995-06-01

    The photochemical activity of the leaves and chloroplasts of several species of plants developed in gaseous hydrocarbon environments (C nH 2 n+2 ) was investigated by the EPR method. The influence of different concentrations of paramagnetic ions [Mn(II), Cu(II) and VO(II), respectively] on the plants grown in dietary media containing these ions was also followed by EPR spectroscopy. The contents of paramagnetic ions, lower than 0.1%, in the nutritive solutions, are the most suitable in the biosynthesis of chlorophyll-like pigments containing paramagnetic ions in their porphyrine ring. The changes in the form, structure and photosensibility of the EPR signals corresponding to the free radicals, as well as the properties of the pheophytins containing paramagnetic ions, such as: Mn(II), Cu(II) and VO(II), were related to the photochemical synthesis in gaseous hydrocarbon environments.

  12. Biochemical Analysis of Yeast Suppressor of Ty 4/5 (Spt4/5) Reveals the Importance of Nucleic Acid Interactions in the Prevention of RNA Polymerase II Arrest.

    Science.gov (United States)

    Crickard, J Brooks; Fu, Jianhua; Reese, Joseph C

    2016-05-06

    RNA polymerase II (RNAPII) undergoes structural changes during the transitions from initiation, elongation, and termination, which are aided by a collection of proteins called elongation factors. NusG/Spt5 is the only elongation factor conserved in all domains of life. Although much information exists about the interactions between NusG/Spt5 and RNA polymerase in prokaryotes, little is known about how the binding of eukaryotic Spt4/5 affects the biochemical activities of RNAPII. We characterized the activities of Spt4/5 and interrogated the structural features of Spt5 required for it to interact with elongation complexes, bind nucleic acids, and promote transcription elongation. The eukaryotic specific regions of Spt5 containing the Kyrpides, Ouzounis, Woese domains are involved in stabilizing the association with the RNAPII elongation complex, which also requires the presence of the nascent transcript. Interestingly, we identify a region within the conserved NusG N-terminal (NGN) domain of Spt5 that contacts the non-template strand of DNA both upstream of RNAPII and in the transcription bubble. Mutating charged residues in this region of Spt5 did not prevent Spt4/5 binding to elongation complexes, but abrogated the cross-linking of Spt5 to DNA and the anti-arrest properties of Spt4/5, thus suggesting that contact between Spt5 (NGN) and DNA is required for Spt4/5 to promote elongation. We propose that the mechanism of how Spt5/NGN promotes elongation is fundamentally conserved; however, the eukaryotic specific regions of the protein evolved so that it can serve as a platform for other elongation factors and maintain its association with RNAPII as it navigates genomes packaged into chromatin.

  13. Impact of initial models and variable accretion rates on the pre-main-sequence evolution of massive and intermediate-mass stars and the early evolution of H II regions

    Science.gov (United States)

    Haemmerlé, Lionel; Peters, Thomas

    2016-05-01

    Massive star formation requires the accretion of gas at high rate while the star is already bright. Its actual luminosity depends sensitively on the stellar structure. We compute pre-main-sequence tracks for massive and intermediate-mass stars with variable accretion rates and study the evolution of stellar radius, effective temperature and ionizing luminosity, starting at 2 M⊙ with convective or radiative structures. The radiative case shows a much stronger swelling of the protostar for high accretion rates than the convective case. For radiative structures, the star is very sensitive to the accretion rate and reacts quickly to accretion bursts, leading to considerable changes in photospheric properties on time-scales as short as 100-1000 yr. The evolution for convective structures is much less influenced by the instantaneous accretion rate, and produces a monotonically increasing ionizing flux that can be many orders of magnitude smaller than in the radiative case. For massive stars, it results in a delay of the H II region expansion by up to 10 000 yr. In the radiative case, the H II region can potentially be engulfed by the star during the swelling, which never happens in the convective case. We conclude that the early stellar structure has a large impact on the radiative feedback during the pre-main-sequence evolution of massive protostars and introduces an important uncertainty that should be taken into account. Because of their lower effective temperatures, our convective models may hint at a solution to an observed discrepancy between the luminosity distribution functions of massive young stellar objects and compact H II regions.

  14. Radial metallicity gradients in spiral galaxies from H II regions and planetary nebulae: probing galactic chemical evolution

    Science.gov (United States)

    Stanghellini, Letizia

    2015-08-01

    Radial metallicity gradients, typically observed in spiral galaxies, are excellent constraints for chemical evolution models. The contemporary studies of the two stellar populations, whose progenitors have formed at different times, yield to the chemical and time constraining of the models. In this context, planetary nebula and HII region analysis proved to be ideal two-epochs test populations. We present an assortment of galaxies whose oxygen abundances have been determined both with weak- and strong-line methods, and whose radial metallicity gradients and their evolution in time have disclosed very interesting correlations with the galaxy characteristics. New results from our Gemini/GMOS observations, and a review of the best literature data, set the stage for a better understanding of spiral galaxy evolution.

  15. Simulation of Biochemical Pathway Adaptability Using Evolutionary Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Bosl, W J

    2005-01-26

    The systems approach to genomics seeks quantitative and predictive descriptions of cells and organisms. However, both the theoretical and experimental methods necessary for such studies still need to be developed. We are far from understanding even the simplest collective behavior of biomolecules, cells or organisms. A key aspect to all biological problems, including environmental microbiology, evolution of infectious diseases, and the adaptation of cancer cells is the evolvability of genomes. This is particularly important for Genomes to Life missions, which tend to focus on the prospect of engineering microorganisms to achieve desired goals in environmental remediation and climate change mitigation, and energy production. All of these will require quantitative tools for understanding the evolvability of organisms. Laboratory biodefense goals will need quantitative tools for predicting complicated host-pathogen interactions and finding counter-measures. In this project, we seek to develop methods to simulate how external and internal signals cause the genetic apparatus to adapt and organize to produce complex biochemical systems to achieve survival. This project is specifically directed toward building a computational methodology for simulating the adaptability of genomes. This project investigated the feasibility of using a novel quantitative approach to studying the adaptability of genomes and biochemical pathways. This effort was intended to be the preliminary part of a larger, long-term effort between key leaders in computational and systems biology at Harvard University and LLNL, with Dr. Bosl as the lead PI. Scientific goals for the long-term project include the development and testing of new hypotheses to explain the observed adaptability of yeast biochemical pathways when the myosin-II gene is deleted and the development of a novel data-driven evolutionary computation as a way to connect exploratory computational simulation with hypothesis

  16. Phenotype prediction of nonsynonymous single nucleotide polymorphisms in human phase II drug/xenobiotic metabolizing enzymes: perspectives on molecular evolution

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Nonsynonymous single nucleotide polymorphisms (nsSNPs) in coding regions can lead to amino acid changes that might alter the protein’s function and account for susceptibility to disease and altered drug/xenobiotic response. Many nsSNPs have been found in genes encoding human phase II metabolizing enzymes; however, there is little known about the relationship between the genotype and phenotype of nsSNPs in these enzymes. We have identified 923 validated nsSNPs in 104 human phase II enzyme genes from the Ensembl genome database and the NCBI SNP database. Using PolyPhen, Panther, and SNAP algorithms, 44%?59% of nsSNPs in phase II enzyme genes were predicted to have functional impacts on protein function. Predictions largely agree with the available experimental annotations. 68% of deleterious nsSNPs were correctly predicted as damaging. This study also identified many amino acids that are likely to be functionally critical, but have not yet been studied experimentally. There was significant concordance between the predicted results of Panther and PolyPhen, and between SNAP non-neutral predictions and PolyPhen scores. Evolutionarily non-neutral (destabilizing) amino acid substitutions are thought to be the pathogenetic basis for the alteration of phase II enzyme activity and to be associated with disease susceptibility and drug/xenobiotic toxicity. Furthermore, the molecular evolutionary patterns of phase II enzymes were characterized with regards to the predicted deleterious nsSNPs.

  17. Rapid-Response Mode VLT/UVES spectroscopy of GRB060418: Conclusive evidence for UV pumping from the time evolution of FeII and NiII excited- and metastable-level populations

    CERN Document Server

    Vreeswijk, P M; Smette, A; Ellison, S L; Jaunsen, A O; Andersen, M I; Fruchter, A S; Fynbo, J P U; Hjorth, J; Kaufer, A; Møller, P; Petitjean, P; Savaglio, S; Wijers, R A M J

    2006-01-01

    We present high-resolution spectroscopic observations of GRB 060418, obtained with VLT/UVES. These observations were triggered using the VLT Rapid-Response Mode (RRM), which allows for automated observations of transient phenomena, without any human intervention. This resulted in the first UVES exposure of GRB 060418 to be started only 10 minutes after the initial Swift satellite trigger. A sequence of spectra covering 330-670 nm were acquired at 11, 16, 25, 41 and 71 minutes (mid-exposure) after the trigger, with a resolving power of 7 km/s, and a signal-to-noise ratio of 10-15. This time-series clearly shows evidence for time variability of allowed transitions involving Fe II fine-structure levels, and metastable levels of both Fe II and Ni II, at the host-galaxy redshift z=1.490. We model the observed evolution of the level populations with three different excitation mechanisms: collisions, excitation by infra-red photons, and fluorescence following excitation by ultraviolet photons. Our data allow us to r...

  18. Evolution of the Milky Way with radial motions of stars and gas II. The evolution of abundance profiles from H to Ni

    CERN Document Server

    Kubryk, M; Athanassoula, E

    2014-01-01

    We study the role of radial motions of stars and gas on the evolution of abundance profiles in the Milky Way disk. We investigate, in a parametrized way, the impact of radial flows of gas and radial migration of stars induced mainly by the Galactic bar and its iteraction with the spiral arms. We use a model with several new or up-dated ingredients (atomic and molecular gas phases, star formation depending on molecular gas, recent sets of metallicity-dependent stellar yields from H to Ni, observationally inferred SNIa rates), which reproduces well most global and local observables of the Milky Way. We obtain abundance profiles flattening both in the inner disk (because of radial flows) and in the outer disk (because of the adopted star formation law). The gas abundance profiles flatten with time, but the corresponding stellar profiles appear to be steeper for younger stars, because of radial migration. We find a correlation between the stellar abundance profiles and O/Fe, which is a proxy for stellar age. Our ...

  19. Structure and Evolution of Nearby Stars with Planets II. Physical Properties of ~1000 Cool Stars from the SPOCS Catalog

    CERN Document Server

    Takeda, G; Sills, A; Rasio, F A; Fischer, D A; Valenti, J A; Takeda, Genya; Ford, Eric B.; Sills, Alison; Rasio, Frederic A.; Fischer, Debra A.; Valenti, Jeff A.

    2006-01-01

    We derive detailed theoretical models for 1074 nearby stars from the SPOCS (Spectroscopic Properties of Cool Stars) Catalog. The California and Carnegie Planet Search has obtained high-quality echelle spectra of over 1000 nearby stars taken with the Hamilton spectrograph at Lick Observatory, the HIRES spectrograph at Keck, and UCLES at the Anglo Australian Observatory. A uniform analysis of the high-resolution spectra has yielded precise stellar parameters, enabling systematic error analyses and accurate theoretical stellar modeling. We have created a large database of theoretical stellar evolution tracks using the Yale Stellar Evolution Code (YREC) to match the observed parameters of the SPOCS stars. Our very dense grids of evolutionary tracks eliminate the need for interpolation between stellar evolutionary tracks and allow precise determinations of physical stellar parameters (mass, age, radius, size and mass of the convective zone, etc.). Combining our stellar models with the observed stellar atmospheric ...

  20. Characterization and evolution of major histocompatibility complex class II genes in the aye-aye, Daubentonia madagascariensis.

    Science.gov (United States)

    Go, Yasuhiro; Rakotoarisoa, Gilbert; Kawamoto, Yoshi; Shima, Taizo; Koyama, Naoki; Randrianjafy, Albert; Mora, Roger; Hirai, Hirohisa

    2005-04-01

    Major histocompatibility complex genes (Mhc-DQB and Mhc-DRB) were sequenced in seven aye-ayes (Daubentonia madagascariecsis), which is an endemic and endangered species in Madagascar. An aye-aye from a north-eastern population showed genetic relatedness to individuals of a north-western population and had a somewhat different repertoire from another north-eastern individual. These observations suggest that the extent of genetic variation in Mhc genes is not excessively small in the aye-aye in spite of recent rapid destruction of their habitat by human activities. In light of Mhc gene evolution, trans-species and allelic polymorphisms can be estimated to have been retained for more than 50 Ma (million years) based on the time scale of lemur evolution.

  1. Imprints of galaxy evolution on H ii regions Memory of the past uncovered by the CALIFA survey

    CERN Document Server

    Sanchez, S F; Rosales-Ortega, F F; Miralles-Caballero, D; Lopez-Sanchez, A R; Iglesias-Páramo, J; Marino, R A; Sánchez-Menguiano, L; García-Benito, R; Mast, D; Mendoza, M A; Papaderos, P; Ellis, S; Galbany, L; Kehrig, C; Monreal-Ibero, A; Delgado, R González; Mollá, M; Ziegler, B; de Lorenzo-Cáceres, A; Mendez-Abreu, J; Bland-Hawthorn, J; Bekeraite, S; Roth, M M; Pasquali, A; Díaz, A; Bomans, D; van de Ven, G; Wisotzki, L

    2014-01-01

    H ii regions in galaxies are the sites of star formation and thus particular places to understand the build-up of stellar mass in the universe. The line ratios of this ionized gas are frequently used to characterize the ionization conditions. We use the Hii regions catalogue from the CALIFA survey (~5000 H ii regions), to explore their distribution across the classical [OIII]/Hbeta vs. [NII]/Halpha diagnostic diagram, and how it depends on the oxygen abundance, ionization parameter, electron density, and dust attenuation. We compared the line ratios with predictions from photoionization models. Finally, we explore the dependences on the properties of the host galaxies, the location within those galaxies and the properties of the underlying stellar population. We found that the location within the BPT diagrams is not totally predicted by photoionization models. Indeed, it depends on the properties of the host galaxies, their galactocentric distances and the properties of the underlying stellar population. Thes...

  2. The evolution of a jet ejection of the ultraluminous X-ray source Holmberg II X-1

    CERN Document Server

    Cseh, D; Jonker, P G; Grise, F; Paragi, Z; Corbel, S; Falcke, H; Frey, S; Kaaret, P; Koerding, E

    2015-01-01

    We present quasi-simultaneous, multi-epoch radio and X-ray measurements of Holmberg II X-1 using the European VLBI Network (EVN), the Karl G. Jansky Very Large Array (VLA), and the Chandra and Swift X-ray telescopes. The X-ray data show apparently hard spectra with steady X-ray luminosities 4 months apart from each other. In the high-resolution EVN radio observations, we have detected an extended milli-arcsecond scale source with unboosted radio emission. The source emits non-thermal, likely optically thin synchrotron emission and its morphology is consistent with a jet ejection. The 9-GHz VLA data show an arcsecond-scale triple structure of Holmberg II X-1 similar to that seen at lower frequencies. However, we find that the central ejection has faded by at least a factor of 7.3 over 1.5 years. We estimate the dynamical age of the ejection to be higher than 2.1 years. We show that such a rapid cooling can be explained with simple adiabatic expansion losses. These properties of Holmberg II X-1 imply that ULX r...

  3. Fifty years of co-evolution and beyond: integrating co-evolution from molecules to species.

    Science.gov (United States)

    Carmona, Diego; Fitzpatrick, Connor R; Johnson, Marc T J

    2015-11-01

    Fifty years after Ehrlich and Raven's seminal paper, the idea of co-evolution continues to grow as a key concept in our understanding of organic evolution. This concept has not only provided a compelling synthesis between evolutionary biology and community ecology, but has also inspired research that extends beyond its original scope. In this article, we identify unresolved questions about the co-evolutionary process and advocate for the integration of co-evolutionary research from molecular to interspecific interactions. We address two basic questions: (i) What is co-evolution and how common is it? (ii) What is the unit of co-evolution? Both questions aim to explore the heart of the co-evolutionary process. Despite the claim that co-evolution is ubiquitous, we argue that there is in fact little evidence to support the view that reciprocal natural selection and coadaptation are common in nature. We also challenge the traditional view that co-evolution only occurs between traits of interacting species. Co-evolution has the potential to explain evolutionary processes and patterns that result from intra- and intermolecular biochemical interactions within cells, intergenomic interactions (e.g. nuclear-cytoplasmic) within species, as well as intergenomic interactions mediated by phenotypic traits between species. Research that bridges across these levels of organization will help to advance our understanding of the importance of the co-evolutionary processes in shaping the diversity of life on Earth.

  4. Probing S-state advancements and recombination pathways in photosystem II with a global fit program for flash-induced oxygen evolution pattern.

    Science.gov (United States)

    Pham, Long Vo; Messinger, Johannes

    2016-06-01

    The oxygen-evolving complex (OEC) in photosystem II catalyzes the oxidation of water to molecular oxygen. Four decades ago, measurements of flash-induced oxygen evolution have shown that the OEC steps through oxidation states S(0), S(1), S(2), S(3) and S(4) before O(2) is released and the S(0) state is reformed. The light-induced transitions between these states involve misses and double hits. While it is widely accepted that the miss parameter is S state dependent and may be further modulated by the oxidation state of the acceptor side, the traditional way of analyzing each flash-induced oxygen evolution pattern (FIOP) individually did not allow using enough free parameters to thoroughly test this proposal. Furthermore, this approach does not allow assessing whether the presently known recombination processes in photosystem II fully explain all measured oxygen yields during Si state lifetime measurements. Here we present a global fit program that simultaneously fits all flash-induced oxygen yields of a standard FIOP (2 Hz flash frequency) and of 11-18 FIOPs each obtained while probing the S(0), S(2) and S(3) state lifetimes in spinach thylakoids at neutral pH. This comprehensive data treatment demonstrates the presence of a very slow phase of S(2) decay, in addition to the commonly discussed fast and slow reduction of S(2) by YD and QB(-), respectively. Our data support previous suggestions that the S(0)→S(1) and S(1)→S(2) transitions involve low or no misses, while high misses occur in the S(2)→S(3) or S(3)→S(0) transitions.

  5. Properties of r modes in rotating magnetic neutron stars. II. Evolution of the r modes and stellar magnetic field

    CERN Document Server

    Rezzolla, L; Markovic, D M; Shapiro, S L; Rezzolla, Luciano; Lamb, Frederick L.; Markovic, Dragoljub; Shapiro, Stuart L.

    2001-01-01

    The evolution of the r-mode instability is likely to be accompanied by secular kinematic effects which will produce differential rotation with large scale drifts of fluid elements, mostly in the azimuthal direction. As first discussed by Rezzolla, Lamb and Shapiro 2000, the interaction of these secular velocity fields with a pre-existing neutron star magnetic field could result in the generation of intense and large scale toroidal fields. Following their derivation in the companion paper, we here discuss the numerical solution of the evolution equations for the magnetic field. The values of the magnetic fields obtained in this way are used to estimate the conditions under which the r-mode instability might be prevented or suppressed. We also assess the impact of the generation of large magnetic fields on the gravitational wave detectability of r-mode unstable neutron stars. Our results indicate that the signal to noise ratio in the detection of gravitational waves from the r-mode instability might be consider...

  6. Evolution of the solar activity over time and effects on planetary atmospheres. II. kappa^1 Ceti, an analog of the Sun when life arose on Earth

    CERN Document Server

    Ribas, I; Ferreira, L D; Hebrard, E; Selsis, F; Catalan, S; Garces, A; Nascimento, J D do; de Medeiros, J R

    2010-01-01

    The early evolution of Earth's atmosphere and the origin of life took place at a time when physical conditions at the Earth where radically different from its present state. The radiative input from the Sun was much enhanced in the high-energy spectral domain, and in order to model early planetary atmospheres in detail, a knowledge of the solar radiative input is needed. We present an investigation of the atmospheric parameters, state of evolution and high-energy fluxes of the nearby star kap^1 Cet, previously thought to have properties resembling those of the early Sun. Atmospheric parameters were derived from the excitation/ionization equilibrium of Fe I and Fe II, profile fitting of Halpha and the spectral energy distribution. The UV irradiance was derived from FUSE and HST data, and the absolute chromospheric flux from the Halpha line core. From careful spectral analysis and the comparison of different methods we propose for kap^1 Cet the following atmospheric parameters: Teff = 5665+/-30 K (Halpha profil...

  7. Speed evolution of fast CME/shocks with SOHO/LASCO, WIND/WAVES, IPS and in-situ WIND data: analysis of kilometric type-II emissions

    Directory of Open Access Journals (Sweden)

    A. Gonzalez-Esparza

    2009-10-01

    Full Text Available Fast CME/shocks propagating in the interplanetary medium can generate kilometric Type II (km-TII radio emissions at the local plasma frequency and/or its harmonic, so these radio emissions provide a means of remotely tracking CME/shocks. We apply a new analysis technique, using the frequency drift of km-TII spectrum obtained by the Thermal Noise Receiver (TNR of the WIND/WAVES experiment, to infer, at some adequate intervals, the propagation speed of six CME/shocks. We combine these results with previously reported speeds from coronagraph white light and interplanetary scintillation observations, and in-situ measurements, to study the temporal speed evolution of the six events. The speed values obtained by the km-TII analysis are in a reasonable agreement with the speed measurements obtained by other techniques at different heliocentric distance ranges. The combination of all the speed measurements show a gradual deceleration of the CME/shocks as they propagate to 1 AU. This new technique can be useful in studying the evolution of fast CME/shocks when adequate intervals of km-TII emissions are available.

  8. Evolution of the P-type II ATPase gene family in the fungi and presence of structural genomic changes among isolates of Glomus intraradices

    Directory of Open Access Journals (Sweden)

    Sanders Ian R

    2006-03-01

    Full Text Available Abstract Background The P-type II ATPase gene family encodes proteins with an important role in adaptation of the cell to variation in external K+, Ca2+ and Na2+ concentrations. The presence of P-type II gene subfamilies that are specific for certain kingdoms has been reported but was sometimes contradicted by discovery of previously unknown homologous sequences in newly sequenced genomes. Members of this gene family have been sampled in all of the fungal phyla except the arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota, which are known to play a key-role in terrestrial ecosystems and to be genetically highly variable within populations. Here we used highly degenerate primers on AMF genomic DNA to increase the sampling of fungal P-Type II ATPases and to test previous predictions about their evolution. In parallel, homologous sequences of the P-type II ATPases have been used to determine the nature and amount of polymorphism that is present at these loci among isolates of Glomus intraradices harvested from the same field. Results In this study, four P-type II ATPase sub-families have been isolated from three AMF species. We show that, contrary to previous predictions, P-type IIC ATPases are present in all basal fungal taxa. Additionally, P-Type IIE ATPases should no longer be considered as exclusive to the Ascomycota and the Basidiomycota, since we also demonstrate their presence in the Zygomycota. Finally, a comparison of homologous sequences encoding P-type IID ATPases showed unexpectedly that indel mutations among coding regions, as well as specific gene duplications occur among AMF individuals within the same field. Conclusion On the basis of these results we suggest that the diversification of P-Type IIC and E ATPases followed the diversification of the extant fungal phyla with independent events of gene gains and losses. Consistent with recent findings on the human genome, but at a much smaller geographic scale, we provided evidence

  9. Starspot evolution, differential rotation, and magnetic cycles in the chromospherically active binaries lambda andromedae, sigma Geminorum, II Pegasi, and V711 Tauri

    Science.gov (United States)

    Henry, Gregory W.; Eaton, Joel A.; Hamer, Jamesia; Hall, Douglas S.

    1995-01-01

    We have analyzed 15-19 yr of photoelectric photometry, obtained manually and with automated telescopes, of the chromospherically active binaries lambda And, sigma Gem, II Peg, and V711 Tau. These observations let us identify individual dark starspots on the stellar surfaces from periodic dimming of the starlight, follow the evolution of these spots, and search for long-term cyclic changes in the properties of these starspots that might reveal magnetic cycles analogous to the Sun's 11 yr sunspot cycle. We developed a computer code to fit a simple two-spot model to our observed light curves that allows us to extract the most easily determinable and most reliable spot parameters from the light curves, i.e., spot longitudes and radii. We then used these measured properties to identify individual spots and to chart their life histories by constructing migration and amplitude curves. We identified and followed 11 spots in lambda And, 16 in sigma Gem, 12 in II Peg, and 15 in V711 Tau. Lifetimes of individual spots ranged from a few months to longer than 6 yr. Differential rotation coefficients, estimated from the observed range of spot rotation periods for each star and defined by equation (2), were 0.04 for lambda And, 0.038 for sigma Gem, 0.005 for II Peg, and 0.006 for V711 Tau, versus 0.19 for the Sun. We searched for cyclic changes in mean brightness, B-V color index, and spot rotation period as evidence for long-term cycles. Of these, long-term variability in mean brightness appears to offer the best evidence for such cycles in these four stars. Cycles of 11.1 yr for lambda And, 8.5 yr for sigma Gem, 11 yr for II Peg, and 16 yr V711 Tau are implied by these mean brightness changes. Cyclic changes in spot rotation period were found in lambda And and possibly II Peg. Errors in B-V were too large for any long-term changes to be detectable.

  10. SN 2005cs in M51 II. Complete Evolution in the Optical and the Near-Infrared

    CERN Document Server

    Pastorello, A; Zampieri, L; Navasardyan, H; Taubenberger, S; Smartt, S J; Arkharov, A A; Baernbantner, O; Barwig, H; Benetti, S; Birtwhistle, P; Botticella, M T; Cappellaro, E; Del Principe, M; Di Mille, F; Di Rico, G; Dolci, M; Elias-Rosa, N; Efimova, N V; Fiedler, M; Harutyunyan, A; Hoeflich, P A; Kloehr, W; Larionov, V M; Lorenzi, V; Maund, J R; Napoleone, N; Ragni, M; Richmond, M; Ries, C; Spiro, S; Temporin, S; Turatto, M; Wheeler, J C

    2009-01-01

    We present the results of the one year long observational campaign of the type II-plateau SN 2005cs, which exploded in the nearby spiral galaxy M51 (the Whirlpool Galaxy). This extensive dataset makes SN 2005cs the best observed low-luminosity, 56Ni-poor type II-plateau event so far and one of the best core-collapse supernovae ever. The optical and near-infrared spectra show narrow P-Cygni lines characteristic of this SN family, which are indicative of a very low expansion velocity (about 1000 km/s) of the ejected material. The optical light curves cover both the plateau phase and the late-time radioactive tail, until about 380 days after core-collapse. Numerous unfiltered observations obtained by amateur astronomers give us the rare opportunity to monitor the fast rise to maximum light, lasting about 2 days. In addition to optical observations, we also present near-infrared light curves that (together with already published UV observations) allow us to construct for the first time a reliable bolometric light...

  11. Coupling dynamical and collisional evolution of small bodies II Forming the Kuiper Belt, the Scattered Disk and the Oort Cloud

    CERN Document Server

    Morbidelli, S C A

    2006-01-01

    The Oort Cloud, the Kuiper Belt and the Scattered Disk are dynamically distinct populations of small bodies evolving in the outer regions of the Solar System. Whereas their collisional activity is now quiet, gravitational interactions with giant planets may have shaped these populations both dynamically and collisionally during their formation. Using a hybrid approach (Charnoz & Morbidelli 2003), the present paper tries to couple the primordial collisional and dynamical evolution of these three populations in a self-consistent way. A critical parameter is the primordial size-distribution. We show that the initial planetesimal size distribution that allows an effective mass depletion of the Kuiper belt by collisional grinding, would decimate also the population of comet-size bodies that end in the Oort Cloud and, in particular, in the Scattered Disk. As a consequence, the Scattered Disk and the Oort Cloud would be too anemic, by a factor 20 to 100, relative to the estimates achieved from the observation of...

  12. Weak convergence of finite element approximations of linear stochastic evolution equations with additive noise II. Fully discrete schemes

    CERN Document Server

    Kovács, M; Lindgren, F

    2012-01-01

    We present an abstract framework for analyzing the weak error of fully discrete approximation schemes for linear evolution equations driven by additive Gaussian noise. First, an abstract representation formula is derived for sufficiently smooth test functions. The formula is then applied to the wave equation, where the spatial approximation is done via the standard continuous finite element method and the time discretization via an I-stable rational approximation to the exponential function. It is found that the rate of weak convergence is twice that of strong convergence. Furthermore, in contrast to the parabolic case, higher order schemes in time, such as the Crank-Nicolson scheme, are worthwhile to use if the solution is not very regular. Finally we apply the theory to parabolic equations and detail a weak error estimate for the linearized Cahn-Hilliard-Cook equation as well as comment on the stochastic heat equation.

  13. Engineering the Electrical Conductivity of Lamellar Silver-Doped Cobalt(II) Selenide Nanobelts for Enhanced Oxygen Evolution.

    Science.gov (United States)

    Zhao, Xu; Zhang, Hantao; Yan, Yu; Cao, Jinhua; Li, Xingqi; Zhou, Shiming; Peng, Zhenmeng; Zeng, Jie

    2017-01-02

    Precisely engineering the electrical conductivity represents a promising strategy to design efficient catalysts towards oxygen evolution reaction (OER). Here, we demonstrate a versatile partial cation exchange method to fabricate lamellar Ag-CoSe2 nanobelts with controllable conductivity. The electrical conductivity of the materials was significantly enhanced by the addition of Ag(+) cations of less than 1.0 %. Moreover, such a trace amount of Ag induced a negligible loss of active sites which was compensated through the effective generation of active sites as shown by the excellent conductivity. Both the enhanced conductivity and the retained active sites contributed to the remarkable electrocatalytic performance of the Ag-CoSe2 nanobelts. Relative to the CoSe2 nanobelts, the as-prepared Ag-CoSe2 nanobelts exhibited a higher current density and a lower Tafel slope towards OER. This strategy represents a rational design of efficient electrocatalysts through finely tuning their electrical conductivities.

  14. Evolution of organo-clay composites with respect to thermal maturity in type II organic-rich source rocks

    Science.gov (United States)

    Berthonneau, Jeremie; Grauby, Olivier; Abuhaikal, Muhannad; Pellenq, Roland J.-M.; Ulm, Franz J.; Van Damme, Henri

    2016-12-01

    Among the proposed pathways of sequestration and progressive transformation of organic matter (OM) during burial, the sorptive protection mechanism explains the strong relationship between total organic carbon (TOC) and mineral surface area (MSA) noted in numerous black shales around the globe. The complete mechanistic framework of preservation and evolution of OM in organo-mineral complexes remains, however, an enigma. On one hand, smectite layers composing the clay fraction are known to have a major influence on available surface area. OM maturation occurs, on the other hand, concurrently with the smectite illitization that provokes the closure of the interlayer spaces. The potential of smectite layers in the sequestration and preservation of organic molecules and the fate of these molecules with respect to the smectite illitization were therefore addressed. Here, the mineralogy of three organic-rich source rocks of various maturities was characterized in regards with the geochemistry of their OM. A thorough examination of the clay minerals present in the clay matrices provided evidences of mixed layer minerals containing smectite and illite layers with an increasing illite component with respect to maturity. The comprehensive interpretation of the X-ray diffractograms and analytical electron microscopy results suggested the presence of organic molecules in the inter-particulate and possibly the interlayer spaces of the smectite-rich components in immature source rocks. This eventuality was further supported by the presence of intercalated clay-organic nanocomposites observed by transmitted electron microscopy coupled with energy dispersive spectroscopy. Textural observations also showed that the increased illite content found in the overmature sample led to the reorganization of the OM and the clay particles into nano-scale aggregates. These results clarify the geochemical mechanism beyond the reported relationship between TOC and MSA and allow generalizing it

  15. Modelling ¹⁸O₂ and ¹⁶O₂ unidirectional fluxes in plants: II. analysis of rubisco evolution.

    Science.gov (United States)

    André, Marcel J

    2011-02-01

    The studies of Rubisco characteristics observed during plant evolution show that the variation of the Rubisco specificity factor only improved by two times from cyanobacteria to modern C3 plants. However we note important variations of the ratio between the maximum rates of oxygenation and carboxylation (V(O)/V(C)). Modelling in vivo ¹⁸O₂ data in plant gas exchange shows that the oxygenation reaction of Rubisco plays a regulating role when the photochemical energy exceeds the carboxylation capacity. A protective index 'oxygenation capacity' is postulated, related to the ratio V(O)/V(C) of Rubisco, and hence to the sink energy effect of photorespiration. Analysing the trends of Rubisco parameters along the evolutionary scale, we show: (1) the increase of both V(C) and V(O); (2) the enhancement of CO₂ affinity; and (3) the rise in oxygenation capacity at the expense of the CO₂ specificity. Hence, the factors of evolutionary pressure have not only directed the enzyme towards a more efficient utilisation of CO₂, but mainly to positively use the unavoidable great loss of energy and assimilated carbon in the process of photorespiration. These observations reinforce the hypothesis of plant-atmosphere co-evolution and of the complex role of Rubisco, which seems to be selected to develop both better CO₂ affinity and oxygenation capacity. The latter increases the capacity of sink of photorespiration, in particular, during water stress or under high irradiance, the two conditions experienced by plants in terrestrial environments. These observations help to explain some handicaps of C4 plants, and the supremacy of CAM and C3 perennial higher plants in arid environments.

  16. Measures of Biochemical Sociology

    Science.gov (United States)

    Snell, Joel; Marsh, Mitchell

    2008-01-01

    In a previous article, the authors introduced a new sub field in sociology that we labeled "biochemical sociology." We introduced the definition of a sociology that encompasses sociological measures, psychological measures, and biological indicators Snell & Marsh (2003). In this article, we want to demonstrate a research strategy that would assess…

  17. Biochemical Education in Brazil.

    Science.gov (United States)

    Vella, F.

    1988-01-01

    Described are discussions held concerning the problems of biochemical education in Brazil at a meeting of the Sociedade Brazileira de Bioquimica in April 1988. Also discussed are other visits that were made to universities in Brazil. Three major recommendations to improve the state of biochemistry education in Brazil are presented. (CW)

  18. The ESO UVES Advanced Data Products Quasar Sample - II. Cosmological Evolution of the Neutral Gas Mass Density

    CERN Document Server

    Zafar, Tayyaba; Popping, Attila; Milliard, Bruno; Deharveng, Jean-Michel; Frank, Stephan

    2013-01-01

    Quasar foreground damped absorbers, associated with HI-rich galaxies allow to estimate the neutral gas mass over cosmic time, which is a possible indicator of gas consumption as star formation proceeds. The DLAs and sub-DLAs are believed to contain a large fraction of neutral gas mass in the Universe. In Paper I of the series, we present the results of a search for DLAs and sub-DLAs in the ESO-UVES Advanced Data Products dataset of 250 quasars. Here we use an unbiased sub-sample of sub-DLAs from this dataset. We build a subset of 122 quasars ranging from 1.5 evolution of the number density and the line density are derived for sub-DLAs and compared with the LLSs and DLAs measurements from the literature. The results indicate that these three classes of absorbers are ...

  19. The growth of disks and bulges during hierarchical galaxy formation. II: metallicity, stellar populations and dynamical evolution

    CERN Document Server

    Tonini, Chiara; Wyithe, J Stuart B; Croton, Darren J

    2016-01-01

    We investigate the properties of the stellar populations of model galaxies, using the new semi-analytic model presented in Tonini et al. (2016a). This new model follows the angular momentum evolution of gas and stars, providing the base for a new star formation recipe, and treatment of the effects of mergers that depends on the central galaxy dynamical structure. We find that the new recipes have the effect of boosting the efficiency of the baryonic cycle in producing and recycling metals, as well as preventing minor mergers from diluting the metallicity of bulges and ellipticals. The model reproduces the stellar mass - stellar metallicity relation for galaxies above 1e10 solar masses, including Brightest Cluster Galaxies. Model disks, galaxies dominated by instability-driven components, and merger-driven objects each stem from different evolutionary channels. These model galaxies therefore occupy different loci in the galaxy mass - size relation, which we find to be in accord with the Atlas 3D classification...

  20. Distance determination for RAVE stars using stellar models II: Most likely values assuming a standard stellar evolution scenario

    CERN Document Server

    Zwitter, T; Breddels, M A; Smith, M C; Helmi, A; Munari, U; Bienaym\\'{e), O; Bland-Hawthorn, J; Boeche, C; Brown, A G A; Campbell, R; Freeman, K C; Fulbright, J; Gibson, B; Gilmore, G; Grebel, E K; Navarro, J F; Parker, Q A; Seabroke, G M; Siebert, A; Siviero, A; Steinmetz, M; Watson, F G; Williams, M; Wyse, R F G

    2010-01-01

    The RAdial Velocity Experiment (RAVE) is a spectroscopic survey of the Milky Way. We use the subsample of spectra with spectroscopically determined values of stellar parameters to determine the distances to these stars. The list currently contains 235,064 high quality spectra which show no peculiarities and belong to 210,872 different stars. The numbers will grow as the RAVE survey progresses. The public version of the catalog will be made available through the CDS services along with the ongoing RAVE public data releases. The distances are determined with a method based on the work by Breddels et al.~(2010). Here we assume that the star undergoes a standard stellar evolution and that its spectrum shows no peculiarities. The refinements include: the use of either of the three isochrone sets, a better account of the stellar ages and masses, use of more realistic errors of stellar parameter values, and application to a larger dataset. The derived distances of both dwarfs and giants match within ~21% to the astr...

  1. Near-Infrared Spectral Monitoring of Triton with IRTF/SpeX II: Spatial Distribution and Evolution of Ices

    CERN Document Server

    Grundy, W M; Stansberry, J A; Buie, M W; Olkin, C B; Young, E F

    2009-01-01

    This report arises from an ongoing program to monitor Neptune's largest moon Triton spectroscopically in the 0.8 to 2.4 micron range using IRTF/SpeX. Our objective is to search for changes on Triton's surface as witnessed by changes in the infrared absorption bands of its surface ices N2, CH4, H2O, CO, and CO2. We have recorded infrared spectra of Triton on 53 nights over the ten apparitions from 2000 through 2009. The data generally confirm our previously reported diurnal spectral variations of the ice absorption bands (Grundy & Young 2004). Nitrogen ice shows a large amplitude variation, with much stronger absorption on Triton's Neptune-facing hemisphere. We present evidence for seasonal evolution of Triton's N2 ice: the 2.15 micron absorption band appears to be diminishing, especially on the Neptune-facing hemisphere. Although it is mostly dissolved in N2 ice, Triton's CH4 ice shows a very different longitudinal variation from the N2 ice, challenging assumptions of how the two ices behave. Unlike Trito...

  2. Variations on a theme - the evolution of hydrocarbon solids: II. Optical property modelling - the optEC(s) model

    CERN Document Server

    Jones, A P

    2015-01-01

    Context. The properties of hydrogenated amorphous carbon (a-C:H) dust are known to evolve in response to the local conditions. Aims. We present an adaptable model for the determination of the optical properties of low-temperature, interstellar a-C:H grains that is based on the fundamental physics of their composition. Methods. The imaginary part of the refractive index, k, for a-C:H materials, from 50 eV to cm wavelengths, is derived and the real part, n, of the refractive index is then calculated using the Kramers-Kronig relations. Results. The formulated optEC(s) model allows a determination of the complex dielectric function, epsilon, and refractive index, m(n, k), for a-C:H materials as a continuous function the band gap, Eg , which is shown to lie in the range = -0.1 to 2.7 eV. We provide expressions that enable a determination of their optical constants and tabulate m(n, k, Eg ) for 14 different values of Eg . We explore the evolution of the likely extinction and emission behaviours of a-C:H grains and ...

  3. The Evolution of Evidence Based Library and Information Practice, Part II: The Broader Professional Purpose of EBLIP

    Directory of Open Access Journals (Sweden)

    Jonathan D. Eldredge

    2013-03-01

    Full Text Available Part I in this series of commentaries in theDecember 2012 issue provided a consensus definition and description of EBLIP. The five steps of the EBLIP process consist of: 1. Formulating an answerable question 2. Searching for the evidence 3. Critically appraising the evidence 4. Making a decision and applying it 5. Evaluating performance Part I reviewed how answering different types of questions raised in step one require differenttypes of evidence. Competing evidence,conceptualized primarily in terms of applied research, study design, and quality of the evidence, will guide the third step of critical appraisal. The completed EBLIP process finally should lead the busy practitioner to an informed decision based on the best available evidence. Part II in this commentary series delves into the broader purpose, or function, of EBLIP within the library and information professions. The deceptively easy answer to this question hinges simplistically upon defining EBLIP as a decision making process, and that would be a technically accurate answer. This commentary explores the deeper function of EBLIP that relates to professional identity and practice, however. By exploring these deeper meanings we might be able to chart our journey toward nurturing and sustaining EBLIP in the future.

  4. The Subparsec-Scale Structure and Evolution of Centaurus A. II. Continued Very Long Baseline Array Monitoring

    Science.gov (United States)

    Tingay, S. J.; Preston, R. A.; Jauncey, D. L.

    2001-10-01

    We present the results of continued 8.4 GHz Very Long Baseline Array monitoring of the subparsec-scale structure and evolution of Centaurus A, following on from the initial results presented in 1998 by Tingay et al. We include, for the first time, multiepoch VLBI images at 22.2 GHz that show that the jet is linear and well collimated on scales as small as 0.02 pc (~1000rs). Two components in the subparsec-scale jet continue to evolve slowly with a speed of 0.12c. We confirm that an additional component, close to the core, has no significant motion. Some evidence is seen for rapid variations within individual components, as noted dramatically in 1991-1992 by Tingay et al., albeit at a lower level of activity. Both the stationary behavior of the component close to the core and the internal variability of components in the subparsec-scale jet of Centaurus A may be explained as being due to the existence of shocks created in the wake of major component ejections from the nucleus, as simulated by Agudo et al. (published in 2001). Tentative evidence is found to suggest that two subparsec-scale counterjet components are in motion away from the nucleus. The estimated apparent speeds of the jet and counterjet components are consistent with the previously suggested likely jet viewing angle range, 50°-80°. We also compare our Centaurus A images with high-resolution VLBI images of M87 to show that the region of the Centaurus A jet in which collimation likely first occurs lies a factor of 10 below our current resolution limit. Future space VLBI missions at high frequency will be required to resolve this region.

  5. Multiplexing oscillatory biochemical signals.

    Science.gov (United States)

    de Ronde, Wiet; ten Wolde, Pieter Rein

    2014-04-01

    In recent years it has been increasingly recognized that biochemical signals are not necessarily constant in time and that the temporal dynamics of a signal can be the information carrier. Moreover, it is now well established that the protein signaling network of living cells has a bow-tie structure and that components are often shared between different signaling pathways. Here we show by mathematical modeling that living cells can multiplex a constant and an oscillatory signal: they can transmit these two signals simultaneously through a common signaling pathway, and yet respond to them specifically and reliably. We find that information transmission is reduced not only by noise arising from the intrinsic stochasticity of biochemical reactions, but also by crosstalk between the different channels. Yet, under biologically relevant conditions more than 2 bits of information can be transmitted per channel, even when the two signals are transmitted simultaneously. These observations suggest that oscillatory signals are ideal for multiplexing signals.

  6. Associative learning in biochemical networks.

    Science.gov (United States)

    Gandhi, Nikhil; Ashkenasy, Gonen; Tannenbaum, Emmanuel

    2007-11-07

    It has been recently suggested that there are likely generic features characterizing the emergence of systems constructed from the self-organization of self-replicating agents acting under one or more selection pressures. Therefore, structures and behaviors at one length scale may be used to infer analogous structures and behaviors at other length scales. Motivated by this suggestion, we seek to characterize various "animate" behaviors in biochemical networks, and the influence that these behaviors have on genomic evolution. Specifically, in this paper, we develop a simple, chemostat-based model illustrating how a process analogous to associative learning can occur in a biochemical network. Associative learning is a form of learning whereby a system "learns" to associate two stimuli with one another. Associative learning, also known as conditioning, is believed to be a powerful learning process at work in the brain (associative learning is essentially "learning by analogy"). In our model, two types of replicating molecules, denoted as A and B, are present in some initial concentration in the chemostat. Molecules A and B are stimulated to replicate by some growth factors, denoted as G(A) and G(B), respectively. It is also assumed that A and B can covalently link, and that the conjugated molecule can be stimulated by either the G(A) or G(B) growth factors (and can be degraded). We show that, if the chemostat is stimulated by both growth factors for a certain time, followed by a time gap during which the chemostat is not stimulated at all, and if the chemostat is then stimulated again by only one of the growth factors, then there will be a transient increase in the number of molecules activated by the other growth factor. Therefore, the chemostat bears the imprint of earlier, simultaneous stimulation with both growth factors, which is indicative of associative learning. It is interesting to note that the dynamics of our model is consistent with certain aspects of

  7. Evolution of newly formed dust in Population III supernova remnants and its impact on the elemental composition of Population II.5 stars

    CERN Document Server

    Nozawa, Takaya; Habe, Asao; Dwek, Eli; Umeda, Hideyuki; Tominaga, Nozomu; Maeda, Keiichi; Nomoto, Ken'ichi

    2008-01-01

    We investigate the evolution of dust formed in Population III supernovae (SNe) by considering its transport and processing by sputtering within the SN remnants (SNRs). We find that the fates of dust grains within SNRs heavily depend on their initial radii $a_{\\rm ini}$. For Type II SNRs expanding into the ambient medium with density of $n_{\\rm H,0} = 1$ cm$^{-3}$, grains of $a_{\\rm ini} 0.2$ $\\mu$m are injected into the surrounding medium without being destroyed significantly. Grains with $a_{\\rm ini}$ = 0.05-0.2 $\\mu$m are finally trapped in the dense shell behind the forward shock. We show that the grains piled up in the dense shell enrich the gas up to 10$^{-6}-10^{-4}$ $Z_\\odot$, high enough to form low-mass stars with 0.1-1 $M_\\odot$. In addition, [Fe/H] in the dense shell ranges from -6 to -4.5, which is in good agreement with the ultra-metal-poor stars with [Fe/H] < -4. We suggest that newly formed dust in a Population III SN can have great impacts on the stellar mass and elemental composition of P...

  8. HIV-1 diversity, drug-resistant mutations, and viral evolution among high-risk individuals in phase II HIV vaccine trial sites in southern China.

    Directory of Open Access Journals (Sweden)

    Haiyan Qi

    Full Text Available HIV-1 prevalence in Guangxi, China, has been growing since 1996, when the first case was reported. Over half of HIV-1 positive patients in Guangxi Province were injecting drug users (IDUs, possibly because of the province's location near drug-trafficking routes. Since a phase II HIV vaccine trial is ongoing there, a current characterization of the subtypes of HIV-1 among IDUs in Guangxi would provide critical information for future HIV vaccine trials, as well as further control and prevention of HIV-1 transmission. Thus, we conducted a molecular epidemiological investigation of HIV-1 samples from 2008-2010 among IDUs in multiple cities in Guangxi Province. Our results, based on the gag/pol fragment, indicated a very high proportion (78.47% of HIV-1 CRF08_BC recombinants, some CRF01_AE (15.38% recombinants, and a low proportion of CRF07_BC (6.15% recombinants among the IDUs. The high proportion of CRF08 HIV-1 strains among recent IDUs matches the vaccine candidate constructs. However, future vaccine development should also incorporate CRF01-targeted vaccine candidates. Distinct Env sequence evolution patterns were observed for CRF08_BC and CRF01_AE, indicating that different local selection pressures have been exerted on these two HIV-1 subtypes. Unique drug-resistant mutations were also detected, and our data indicate that HIV treatment programs should consider pre-existing drug-resistant mutations.

  9. Kinetics of Formation of Cobalt(II)- and Nickel(II) Carbonic Anhydrase.

    Science.gov (United States)

    McQuate, Robert S.; Reardon, John E.

    1978-01-01

    Discusses the kinetic behavior associated with the interaction of metal ions with apocarbonic anhydrase, focusing on the formation of two metallocarbonic anhydrase--the biochemically active Co(II) and the inactive Ni(II)derivatives. (GA)

  10. Biochemical Hypermedia: Galactose Metabolism.

    Directory of Open Access Journals (Sweden)

    J.K. Sugai

    2013-05-01

    Full Text Available Introduction: Animations of biochemical processes and virtual laboratory environments lead to true molecular simulations. The use of interactive software’s in education can improve cognitive capacity, better learning and, mainly, it makes information acquisition easier. Material and Methods: This work presents the development of a biochemical hypermedia to understanding of the galactose metabolism. It was developed with the help of concept maps, ISIS Draw, ADOBE Photoshop and FLASH MX Program. Results and Discussion: A step by step animation process shows the enzymatic reactions of galactose conversion to glucose-1-phosphate (to glycogen synthesis, glucose-6-phosphate (glycolysis intermediary, UDP-galactose (substrate to mucopolysaccharides synthesis and collagen’s glycosylation. There are navigation guide that allow scrolling the mouse over the names of the components of enzymatic reactions of via the metabolism of galactose. Thus, explanatory text box, chemical structures and animation of the actions of enzymes appear to navigator. Upon completion of the module, the user’s response to the proposed exercise can be checked immediately through text box with interactive content of the answer. Conclusion: This hypermedia was presented for undergraduate students (UFSC who revealed that it was extremely effective in promoting the understanding of the theme.

  11. Interisland mutation of a novel phospholipase A2 from Trimeresurus flavoviridis venom and evolution of Crotalinae group II phospholipases A2.

    Science.gov (United States)

    Chijiwa, Takahito; Hamai, Sachiko; Tsubouchi, Shoji; Ogawa, Tomohisa; Deshimaru, Masanobu; Oda-Ueda, Naoko; Hattori, Shosaku; Kihara, Hiroshi; Tsunasawa, Susumu; Ohno, Motonori

    2003-11-01

    Trimeresurus flavoviridis (Crotalinae) snakes inhabit the southwestern islands of Japan: Amami-Oshima, Tokunoshima, and Okinawa. Affinity and conventional chromatographies of Amami-Oshima T. flavoviridis venom led to isolation of a novel phospholipase A2 (PLA2). This protein was highly homologous (91%) in sequence to trimucrotoxin, a neurotoxic PLA2, which had been isolated from T. mucrosquamatus (Taiwan) venom, and exhibited weak neurotoxicity. This protein was named PLA-N. Its LD50 for mice was 1.34 microg/g, which is comparable to that of trimucrotoxin. The cDNA encoding PLA-N was isolated from both the Amami-Oshima and the Tokunoshima T. flavoviridis venom-gland cDNA libraries. Screening of the Okinawa T. flavoviridis venom-gland cDNA library with PLA-N cDNA led to isolation of the cDNA encoding one amino acid-substituted PLA-N homologue, named PLA-N(O), suggesting that interisland mutation occurred and that Okinawa island was separated from a former island prior to dissociation of Amami-Oshima and Tokunoshima islands. Construction of a phylogenetic tree of Crotalinae venom group II PLA2's based on the amino acid sequences revealed that neurotoxic PLA2's including PLA-N and PLA-N(O) form an independent cluster which is distant from other PLA2 groups such as PLA2 type, basic [Asp49]PLA2 type, and [Lys49]PLA2 type. Comparison of the nucleotide sequence of PLA-N cDNA with those of the cDNAs encoding other T. flavoviridis venom PLA2's showed that they have evolved in an accelerated manner. However, when comparison was made within the cDNAs encoding Crotalinae venom neurotoxic PLA2's, their evolutionary rates appear to be reduced to a level between accelerated evolution and neutral evolution. It is likely that ancestral genes of neurotoxic PLA2's evolved in an accelerated manner until they had acquired neurotoxic function and since then they have evolved with less frequent mutation, possibly for functional conservation.

  12. Measuring galaxy clustering and the evolution of [C II] mean intensity with far-IR line intensity mapping during 0.5 < z < 1.5

    Energy Technology Data Exchange (ETDEWEB)

    Uzgil, B. D.; Aguirre, J. E.; Lidz, A. [University of Pennsylvania, Philadelphia, PA 19104 (United States); Bradford, C. M., E-mail: badeu@sas.upenn.edu [Jet Propulsion Laboratory, Pasadena, CA 91109 (United States)

    2014-10-01

    Infrared fine-structure emission lines from trace metals are powerful diagnostics of the interstellar medium in galaxies. We explore the possibility of studying the redshifted far-IR fine-structure line emission using the three-dimensional (3D) power spectra obtained with an imaging spectrometer. The intensity mapping approach measures the spatio-spectral fluctuations due to line emission from all galaxies, including those below the individual detection threshold. The technique provides 3D measurements of galaxy clustering and moments of the galaxy luminosity function. Furthermore, the linear portion of the power spectrum can be used to measure the total line emission intensity including all sources through cosmic time with redshift information naturally encoded. Total line emission, when compared to the total star formation activity and/or other line intensities, reveals evolution of the interstellar conditions of galaxies in aggregate. As a case study, we consider measurement of [C II] autocorrelation in the 0.5 < z < 1.5 epoch, where interloper lines are minimized, using far-IR/submillimeter balloon-borne and future space-borne instruments with moderate and high sensitivity, respectively. In this context, we compare the intensity mapping approach to blind galaxy surveys based on individual detections. We find that intensity mapping is nearly always the best way to obtain the total line emission because blind, wide-field galaxy surveys lack sufficient depth and deep pencil beams do not observe enough galaxies in the requisite luminosity and redshift bins. Also, intensity mapping is often the most efficient way to measure the power spectrum shape, depending on the details of the luminosity function and the telescope aperture.

  13. The C-terminal extension peptide of non-photoconvertible water-soluble chlorophyll-binding proteins (Class II WSCPs) affects their solubility and stability: comparative analyses of the biochemical and chlorophyll-binding properties of recombinant Brassica, Raphanus and Lepidium WSCPs with or without their C-terminal extension peptides.

    Science.gov (United States)

    Takahashi, Shigekazu; Uchida, Akira; Nakayama, Katsumi; Satoh, Hiroyuki

    2014-02-01

    Numerous members of the Brassicaceae possess non-photoconvertible water-soluble chlorophyll (Chl)-binding proteins (Class II WSCPs), which function as Chl scavengers during cell disruption caused by wounding, pest/pathogen attacks, and/or environmental stress. Class II WSCPs have two extension peptides, one at the N-terminus and one at the C-terminus. The N-terminal peptide acts as a signal peptide, targeting the protein to the endoplasmic reticulum body, a unique defensive organelle found only in the Brassicaceae. However, the physiological and biochemical functions of the C-terminal extension peptide had not been characterized previously. To investigate the function of the C-terminal extension peptide, we produced expression constructs of recombinant WSCPs with or without the C-terminal extension peptide. The WSCPs used were of Brussels sprouts (Brassica oleracea), Japanese wild radish (Raphanus sativus) and Virginia pepperweed (Lepidium virginicum). The solubility of all of the WSCPs with the C-terminal extension peptide was drastically lower than that of the recombinant WSCPs without the C-terminal extension peptide. In addition, the stability of the reconstituted WSCPs complexes with the C-terminal extension peptide was altered compared with that of the proteins without the C-terminal extension peptide. These finding indicate that the C-terminal extension peptide affects not only the solubility, but also the stability of Class II WSCP. Furthermore, we characterized the Chl-binding properties of the recombinant WSCP from Japanese wild radish (RshWSCP-His) in a 40 % methanol solution. An electrophoretic mobility shift assay revealed that RshWSCP-His required a half-molar ratio of Chls to form a tetramer.

  14. Transverse Single Spin Asymmetry in $e+p^\\uparrow \\to e+J/\\psi +X $ and $Q^2$ -evolution of Sivers Function-II

    CERN Document Server

    Godbole, Rohini M; Misra, Anuradha; Rawoot, Vaibhav S

    2014-01-01

    We present estimates of Single Spin Asymmetry(SSA) in the electroproduction of J/{\\psi} taking into account the transverse momentum dependent(TMD) evolution of the Sivers function. We estimate SSA for JLab, HERMES, COMPASS and eRHIC energies using color evaporation model of J/{\\psi}. We have calculated the asymmetry using recent parameters extracted by Echevarria et al. using the CSS approach to TMD evolution. These recent TMD evolution fits are based on the evolution kernel in which the perturbative part is resummed up to NLL accuracy. We have also estimated the asymmetry by using parameters which had been obtained by a fit by Anselmino et al., using both an exact numerical and an approximate analytical solution of the TMD evolution equations. We find that the variation among the different estimates obtained using TMD evolution is much smaller than between these on one hand and the estimates obtained using DGLAP evolution on the other. Even though the use of TMD evolution causes an overall reduction in asymm...

  15. Unquiet Evolution: Consideration of a Previous Synthesis

    Science.gov (United States)

    Angseesing, J. P. A.

    1972-01-01

    Presents genetical and biochemical data to show that the conclusion presented by Dyer (EJ 036 108) is by no meas settled. Evidence to support the concept: evolution by selectively neutral polymorphisms is inconclusive. (AL)

  16. Ouroboros - Playing A Biochemical

    Directory of Open Access Journals (Sweden)

    D. T. Rodrigues

    2014-08-01

    Full Text Available Ouroboros: Playing A Biochemical RODRIGUES,D.T.1,2;GAYER, M.C.1,2; ESCOTO, D.F.1; DENARDIN, E.L.G.2, ROEHRS, R.1,2 1Interdisciplinary Research Group on Teaching Practice, Graduate Program in Biochemistry, Unipampa, RS, Brazil 2Laboratory of Physicochemical Studies and Natural Products, Post Graduate Program in Biochemistry, Unipampa, RS, Brazil Introduction: Currently, teachers seek different alternatives to enhance the teaching-learning process. Innovative teaching methodologies are increasingly common tools in educational routine. The use of games, electronic or conventional, is an effective tool to assist in learning and also to raise the social interaction between students. Objective: In this sense our work aims to evaluate the card game and "Ouroboros" board as a teaching and learning tool in biochemistry for a graduating class in Natural Sciences. Materials and methods: The class gathered 22 students of BSc in Natural Sciences. Each letter contained a question across the board that was drawn to a group to answer within the allotted time. The questions related concepts of metabolism, organic and inorganic chemical reactions, bioenergetics, etc.. Before the game application, students underwent a pre-test with four issues involving the content that was being developed. Soon after, the game was applied. Then again questions were asked. Data analysis was performed from the ratio of the number of correct pre-test and post-test answers. Results and discussion: In the pre-test 18.1% of the students knew all issues, 18.1% got 3 correct answers, 40.9% answered only 2 questions correctly and 22.7% did not hit any. In post-test 45.4% answered all the questions right, 31.8% got 3 questions and 22.7% got 2 correct answers. The results show a significant improvement of the students about the field of content taught through the game. Conclusion: Generally, traditional approaches of chemistry and biochemistry are abstract and complex. Thus, through games

  17. Enzyme and biochemical producing fungi

    DEFF Research Database (Denmark)

    Lübeck, Peter Stephensen; Lübeck, Mette; Nilsson, Lena

    2010-01-01

    factories for sustainable production of important molecules. For developing fungi into efficient cell factories, the project includes identification of important factors that control the flux through the pathways using metabolic flux analysis and metabolic engineering of biochemical pathways....

  18. Mathematical Models of Biochemical Oscillations

    OpenAIRE

    Conrad, Emery David

    1999-01-01

    The goal of this paper is to explain the mathematics involved in modeling biochemical oscillations. We first discuss several important biochemical concepts fundamental to the construction of descriptive mathematical models. We review the basic theory of differential equations and stability analysis as it relates to two-variable models exhibiting oscillatory behavior. The importance of the Hopf Bifurcation will be discussed in detail for the central role it plays in limit cycle behavior and...

  19. Biochemical mechanisms underlying atherogenesis

    Directory of Open Access Journals (Sweden)

    Dr.P.V.L.N. Srinivasa Rao

    2012-02-01

    Full Text Available Atherosclerosis remains one of the major causes of death and premature disability in developed countries. Though atherosclerosis was formerly considered a bland lipid storage disease, substantial advances in basic and experimental sciences have illuminated the role of endothelium, inflammation and immune mechanisms in its pathogenesis. Current concept of atherosclerosis is that of a dynamic and progressive disease arising from in- jury to endothelium, also known as endothelial dysfunction and an inflammatory response to that injury. The lesions of atherosclerosis occur principally in large and medium sized arteries. Atherosclerosis affects various regions of the circulation preferentially and can lead to ischemia of heart, brain or extremities resulting in in- farction.This produces distinct clinical manifestations depending on the vessel involved. Several predisposing factors to cardiovascular diseases such as diabetes mellitus, hypertension, obesity, infections act as triggers to the devel- opment of atherosclerosis by causing endothelial dysfunction and/or promoting inflammatory response. The evolution of pathogenetic mechanisms has passed through various directions such as oxidative stress, inflam- mation and immune responses. It is now known that all these are not acting independently but are interrelated and getting unified in the current concept of atherogenesis. The following discussion aims at providing an in- sight into these developments which can help in a better comprehension of the disease and management of its clinical complications

  20. Copper complexes relevant to the catalytic cycle of copper nitrite reductase: electrochemical detection of NO(g) evolution and flipping of NO2 binding mode upon Cu(II) → Cu(I) reduction.

    Science.gov (United States)

    Maji, Ram Chandra; Barman, Suman Kumar; Roy, Suprakash; Chatterjee, Sudip K; Bowles, Faye L; Olmstead, Marilyn M; Patra, Apurba K

    2013-10-07

    Copper complexes of the deprotonated tridentate ligand, N-2-methylthiophenyl-2'-pyridinecarboxamide (HL1), were synthesized and characterized as part of our investigation into the reduction of copper(II) o-nitrito complexes into the related copper nitric oxide complexes and subsequent evolution of NO(g) such as occurs in the enzyme copper nitrite reductase. Our studies afforded the complexes [(L1)Cu(II)Cl]n (1), [(L1)Cu(II)(ONO)] (2), [(L1)Cu(II)(H2O)](ClO4)·H2O (3·H2O), [(L1)Cu(II)(CH3OH)](ClO4) (4), [(L1)Cu(II)(CH3CO2)]·H2O (5·H2O), and [Co(Cp)2][(L1)Cu(I)(NO2)(CH3CN)] (6). X-ray crystal structure determinations revealed distorted square-pyramidal coordination geometry around Cu(II) ion in 1-5. Substitution of the H2O of 3 by nitrite quantitatively forms 2, featuring the κ(2)-O,O binding mode of NO2(-) to Cu(II). Reduction of 2 generates two Cu(I) species, one with κ(1)-O and other with the κ(1)-N bonded NO2(-) group. The Cu(I) analogue of 2, compound 6, was synthesized. The FTIR spectrum of 6 reveals the presence of κ(1)-N bonded NO2(-). Constant potential electrolysis corresponding to Cu(II) → Cu(I) reduction of a CH3CN solution of 2 followed by reaction with acids, CH3CO2H or HClO4 generates 5 or 3, and NO(g), identified electrochemically. The isolated Cu(I) complex 6 independently evolves one equivalent of NO(g) upon reaction with acids. Production of NO(g) was confirmed by forming [Co(TPP)NO] in CH2Cl2 (λ(max) in CH2Cl2: 414 and 536 nm, ν(NO) = 1693 cm(-1)).

  1. Biochemical toxicity of benzene.

    Science.gov (United States)

    Rana, S V S; Verma, Yeshvandra

    2005-04-01

    Human exposure to benzene in work environment is a global occupational health problem. After inhalation or absorption, benzene targets organs viz. liver, kidney, lung, heart and brain etc. It is metabolized mainly in the liver by cytochrome P450 multifunctional oxygenase system. Benzene causes haematotoxicity through its phenolic metabolites that act in concert to produce DNA strand breaks, chromosomal damage, sister chromatid exchange, inhibition of topoisomerase II and damage to mitotic spindle. The carcinogenic and myelotoxic effects of benzene are associated with free radical formation either as benzene metabolites or lipid peroxidation products. Benzene oxide and phenol have been considered as proheptons. Liver microsomes play an important role in biotransformation of benzene whereas in kidney, it produces degenerative intracellular changes. Cohort studies made in different countries suggest that benzene induces multiple myeloma in petrochemical workers. Though extensive studies have been performed on its toxicity, endocrinal disruption caused by benzene remains poorly known. Transgenic cytochrome P450 IIE1 mice may help in understanding further toxic manifestations of benzene.

  2. Biochemical Characterization and Complete Conversion of Coenzyme Specificity of Isocitrate Dehydrogenase from Bifidobacterium longum.

    Science.gov (United States)

    Huang, Shi-Ping; Cheng, Hong-Mei; Wang, Peng; Zhu, Guo-Ping

    2016-02-26

    Bifidobacterium longum is a very important gram-positive non-pathogenic bacterium in the human gastrointestinal tract for keeping the digestive and immune system healthy. Isocitrate dehydrogenase (IDH) from B. longum (BlIDH), a novel member in Type II subfamily, was overexpressed, purified and biochemically characterized in detail. The active form of BlIDH was an 83-kDa homodimer. Kinetic analysis showed BlIDH was a NADP⁺-dependent IDH (NADP-IDH), with a 567- and 193-fold preference for NADP⁺ over NAD⁺ in the presence of Mg(2+) and Mn(2+), respectively. The maximal activity for BlIDH occurred at 60 °C (with Mn(2+)) and 65 °C (with Mg(2+)), and pH 7.5 (with Mn(2+)) and pH 8.0 (with Mg(2+)). Heat-inactivation profiles revealed that BlIDH retained 50% of maximal activity after incubation at 45 °C for 20 min with either Mn(2+) or Mg(2+). Furthermore, the coenzyme specificity of BlIDH can be completely reversed from NADP⁺ to NAD⁺ by a factor of 2387 by replacing six residues. This current work, the first report on the coenzyme specificity conversion of Type II NADP-IDHs, would provide better insight into the evolution of NADP⁺ use by the IDH family.

  3. Biochemical Characterization and Complete Conversion of Coenzyme Specificity of Isocitrate Dehydrogenase from Bifidobacterium longum

    Directory of Open Access Journals (Sweden)

    Shi-Ping Huang

    2016-02-01

    Full Text Available Bifidobacterium longum is a very important gram-positive non-pathogenic bacterium in the human gastrointestinal tract for keeping the digestive and immune system healthy. Isocitrate dehydrogenase (IDH from B. longum (BlIDH, a novel member in Type II subfamily, was overexpressed, purified and biochemically characterized in detail. The active form of BlIDH was an 83-kDa homodimer. Kinetic analysis showed BlIDH was a NADP+-dependent IDH (NADP-IDH, with a 567- and 193-fold preference for NADP+ over NAD+ in the presence of Mg2+ and Mn2+, respectively. The maximal activity for BlIDH occurred at 60 °C (with Mn2+ and 65 °C (with Mg2+, and pH 7.5 (with Mn2+ and pH 8.0 (with Mg2+. Heat-inactivation profiles revealed that BlIDH retained 50% of maximal activity after incubation at 45 °C for 20 min with either Mn2+ or Mg2+. Furthermore, the coenzyme specificity of BlIDH can be completely reversed from NADP+ to NAD+ by a factor of 2387 by replacing six residues. This current work, the first report on the coenzyme specificity conversion of Type II NADP-IDHs, would provide better insight into the evolution of NADP+ use by the IDH family.

  4. Convergent Evolution of Fern-Specific Mitochondrial Group II Intron atp1i361g2 and Its Ancient Source Paralogue rps3i249g2 and Independent Losses of Intron and RNA Editing among Pteridaceae

    Science.gov (United States)

    Zumkeller, Simon Maria; Knoop, Volker; Knie, Nils

    2016-01-01

    Mitochondrial intron patterns are highly divergent between the major land plant clades. An intron in the atp1 gene, atp1i361g2, is an example for a group II intron specific to monilophytes (ferns). Here, we report that atp1i361g2 is lost independently at least 4 times in the fern family Pteridaceae. Such plant organelle intron losses have previously been found to be accompanied by loss of RNA editing sites in the flanking exon regions as a consequence of genomic recombination of mature cDNA. Instead, we now observe that RNA editing events in both directions of pyrimidine exchange (C-to-U and U-to-C) are retained in atp1 exons after loss of the intron in Pteris argyraea/biaurita and in Actiniopteris and Onychium. We find that atp1i361g2 has significant similarity with intron rps3i249g2 present in lycophytes and gymnosperms, which we now also find highly conserved in ferns. We conclude that atp1i361g2 may have originated from the more ancestral rps3i249g2 paralogue by a reverse splicing copy event early in the evolution of monilophytes. Secondary structure elements of the two introns, most characteristically their domains III, show strikingly convergent evolution in the monilophytes. Moreover, the intron paralogue rps3i249g2 reveals relaxed evolution in taxa where the atp1i361g2 paralogue is lost. Our findings may reflect convergent evolution of the two related mitochondrial introns exerted by co-evolution with an intron-binding protein simultaneously acting on the two paralogues. PMID:27492234

  5. A Comprehensive Analysis of Fermi Gamma-ray Burst Data: II. $E_{\\rm p}$-Evolution Patterns and Implications for the Observed Spectrum-Luminosity Relations

    CERN Document Server

    Lu, Rui-Jing; Liang, En-Wei; Zhang, Bin-Bin; Lü, Hou-Jun; Lian-Zhong,; Lü,; Lei, Wei-Hua; Zhang, Bing

    2012-01-01

    We present a time-resolved spectral analysis of 51 long and 11 short bright GRBs observed with the {\\em Femri}/GBM, paying special attention to $E_{\\rm p}$ evolution within a same burst. Among 8 single-pulse long GRBs, 5 show hard-to-soft evolution, while 3 show intensity-tracking. The multi-pulse long GRBs have more complicated patterns. Among the GRBs whose time-resolved spectrum is available for the first pulse, almost half (15/32 GRBs) show clear hard-to-soft evolution, and the other half (17/32 GRBs) show clear intensity-tracking. Later pulses typically show the tracking behavior, although a hard-to-soft evolution pattern was identified in the 2nd pulse of 2 GRBs whose pulses are well separated. Statistically, the hard-to-soft evolution pulses tend to be more asymmetric than the intensity-tracking ones, with a steeper rising wing than the falling wing. Short GRBs have $E_{\\rm p}$ tracking intensity exclusively with the 16ms time resolution analysis. We performed a simulation analysis, and suggest that at...

  6. Evolution along the sequence of S0 Hubble types induced by dry minor mergers. II - Bulge-disk coupling in the photometric relations through merger-induced internal secular evolution

    CERN Document Server

    Eliche-Moral, M Carmen; Aguerri, J Alfonso L; Gallego, Jesus; Zamorano, Jaime; Balcells, Marc; Prieto, Mercedes

    2013-01-01

    Galaxy mergers are considered as questionable mechanisms for the evolution of lenticular galaxies (S0's), on the basis that even minor ones induce structural changes that are difficult to reconcile with the strong bulge-disk coupling observed in the photometric scaling relations of S0's. We check if the evolution induced onto S0's by dry intermediate and minor mergers can reproduce their photometric scaling relations, analysing the bulge-disk decompositions of the merger simulations presented in Eliche-Moral et al. (2012). The mergers induce an evolution in the photometric planes compatible with the data of S0's, even in those ones indicating a strong bulge-disk coupling. The mergers drive the formation of the observed photometric relation in some cases, whereas they induce a slight dispersion compatible with data in others. Therefore, this evolutionary mechanism tends to preserve these scaling relations. In those photometric planes where the morphological types segregate, the mergers always induce evolution ...

  7. Identification of biochemical network modules based on shortest retroactive distances.

    Directory of Open Access Journals (Sweden)

    Gautham Vivek Sridharan

    2011-11-01

    Full Text Available Modularity analysis offers a route to better understand the organization of cellular biochemical networks as well as to derive practically useful, simplified models of these complex systems. While there is general agreement regarding the qualitative properties of a biochemical module, there is no clear consensus on the quantitative criteria that may be used to systematically derive these modules. In this work, we investigate cyclical interactions as the defining characteristic of a biochemical module. We utilize a round trip distance metric, termed Shortest Retroactive Distance (ShReD, to characterize the retroactive connectivity between any two reactions in a biochemical network and to group together network components that mutually influence each other. We evaluate the metric on two types of networks that feature feedback interactions: (i epidermal growth factor receptor (EGFR signaling and (ii liver metabolism supporting drug transformation. For both networks, the ShReD partitions found hierarchically arranged modules that confirm biological intuition. In addition, the partitions also revealed modules that are less intuitive. In particular, ShReD-based partition of the metabolic network identified a 'redox' module that couples reactions of glucose, pyruvate, lipid and drug metabolism through shared production and consumption of NADPH. Our results suggest that retroactive interactions arising from feedback loops and metabolic cycles significantly contribute to the modularity of biochemical networks. For metabolic networks, cofactors play an important role as allosteric effectors that mediate the retroactive interactions.

  8. Domain structures and molecular evolution of class I and class II major histocompatibility gene complex (MHC) products deduced from amino acid and nucleotide sequence homologies.

    Science.gov (United States)

    Ohnishi, K

    1984-01-01

    Domain structures of class I and class II MHC products were analyzed from a viewpoint of amino acid and nucleotide sequence homologies. Alignment statistics revealed that class I (transplantation) antigen H chains consist of four mutually homologous domains, and that class II (HLA-DR) antigen beta and alpha chains are both composed of three mutually homologous ones. The N-terminal three and two domains of class I and class II (both beta and alpha) gene products, respectively, all of which being approximately 90 residues long, were concluded to be homologous to beta2-microglobulin (beta2M). The membrane-embedded C-terminal shorter domains of these MHC products were also found to be homologous to one another and to the third domain of class I H chains. Class I H chains were found to be more closely related to class II alpha chains than to class II beta chains. Based on these findings, an exon duplication history from a common ancestral gene encoding a beta2M-like primodial protein of one-domain-length up to the contemporary MHC products was proposed.

  9. BEST: Biochemical Engineering Simulation Technology

    Energy Technology Data Exchange (ETDEWEB)

    1996-01-01

    The idea of developing a process simulator that can describe biochemical engineering (a relatively new technology area) was formulated at the National Renewable Energy Laboratory (NREL) during the late 1980s. The initial plan was to build a consortium of industrial and U.S. Department of Energy (DOE) partners to enhance a commercial simulator with biochemical unit operations. DOE supported this effort; however, before the consortium was established, the process simulator industry changed considerably. Work on the first phase of implementing various fermentation reactors into the chemical process simulator, ASPEN/SP-BEST, is complete. This report will focus on those developments. Simulation Sciences, Inc. (SimSci) no longer supports ASPEN/SP, and Aspen Technology, Inc. (AspenTech) has developed an add-on to its ASPEN PLUS (also called BioProcess Simulator [BPS]). This report will also explain the similarities and differences between BEST and BPS. ASPEN, developed by the Massachusetts Institute of Technology for DOE in the late 1970s, is still the state-of-the-art chemical process simulator. It was selected as the only simulator with the potential to be easily expanded into the biochemical area. ASPEN/SP, commercially sold by SimSci, was selected for the BEST work. SimSci completed work on batch, fed-batch, and continuous fermentation reactors in 1993, just as it announced it would no longer commercially support the complete ASPEN/SP product. BEST was left without a basic support program. Luckily, during this same time frame, AspenTech was developing a biochemical simulator with its version of ASPEN (ASPEN PLUS), which incorporates most BEST concepts. The future of BEST will involve developing physical property data and models appropriate to biochemical systems that are necessary for good biochemical process design.

  10. Distinct form I, II, III, and IV Rubisco proteins from the three kingdoms of life provide clues about Rubisco evolution and structure/function relationships.

    Science.gov (United States)

    Tabita, F Robert; Satagopan, Sriram; Hanson, Thomas E; Kreel, Nathan E; Scott, Stephanie S

    2008-01-01

    There are four forms of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) found in nature. Forms I, II, and III catalyse the carboxylation and oxygenation of ribulose 1,5-bisphosphate, while form IV, also called the Rubisco-like protein (RLP), does not catalyse either of these reactions. There appear to be six different clades of RLP. Although related to bona fide Rubisco proteins at the primary sequence and tertiary structure levels, RLP from two of these clades is known to perform other functions in the cell. Forms I, II, and III Rubisco, along with form IV (RLP), are thought to have evolved from a primordial archaeal Rubisco. Structure/function studies with both archaeal form III (methanogen) and form I (cyanobacterial) Rubisco have identified residues that appear to be specifically involved with interactions with molecular oxygen. A specific region of all form I, II, and III Rubisco was identified as being important for these interactions.

  11. Formation of nanoscale spatially indirect excitons: Evolution of the type-II optical character of CdTe/CdSe heteronanocrystals

    NARCIS (Netherlands)

    de Mello Donega, C.

    2010-01-01

    In this work, the evolution of the optical properties of nanoscale spatially indirect excitons as a function of the size, shape, and composition of the heteronanostructure is investigated, using colloidal CdTe/CdSe heteronanocrystals (2.6 nm diameter CdTe core and increasing CdSe volume fraction) as

  12. Evolution of gaseous disk viscosity driven by supernova explosion. II. Structure and emissions from star-forming galaxies at high redshift

    CERN Document Server

    Yan, Chang-Shuo

    2010-01-01

    (Abridged) High redshift galaxies are undergoing intensive evolution of dynamical structure and morphologies. We incorporate the feedback into the dynamical equations through mass dropout and angular momentum transportation driven by the SNexp-excited turbulent viscosity. We numerically solve the equations and show that there can be intensive evolution of structure of the gaseous disk. Secular evolution of the disk shows interesting characteristics that are 1) high viscosity excited by SNexp can efficiently transport the gas from 10kpc to $\\sim 1$kpc forming a stellar disk whereas a stellar ring forms for the case with low viscosity; 2) starbursts trigger SMBH activity with a lag $\\sim 10^8$yr depending on star formation rates, prompting the joint evolution of SMBHs and bulges; 3) the velocity dispersion is as high as $\\sim 100~\\kms$ in the gaseous disk. In order to compare the present models with the observed dynamical structure and images, we use the incident continuum from the simple stellar synthesis (GAL...

  13. From Miras to planetary nebulae: Which path for stellar evolution?; Proceedings of the International Colloquium, Universite de Montpellier II, France, Sept. 4-7, 1989

    Science.gov (United States)

    Mennessier, M. O.; Omont, A.

    This book considers stellar evolution of Mira variables to planetary nebulae. Topics discussed include pulsation and shock waves; mass loss; circumstellar dust; maser emission and OH/IR stars; C stars; and post-AGB evolution to planetary nebulae, protoplanetary nebulae, and prewhite dwarfs and binaries. Papers are presented on pulsations of model Mira variables, the environment of Miras from interferometry, the physics of mass loss from AGB stars, the mixing length and the mass loss rate, dust formation and stellar wind, dust formation in circumstellar shells of Mira variables, the evolution of water masers on the AGB, and phase lags from OH/IR stars. Attention is also given to the variability of carbon stars, transfer reactions as neutron sources for the s-process, planetary nebulae as post-AGB objects, the kinematic structure of NGC 7139, the post-AGB evolution of low-mass stars, OH/IR stars as the progenitors of planetary nebulae, atmospheric parameters for pre-WD, and a new protoplanetary nebula.

  14. Dust evolution, a global view: II. Top-down branching, nanoparticle fragmentation and the mystery of the diffuse interstellar band carriers

    Science.gov (United States)

    Jones, A. P.

    2016-12-01

    The origin of the diffuse interstellar bands (DIBs), one of the longest-standing mysteries of the interstellar medium (ISM), is explored within the framework of The Heterogeneous dust Evolution Model for Interstellar Solids (THEMIS). The likely nature of the DIB carriers and their evolution is here explored within the framework of the structures and sub-structures inherent to doped hydrogenated amorphous carbon grains in the ISM. Based on the natural aromatic-rich moieties (asphaltenes) recovered from coal and oil, the likely structure of their interstellar analogues is investigated within the context of the diffuse band problem. It is here proposed that the top-down evolution of interstellar carbonaceous grains, and, in particular, a-C(:H) nanoparticles, is at the heart of the formation and evolution of the DIB carriers and their associations with small molecules and radicals, such as C2, C3, CH and CN. It is most probable that the DIBs are carried by dehydrogenated, ionized, hetero-cyclic, olefinic and aromatic-rich moieties that form an integral part of the contiguous structure of hetero-atom-doped hydrogenated amorphous carbon nanoparticles and their daughter fragmentation products. Within this framework, it is proposed that polyene structures in all their variants could be viable DIB carrier candidates.

  15. Evolution of Biochemical Parameters During Composting of Various Wastes Compost

    Directory of Open Access Journals (Sweden)

    N. Saidi

    2008-01-01

    Full Text Available In Tunisia the most treatment waste is landfill (50% of wastes were land filled and only 5% are composted. And since our soil become more and more poor in organic matter, green waste can be a significant source of organic matter; in parallel we cited the domestic waste and dead posodonia collected from beaches. All these wastes coming from various origins can be exploited to produce stable compost able to correct the deficiency of soil. Exploiting waste could lead at different quality of mature compost. We are not interested in only the quality of the mature compost but we are interested in the time of the composting cycle. The goals of this study were to characterize the maturity and the sanitary quality of compost in relation with the feed stock source (green waste (C1, green waste mixed with Posidonia (C2 and municipal solid waste (C3. The results obtained showed that the duration of the cycle of composting depends on the nature of the substrate. The longest cycle (200 days was observed with the feed stock source C3. The C/N ratios ranged between 22 and 27 at the beginning of the cycle of composting and decreased notably during time of composting. NH4-N decreased over the progress cycle and at the end of composting progress, all wastes presented a content of NH4-N not exceeding the maximal value recommended for mature compost (400 mg kg-1. The CO2 released by C1 was of approximately 6000 mg C-CO2 DM kg-1 at the start of the cycle and it reached at the end of the cycle of composting 2300 mg C-CO2 DM kg-1. Nevertheless, the deshydrogenase activity (DHA recorded was important during the thermophilous phase at the level of the three piles C1, C2 and C3, where it reached the respective values of 5.9; 6.2 and 4 TPFS/TPF/g of DM. Maturity stage showed the values of 0.3; 0.8 and 0.4 TPFS/TPF/g of DM, respectively. Salmonella appeared only at the level of the piles C2 et C3 at the beginning of composting. After 40th days composting these bacteria are not detected. Staphylocoques were not detected at the level of the two piles C1 and C2. The number of these bacteria was important in the compost C3, where it fluctuated between 103 and 105 bacteria g-1 of dry matter. Statistical analyses showed that the compost of municipal solid waste C3 presented a value of salinity (6.8 g Kg-1 of DM higher than those obtained at the level of the other studied piles 2.6 g kg%/1 of DM for C1; 4 g Kg-1 of DM for C2. We also noted that the compost C2 was relatively rich in P (2.17%/ of DM and MgO (2.62% of DM as compared with the two other studied piles which contain a percentage of MgO of 0. 73 in C1 pile and 0. 8 in C3 pile. Although important heavy metals contents determined in the three studied composts were lower than the levels indicated by the standards of the European Union.

  16. Photosystem II antennae are not energetically connected: evidence based on flash-induced O2 evolution and chlorophyll fluorescence in sunflower leaves.

    Science.gov (United States)

    Oja, Vello; Laisk, Agu

    2012-10-01

    Oxygen evolution was measured in sunflower leaves in steady-state and during multiple-turnover pulses (MTP) of different light (630 nm LED plus far-red light) intensity and duration. In parallel, Chl fluorescence yields F(0) (minimum), F(s) (steady-state), and F(m) (pulse-saturated), as well as fluorescence induction during MTPs were recorded. Extra O(2) evolution was measured in response to a saturating single-turnover Xe flash (STF) applied immediately subsequently to the actinic light in the steady-state and to each MTP. Under the used anaerobic conditions and randomized S-states electron transport per STF was calculated as 4O(2) evolution. The STF-induced electron transport (=the number of open PSII) was maximal at the low background light, but decreased with progressing light saturation in steady-state and with the increasing duration of MTP. The quantum yield (effective antenna size) of open PSII centers remained constant when adjacent centers became closed. The photochemical quenching of fluorescence q(P) = (F(m) - F(s))/(F(m) - F(0)) was proportional with the portion of open PSII centers in the steady-state (variable non-photochemical quenching, NPQ) and with increasing MTP duration (NPQ absent). Comparison of experimental responses to a model based on PSII dimers with well-connected antennae showed no energetic connectivity between PSII antennae in intact leaves, suggesting that in vivo PSII exist as monomers, or dimers with energetically disconnected antennae.

  17. Transcription fluctuation effects on biochemical oscillations.

    Directory of Open Access Journals (Sweden)

    Ryota Nishino

    Full Text Available Some biochemical systems show oscillation. They often consist of feedback loops with repressive transcription regulation. Such biochemical systems have distinctive characteristics in comparison with ordinary chemical systems: i numbers of molecules involved are small, ii there are typically only a couple of genes in a cell with a finite regulation time. Due to the fluctuations caused by these features, the system behavior can be quite different from the one by deterministic rate equations, because the rate equations ignore molecular fluctuations and thus are exact only in the infinite molecular number limit. The molecular fluctuations on a free-running circadian system have been studied by Gonze et al. (2002 by introducing a scale parameter [Formula: see text] for the system size. They consider, however, only the first effect, assuming that the gene process is fast enough for the second effect to be ignored, but this has not been examined systematically yet. Here we study fluctuation effects due to the finite gene regulation time by introducing a new scale parameter [Formula: see text], which we take as the unbinding time of a nuclear protein from the gene. We focus on the case where the fluctuations due to small molecular numbers are negligible. In simulations on the same system studied by Gonze et al., we find the system is unexpectedly sensitive to the fluctuation in the transcription regulation; the period of oscillation fluctuates about 30 min even when the regulation time scale [Formula: see text] is around 30 s, that is even smaller than 1/1000 of its circadian period. We also demonstrate that the distribution width for the oscillation period and amplitude scales with [Formula: see text], and the correlation time scales with [Formula: see text] in the small [Formula: see text] regime. The relative fluctuations for the period are about half of that for the amplitude, namely, the periodicity is more stable than the amplitude.

  18. Observations of the northern seasonal polar cap on Mars II: HiRISE photometric analysis of evolution of northern polar dunes in spring

    Science.gov (United States)

    Portyankina, Ganna; Pommerol, Antoine; Aye, Klaus-Michael; Hansen, Candice J.; Thomas, Nicolas

    2013-08-01

    We present an overview of our analyses of HiRISE observations of spring evolution of selected dune areas of the north polar erg. The north polar erg is covered annually by seasonal volatile ice layer, a mixture of CO2 and H2O with mineral dust contamination. In spring, this layer sublimes creating visually enigmatic phenomena, e.g. dark and bright fan-shaped deposits, dark-bright-dark bandings, dark down-slope streaks, and seasonal polygonal cracks. Similar phenomena in southern polar areas are believed to be related to the specific process of solid-state greenhouse effect. In the north, it is currently unclear if the solid-state greenhouse effect is able to explain all the observed phenomena especially because the increased influence of H2O on the time scales of this process has not yet been quantified. HiRISE observations of our selected locations show that the ground exhibits a temporal behaviour similar to the one observed in the southern polar areas: a brightening phase starting close to the spring equinox with a subsequent darkening towards summer solstice. The resolution of HiRISE enabled us to study dunes and substrate individually and even distinguish between different developments on windward and slip face sides of single dunes. Differences in the seasonal evolution between steep slip faces and flatter substrate and windward sides of dunes have been identified and compared to CRISM data of CO2 and H2O distributions on dunes. We also observe small scale dark blotches that appear in early observations and tend to sustain a low reflectivity throughout the spring. These blotches can be regarded as the analogue of dark fan deposits in southern polar areas, leading us to the conclusion that both martian polar areas follow similar spring evolutions.

  19. Enzymology of the carotenoid cleavage dioxygenases: reaction mechanisms, inhibition and biochemical roles.

    Science.gov (United States)

    Harrison, Peter J; Bugg, Timothy D H

    2014-02-15

    Carotenoid cleavage dioxygenases (CCDs) are a large family of non-heme iron (II) dependent enzymes. CCDs catalyse the selective oxidative cleavage of carotenoids to produce apocarotenoids. Apocarotenoid derived molecules form important signalling molecules in plants in the form of abscisic acid and strigolactone and in mammals in the form of retinal. Very little is known biochemically about the CCDs and only a handful of CCDs have been biochemically characterised. Mechanistically, debate surrounds whether CCDs utilise a mono or dioxygenase mechanism. Here, we review the biochemical roles of CCDs, discuss the mechanisms by which CCD cleavage is proposed to occur, and discuss recent reports of selective CCD enzyme inhibitors.

  20. Associative learning in biochemical networks

    OpenAIRE

    Ghandi, Nikhil; Ashkenasy, Gonen; Tannenbaum, Emmanuel

    2007-01-01

    We develop a simple, chemostat-based model illustrating how a process analogous to associative learning can occur in a biochemical network. Associative learning is a form of learning whereby a system "learns" to associate two stimuli with one another. In our model, two types of replicating molecules, denoted A and B, are present in some initial concentration in the chemostat. Molecules A and B are stimulated to replicate by some growth factors, denoted GA and GB, respectively. It is also assu...

  1. Biochemical markers of bone turnover

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Deog Yoon [College of Medicine, Kyunghee Univ., Seoul (Korea, Republic of)

    1999-08-01

    Biochemical markers of bone turnover has received increasing attention over the past few years, because of the need for sensitivity and specific tool in the clinical investigation of osteoporosis. Bone markers should be unique to bone, reflect changes of bone less, and should be correlated with radiocalcium kinetics, histomorphometry, or changes in bone mass. The markers also should be useful in monitoring treatment efficacy. Although no bone marker has been established to meet all these criteria, currently osteocalcin and pyridinium crosslinks are the most efficient markers to assess the level of bone turnover in the menopausal and senile osteoporosis. Recently, N-terminal telopeptide (NTX), C-terminal telopeptide (CTX) and bone specific alkaline phosphatase are considered as new valid markers of bone turnover. Recent data suggest that CTX and free deoxypyridinoline could predict the subsequent risk of hip fracture of elderly women. Treatment of postmenopausal women with estrogen, calcitonin and bisphosphonates demonstrated rapid decrease of the levels of bone markers that correlated with the long-term increase of bone mass. Factors such as circadian rhythms, diet, age, sex, bone mass and renal function affect the results of biochemical markers and should be appropriately adjusted whenever possible. Each biochemical markers of bone turnover may have its own specific advantages and limitations. Recent advances in research will provide more sensitive and specific assays.

  2. Properties of High Redshift Quasars-II: What does the quasar luminosity function tell us about super-massive black-hole evolution?

    CERN Document Server

    Wyithe, S; Wyithe, Stuart

    2006-01-01

    In the local universe, the masses of Super-Massive Black-Holes (SMBH) appear to correlate with the physical properties of their hosts, including the mass of the dark-matter halo. Using these clues as a starting point many studies have produced models that can explain phenomena like the quasar luminosity function. The shortcoming of this approach is that working models are not unique, and as a result it is not always clear what input physics is being constrained. Here we take a different approach. We identify critical parameters that describe the evolution of SMBHs at high redshift, and constrain their parameter space based on observations of high redshift quasars from the Sloan Digital Sky Survey. We find that the luminosity function taken in isolation is somewhat limited in its ability to constrain SMBH evolution due to some strong degeneracies. This explains the presence in the literature of a range of equally successful models based on different physical hypotheses. Including the constraint of the local SM...

  3. Evolution and nucleosynthesis of extremely metal-poor and metal-free low- and intermediate-mass stars II. s-process nucleosynthesis during the core He flash

    CERN Document Server

    Campbell, Simon W; Karakas, Amanda I

    2010-01-01

    Models of primordial and hyper-metal-poor stars with masses similar to the Sun experience an ingestion of protons into the hot core during the core helium flash phase at the end of their red giant branch evolution. This produces a concurrent secondary flash powered by hydrogen burning that gives rise to further nucleosynthesis in the core. We perform post-process nucleosynthesis calculations on a one-dimensional stellar evolution calculation of a star of 1 solar mass and metallicity [Fe/H] = -6.5 that suffers a proton ingestion episode. Our network includes 320 nuclear species and 2,366 reactions and treats mixing and burning simultaneously. The mixing and burning of protons into the hot convective core leads to the production of 13C, which then burns via the 13C(alpha,n)16O reaction releasing a large number of free neutrons. During the first two years of neutron production the neutron poison 14N abundance is low, allowing the prodigious production of heavy elements such as strontium, barium, and lead via slo...

  4. Speckle temporal stability in XAO coronagraphic images II. Refine model for quasi-static speckle temporal evolution for VLT/SPHERE

    CERN Document Server

    Martinez, P; Costille, A; Sauvage, J F; Dohlen, K; Puget, P; Beuzit, J L

    2013-01-01

    Observing sequences have shown that the major noise source limitation in high-contrast imaging is due to the presence of quasi-static speckles. The timescale on which quasi-static speckles evolve, is determined by various factors, among others mechanical or thermal deformations. Understanding of these time-variable instrumental speckles, and especially their interaction with other aberrations, referred to as the pinning effect, is paramount for the search of faint stellar companions. The temporal evolution of quasi-static speckles is for instance required for a quantification of the gain expected when using angular differential imaging (ADI), and to determine the interval on which speckle nulling techniques must be carried out. Following an early analysis of a time series of adaptively corrected, coronagraphic images obtained in a laboratory condition with the High-Order Test bench (HOT) at ESO Headquarters, we confirm our results with new measurements carried out with the SPHERE instrument during its final t...

  5. Emission-Line Galaxies from the Hubble Space Telescope Probing Evolution and Reionization Spectroscopically (PEARS) Grism Survey. II: The Complete Sample

    CERN Document Server

    Pirzkal, Nor; Ly, Chun; Malhotra, Sangeeta; Rhoads, James E; Grogin, Norman A; Dahlen, Tomas; Meurer, Gerhardt R; Walsh, Jeremy R; Hathi, Nimish P; Cohen, Seth H; Bellini, Andrea; Holwerda, Benne W; Straughn, Amber N; Mechtley, Matthew

    2012-01-01

    We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on HST. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations to support the spectroscopic results. Using the PEARS data we are able to identify star forming galaxies within the redshift volume 0 1e9} M_sun decreases by an order of magnitude at z<0.5 relative to the number at 0.5

  6. Biochemical effects of Calotropis procera on hepatotoxicity

    Directory of Open Access Journals (Sweden)

    Ali Ismaiel Ali Abd Alrheam

    2015-12-01

    Full Text Available Introduction: Calotropis procera commonly known as Sodom apple is a 6-meter high shrub that belongs to the Aclepiadaceae plant family and is commonly found in West Africa and other tropical places. In Saudi Arabia the plant is commonly used in traditional medicine for the treatment of variety of diseases including fever, constipation, muscular spasm and joint pain. Aim: In the present study C. procera were investigated for the hepatoprotective activity. Material and Methods: Carbon tetrachloride is used to produce hepatotoxicity. Forty two male albino rats, weighting 150-200 gm divided into seven groups, each consisted of 6 rats. Carbon tetrachloride 2ml/kg was administered twice a week to all of the groups of animals except group I, which served as control and given the normal saline. Group II served as Carbon tetrachloirde control. Group III received Silymarin at 100 mg/kg/day dose, Group IV received aqueous leaves extracts C. procera 200mg/kg, Group V received chloroform leaves extracts C. procera 200mg/kg, Group VI received ethanol leaves extracts C. procera 200 mg/kg, Group VII received latex of C. procera 200mg/kg. The effect of aqueous, chloroform, ethanol leaves extract and latex C. procera on biochemical parameters of liver was measured. Results: The results showed that the aqueous, chloroform, ethanol leaves extract and latex C. procera produced significant decrease in Acid phosphatase, Alkaline phosphatase, Aspartate aminotransferase, Alanine aminotransferase, Total protein, Albumin and total bilirubin levels compared to the CCL4 treated group II. Conclusion: Calotropis procera appears to to have hepatoprotective activity and these may be due to enrich of the plant by phytoconstituents that activate and in hence a pharmacological response of different parts of the body and this study need further studies to shows the complete properties of the plant. [Biomed Res Ther 2015; 2(12.000: 446-453

  7. Biochemical structure of Calendula officinalis.

    Science.gov (United States)

    Korakhashvili, A; Kacharava, T; Kiknavelidze, N

    2007-01-01

    Calendula officinalis is a well known medicinal herb. It is common knowledge that its medicinal properties are conditioned on biologically active complex substances of Carotin (Provitamin A), Stearin, Triterpiniod, Plavonoid, Kumarin, macro and micro compound elements. Because of constant need in raw material of Calendula officinalis, features of its ontogenetic development agro-biological qualities in various eco regions of Georgia were investigated. The data of biologically active compounds, biochemical structure and the maintenance both in flowers and in others parts of plant is presented; the pharmacological activity and importance in medicine was reviewed.

  8. PROSAC: A Submillimeter Array survey of low-mass protostars. II. The mass evolution of envelopes, disks, and stars from the Class 0 through I stages

    CERN Document Server

    Jorgensen, Jes K; Visser, Ruud; Bourke, Tyler L; Wilner, David J; Lommen, Dave; Hogerheijde, Michiel R; Myers, Philip C

    2009-01-01

    The key question about early protostellar evolution is how matter is accreted from the large-scale molecular cloud, through the circumstellar disk onto the central star. A sample of 20 Class 0 and I protostars has been observed in continuum at (sub)millimeter wavelengths at high angular resolution with the Submillimeter Array. Using detailed dust radiative transfer models, we have developed a framework for disentangling the continuum emission from the envelopes and disks, and from that estimated their masses. For the Class I sources in the sample, HCO+ 3-2 line emission has furthermore been observed with the Submillimeter Array. Four of these sources show signs of Keplerian rotation, constraining the masses of the central stars. Both Class 0 and I protostars are surrounded by disks with typical masses of about 0.05 M_sun. No evidence is found for a correlation between the disk mass and evolutionary stage of the young stellar objects. This contrasts the envelope mass, which decreases sharply from 1 M_sun in th...

  9. A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: II. Formation of Red Ellipticals

    CERN Document Server

    Hopkins, Philip F; Keres, Dusan; Hernquist, Lars

    2007-01-01

    (Abridged) We develop and test a model for the cosmological role of mergers in the formation and quenching of red, early-type galaxies. Making the ansatz that star formation is quenched after a gas-rich, spheroid-forming major merger, we demonstrate that this naturally predicts the turnover in the efficiency of star formation at ~L_star, as well as the observed mass functions/density of red galaxies as a function of redshift, the formation times of spheroids as a function of mass, and the fraction of quenched galaxies as a function of galaxy and halo mass, environment, and redshift. Comparing to a variety of semi-analytic models in which quenching is primarily driven by halo mass considerations or secular/disk instabilities, we demonstrate that our model and different broad classes of models make unique and robust qualitative predictions for a number of observables, including the red fraction as a function of galaxy and halo mass, the density of passive galaxies and evolution of the color-morphology-density r...

  10. Studying the evolution of galaxies in compact groups over the past 3 Gyr - II. The importance of environment in the suppression of star formation

    CERN Document Server

    Bitsakis, T; Ciesla, L; Diaz-Santos, T; Appleton, P; Charmandaris, V; Krongold, Y; Guillard, P; Alatalo, K; Zezas, A; Gonzalez, J; Lanz, L

    2016-01-01

    We present an in depth study on the evolution of galaxy properties in compact groups over the past 3 Gyr. We are using the largest multi-wavelength sample to-date, comprised 1770 groups (containing 7417 galaxies), in the redshift range of 0.01

  11. Surveying the Agents of Galaxy Evolution in the Tidally-Stripped, Low Metallicity Small Magellanic Cloud (SAGE-SMC) II. Cool Evolved Stars

    CERN Document Server

    Boyer, Martha L; van Loon, Jacco Th; McDonald, Iain; Meixner, Margaret; Zaritsky, Dennis; Gordon, Karl D; Kemper, F; Babler, Brian; Block, Miwa; Bracker, Steve; Engelbracht, Charles W; Hora, Joe; Indebetouw, Remy; Meade, Marilyn; Misselt, Karl; Robitaille, Thomas; Sewilo, Marta; Shiao, Bernie; Whitney, Barbara

    2011-01-01

    We investigate the infrared (IR) properties of cool, evolved stars in the Small Magellanic Cloud (SMC), including the red giant branch (RGB) stars and the dust-producing red supergiant (RSG) and asymptotic giant branch (AGB) stars using observations from the Spitzer Space Telescope Legacy program entitled: "Surveying the Agents of Galaxy Evolution in the Tidally-stripped, Low Metallicity SMC", or SAGE-SMC. The survey includes, for the first time, full spatial coverage of the SMC bar, wing, and tail regions at infrared (IR) wavelengths (3.6 - 160 microns). We identify evolved stars using a combination of near-IR and mid-IR photometry and point out a new feature in the mid-IR color-magnitude diagram that may be due to particularly dusty O-rich AGB stars. We find that the RSG and AGB stars each contribute ~20% of the global SMC flux (extended + point-source) at 3.6 microns, which emphasizes the importance of both stellar types to the integrated flux of distant metal-poor galaxies. The equivalent SAGE survey of t...

  12. Morphologies of ~190,000 Galaxies at z=0-10 Revealed with HST Legacy Data II. Evolution of Clumpy Galaxies

    CERN Document Server

    Shibuya, Takatoshi; Kubo, Mariko; Harikane, Yuichi

    2015-01-01

    We investigate evolution of clumpy galaxies with the Hubble Space Telescope (HST) samples of ~190,000 photo-z and Lyman break galaxies at z~0-8. We detect clumpy galaxies with off-center clumps in a self-consistent algorithm that is well tested with previous study results, and measure the number fraction of clumpy galaxies at the rest-frame UV, f_clumpy^UV. We identify an evolutionary trend of f_clumpy^UV over z~0-8 for the first time: f_clumpy^UV increases from z~8 to z~1-3 and subsequently decreases from z~1 to z~0, which follows the trend of Madau-Lilly plot. A low average Sersic index of n~1 is found in the underlining components of our clumpy galaxies at z~0-2, indicating that typical clumpy galaxies have disk-like surface brightness profiles. Our f_clumpy^UV values correlate with physical quantities related to star formation activities for star-forming galaxies at z~0-7. We find that clump colors tend to be red at a small galactocentric distance for massive galaxies with log(M_*/M_sun)>~11. All of these...

  13. Local potential evolutions during proton exchange membrane fuel cell operation with dead-ended anode - Part II: Aging mitigation strategies based on water management and nitrogen crossover

    Science.gov (United States)

    Abbou, S.; Dillet, J.; Maranzana, G.; Didierjean, S.; Lottin, O.

    2017-02-01

    Proton exchange membrane (PEM) fuel cells operate with dead-ended anode in order to reduce system cost and complexity when compared with hydrogen re-circulation systems. In the first part of this work, we showed that localized fuel starvation events may occur, because of water and nitrogen accumulation in the anode side, which could be particularly damaging to the cell performance. To prevent these degradations, the anode compartment must be purged which may lead to an overall system efficiency decrease because of significant hydrogen waste. In the second part, we present several purge strategies in order to minimize both hydrogen waste and membrane-electrode assembly degradations during dead-ended anode operation. A linear segmented cell with reference electrodes was used to monitor simultaneously the current density distribution along the gas channel and the time evolution of local anode and cathode potentials. To asses MEA damages, Platinum ElectroChemical Surface Area (ECSA) and cell performance were periodically measured. The results showed that dead-end mode operation with an anode plate maintained at a temperature 5 °C hotter than the cathode plate limits water accumulation in the anode side, reducing significantly purge frequency (and thus hydrogen losses) as well as MEA damages. As nitrogen contribution to hydrogen starvation is predominant in this thermal configuration, we also tested a microleakage solution to discharge continuously most the nitrogen accumulating in the anode side while ensuring low hydrogen losses and minimum ECSA losses provided the right microleakage flow rate is chosen.

  14. SImulating the LifeCycle of molecular Clouds (SILCC): II. Dynamical evolution of the supernova-driven ISM and the launching of outflows

    CERN Document Server

    Girichidis, Philipp; Naab, Thorsten; Gatto, Andrea; Wünsch, Richard; Glover, Simon C O; Klessen, Ralf S; Clark, Paul C; Peters, Thomas; Derigs, Dominik; Baczynski, Christian

    2015-01-01

    The SILCC project (SImulating the Life-Cycle of molecular Clouds) aims at a more self-consistent understanding of the interstellar medium (ISM) on small scales and its link to galaxy evolution. We present three-dimensional (magneto)hydrodynamic simulations of the ISM in a vertically stratified box including self-gravity, an external potential due to the stellar component of the galactic disc, and stellar feedback in the form of an interstellar radiation field and supernovae (SNe). The cooling of the gas is based on a chemical network that follows the abundances of H+, H, H2, C+, and CO and takes shielding into account consistently. We vary the SN feedback by comparing different SN rates, clustering and different positioning, in particular SNe in density peaks and at random positions, which has a major impact on the dynamics. Only for random SN positions the energy is injected in sufficiently low-density environments to reduce energy losses and enhance the effective kinetic coupling of the SNe with the gas. Th...

  15. Chemical evolution of high-mass stars in close binaries. II. The evolved component of the eclipsing binary V380 Cygni

    CERN Document Server

    Pavlovski, K; Koubsky, P; Southworth, J; Yang, S; Kolbas, V

    2009-01-01

    The eclipsing and double-lined spectroscopic binary V380 Cyg is an extremely important probe of stellar evolution: its primary component is a high-mass star at the brink of leaving the main sequence whereas the secondary star is still in the early part of its main sequence lifetime. We present extensive high-resolution echelle and grating spectroscopy from Ondrejov, Calar Alto, Victoria and La Palma. We apply spectral disentangling to unveil the individual spectra of the two stars and obtain new spectroscopic elements. The secondary star contributes only about 6% of the total light, which remains the main limitation to measuring the system's characteristics. We determine improved physical properties, finding masses 13.1 +/- 0.3 and 7.8 +/- 0.1 M_sun, radii 16.2 +/- 0.3 and 4.06 +/- 0.08 R_sun, and effective temperatures 21750 +/- 280 and 21600 +/- 550 K, for the primary and secondary components respectively. We perform a detailed abundance analysis by fitting non-LTE theoretical line profiles to the disentang...

  16. Carbon-enhanced metal-poor stars: a window on AGB nucleosynthesis and binary evolution. II. Statistical analysis of a sample of 67 CEMP-$s$ stars

    CERN Document Server

    Abate, C; Izzard, R G; Karakas, A I

    2015-01-01

    Many observed CEMP stars are found in binary systems and show enhanced abundances of $s$-elements. The origin of the chemical abundances of these CEMP-$s$ stars is believed to be accretion in the past of enriched material from a primary star in the AGB phase. We investigate the mechanism of mass transfer and the process of nucleosynthesis in low-metallicity AGB stars by modelling the binary systems in which the observed CEMP-$s$ stars were formed. For this purpose we compare a sample of $67$ CEMP-$s$ stars with a grid of binary stars generated by our binary evolution and nucleosynthesis model. We classify our sample CEMP-$s$ stars in three groups based on the observed abundance of europium. In CEMP$-s/r$ stars the europium-to-iron ratio is more than ten times higher than in the Sun, whereas it is lower than this threshold in CEMP$-s/nr$ stars. No measurement of europium is currently available for CEMP-$s/ur$ stars. On average our models reproduce well the abundances observed in CEMP-$s/nr$ stars, whereas in C...

  17. Porosity Evolution of Activated Carbon Fiber Prepared from Liquefied Wood. Part II: Water Steam Activation from 850 to 950 °C

    Directory of Open Access Journals (Sweden)

    Zhi Jin

    2014-09-01

    Full Text Available To acquire activated carbon fiber from phenol-liquefied wood (PLWACF with better developed pore structure and a high proportion of mesoporosity, the porosity evolution of PLWACF activated at temperatures from 850 to 950 °C by water steam was detected by the physical adsorption of N2 at -196 °C. Results showed that the pore structure was well developed by prolonging the activation time at 850 to 910 °C, and it was easy to obtain PLWACF having exceptionally high surface area (larger than 2560 m2 g-1. However, PLWACF with a specific surface area larger than 3000 m2 g-1 could only be obtained in the late activation stages from 850 to 880 °C. Using this activation process, the mesoporosity was remarkably developed. The mesopore proportion drastically increased with an increase in activation temperature or time, reaching a maximum of 49.5%. The pore size distribution widened as the activation time increased and appeared to accelerate with the use of a higher activation temperature. The mesopore size distribution was enlarged from 2.8 to 5.8 nm.

  18. Biochemical aspects of Huntington's chorea.

    Science.gov (United States)

    Caraceni, T; Calderini, G; Consolazione, A; Riva, E; Algeri, S; Girotti, F; Spreafico, R; Branciforti, A; Dall'olio, A; Morselli, P L

    1977-01-01

    Fifteen patients affected by Huntington's chorea were divided into two groups, 'slow' and 'fast', according to IQ scores on the Wechsler-Bellevue scale, and scores on some motor performance tests. A possible correlation was looked for between some biochemical data (cerebrospinal fluid (CSF), homovanillic acid (HVA), and 5-hydroxyindolacetic acid (5HIAA) levels, plasma dopamine-beta-hydroxylase (DBH), dopamine (DA) uptake by platelets), and clinical data (duration of illness, severity of symptoms, age of patients, IQ scores, 'slow' and 'fast' groups). The CSF, HVA, and 5HIAA levels were found to be significantly lowered in comparison with normal controls. DBH activity and DA uptake by platelets did not differ significantly from normal subjects. Treatment with haloperidol in all patients and with dipropylacetic acid in three patients did not appear to modify the CSF, HVA, and 5HIAA concentrations, the plasma DBH activity, or the DA uptake. There were no significant differences in the CSF, HVA, and 5HIAA contents between the two groups of patients, and there was no correlation between biochemical data and clinical features. PMID:143508

  19. Biochemical abnormalities in Pearson syndrome.

    Science.gov (United States)

    Crippa, Beatrice Letizia; Leon, Eyby; Calhoun, Amy; Lowichik, Amy; Pasquali, Marzia; Longo, Nicola

    2015-03-01

    Pearson marrow-pancreas syndrome is a multisystem mitochondrial disorder characterized by bone marrow failure and pancreatic insufficiency. Children who survive the severe bone marrow dysfunction in childhood develop Kearns-Sayre syndrome later in life. Here we report on four new cases with this condition and define their biochemical abnormalities. Three out of four patients presented with failure to thrive, with most of them having normal development and head size. All patients had evidence of bone marrow involvement that spontaneously improved in three out of four patients. Unique findings in our patients were acute pancreatitis (one out of four), renal Fanconi syndrome (present in all patients, but symptomatic only in one), and an unusual organic aciduria with 3-hydroxyisobutyric aciduria in one patient. Biochemical analysis indicated low levels of plasma citrulline and arginine, despite low-normal ammonia levels. Regression analysis indicated a significant correlation between each intermediate of the urea cycle and the next, except between ornithine and citrulline. This suggested that the reaction catalyzed by ornithine transcarbamylase (that converts ornithine to citrulline) might not be very efficient in patients with Pearson syndrome. In view of low-normal ammonia levels, we hypothesize that ammonia and carbamylphosphate could be diverted from the urea cycle to the synthesis of nucleotides in patients with Pearson syndrome and possibly other mitochondrial disorders.

  20. Vector Encoding in Biochemical Networks

    Science.gov (United States)

    Potter, Garrett; Sun, Bo

    Encoding of environmental cues via biochemical signaling pathways is of vital importance in the transmission of information for cells in a network. The current literature assumes a single cell state is used to encode information, however, recent research suggests the optimal strategy utilizes a vector of cell states sampled at various time points. To elucidate the optimal sampling strategy for vector encoding, we take an information theoretic approach and determine the mutual information of the calcium signaling dynamics obtained from fibroblast cells perturbed with different concentrations of ATP. Specifically, we analyze the sampling strategies under the cases of fixed and non-fixed vector dimension as well as the efficiency of these strategies. Our results show that sampling with greater frequency is optimal in the case of non-fixed vector dimension but that, in general, a lower sampling frequency is best from both a fixed vector dimension and efficiency standpoint. Further, we find the use of a simple modified Ornstein-Uhlenbeck process as a model qualitatively captures many of our experimental results suggesting that sampling in biochemical networks is based on a few basic components.

  1. The spectroscopic evolution of the recurrent nova T Pyxidis during its 2011 outburst. II.The optically thin phase and the structure of the ejecta in recurrent novae

    CERN Document Server

    Shore, S N; Aquino, I De Gennaro; Augusteijn, T; Walter, F M; Starrfield, S; Sion, E M

    2012-01-01

    We continue our study of the physical properties of the recurrent nova T Pyx, focussing on the structure of the ejecta in the nebular stage of expansion during the 2011 outburst. The nova was observed contemporaneously with the Nordic Optical Telescope (NOT), at high resolution spectroscopic resolution (R ~ 65000) on 2011 Oct. 11 and 2012 Apr. 8 (without absolute flux calibration), and with the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope, at high resolution (R ~ 30000) on 2011 Oct. 10 and 2012 Mar. 28 (absolute fluxes). We use standard plasma diagnostics (e.g. [O III] and [N II] line ratios and the H$\\beta$ line fluxes) to constrain electron densities and temperatures. Using Monte Carlo modeling of the ejecta, we derive the structure and filling factor from comparisons to the optical and ultraviolet line profiles. The ejecta can be modeled using an axisymmetric conical -- bipolar -- geometry with a low inclination of the axis to the line of sight, i=15+/-5 degrees, compatible...

  2. Measuring Galaxy Clustering and the Evolution of [C II] Mean Intensity with Far-IR Line Intensity Mapping during 0.5 < z < 1.5

    Science.gov (United States)

    Uzgil, Bade; Aguirre, James E.; Bradford, Charles; Lidz, Adam

    2016-01-01

    Infrared fine-structure emission lines from trace metals are powerful diagnostics of the interstellar medium in galaxies. We explore the possibility of studying the redshifted far-IR fine-structure line emission using the three-dimensional (3D) power spectra obtained with an imaging spectrometer. The intensity mapping approach measures the spatio-spectral fluctuations due to line emission from all galaxies, including those below the individual detection threshold. The technique provides 3D measurements of galaxy clustering and moments of the galaxy luminosity function. Furthermore, the linear portion of the power spectrum can be used to measure the total line emission intensity including all sources through cosmic time with redshift information naturally encoded. As a case study, we consider measurement of [C II] autocorrelation in the 0.5 < z < 1.5 epoch, where interloper lines are minimized, using far-IR/submillimeter balloon-borne and future space-borne instruments with moderate and high sensitivity, respectively. In this context, we compare the intensity mapping approach to blind galaxy surveys based on individual detections. We find that intensity mapping is nearly always the best way to obtain the total line emission because blind, wide-field galaxy surveys lack sufficient depth and deep pencil beams do not observe enough galaxies in the requisite luminosity and redshift bins. Also, intensity mapping is often the most efficient way to measure the power spectrum shape, depending on the details of the luminosity function and the telescope aperture.

  3. TOPoS: II. On the bimodality of carbon abundance in CEMP stars. Implications on the early chemical evolution of galaxies

    CERN Document Server

    Bonifacio, P; Spite, M; Limongi, M; Chieffi, A; Klessen, R S; François, P; Molaro, P; Ludwig, H G; Zaggia, S; Spite, F; Plez, B; Cayrel, R; Christlieb, N; Clark, P C; Glover, S C O; Hammer, F; Koch, A; Monaco, L; Sbordone, L; Steffen, M

    2015-01-01

    In the course of the TOPoS (Turn Off Primordial Stars) survey, aimed at discovering the lowest metallicity stars, we have found several carbon-enhanced metal-poor (CEMP) stars. We here present our analysis of six CEMP stars. Calcium and carbon are the only elements that can be measured in all six stars. The range is -5.0<=[Ca/H]< -2.1 and 7.12<=A(C)<=8.65. For star SDSS J1742+2531 we were able to detect three FeI lines from which we deduced [Fe/H]=-4.80, from four CaII lines we derived [Ca/H]=-4.56, and from synthesis of the G-band we derived A(C)=7.26. For SDSS J1035+0641 we were not able to detect any iron lines, yet we could place a robust (3sigma) upper limit of [Fe/H]< -5.0 and measure the Ca abundance, with [Ca/H]=-5.0, and carbon, A(C)=6.90. No lithium is detected in the spectrum of SDSS J1742+2531 or SDSS J1035+0641, which implies a robust upper limit of A(Li)<1.8 for both stars. Our measured carbon abundances confirm the bimodal distribution of carbon in CEMP stars, identifying a hi...

  4. A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies. II. Formation of Red Ellipticals

    Science.gov (United States)

    Hopkins, Philip F.; Cox, Thomas J.; Kereš, Dušan; Hernquist, Lars

    2008-04-01

    We develop and test a model for the cosmological role of mergers in the formation and quenching of red, early-type galaxies. By combining theoretically well-constrained halo and subhalo mass functions as a function of redshift and environment with empirical halo occupation models, we predict the distribution of mergers as a function of redshift, environment, and physical galaxy properties. Making the simple Ansatz that star formation is quenched after a gas-rich, spheroid-forming major merger, we demonstrate that this naturally predicts the turnover in the efficiency of star formation and baryon fractions in galaxies at ~L* (without any parameters tuned to this value), as well as the observed mass functions and mass density of red galaxies as a function of redshift, the formation times of early-type galaxies as a function of mass, and the fraction of quenched galaxies as a function of galaxy and halo mass, environment, and redshift. Comparing our model to a variety of semianalytic models in which quenching is primarily driven by halo mass considerations or secular/disk instabilities, we demonstrate that our model makes unique and robust qualitative predictions for a number of observables, including the bivariate red fraction as a function of galaxy and halo mass, the density of passive galaxies at high redshifts, the emergence/evolution of the color-morphology-density relations at high redshift, and the fraction of disky/boxy (or cusp/core) spheroids as a function of mass. In each case, the observations favor a model in which some mechanism quenches future star formation after a major merger builds a massive spheroid. Models where quenching is dominated by a halo mass threshold fail to match the behavior of the bivariate red fractions, predict too low a density of passive galaxies at high redshift, and overpredict by an order of magnitude the mass of the transition from disky to boxy ellipticals. Models driven by secular disk instabilities also qualitatively

  5. Thermal and chemical evolution in the early Solar System as recorded by FUN CAIs: Part II - Laboratory evaporation of potential CMS-1 precursor material

    Science.gov (United States)

    Mendybaev, Ruslan A.; Williams, Curtis D.; Spicuzza, Michael J.; Richter, Frank M.; Valley, John W.; Fedkin, Alexei V.; Wadhwa, Meenakshi

    2017-03-01

    We present the results of laboratory experiments in which a forsterite-rich melt estimated to be a potential precursor of Allende CMS-1 FUN CAI was evaporated into vacuum for different lengths of time at 1900 °C. The evaporation of this melt resulted in residues that define trajectories in chemical as well as magnesium, silicon and oxygen isotopic composition space and come very close to the measured properties of CMS-1. The isotopic composition of the evaporation residues was also used to determine the kinetic isotopic fractionation factors [α2,1 (vapor-melt) defined as the ratio of isotopes 2 and 1 of a given element in the evaporating gas divided by their ratio in the evaporating source] for evaporation of magnesium (α25,24 for 25Mg/24Mg), silicon (α29,28 for 29Si/28Si) and oxygen (α18,16 for 18O/16O) from the forsterite-rich melt at 1900 °C. The values of α25,24 = 0.98383 ± 0.00033 and α29,28 = 0.99010 ± 0.00038 are essentially independent of change in the melt composition as evaporation proceeds. In contrast, α18,16 changes from 0.9815 ± 0.0016 to ∼0.9911 when the residual melt composition changes from forsteritic to melilitic. Using the determined values of α25,24 and α29,28 and present-day bulk chemical composition of the CMS-1, the composition of the precursor of the inclusion was estimated to be close to the clinopyroxene + spinel + forsterite assemblage condensed from a solar composition gas. The correspondence between the chemical composition and isotopic fractionation of experimental evaporation residues and the present-day bulk chemical and isotopic compositions of CMS-1 is evidence that evaporation played a major role in the chemical evolution of CMS-1.

  6. A Microstructure Evolution Model for the Processing of Single-Crystal Alloy CMSX-4 Through Scanning Laser Epitaxy for Turbine Engine Hot-Section Component Repair (Part II)

    Science.gov (United States)

    Acharya, Ranadip; Bansal, Rohan; Gambone, Justin J.; Das, Suman

    2014-12-01

    Part I [Metall. Mater. Trans. B, 2014, DOI:10.1007/s11663-014-0117-9] presented a comprehensive thermal, fluid flow, and solidification model that can predict the temperature distribution and flow characteristics for the processing of CMSX-4 alloy powder through scanning laser epitaxy (SLE). SLE is an additive manufacturing technology aimed at the creation of equiaxed, directionally solidified and single-crystal (SX) deposits of nickel-based superalloys using a fast-scanning laser beam. Part II here further explores the Marangoni convection-based model to predict the solidification microstructure as a function of the conditions at the trailing edge of the melt pool formed during the SLE process. Empirical values for several microstructural characteristics such as the primary dendrite arm spacing (PDAS), the columnar-to-equiaxed transition (CET) criterion and the oriented-to-misoriented transition (OMT) criterion are obtained. Optical microscopy provides visual information on the various microstructural characteristics of the deposited material such as melt depth, CET location, OMT location, PDAS, etc. A quantitative and consistent investigation of this complex set of characteristics is both challenging and unprecedented. A customized image-analysis technique based on active contouring is developed to automatically extract these data from experimental micrographs. Quantitative metallography verifies that even for the raster scan pattern in SLE and the corresponding line heat source assumption, the PDAS follows the growth relation w ~ G -0.5 V -0.25 ( w = PDAS, G = temperature gradient and V = solidification velocity) developed for marginal stability under constrained growth. Models for the CET and OMT are experimentally validated, thereby providing powerful predictive capabilities for controlling the microstructure of SX alloys processed through SLE.

  7. 论二战时期日军对盟军高级战俘奉行政策之演变%Discuss the Evolution of Japanese Policy towards the Implementation of Advanced Allied War Prisoners During World War II

    Institute of Scientific and Technical Information of China (English)

    陈春萍

    2015-01-01

    二战时期,日军在进攻东南亚时,俘虏了大量美国、英国与荷兰的军政高级官员。这些高级战俘从1942年8月开始,从各自被关押地运送到台湾,最后又转押到中国东北。日军频繁变更盟军高级战俘的关押地,主要是太平洋战争局势的变化以及日本对待高级战俘政策变化的外在反映。本文即在探讨日本在各个时期对于高级战俘关押地的变化和待遇与日军太平洋战局的关系,以总结出二战时期日军对高级战俘们所奉行政策的演变过程。%During World War II, the Japanese army attacked Southeast Asia, captured a large number of Unit-ed States, Britain and the Netherlands military senior officials.From the beginning of August 1942, these senior prisoners were transported from their places to Taiwan, and finally transferred to northeast China, was the main re-flection of changes the situation in the Pacific War, and Japanese treatment of prisoners of war policy changes ad-vanced external.This article discussed the relationship between changes and treatment of the Japanese advanced prisoners of war in all period, and the situation of Japanese Pacific war during World War II to summarize the senior prisoner of War pursued the policy evolution.

  8. The SILCC (SImulating the LifeCycle of molecular Clouds) project - II. Dynamical evolution of the supernova-driven ISM and the launching of outflows

    Science.gov (United States)

    Girichidis, Philipp; Walch, Stefanie; Naab, Thorsten; Gatto, Andrea; Wünsch, Richard; Glover, Simon C. O.; Klessen, Ralf S.; Clark, Paul C.; Peters, Thomas; Derigs, Dominik; Baczynski, Christian

    2016-03-01

    The SILCC project (SImulating the Life-Cycle of molecular Clouds) aims at a more self-consistent understanding of the interstellar medium (ISM) on small scales and its link to galaxy evolution. We present three-dimensional (magneto)hydrodynamic simulations of the ISM in a vertically stratified box including self-gravity, an external potential due to the stellar component of the galactic disc, and stellar feedback in the form of an interstellar radiation field and supernovae (SNe). The cooling of the gas is based on a chemical network that follows the abundances of H+, H, H2, C+, and CO and takes shielding into account consistently. We vary the SN feedback by comparing different SN rates, clustering and different positioning, in particular SNe in density peaks and at random positions, which has a major impact on the dynamics. Only for random SN positions the energy is injected in sufficiently low-density environments to reduce energy losses and enhance the effective kinetic coupling of the SNe with the gas. This leads to more realistic velocity dispersions (σ _H I≈ 0.8σ _{300{-}8000 K}˜ 10-20 km s^{-1}, σ _H α ≈ 0.6σ _{8000-3× 10^5 K}˜ 20-30 km s^{-1}), and strong outflows with mass loading factors (ratio of outflow to star formation rate) of up to 10 even for solar neighbourhood conditions. Clustered SNe abet the onset of outflows compared to individual SNe but do not influence the net outflow rate. The outflows do not contain any molecular gas and are mainly composed of atomic hydrogen. The bulk of the outflowing mass is dense (ρ ˜ 10-25-10-24 g cm-3) and slow (v ˜ 20-40 km s-1) but there is a high-velocity tail of up to v ˜ 500 km s-1 with ρ ˜ 10-28-10-27 g cm-3.

  9. The Metal Abundances across Cosmic Time (MACT) Survey. II. Evolution of the Mass-metallicity Relation over 8 Billion Years, Using [OIII]4363AA-based Metallicities

    Science.gov (United States)

    Ly, Chun; Malkan, Matthew A.; Rigby, Jane R.; Nagao, Tohru

    2016-09-01

    We present the first results from MMT and Keck spectroscopy for a large sample of 0.1≤slant z≤slant 1 emission-line galaxies selected from our narrowband imaging in the Subaru Deep Field. We measured the weak [O iii] λ4363 emission line for 164 galaxies (66 with at least 3σ detections, and 98 with significant upper limits). The strength of this line is set by the electron temperature for the ionized gas. Because the gas temperature is regulated by the metal content, the gas-phase oxygen abundance is inversely correlated with [O iii] λ4363 line strength. Our temperature-based metallicity study is the first to span ≈ 8 Gyr of cosmic time and ≈ 3 dex in stellar mass for low-mass galaxies, {log}({M}\\star /{M}⊙ )≈ 6.0-9.0. Using extensive multi-wavelength photometry, we measure the evolution of the stellar mass-gas metallicity relation and its dependence on dust-corrected star formation rate (SFR). The latter is obtained from high signal-to-noise Balmer emission-line measurements. Our mass-metallicity relation is consistent with Andrews & Martini at z≤slant 0.3, and evolves toward lower abundances at a given stellar mass, {log}{({{O/H}})\\propto (1+z)}-{2.32-0.26+0.52}. We find that galaxies with lower metallicities have higher SFRs at a given stellar mass and redshift, although the scatter is large (≈ 0.3 dex) and the trend is weaker than seen in local studies. We also compare our mass-metallicity relation against predictions from high-resolution galaxy formation simulations, and find good agreement with models that adopt energy- and momentum-driven stellar feedback. We identified 16 extremely metal-poor galaxies with abundances of less than a tenth of solar; our most metal-poor galaxy at z≈ 0.84 is similar to I Zw 18.

  10. Organizing MHC Class II Presentation

    Directory of Open Access Journals (Sweden)

    David R Fooksman

    2014-04-01

    Full Text Available Major histocompatibility complex (MHC class II molecules are ligands for CD4+ T cells and are critical for initiating the adaptive immune response. This review is focused on what is currently known about MHC class II organization at the plasma membrane of antigen presenting cells and how this affects antigen presentation to T cells. The organization and diffusion of class II molecules have been measured by a variety of biochemical and microscopic techniques. Membrane lipids and other proteins have been implicated in MHC class II organization and function. However, when compared with the organization of MHC class I or TCR complexes, much less is known about MHC class II. Since clustering of T cell receptors occurs during activation, the organization of MHC molecules prior to recognition and during synapse formation may be critical for antigen presentation.

  11. Nonlinear Biochemical Signal Processing via Noise Propagation

    OpenAIRE

    Kim, Kyung Hyuk; Qian, Hong; Sauro, Herbert M.

    2013-01-01

    Single-cell studies often show significant phenotypic variability due to the stochastic nature of intra-cellular biochemical reactions. When the numbers of molecules, e.g., transcription factors and regulatory enzymes, are in low abundance, fluctuations in biochemical activities become significant and such "noise" can propagate through regulatory cascades in terms of biochemical reaction networks. Here we develop an intuitive, yet fully quantitative method for analyzing how noise affects cell...

  12. Biochemical Abnormalities in Batten's Syndrome

    DEFF Research Database (Denmark)

    Clausen, Jytte Lene; Nielsen, Gunnar Gissel; Jensen, Gunde Egeskov;

    1978-01-01

    The present data indicate that a group of ten patients with Batten's syndrome showed reduced activity of erythrocyte glutathione (GSH) peroxidase (Px) (glutathione: H2O2 oxidoreductase, EC 1.1.1.9.) using H2O2 as peroxide donor. Assay of erythrocyte GSHPx using H2O2, cumene hydroperoxide and t......-butyl hydroperoxide as donors also makes it possible biochemically to divide Batten's syndrome into two types: (1) one type with decreased values when H2O2 and cumene hydroperoxide are used, and (2) one type with increased values when t-butyl hydroperoxide is used. Furthermore an increased content of palmitic, oleic...... in whole blood. In normal human beings a connection was found between the erythrocyte selenium content and GSHPx activity assayed by cumene hydroperoxide as a peroxide donor....

  13. Biochemical nature of Russell Bodies.

    Science.gov (United States)

    Mossuto, Maria Francesca; Ami, Diletta; Anelli, Tiziana; Fagioli, Claudio; Doglia, Silvia Maria; Sitia, Roberto

    2015-07-30

    Professional secretory cells produce and release abundant proteins. Particularly in case of mutations and/or insufficient chaperoning, these can aggregate and become toxic within or amongst cells. Immunoglobulins (Ig) are no exception. In the extracellular space, certain Ig-L chains form fibrils causing systemic amyloidosis. On the other hand, Ig variants lacking the first constant domain condense in dilated cisternae of the early secretory compartment, called Russell Bodies (RB), frequently observed in plasma cell dyscrasias, autoimmune diseases and chronic infections. RB biogenesis can be recapitulated in lymphoid and non-lymphoid cells by expressing mutant Ig-μ, providing powerful models to investigate the pathophysiology of endoplasmic reticulum storage disorders. Here we analyze the aggregation propensity and the biochemical features of the intra- and extra-cellular Ig deposits in human cells, revealing β-aggregated features for RB.

  14. Consortia based production of biochemicals

    DEFF Research Database (Denmark)

    Ingemann Jensen, Sheila; Sukumara, Sumesh; Özdemir, Emre;

    -based modelling, and state-of-the art metabolic engineering tools to develop a consortium of cells capable of efficient valorization of synthetic hemicellulosic hydrolysate. Stable co-existence and effective covalorization was achieved through niche-differentiation, auxotrophy, and adaptive evolution. In another...... study, stable consortia based fermentation was achieved through niche partitioning, syntrophy (auxotrophy combined with removal of inhibitory side product), and CRISPRi mediated gene silencing. The achieved results demonstrate that consortium based approaches for valorizing complex biomass and waste...

  15. Computational optimization and biological evolution.

    Science.gov (United States)

    Goryanin, Igor

    2010-10-01

    Modelling and optimization principles become a key concept in many biological areas, especially in biochemistry. Definitions of objective function, fitness and co-evolution, although they differ between biology and mathematics, are similar in a general sense. Although successful in fitting models to experimental data, and some biochemical predictions, optimization and evolutionary computations should be developed further to make more accurate real-life predictions, and deal not only with one organism in isolation, but also with communities of symbiotic and competing organisms. One of the future goals will be to explain and predict evolution not only for organisms in shake flasks or fermenters, but for real competitive multispecies environments.

  16. 基于病毒进化改进NSGA-II算法的扩展黑启动多目标优化%Multi-objective extended black-start schemes optimization based on virus evolution improved NSGA-II algorithm

    Institute of Scientific and Technical Information of China (English)

    陈亮; 顾雪平; 贾京华

    2014-01-01

    To ensure the safe recovery of the black-start system and well synthesize the quick search and local search of multi-objective optimization method, an extended black-start multi-objective optimization method based on virus evolution improved NSGA-II algorithm considering power support and restoration security margin comprehensively is proposed. The optimization goals are designed to maximize the total weighted power generation output (MWh) of the black-start system, to maximize voltage stability margin and to maintain bus voltage at a satisfactory level. Biological virus mechanism and the infection-based operation are introduced into the chromosome of the fast and elitist non-dominated sorting genetic algorithm (NSGA-II). Horizontal infection of the virus is applied to improve local search capability in solution space and avoid the frontier degradation. The virus evolution improved NSGA-II algorithm and the Dijkstra algorithm are employed to solve the Pareto-optimal solutions of the extended black-start schemes. The effectiveness of the proposed method is validated by the optimization results on the New England 10-unit 39-bus power system and the southern power system of Hebei province. The method can provide decision-makers with greater choice of space and guarantee the extended initial black-start power system to recover more power generation output safely and reliably.%为了保证黑启动小系统的安全恢复和合理兼顾多目标优化方法的快速搜索与局部搜索,提出基于病毒进化改进NSGA-II算法的综合功率支持和恢复安全裕度的扩展黑启动方案多目标优化方法。以初期阶段内发电量加权和最大化、电压稳定裕度最大化和维持节点电压在满意水平为目标建立多目标优化模型。在快速非支配排序遗传算法(NSGA-II)的染色体中引入生物病毒机制和病毒感染操作,利用病毒的横向感染对解空间进行局部搜索,避免强化全局寻优时的前

  17. Engine of life and big bang of evolution: a personal perspective.

    Science.gov (United States)

    Barber, James

    2004-01-01

    Photosystem II (PS II) is the engine for essentially all life on our planet and its beginning 2.5 billion years ago was the 'big bang of evolution.' It produces reducing equivalents for making organic compounds on an enormous scale and at the same time provides us with an oxygenic atmosphere and protection against UV radiation (in the form of the ozone layer). In 1967, when I began my career in photosynthesis research, little was known about PS II. The Z-scheme had been formulated [Hill and Bendall (1960) Nature 186: 136-137] and Boardman and Anderson [(1964) Nature 203: 166-167] had isolated PS II as a discrete biochemical entity. PS II was known not only to be the source of oxygen but of variable chlorophyll fluorescence [Duysens and Sweers (1963) In: Studies on Microalgae and Photosynthetic Bacteria, pp. 353-372. University of Tokyo Press, Tokyo] and delayed chlorophyll fluorescence [Arnold and Davidson (1954) J Gen Physiol 37: 677-684]. P680 had just been discovered [Döring et al. (1967) Z Naturforsch 22b: 639-644]. No wonder the 'black box of PS II' was described at that time by Bessel Kok and George Cheniae [Current Topics in Bioenergetics 1: 1-47 (1966)] as the 'inner sanctum of photosynthesis.' What a change in our level of understanding of PS II since then! The contributions of many talented scientists have unraveled the mechanisms and structural basis of PS II function and we are now very close to revealing the molecular details of the remarkable and thermodynamically demanding reaction which it catalyzes, namely the splitting of water into its elemental constituents. It has been a privilege to be involved in this journey.

  18. Biochemical genetic markers in sugarcane.

    Science.gov (United States)

    Glaszmann, J C; Fautret, A; Noyer, J L; Feldmann, P; Lanaud, C

    1989-10-01

    Isozyme variation was used to identify biochemical markers of potential utility in sugarcane genetics and breeding. Electrophoretic polymorphism was surveyed for nine enzymes among 39 wild and noble sugarcane clones, belonging to the species most closely related to modern varieties. Up to 114 distinct bands showing presence versus absence type of variation were revealed and used for qualitative characterization of the materials. Multivariate analysis of the data isolated the Erianthus clone sampled and separated the Saccharum spontaneum clones from the S. robustum and S. officinarum clones; the latter two were not differentiated from one another. The analysis of self-progenies of a 2n=112 S. spontaneum and of a commercial variety showed examples of mono- and polyfactorial segregations. Within the progeny of the variety, co-segregation of two isozymes frequent in S. spontaneum led to them being assigned to a single chromosome initially contributed by a S. spontaneum donor. This illustrates how combined survey of ancestral species and segregation analysis in modern breeding materials should permit using the lack of interspecific cross-over to establish linkage groups in a sugarcane genome.

  19. Hunter syndrome in an 11-year old girl on enzyme replacement therapy with idursulfase: brain magnetic resonance imaging features and evolution.

    Science.gov (United States)

    Manara, Renzo; Rampazzo, Angelica; Cananzi, Mara; Salviati, Leonardo; Mardari, Rodica; Drigo, Paola; Tomanin, Rosella; Gasparotto, Nicoletta; Priante, Elena; Scarpa, Maurizio

    2010-12-01

    Mucopolysaccharidosis type II (MPS-II, Hunter disease) is a X-linked recessive disorder. Affected females are extremely rare, mostly due to skewed X chromosome inactivation. A few papers outline MPS-II brain magnetic resonance imaging (MRI) "gestalt" in males, but neuroradiological reports on females are still lacking. We present an 11-year-old girl affected by the severe form of MPS-II who was followed up over a time span of 8 years, focusing on clinical and brain MRI evolution. In the last 2.5 years, the patient has been treated with enzyme replacement therapy (ERT) with idursulfase (Elaprase™, Shire Human Genetic Therapies AB, Sweden). On brain and cervical MRI examination, abnormalities in our patient did not differ from those detected in male patients: J-shaped pituitary sella, enlargement of perivascular spaces, brain atrophy, mild T2-hyperintensity in the paratrigonal white matter, diffuse platyspondylia, and mild odontoid dysplasia with odontoid cup. Brain atrophy progressed despite ERT introduction, whereas perivascular space enlargement did not change significantly before and after ERT. Cognitive impairment worsened independently from the course of white matter abnormality. Despite a profound knowledge of genetic and biochemical aspects in MPS-II, neuroradiology is still poorly characterized, especially in female patients. Spinal and brain involvement and its natural course and evolution after ERT introduction still need to be clarified.

  20. Viral quasispecies evolution

    OpenAIRE

    Domingo, Esteban; Sheldon, Julie; Perales, Celia

    2012-01-01

    Summary: Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of...

  1. BIOCHEMICAL SCREENING OF DIABETIC NEPHROPATHY

    Directory of Open Access Journals (Sweden)

    Vivek

    2016-01-01

    Full Text Available Diabetic nephropathy is a clinical syndrome characterized by the following- Persistent albuminuria (>300mg/d or >200μg/min, that is confirmed on at least 2 occasions 3-6 months apart diabetic, progressive decline in the Glomerular Filtration Rate (GFR, elevated arterial blood pressure. The earliest biochemical criteria for the diagnosis of diabetic nephropathy is the presence of micro-albumin in the urine, which if left untreated will eventually lead to End-Stage Renal Disease (ESRD. Micro-albuminuria refers to the excretion of albumin in the urine at a rate that exceeds normal limits. The current study was conducted to establish the prevalence of micro-albuminuria in a sequential sample of diabetic patients attending hospital and OPD Clinic to determine its relationship with known and putative risk factors to identify micro- and normo-albuminuric patients in their sample for subsequent comparison in different age, sex, weight and creatinine clearance of the micro- and normo-albuminuric patients. This cross-sectional analytical study was conducted in one hundred patients at Saraswathi Institute of Medical Sciences, Anwarpur, Hapur, U. P. Patients having diabetes mellitus in different age group ranging from 30 to 70 years were selected. Data was analysed by SPSS software. Micro-albuminuria was observed in 35% in patients with type 2 diabetes mellitus. It was observed that 65% patients were free from any type of albuminuria. Also micro-albuminuria was present in 10% of the patients less than 50 yrs. of age, while 15% of the patients more than 50 yrs. of age were having micro-albuminuria. There was a statistically significant correlation of micro-albuminuria with duration of diabetes. Incidence of micro-albuminuria increases with age as well as increased duration of diabetes mellitus. Our study shows that only 5% patients developed macro-albuminuria. Glycosylated haemoglobin and fasting plasma glucose was significantly raised among all these

  2. Biochemical kinetics in changing volumes.

    Science.gov (United States)

    Pawłowski, Piotr H; Zielenkiewicz, Piotr

    2004-01-01

    The need of taking into account the change of compartment volume when developing chemical kinetics analysis inside the living cell is discussed. Literature models of a single enzymatic Michaelis-Menten process, glycolytic oscillations, and mitotic cyclin oscillations were tested with appropriate theoretical extension in the direction of volume modification allowance. Linear and exponential type of volume increase regimes were compared. Due to the above, in a growing cell damping of the amplitude, phase shift, and time pattern deformation of the metabolic rhythms considered were detected, depending on the volume change character. The performed computer simulations allow us to conclude that evolution of the cell volume can be an essential factor of the chemical kinetics in a growing cell. The phenomenon of additional metabolite oscillations caused by the periodic cell growth and division was theoretically predicted and mathematically described. Also, the hypothesis of the periodized state in the growing cell as the generalization of the steady-state was formulated.

  3. A Program on Biochemical and Biomedical Engineering.

    Science.gov (United States)

    San, Ka-Yiu; McIntire, Larry V.

    1989-01-01

    Presents an introduction to the Biochemical and Biomedical Engineering program at Rice University. Describes the development of the academic and enhancement programs, including organizational structure and research project titles. (YP)

  4. RNA polymerase II collision interrupts convergent transcription

    DEFF Research Database (Denmark)

    Hobson, David J; Wei, Wu; Steinmetz, Lars M

    2012-01-01

    Antisense noncoding transcripts, genes-within-genes, and convergent gene pairs are prevalent among eukaryotes. The existence of such transcription units raises the question of what happens when RNA polymerase II (RNAPII) molecules collide head-to-head. Here we use a combination of biochemical...

  5. A general method for modeling biochemical and biomedical response

    Science.gov (United States)

    Ortiz, Roberto; Lerd Ng, Jia; Hughes, Tyler; Abou Ghantous, Michel; Bouhali, Othmane; Arredouani, Abdelilah; Allen, Roland

    2012-10-01

    The impressive achievements of biomedical science have come mostly from experimental research with human subjects, animal models, and sophisticated laboratory techniques. Additionally, theoretical chemistry has been a major aid in designing new drugs. Here we introduce a method which is similar to others already well known in theoretical systems biology, but which specifically addresses biochemical changes as the human body responds to medical interventions. It is common in systems biology to use first-order differential equations to model the time evolution of various chemical concentrations, and we as physicists can make a significant impact through designing realistic models and then solving the resulting equations. Biomedical research is rapidly advancing, and the technique presented in this talk can be applied in arbitrarily large models containing tens, hundreds, or even thousands of interacting species, to determine what beneficial effects and side effects may result from pharmaceuticals or other medical interventions.

  6. Model building and model checking for biochemical processes.

    Science.gov (United States)

    Antoniotti, Marco; Policriti, Alberto; Ugel, Nadia; Mishra, Bud

    2003-01-01

    A central claim of computational systems biology is that, by drawing on mathematical approaches developed in the context of dynamic systems, kinetic analysis, computational theory and logic, it is possible to create powerful simulation, analysis, and reasoning tools for working biologists to decipher existing data, devise new experiments, and ultimately to understand functional properties of genomes, proteomes, cells, organs, and organisms. In this article, a novel computational tool is described that achieves many of the goals of this new discipline. The novelty of this system involves an automaton-based semantics of the temporal evolution of complex biochemical reactions starting from the representation given as a set of differential equations. The related tools also provide ability to qualitatively reason about the systems using a propositional temporal logic that can express an ordered sequence of events succinctly and unambiguously. The implementation of mathematical and computational models in the Simpathica and XSSYS systems is described briefly. Several example applications of these systems to cellular and biochemical processes are presented: the two most prominent are Leibler et al.'s repressilator (an artificial synthesized oscillatory network), and Curto- Voit-Sorribas-Cascante's purine metabolism reaction model.

  7. Schumpeter's Evolution

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    reworking of his basic theory of economic evolution in Development from 1934, and this reworking was continued in Cycles from 1939. Here Schumpeter also tried to handle the statistical and historical evidence on the waveform evolution of the capitalist economy. Capitalism from 1942 modified the model...

  8. 40 CFR 158.2010 - Biochemical pesticides data requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Biochemical pesticides data...) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical Pesticides § 158.2010 Biochemical pesticides... required to support registration of biochemical pesticides. Sections 158.2080 through 158.2084 identify...

  9. Nonlinear biochemical signal processing via noise propagation.

    Science.gov (United States)

    Kim, Kyung Hyuk; Qian, Hong; Sauro, Herbert M

    2013-10-14

    Single-cell studies often show significant phenotypic variability due to the stochastic nature of intra-cellular biochemical reactions. When the numbers of molecules, e.g., transcription factors and regulatory enzymes, are in low abundance, fluctuations in biochemical activities become significant and such "noise" can propagate through regulatory cascades in terms of biochemical reaction networks. Here we develop an intuitive, yet fully quantitative method for analyzing how noise affects cellular phenotypes based on identifying a system's nonlinearities and noise propagations. We observe that such noise can simultaneously enhance sensitivities in one behavioral region while reducing sensitivities in another. Employing this novel phenomenon we designed three biochemical signal processing modules: (a) A gene regulatory network that acts as a concentration detector with both enhanced amplitude and sensitivity. (b) A non-cooperative positive feedback system, with a graded dose-response in the deterministic case, that serves as a bistable switch due to noise-induced ultra-sensitivity. (c) A noise-induced linear amplifier for gene regulation that requires no feedback. The methods developed in the present work allow one to understand and engineer nonlinear biochemical signal processors based on fluctuation-induced phenotypes.

  10. Rare genetic diseases with human lean and/or starvation phenotype open new avenues for obesity and type II diabetes treatment.

    Science.gov (United States)

    Harosh, Itzik

    2014-01-01

    Treatments of obesity and type II diabetes target often gene functions involved in appetite-satiety, fat and carbohydrate metabolism or thermogenesis. None of these, have provided efficient drug therapy due to a large number of genes involved in weight and energy management, the redundancy of biochemical pathways and the environmental factors. Here I discuss a new approach based on studies of genes/proteins that are associated with human "lean or starvation" phenotype that became very rare in the course of evolution. This approach has led to the identification of the congenital enteropeptidase deficiency gene and the Anderson's Disease gene as a potential targets for obesity and type II diabetes treatment. The advantages of these targets are: 1) they are expressed exclusively in the intestine; 2) they are peripheral targets as opposed to systemic targets; 3) they are not redundant targets. These targets open new hopes for the development of novel drugs for the treatment of common metabolic syndrome.

  11. Chemical evolution and the origin of life

    Science.gov (United States)

    Oro, J.

    1983-01-01

    A review is presented of recent advances made in the understanding of the formation of carbon compounds in the universe and the occurrence of processes of chemical evolution. Topics discussed include the principle of evolutionary continuity, evolution as a fundamental principle of the physical universe, the nuclear synthesis of biogenic elements, organic cosmochemistry and interstellar molecules, the solar nebula and the solar system in chemical evolution, the giant planets and Titan in chemical evolution, and comets and their interaction with the earth. Also examined are carbonaceous chondrites, environment of the primitive earth, energy sources available on the primitive earth, the synthesis of biochemical monomers and oligomers, the abiotic transcription of nucleotides, unified prebiotic and enzymatic mechanisms, phospholipids and membranes, and protobiological evolution.

  12. Silencing, positive selection and parallel evolution: busy history of primate cytochromes C.

    Directory of Open Access Journals (Sweden)

    Denis Pierron

    Full Text Available Cytochrome c (cyt c participates in two crucial cellular processes, energy production and apoptosis, and unsurprisingly is a highly conserved protein. However, previous studies have reported for the primate lineage (i loss of the paralogous testis isoform, (ii an acceleration and then a deceleration of the amino acid replacement rate of the cyt c somatic isoform, and (iii atypical biochemical behavior of human cyt c. To gain insight into the cause of these major evolutionary events, we have retraced the history of cyt c loci among primates. For testis cyt c, all primate sequences examined carry the same nonsense mutation, which suggests that silencing occurred before the primates diversified. For somatic cyt c, maximum parsimony, maximum likelihood, and Bayesian phylogenetic analyses yielded the same tree topology. The evolutionary analyses show that a fast accumulation of non-synonymous mutations (suggesting positive selection occurred specifically on the anthropoid lineage root and then continued in parallel on the early catarrhini and platyrrhini stems. Analysis of evolutionary changes using the 3D structure suggests they are focused on the respiratory chain rather than on apoptosis or other cyt c functions. In agreement with previous biochemical studies, our results suggest that silencing of the cyt c testis isoform could be linked with the decrease of primate reproduction rate. Finally, the evolution of cyt c in the two sister anthropoid groups leads us to propose that somatic cyt c evolution may be related both to COX evolution and to the convergent brain and body mass enlargement in these two anthropoid clades.

  13. eQuilibrator--the biochemical thermodynamics calculator.

    Science.gov (United States)

    Flamholz, Avi; Noor, Elad; Bar-Even, Arren; Milo, Ron

    2012-01-01

    The laws of thermodynamics constrain the action of biochemical systems. However, thermodynamic data on biochemical compounds can be difficult to find and is cumbersome to perform calculations with manually. Even simple thermodynamic questions like 'how much Gibbs energy is released by ATP hydrolysis at pH 5?' are complicated excessively by the search for accurate data. To address this problem, eQuilibrator couples a comprehensive and accurate database of thermodynamic properties of biochemical compounds and reactions with a simple and powerful online search and calculation interface. The web interface to eQuilibrator (http://equilibrator.weizmann.ac.il) enables easy calculation of Gibbs energies of compounds and reactions given arbitrary pH, ionic strength and metabolite concentrations. The eQuilibrator code is open-source and all thermodynamic source data are freely downloadable in standard formats. Here we describe the database characteristics and implementation and demonstrate its use.

  14. Advances in Biochemical Indices of Zooplankton Production.

    Science.gov (United States)

    Yebra, L; Kobari, T; Sastri, A R; Gusmão, F; Hernández-León, S

    2017-01-01

    Several new approaches for measuring zooplankton growth and production rates have been developed since the publication of the ICES (International Council for the Exploration of the Sea) Zooplankton Methodology Manual (Harris et al., 2000). In this review, we summarize the advances in biochemical methods made in recent years. Our approach explores the rationale behind each method, the design of calibration experiments, the advantages and limitations of each method and their suitability as proxies for in situ rates of zooplankton community growth and production. We also provide detailed protocols for the existing methods and information relevant to scientists wanting to apply, calibrate or develop these biochemical indices for zooplankton production.

  15. Stellar evolution

    CERN Document Server

    Meadows, A J

    2013-01-01

    Stellar Evolution, Second Edition covers the significant advances in the understanding of birth, life, and death of stars.This book is divided into nine chapters and begins with a description of the characteristics of stars according to their brightness, distance, size, mass, age, and chemical composition. The next chapters deal with the families, structure, and birth of stars. These topics are followed by discussions of the chemical composition and the evolution of main-sequence stars. A chapter focuses on the unique features of the sun as a star, including its evolution, magnetic fields, act

  16. Single molecule studies of RNA polymerase II transcription in vitro.

    Science.gov (United States)

    Horn, Abigail E; Goodrich, James A; Kugel, Jennifer F

    2014-01-01

    Eukaryotic mRNA transcription by RNA polymerase II (RNAP II) is the first step in gene expression and a key determinant of cellular regulation. Elucidating the mechanism by which RNAP II synthesizes RNA is therefore vital to determining how genes are controlled under diverse biological conditions. Significant advances in understanding RNAP II transcription have been achieved using classical biochemical and structural techniques; however, aspects of the transcription mechanism cannot be assessed using these approaches. The application of single-molecule techniques to study RNAP II transcription has provided new insight only obtainable by studying molecules in this complex system one at a time.

  17. Characterizing multistationarity regimes in biochemical reaction networks.

    Directory of Open Access Journals (Sweden)

    Irene Otero-Muras

    Full Text Available Switch like responses appear as common strategies in the regulation of cellular systems. Here we present a method to characterize bistable regimes in biochemical reaction networks that can be of use to both direct and reverse engineering of biological switches. In the design of a synthetic biological switch, it is important to study the capability for bistability of the underlying biochemical network structure. Chemical Reaction Network Theory (CRNT may help at this level to decide whether a given network has the capacity for multiple positive equilibria, based on their structural properties. However, in order to build a working switch, we also need to ensure that the bistability property is robust, by studying the conditions leading to the existence of two different steady states. In the reverse engineering of biological switches, knowledge collected about the bistable regimes of the underlying potential model structures can contribute at the model identification stage to a drastic reduction of the feasible region in the parameter space of search. In this work, we make use and extend previous results of the CRNT, aiming not only to discriminate whether a biochemical reaction network can exhibit multiple steady states, but also to determine the regions within the whole space of parameters capable of producing multistationarity. To that purpose we present and justify a condition on the parameters of biochemical networks for the appearance of multistationarity, and propose an efficient and reliable computational method to check its satisfaction through the parameter space.

  18. Biochemical Applications in the Analytical Chemistry Lab

    Science.gov (United States)

    Strong, Cynthia; Ruttencutter, Jeffrey

    2004-01-01

    An HPLC and a UV-visible spectrophotometer are identified as instruments that helps to incorporate more biologically-relevant experiments into the course, in order to increase the students understanding of selected biochemistry topics and enhances their ability to apply an analytical approach to biochemical problems. The experiment teaches…

  19. 2009 Biochemical Conversion Platform Review Report

    Energy Technology Data Exchange (ETDEWEB)

    Ferrell, John [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2009-12-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the U.S. Department of Energy Biomass Program’s Biochemical Conversion platform review meeting, held on April 14-16, 2009, at the Sheraton Denver Downtown, Denver, Colorado.

  20. Biochemical and Anatomical Characteristics of Dolphin Muscles.

    Science.gov (United States)

    1984-01-01

    hexosamines. These data suggest a biochemical difference in dolphin and rat tendon, which may be of relevance to the unique myofascial design of the...glycosaminoglycan (GAG) chains . The GAG chain is a polymer of repeating disaccharides, each disaccharide containing a hexosamine and either a

  1. Biochemical Thermodynamics under near Physiological Conditions

    Science.gov (United States)

    Mendez, Eduardo

    2008-01-01

    The recommendations for nomenclature and tables in Biochemical Thermodynamics approved by IUBMB and IUPAC in 1994 can be easily introduced after the chemical thermodynamic formalism. Substitution of the usual standard thermodynamic properties by the transformed ones in the thermodynamic equations, and the use of appropriate thermodynamic tables…

  2. Evolution of seismic monitoring systems of nuclear power plants. Improvements and practical applications; Evolucion de los sistemas de vigilancia sismica de las II.NN. Mejoras introducidas y aplicaciones practicas

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Cabanero, J. G.; Jimenez Juan, A.

    2010-07-01

    The II. NN. Spanish have a seismic monitoring system (SVS) covering two objectives relevant to nuclear security: determining earthquake leave operation, and specific data that serve to limit or reduce the uncertainties associated with the seismic source, the site and design. Since its construction, the major SVS II. NN. have been equipped with the best time of seismic instrumentation to record earthquakes strong, but with limited resolution for recording in the free field and appropriately moderate earthquakes.

  3. Container II

    OpenAIRE

    Baraklianou, Stella

    2016-01-01

    Container II, self-published artists book.\\ud The book was made on the occasion of the artists residency at the Banff Arts Centre, in Alberta Canada. \\ud \\ud Container II is a performative piece, it worked in conjunction with the photographic installation "Stage Set: Cool Tone" . (photographic floor installation, Reclaimed wood, frames, 130x145cm, 2016) \\ud The photographic installation was also part of the artists residency titled "New Materiality" at the Banff Arts Centre. \\ud \\ud Limited E...

  4. Kombucha tea fermentation: Microbial and biochemical dynamics.

    Science.gov (United States)

    Chakravorty, Somnath; Bhattacharya, Semantee; Chatzinotas, Antonis; Chakraborty, Writachit; Bhattacharya, Debanjana; Gachhui, Ratan

    2016-03-02

    Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties will change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher D-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentations. Our

  5. Galaxy Evolution

    Science.gov (United States)

    Matteucci, F.

    We review both the observational and theoretical constraints on the evolution of the abundances of heavy elements in gas and stars in galaxies of different morphological type. The main aim of this work is to document the progress made in our understanding of the physical processes regulating the chemical evolution of galaxies during the last sixteen years since the appearance, in this same journal (volume 5, page 287), of the well know review of Beatrice Tinsley, to whom I dedicate this paper. Finally, this article is addressed particularly to readers who do not actively work on galactic chemical evolution and who might use it as a cook book where the main ingredients are discussed and useful recipes can be found.

  6. Tyrosine aminotransferase: biochemical and structural properties and molecular dynamics simulations.

    Science.gov (United States)

    Mehere, Prajwalini; Han, Qian; Lemkul, Justin A; Vavricka, Christopher J; Robinson, Howard; Bevan, David R; Li, Jianyong

    2010-11-01

    Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using α-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 Å resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structures of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.

  7. [Renal lithiasis. Biochemical changes in the follow-up].

    Science.gov (United States)

    Spivacow, Francisco R; del Valle, Elisa E; Zancheta, José R

    2006-01-01

    With the aim of assessing if biochemical changes occur in the follow up of patients with renal lithiasis, 237 patients were studied (115 women and 122 men, mean age 39 +/- 8 and 42 +/- 7 years, respectively) and controlled during 27.3 +/- 19.3 months. All of them had previously undergone metabolic evaluations at baseline and one or more than one control studies afterwards. Patients with a diagnosis of sponge kidney, renal tubular acidosis, primary hyperparathyroidism, anatomical malformations of the urinary tract, or urinary infections were not included. Two populations were identified: those who presented changes in the baseline diagnosis (139 patients, Group I) and those who presented no changes (98 patients, Group II). In these groups, no differences were observed in baseline metabolic diagnoses or in the follow-up period. Hypocitraturia was the additional diagnosis most frequently observed (43.1%), followed by Idiopatic hypercalciuria (20.8%) and abnormalities of uric acid (16.5%). In the group of 110 patients followed up for more than 3 years, 37 patients recurred (33%). Among the latter, 25 (23%) changed the baseline metabolic diagnosis vs. 12 (11%) that maintained the same diagnosis (p < 0.002). Changes in metabolic disorders were frequently observed in the follow up of patients with nephrolithiasis. These changes are not necessarily associated with the diet indicated or drug treatment. Hypocitraturia was the additional metabolic disorder most frequently found. In general, there is a higher recurrence rate in those patients who present changes in their biochemical parameters and undergo no treatment.

  8. Tyrosine Aminotransferase: Biochemical and Structural Properties and Molecular Dynamics Simulations

    Energy Technology Data Exchange (ETDEWEB)

    P Mehere; Q Han; J Lemkul; C Vavricka; H Robinson; D Bevan; J Li

    2011-12-31

    Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using {alpha}-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 {angstrom} resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structures of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.

  9. Tyrosine aminotransferase: biochemical and structural properties and molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Mehere, P.; Robinson, H.; Han, Q.; Lemkul, J. A.; Vavricka, C. J.; Bevan, D. R.; Li, J.

    2010-11-01

    Tyrosine aminotransferase (TAT) catalyzes the transamination of tyrosine and other aromatic amino acids. The enzyme is thought to play a role in tyrosinemia type II, hepatitis and hepatic carcinoma recovery. The objective of this study is to investigate its biochemical and structural characteristics and substrate specificity in order to provide insight regarding its involvement in these diseases. Mouse TAT (mTAT) was cloned from a mouse cDNA library, and its recombinant protein was produced using Escherichia coli cells and purified using various chromatographic techniques. The recombinant mTAT is able to catalyze the transamination of tyrosine using {alpha}-ketoglutaric acid as an amino group acceptor at neutral pH. The enzyme also can use glutamate and phenylalanine as amino group donors and p-hydroxy-phenylpyruvate, phenylpyruvate and alpha-ketocaproic acid as amino group acceptors. Through macromolecular crystallography we have determined the mTAT crystal structure at 2.9 {angstrom} resolution. The crystal structure revealed the interaction between the pyridoxal-5'-phosphate cofactor and the enzyme, as well as the formation of a disulphide bond. The detection of disulphide bond provides some rational explanation regarding previously observed TAT inactivation under oxidative conditions and reactivation of the inactive TAT in the presence of a reducing agent. Molecular dynamics simulations using the crystal structures of Trypanosoma cruzi TAT and human TAT provided further insight regarding the substrate-enzyme interactions and substrate specificity. The biochemical and structural properties of TAT and the binding of its cofactor and the substrate may help in elucidation of the mechanism of TAT inhibition and activation.

  10. Achilles tendinosis: Changes in biochemical composition and collagen turnover rate

    NARCIS (Netherlands)

    Mos, M. de; El, B. van; Groot, J. de; Jahr, H.; Schie, H.T.M. van; Arkel, E.R. van; Tol, H.; Heijboer, R.; Osch, G.J.V.M. van; Verhaar, J.A.N.

    2007-01-01

    Background: Understanding biochemical and structural changes of the extracellular matrix in Achilles tendinosis might be important for developing mechanism-based therapies. Hypothesis: In Achilles tendinosis, changes occur in biochemical composition and collagen turnover rate. Study Design: Descript

  11. Achilles tendinosis - Changes in biochemical composition and collagen turnover rate

    NARCIS (Netherlands)

    de Mos, Marieke; van El, Benno; DeGroot, Jeroen; Jahr, Holger; van Schie, Hans T. M.; van Arkel, Ewoud R.; Tol, Hans; Heijboer, Rien; van Osch, Gerjo J. V. M.; Verhaar, Jan A. N.

    2007-01-01

    Background: Understanding biochemical and structural changes of the extracellular matrix in Achilles tendinosis might be important for developing mechanism-based therapies. Hypothesis: In Achilles tendinosis, changes occur in biochemical composition and collagen turnover rate. Study Design: Descript

  12. Advancement in biochemical assays in andrology

    Institute of Scientific and Technical Information of China (English)

    Wolf-BernhardSchill; RaftHenkel

    1999-01-01

    Determination of maikers of sperm function, accessory sex gland secretion and silent male genital tract inflammation is of considerable diagnostic value in the evaluation of male infertility. The introduction of biochemical tests into the analysis of male factor has the advantage that standardized assays with a coefficient of variafion characteristic of clinical chemistry are performed, in contrast to biological test systems with a large variability .Biochemical parameters may be used in clinical practice to evaluate the sperm fertitizing capacity (acrosin, aniline blue,ROS), to characterize male accessory sex gland secretinns (fructose, a-glucosidase, PSA), and to identify men with silent genital tract inflammation (elastase, C'3 complement component, coeruloplasmin, IgA, IgG, ROS). (As/an J Androl 1999 Jun; 1: 45-51)

  13. Optical Slot-Waveguide Based Biochemical Sensors

    Directory of Open Access Journals (Sweden)

    Carlos Angulo Barrios

    2009-06-01

    Full Text Available Slot-waveguides allow light to be guided and strongly confined inside a nanometer-scale region of low refractive index. Thus stronger light-analyte interaction can be obtained as compared to that achievable by a conventional waveguide, in which the propagating beam is confined to the high-refractive-index core of the waveguide. In addition, slot-waveguides can be fabricated by employing CMOS compatible materials and technology, enabling miniaturization, integration with electronic, photonic and fluidic components in a chip, and mass production. These advantages have made the use of slot-waveguides for highly sensitive biochemical optical integrated sensors an emerging field. In this paper, recent achievements in slot-waveguide based biochemical sensing will be reviewed. These include slot-waveguide ring resonator based refractometric label-free biosensors, label-based optical sensing, and nano-opto-mechanical sensors.

  14. Biochemical changes in blood under Cr6+

    OpenAIRE

    Kuzenko E.V.; Romaniuk A.M.; Butko H.Yu.; Logvinova H.V.

    2013-01-01

    Background. For the manufacture of dentures many different alloys containing chromium are used. Interaction with oral fluid, organic acids and food, results in formation of Cr3+, Cr6+ ions, but their influence on the whole organism is poorly investigated. Objective. To analyze the biochemical changes in blood plasma during the influence of Cr6+ ions. Methods. 15 animals of experimental group were receiving drinking water with potassium dichromate in a dose of 0,2 mol/l. Rats of control group ...

  15. Evolution of nutritional, hematologic and biochemical changes in obese women during 8 weeks after Roux-en-Y gastric bypasss Evolución de los cambios nutricionales, hematológicos y bioquímicos en mujeres obesas durante 8 semanas después de bypass gástrico en Y de Roux

    Directory of Open Access Journals (Sweden)

    V. Custódio Afonso Rocha

    2012-08-01

    Full Text Available Obesity is a chronic disease of multifactorial origin and currently is a serious public health problem. The treatment of morbid obesity can be effectively done by bariatric surgery. The present study aimed to evaluate the influence of changes in food intake on body composition and some hematologic and biochemical variables in the period of eight weeks after Roux-en-Y gastric bypass (RYGB. The study included 22 women submitted to RYGB. We evaluated anthropometric, nutritional, hematologic and biochemical variables before and 14, 28, 42 and 56 days after surgery. The patients showed a decrease in caloric intake and hence macro- and micronutrients, with significant loss of weight and decrease in body mass index (BMI. Decreases in body weight and BMI were associated with reduced blood levels of total cholesterol, VLDL-C, LDL-C, triglycerides and glucose with time after surgery. The decrease in caloric intake was also associated with decreased intake of protein, iron and calcium, with a decline in hemoglobin, hematocrit and red blood count, and RDW increased after surgery.La obesidad es una enfermedad crónica de origen multifactorial y actualmente es un problema grave de salud pública. El tratamiento de la obesidad mórbida puede hacerse eficazmente por la cirugía bariátrica. El presente estudio tuvo como objetivo evaluar la influencia de los cambios en la ingesta de alimentos sobre la composición corporal y algunas variables hematológicas y bioquímicas en el plazo de ocho semanas después de bypass gástrico en Y de Roux (BGYR. El estudio incluyó a 22 mujeres sometidas a BGYR. Se evaluaron los parámetros antropométricos, nutricionales, bioquímicos antes de la operación y el 14º, 28º, 42º e 56º día después de la cirugía. Los pacientes mostraron cambios significativos en la ingesta de alimentos, con una disminución en la ingesta de calorías y por lo tanto, los macro y micronutrientes, con una pérdida significativa de peso y

  16. Electronic modulation of biochemical signal generation

    Science.gov (United States)

    Gordonov, Tanya; Kim, Eunkyoung; Cheng, Yi; Ben-Yoav, Hadar; Ghodssi, Reza; Rubloff, Gary; Yin, Jun-Jie; Payne, Gregory F.; Bentley, William E.

    2014-08-01

    Microelectronic devices that contain biological components are typically used to interrogate biology rather than control biological function. Patterned assemblies of proteins and cells have, however, been used for in vitro metabolic engineering, where coordinated biochemical pathways allow cell metabolism to be characterized and potentially controlled on a chip. Such devices form part of technologies that attempt to recreate animal and human physiological functions on a chip and could be used to revolutionize drug development. These ambitious goals will, however, require new biofabrication methodologies that help connect microelectronics and biological systems and yield new approaches to device assembly and communication. Here, we report the electrically mediated assembly, interrogation and control of a multi-domain fusion protein that produces a bacterial signalling molecule. The biological system can be electrically tuned using a natural redox molecule, and its biochemical response is shown to provide the signalling cues to drive bacterial population behaviour. We show that the biochemical output of the system correlates with the electrical input charge, which suggests that electrical inputs could be used to control complex on-chip biological processes.

  17. Haematological and biochemical analysis in canine enteritis

    Directory of Open Access Journals (Sweden)

    Abid Ali Bhat

    Full Text Available Aim: The present investigation screened eighteen clinical cases of canine enteritis for haematological and biochemical analyses. Materials and Methods: Eighteen dogs suffering from enteritis were selected and detailed clinical manifestations were noted. Hematological and biochemical parameters were estimated by using various kits. Blood was also collected from twelve healthy dogs for establishing control values and data obtained were subjected to statistical analysis. Results: The affected dogs showed anorexia, diarrhoea, depression, varying degree of dehydration and tachycardia. There were significant changes in packed cell volume, neutrophils, lymphocytes and mean corpuscular haemoglobin concentration. Biochemical investigation revealed significant decrease in plasma glucose, total plasma protein, albumin and albumin:globulin ratio (A:G ratio. The level of potassium and chloride was markedly decreased. Significant increase in alanine aminotransferase (ALT and blood urea nitrogen (BUN was observed. Conclusion: Packed Cell Volume (PCV and Total Erythrocyte Count (TEC remained almost similar between healthy dogs and dogs affected with diarrhoea. Mean Total Leukocyte Count (TLC value was significantly higher as compared to the control group. Hypoglycemia, hypoproteinemia, hypokalemia, hypochloremia and increase in blood urea nitrogen was observed in dogs suffering from enteritis. [Vet World 2013; 6(7.000: 380-383

  18. Explorations into Chemical Reactions and Biochemical Pathways.

    Science.gov (United States)

    Gasteiger, Johann

    2016-12-01

    A brief overview of the work in the research group of the present author on extracting knowledge from chemical reaction data is presented. Methods have been developed to calculate physicochemical effects at the reaction site. It is shown that these physicochemical effects can quite favourably be used to derive equations for the calculation of data on gas phase reactions and on reactions in solution such as aqueous acidity of alcohols or carboxylic acids or the hydrolysis of amides. Furthermore, it is shown that these physicochemical effects are quite effective for assigning reactions into reaction classes that correspond to chemical knowledge. Biochemical reactions constitute a particularly interesting and challenging task for increasing our understanding of living species. The BioPath.Database is a rich source of information on biochemical reactions and has been used for a variety of applications of chemical, biological, or medicinal interests. Thus, it was shown that biochemical reactions can be assigned by the physicochemical effects into classes that correspond to the classification of enzymes by the EC numbers. Furthermore, 3D models of reaction intermediates can be used for searching for novel enzyme inhibitors. It was shown in a combined application of chemoinformatics and bioinformatics that essential pathways of diseases can be uncovered. Furthermore, a study showed that bacterial flavor-forming pathways can be discovered.

  19. [Basic biochemical processes in glaucoma progression].

    Science.gov (United States)

    von Thun und Hohenstein-Blaul, N; Kunst, S; Pfeiffer, N; Grus, F H

    2015-05-01

    The term glaucoma summarizes a group of eye diseases that are accompanied by impairments of the optic nerve and related visual field deficits. An early diagnosis of glaucoma is currently not possible due to a lack of diagnostic tests; therefore, in most cases the disease is diagnosed many years after onset, which prevents an early therapy. The known risk factors for the development and progression of glaucomatous optic neuropathy comprise elevated intraocular pressure and a broad range of pressure fluctuations as well as lipometabolic disorders, genetic factor and diabetes. The consequences include the induction of anti-inflammatory proteins, elevated levels of oxidative stress and the destruction of retinal ganglion cells. Changes in the autoantibody repertoire have also been observed in the course of the disease. Basic ophthalmological research therefore focuses on the investigation of basic biochemical processes in the course of the disease. A better understanding of physiological and biochemical events is sought in order to develop new and more sensitive diagnostic options and to allow more targeted therapeutic measures. The understanding of biochemical processes allows a better insight into glaucoma progression to be gained, which will lead to improvements in diagnosis and therapy.

  20. Representing Evolution

    DEFF Research Database (Denmark)

    Hedin, Gry

    2012-01-01

    . This article discusses Willumsen's etching in the context of evolutionary theory, arguing that Willumsen is a rare example of an artist who not only let the theory of evolution fuel his artistic imagination, but also concerned himself with a core issue of the theory, namely to what extent it could be applied...

  1. The Use of Item Analysis for Improvement of Biochemical Teaching

    Science.gov (United States)

    Nagata, Ryoichi

    2004-01-01

    Item analysis was used to find out which biochemical explanations need to be improved in biochemical teaching, not which items are to be discarded, improved, or reusable in biochemical examinations. The analysis revealed the basic facts of which less able students had more misunderstanding than able students. Identifying these basic facts helps…

  2. Changes in serum mineral concentrations, biochemical and hematological parameters in horses with pica.

    Science.gov (United States)

    Aytekin, Ismail; Onmaz, Ali Cesur; Aypak, Serap Unubol; Gunes, Vehbi; Kucuk, Osman

    2011-03-01

    The aim of this study was to compare hematological, some biochemical parameters, and serum trace element concentrations in horses with or without pica. Fifteen horses with pica (group I) and another 15 healthy horses without pica (group II) were used. The hematological parameters were not changed between the two groups. In group I, hemoglobin values were lower than those of group II. However, the difference in hemoglobin values between the two groups was not significant (P > 0.05). Serum iron and copper concentrations and the copper/zinc ratio were lower in group I than those of group II (P  0.05). It was concluded that serum iron and copper deficiency may play an important role for the etiology of pica in horses. Prophylactic use of iron and copper supplements in horses may be beneficial to prevent pica.

  3. TBscore II

    DEFF Research Database (Denmark)

    Rudolf, Frauke; Lemvik, Grethe; Abate, Ebba;

    2013-01-01

    Abstract Background: The TBscore, based on simple signs and symptoms, was introduced to predict unsuccessful outcome in tuberculosis patients on treatment. A recent inter-observer variation study showed profound variation in some variables. Further, some variables depend on a physician assessing...... them, making the score less applicable. The aim of the present study was to simplify the TBscore. Methods: Inter-observer variation assessment and exploratory factor analysis were combined to develop a simplified score, the TBscore II. To validate TBscore II we assessed the association between start...

  4. Balanced biochemical reactions: a new approach to unify chemical and biochemical thermodynamics.

    Directory of Open Access Journals (Sweden)

    Antonio Sabatini

    Full Text Available A novel procedure is presented which, by balancing elements and electric charge of biochemical reactions which occur at constant pH and pMg, allows assessing the thermodynamics properties of reaction Δ(rG'⁰, Δ(rH'⁰, Δ(rS'⁰ and the change in binding of hydrogen and magnesium ions of these reactions. This procedure of general applicability avoids the complex calculations required by the use of the Legendre transformed thermodynamic properties of formation Δ(fG'⁰, Δ(fH'⁰ and Δ(fS'⁰ hitherto considered an obligatory prerequisite to deal with the thermodynamics of biochemical reactions. As a consequence, the term "conditional" is proposed in substitution of "Legendre transformed" to indicate these thermodynamics properties. It is also shown that the thermodynamic potential G is fully adequate to give a criterion of spontaneous chemical change for all biochemical reactions and then that the use of the Legendre transformed G' is unnecessary. The procedure proposed can be applied to any biochemical reaction, making possible to re-unify the two worlds of chemical and biochemical thermodynamics, which so far have been treated separately.

  5. Vitalism as an Epistemological Obstacle to Biochemical Knowledge

    Directory of Open Access Journals (Sweden)

    R.V. Almeida

    2010-05-01

    Full Text Available This work resulted from the study of Gaston Bachelard’s epistemology in the Logic and Philosophy of Science discipline, Biochemistry Graduate Program, UFRJ, which lead to discussions of epistemological obstacles on biochemical knowledge construction. The aim was to identify barriers to scientific knowledge development in the praxis of graduate students of biochemistry and correlated areas, emphasizing the vitalist (animist and teleological (unitary and pragmatic obstacles conceptions. In order to verify whether students, which never attended classes in epistemology, agree or are able to identify the vitalist conception, a questionnaire containing also selected excerpts of scientific papers in high impact factor journals was delivered to thirty graduating students from different courses at UFRJ and other Brazilian universities. Not only those conceptions were accepted or were not recognized, but it was also possible to observe a vitalist approach in the answers. We could also perceive a pragmatic and teleological vision of the evolution process, expressed in apologies of immanent purposes in organisms adaptations. Considering these facts, it is clear the necessity to emphasize the material, non-teleological character of biochemistry/biology, especially in disciplines offered in under-graduate courses.

  6. Biochemical Markers for Assessing Aquatic Contamination

    Directory of Open Access Journals (Sweden)

    Zdeňka Svobodová

    2007-11-01

    Full Text Available Biochemical markers, specifically enzymes of the first phase of xenobiotic transformation - cytochrome P450 and ethoxyresorufin-O-deethylase (EROD - were used to determine the quantities of persistent organic pollutants (POPs in fish muscle (PCB, HCB, HCH, OCS, DDT. Eight rivers were monitored (Orlice, Chrudimka, Cidlina, Jizera, Vltava, Ohře and Bílina; and the River Blanice was used as a control. The indicator species selected was the chub (Leuciscus cephalus L.. There were no significant differences in cytochrome P450 content between the locations monitored. The highest concentration of cytochrome P450 in fish liver was in the Vltava (0.241 nmol mg-1 protein, and the lowest was in the Orlice (0.120 nmol mg-1 protein. Analysis of EROD activity showed a significant difference between the Blanice and the Vltava (P< 0.05, and also between the Orlice and the Vltava (P< 0.01, the Orlice and the Bílina (P< 0.01, and the Orlice and the Ohře (P< 0.05. The highest EROD activity in fish liver was in the Vltava (576.4 pmol min-1 mg-1 protein, and the lowest was in the Orlice (63.05 pmol min-1 mg-1 protein. In individual locations, results of chemical monitoring and values of biochemical markers were compared. A significant correlation (P< 0.05 was found between biochemical markers and OCS, and PCB. Among the tributaries studied those that contaminated the Elbe most were the Vltava and the Bílina. These tributaries should not be considered the main sources of industrial contamination of the River Elbe, because the most important contamination sources were along the river Elbe itself.

  7. BNDB – The Biochemical Network Database

    Directory of Open Access Journals (Sweden)

    Kaufmann Michael

    2007-10-01

    Full Text Available Abstract Background Technological advances in high-throughput techniques and efficient data acquisition methods have resulted in a massive amount of life science data. The data is stored in numerous databases that have been established over the last decades and are essential resources for scientists nowadays. However, the diversity of the databases and the underlying data models make it difficult to combine this information for solving complex problems in systems biology. Currently, researchers typically have to browse several, often highly focused, databases to obtain the required information. Hence, there is a pressing need for more efficient systems for integrating, analyzing, and interpreting these data. The standardization and virtual consolidation of the databases is a major challenge resulting in a unified access to a variety of data sources. Description We present the Biochemical Network Database (BNDB, a powerful relational database platform, allowing a complete semantic integration of an extensive collection of external databases. BNDB is built upon a comprehensive and extensible object model called BioCore, which is powerful enough to model most known biochemical processes and at the same time easily extensible to be adapted to new biological concepts. Besides a web interface for the search and curation of the data, a Java-based viewer (BiNA provides a powerful platform-independent visualization and navigation of the data. BiNA uses sophisticated graph layout algorithms for an interactive visualization and navigation of BNDB. Conclusion BNDB allows a simple, unified access to a variety of external data sources. Its tight integration with the biochemical network library BN++ offers the possibility for import, integration, analysis, and visualization of the data. BNDB is freely accessible at http://www.bndb.org.

  8. [Chronic fatigue syndrome: biochemical examination of blood].

    Science.gov (United States)

    Hakariya, Yukiko; Kuratsune, Hirohiko

    2007-06-01

    Though patients with chronic fatigue syndrome (CFS) have lots of complaints, abnormal findings cannot be detected by biochemical screening tests. However, some specialized blood tests have revealed neuroendocrine immune axis abnormalities, which is closely associated with each other. Recent studies indicate that CFS can be understood as a special condition based on abnormality of the psycho-neuro-endocrino-immunological system, with the distinguishing feature of CFS seeming to be the secondary brain dysfunction caused by several cytokines and/or autoantibodies. In this paper, we summarize these abnormalities found in CFS and show the neuro-molecular mechanism leading to chronic fatigue.

  9. Azoospermia: clinical, hormonal, and biochemical investigation.

    Science.gov (United States)

    Papadimas, J; Papadopoulou, F; Ioannidis, S; Spanos, E; Tarlatzis, B; Bontis, J; Mantalenakis, S

    1996-01-01

    The aim of this study was to evaluate the clinical, hormonal and biochemical characteristics of infertile men with azoospermia. A total of 187 azoospermic out of 2610 infertile men (7.2%) were studied. Mean testicular volume and basal plasma levels of FSH were the most useful parameters concerning the evaluation of azoospermia. Basal plasma levels of LH and T were useful only in azoospermic men with hypogonadism, whereas plasma PRL levels, semen volume, and seminal plasma fructose levels were not found to be of common use except in selected cases.

  10. Biochemical Disincentives to Fertilizing Cellulosic Ethanol Crops

    Science.gov (United States)

    Gallagher, M. E.; Hockaday, W. C.; Snapp, S.; McSwiney, C.; Baldock, J.

    2010-12-01

    Corn grain biofuel crops produce the highest yields when the cropping ecosystem is not nitrogen (N)-limited, achieved by application of fertilizer. There are environmental consequences for excessive fertilizer application to crops, including greenhouse gas emissions, hypoxic “dead zones,” and health problems from N runoff into groundwater. The increase in corn acreage in response to demand for alternative fuels (i.e. ethanol) could exacerbate these problems, and divert food supplies to fuel production. A potential substitute for grain ethanol that could reduce some of these impacts is cellulosic ethanol. Cellulosic ethanol feedstocks include grasses (switchgrass), hardwoods, and crop residues (e.g. corn stover, wheat straw). It has been assumed that these feedstocks will require similar N fertilization rates to grain biofuel crops to maximize yields, but carbohydrate yield versus N application has not previously been monitored. We report the biochemical stocks (carbohydrate, protein, and lignin in Mg ha-1) of a corn ecosystem grown under varying N levels. We measured biochemical yield in Mg ha-1 within the grain, leaf and stem, and reproductive parts of corn plants grown at seven N fertilization rates (0-202 kg N ha-1), to evaluate the quantity and quality of these feedstocks across a N fertilization gradient. The N fertilization rate study was performed at the Kellogg Biological Station-Long Term Ecological Research Site (KBS-LTER) in Michigan. Biochemical stocks were measured using 13C nuclear magnetic resonance spectroscopy (NMR), combined with a molecular mixing model (Baldock et al. 2004). Carbohydrate and lignin are the main biochemicals of interest in ethanol production since carbohydrate is the ethanol feedstock, and lignin hinders the carbohydrate to ethanol conversion process. We show that corn residue carbohydrate yields respond only weakly to N fertilization compared to grain. Grain carbohydrate yields plateau in response to fertilization at

  11. Biochemical Markers of Joint Tissue Turnover

    DEFF Research Database (Denmark)

    Bay-Jensen, Anne-Christine; Sondergaard, Bodil Cecilie; Christiansen, Claus;

    2009-01-01

    Recent disappointments in late stage developments of anti-osteoarthritic drugs have reinforced efforts to develop better biomarkers for application in both the drug development process as well as in the routine management of these patients. Here we provide a brief review of biochemical tests...... available for the study of tissue turnover in each of the three compartments of the articular joint, that is the bone, the cartilage, and the synovium. Finally, we provide some perspective to future developments in biomarker discovery and discuss the potential impact such technologies could have on the drug...

  12. Biochemical composition of tangerine fruits under microfertilizers

    OpenAIRE

    Oksana Belous; Yuliya Abilfazova

    2016-01-01

    The paper presents the long-term research and its results in the field of biochemical composition and mechanical analysis of dwarf tangerine fruits ('Miagava-Vase') growing in the subtropical zone of the Black Sea coast, Krasnodar region. The given results have been obtained after treatments with the following micro fertilizers: H3BO3 (at a concentration of 0.06%), MnSO4 H2O (0.4%), ZnSO4 H2O (0.3%) and CuSO4 H2O (0.06%), an option with foliar water spraying served as a control. It is shown t...

  13. [Fe]-hydrogenases in green algae: photo-fermentation and hydrogen evolution under sulfur deprivation

    Energy Technology Data Exchange (ETDEWEB)

    Winkler, M.; Hemschemeier, A.; Happe, T. [Botanisches Institut der Universitat Bonn (Germany); Gotor, C. [CSIC y Universidad de Sevilla (Spain). Instituto de Bioquimica Vegetal y Fotosintesis; Melis, A. [University of California, Berkeley, CA (United States). Department of Plant and Microbial Biology

    2002-12-01

    Recent studies indicate that [Fe]-hydrogenases and H{sub 2} metabolism are widely distributed among green algae. The enzymes are simple structured and catalyze H{sub 2} evolution with similar rates than the more complex [Fe]-hydrogenases from bacteria. Different green algal species developed diverse strategies to survive under sulfur deprivation. Chlamydomonas reinhardtii evolves large quantities of hydrogen gas in the absence of sulfur. In a sealed culture of C. reinhardtii, the photosynthetic O{sub 2} evolution rate drops below the rate of respiratory O{sub 2} consumption due to a reversible inhibition of photosystem II, thus leading to an intracellular anaerobiosis. The algal cells survive under these anaerobic conditions by switching their metabolism to a kind of photo-fermentation. Although possessing a functional [Fe]-hydrogenase gene, the cells of Scenedesmus obliquus produce no significant amounts of H{sub 2} under S-depleted conditions. Biochemical analyses indicate that S. obliquus decreases almost the complete metabolic activities while maintaining a low level of respiratory activity. (author)

  14. Pheochromocytoma-paraganglioma: Biochemical and genetic diagnosis.

    Science.gov (United States)

    Cano Megías, Marta; Rodriguez Puyol, Diego; Fernández Rodríguez, Loreto; Sención Martinez, Gloria Lisette; Martínez Miguel, Patricia

    Pheochromocytomas and paragangliomas are tumours derived from neural crest cells, which can be diagnosed by biochemical measurement of metanephrine and methoxytyramine. Advances in genetic research have identified many genes involved in the pathogenesis of these tumours, suggesting that up to 35-45% may have an underlying germline mutation. These genes have a singular transcriptional signature and can be grouped into 2 clusters (or groups): cluster 1 (VHL and SHDx), involved in angiogenesis and hypoxia pathways; and cluster 2 (MEN2 and NF1), linked to the kinase signalling pathway. In turn, these genes are associated with a characteristic biochemical phenotype (noradrenergic and adrenergic), and clinical features (location, biological behaviour, age of presentation, etc.) in a large number of cases. Early diagnosis of these tumours, accompanied by a correct genetic diagnosis, should eventually become a priority to enable better treatment, early detection of complications, proper screening of family members and related tumours, as well as an improvement in the overall prognosis of these patients.

  15. Biotin: biochemical, physiological and clinical aspects.

    Science.gov (United States)

    Said, Hamid M

    2012-01-01

    Significant progress has been made in our understanding of the biochemical, physiological and nutritional aspects of the water-soluble vitamin biotin (vitamin H). It is well know now that biotin plays important roles in a variety of critical metabolic reactions in the cell, and thus, is essential for normal human health, growth and development. This is underscored by the serious clinical abnormalities that occur in conditions of biotin deficiency, which include, among other things, growth retardation, neurological disorders, and dermatological abnormalities (reviewed in 1). Studies in animals have also shown that biotin deficiency during pregnancy leads to embryonic growth retardation, congenital malformation and death (Watanabe 1983; Cooper and Brown 1958; Mock et al. 2003; Zempleni and Mock 2000). The aim of this chapter is to provide coverage of current knowledge of the biochemical, physiological, and clinical aspects of biotin nutrition. Many sections of this chapter have been the subject of excellent recent reviews by others (Wolf 2001; McMahon 2002; Mock 2004; Rodriguez-Melendez and Zempleni 2003; Said 2004; Said et al. 2000; Said and Seetheram 2006), and thus, for more information the reader is advised to consider these additional sources.

  16. Biochemical research elucidating metabolic pathways in Pneumocystis*

    Directory of Open Access Journals (Sweden)

    Kaneshiro E.S.

    2010-12-01

    Full Text Available Advances in sequencing the Pneumocystis carinii genome have helped identify potential metabolic pathways operative in the organism. Also, data from characterizing the biochemical and physiological nature of these organisms now allow elucidation of metabolic pathways as well as pose new challenges and questions that require additional experiments. These experiments are being performed despite the difficulty in doing experiments directly on this pathogen that has yet to be subcultured indefinitely and produce mass numbers of cells in vitro. This article reviews biochemical approaches that have provided insights into several Pneumocystis metabolic pathways. It focuses on 1 S-adenosyl-L-methionine (AdoMet; SAM, which is a ubiquitous participant in numerous cellular reactions; 2 sterols: focusing on oxidosqualene cyclase that forms lanosterol in P. carinii; SAM:sterol C-24 methyltransferase that adds methyl groups at the C-24 position of the sterol side chain; and sterol 14α-demethylase that removes a methyl group at the C-14 position of the sterol nucleus; and 3 synthesis of ubiquinone homologs, which play a pivotal role in mitochondrial inner membrane and other cellular membrane electron transport.

  17. Biochemical Manifestation of HIV Lipodystrophy Syndrome

    Directory of Open Access Journals (Sweden)

    Kenneth Ihenetu, PhD

    2012-11-01

    Full Text Available Objectives:Highly active anti-retroviral therapy (HAART, including protease inhibitors (PI have led to dramatic improvements in the quality and quantity of life in patients with acquired immunodeficiency syndrome (AIDS. However, a significant number of AIDS patients on HAART develop characteristic changes in body fat redistribution referred to as lipodystrophy syndrome (LDS. Features of LDS include hypertrophy in the neck fat pad (buffalo hump, increased fat in the abdominal region (protease paunch, gynecomastia and loss of fat in the mid-face and extremities.Methods:The aim of this paper is to review the current knowledge regarding this syndrome. This article reviews the published investigations on biochemical manifestation of HIV lipodystrophy syndrome.Results:It is estimated that approximately 64% of patients treated with PI will experience this syndrome. Biochemically, these patients have increased triglycerides (Trig, total cholesterol (TC, low-density lipoprotein-cholesterol (LDL-C and extremely low high-density lipoprotein-cholesterol (HDL-C.Conclusions and Public Health Implications:It is hoped that awareness of this syndrome would aid in early diagnosis and better patient management, possibly leading to a lower incidence of cardiovascular complications among these patients.

  18. [Biochemical principles of early saturnism recognition].

    Science.gov (United States)

    Tsimakuridze, M P; Mansuradze, E A; Zurashvili, D G; Tsimakuridze, M P

    2009-03-01

    The aim of the work is to determine the major sensitive criteria of biochemical indicators that allow timely discovery of negative influence of lead on organism and assist in early diagnosis of primary stages of saturnism. The workers of Georgian typographies, performing technological processes of letterpress printing were observed. Professional groups having contact with lead aerosols (main group of 66 people) and the workers of the same typography not being in touch with the poison (control group of 24 people) were studied. It was distinguished that, protracted professional contact with lead causes moderate increase of lead, coproporphyrin and DALA in daily urine in most cases; it is more clearly evidenced in the professional groups of lead smelters and lino operators and less clearly among typesetter and printers. Upon the checkup of people, having a direct contact with lead, biochemical analysis of urine should be given a preference, especially the determination of quantitative content of lead and coproporphyrin in urine with the aim of revealing the lead carrier, which is one of the first signals for occupational lookout and medical monitoring of the similar contingent.

  19. Serum biochemical markers in carcinoma breast.

    Directory of Open Access Journals (Sweden)

    Seth R

    2003-08-01

    Full Text Available BACKGROUND: Despite the extensive research for many years throughout the world, the etiopathogenesis of cancer still remains obscure. For the early detection of carcinoma of various origins, a number of biochemical markers have been studied to evaluate the malignancy. AIM: To analyse serum gamma glutamyl transpeptidase (GGTP, lactate dehydrogenase (LDH and superoxide dismutase (SOD in carcinoma breast patients. SETTINGS & DESIGN: The serum biochemical markers were estimated in twenty five histopathologically confirmed patients with carcinoma breast and equal number of healthy age- matched individuals served as control. MATERIAL & METHODS: Serum gamma glutamyl transpeptidase (GGTP, lactate dehydrogenase (LDH and superoxide dismutase (SOD were estimated and their sensitivity determined. Statistics: Data was analysed with student′s ′t′-test and sensitivity score of these markers was determined. RESULTS & CONCLUSIONS: The mean serum GGTP, LDH and SOD activities in patients with carcinoma breast were tremendously increased as compared to controls, and a steady increase was observed in their activities from stage I through stage IV as well as following distant metastasis. Serum GGTP, LDH and SOD might prove to be most sensitive biomarkers in carcinoma breast in early detection of the disease.

  20. Viral quasispecies evolution.

    Science.gov (United States)

    Domingo, Esteban; Sheldon, Julie; Perales, Celia

    2012-06-01

    Evolution of RNA viruses occurs through disequilibria of collections of closely related mutant spectra or mutant clouds termed viral quasispecies. Here we review the origin of the quasispecies concept and some biological implications of quasispecies dynamics. Two main aspects are addressed: (i) mutant clouds as reservoirs of phenotypic variants for virus adaptability and (ii) the internal interactions that are established within mutant spectra that render a virus ensemble the unit of selection. The understanding of viruses as quasispecies has led to new antiviral designs, such as lethal mutagenesis, whose aim is to drive viruses toward low fitness values with limited chances of fitness recovery. The impact of quasispecies for three salient human pathogens, human immunodeficiency virus and the hepatitis B and C viruses, is reviewed, with emphasis on antiviral treatment strategies. Finally, extensions of quasispecies to nonviral systems are briefly mentioned to emphasize the broad applicability of quasispecies theory.

  1. Recent progress in the crystallographic studies of photosystem II

    NARCIS (Netherlands)

    Guskov, Albert; Gabdulkhakov, Azat; Broser, Matthias; Glöckner, Carina; Hellmich, Julia; Kern, Jan; Frank, Joachim; Müh, Frank; Saenger, Wolfram; Zouni, Athina

    2010-01-01

    The photosynthetic oxygen-evolving photosystem II (PSII) is the only known biochemical system that is able to oxidize water molecules and thereby generates almost all oxygen in the Earth's atmosphere. The elucidation of the structural and mechanistic aspects of PSII keeps scientists all over the wor

  2. Evolution and the complexity of bacteriophages

    Directory of Open Access Journals (Sweden)

    Serwer Philip

    2007-03-01

    Full Text Available Abstract Background The genomes of both long-genome (> 200 Kb bacteriophages and long-genome eukaryotic viruses have cellular gene homologs whose selective advantage is not explained. These homologs add genomic and possibly biochemical complexity. Understanding their significance requires a definition of complexity that is more biochemically oriented than past empirically based definitions. Hypothesis Initially, I propose two biochemistry-oriented definitions of complexity: either decreased randomness or increased encoded information that does not serve immediate needs. Then, I make the assumption that these two definitions are equivalent. This assumption and recent data lead to the following four-part hypothesis that explains the presence of cellular gene homologs in long bacteriophage genomes and also provides a pathway for complexity increases in prokaryotic cells: (1 Prokaryotes underwent evolutionary increases in biochemical complexity after the eukaryote/prokaryote splits. (2 Some of the complexity increases occurred via multi-step, weak selection that was both protected from strong selection and accelerated by embedding evolving cellular genes in the genomes of bacteriophages and, presumably, also archaeal viruses (first tier selection. (3 The mechanisms for retaining cellular genes in viral genomes evolved under additional, longer-term selection that was stronger (second tier selection. (4 The second tier selection was based on increased access by prokaryotic cells to improved biochemical systems. This access was achieved when DNA transfer moved to prokaryotic cells both the more evolved genes and their more competitive and complex biochemical systems. Testing the hypothesis I propose testing this hypothesis by controlled evolution in microbial communities to (1 determine the effects of deleting individual cellular gene homologs on the growth and evolution of long genome bacteriophages and hosts, (2 find the environmental conditions that

  3. Biochemical subtypes of oligodendrocyte in the anterior medullary velum of the rat as revealed by the monoclonal antibody Rip.

    Science.gov (United States)

    Butt, A M; Ibrahim, M; Ruge, F M; Berry, M

    1995-07-01

    Oligodendrocytes were studied in the anterior medullary velum (AMV) of the rat using the monoclonal antibody Rip, an oligodendrocyte marker of unknown function. Confocal microscopic imaging of double immunofluorescent labelling with antibodies to Rip and carbonic anhydrase II (CAII) revealed two biochemically and morphologically distinct populations of oligodendrocyte which were either Rip+CAII+ or Rip+CAII-. Double immunofluorescent labelling with Rip and myelin basic protein (MBP) or glial fibrillary acidic protein (GFAP) provided direct evidence that Rip-labelled cells were phenotypically oligodendrocytes and confirmed that Rip did not recognise astrocytes. Oligodendrocytes which were Rip+CAII+ supported numerous myelin sheaths for small diameter axons, whilst Rip+CAII- oligodendrocytes supported fewer myelin sheaths for large diameter axons. Morphologically, Rip+CAII+ oligodendrocytes corresponded to types I or II of classical nomenclature, whilst Rip+CAII- oligodendrocytes corresponded to types III and IV. The results demonstrated a biochemical difference between oligodendrocytes which myelinated small and large diameter fibres.

  4. CHEMICAL EVOLUTION

    Energy Technology Data Exchange (ETDEWEB)

    Calvin, Melvin

    1965-06-01

    How did life come to be on the surface of the earth? Darwin himself recognized that his basic idea of evolution by variation and natural selection must be a continuous process extending backward in time through that period in which the first living things arose and into the period of 'Chemical Evolution' which preceded it. We are approaching the examination of these events by two routes. One is to seek for evidence in the ancient rocks of the earth which were laid down prior to that time in which organisms capable of leaving their skeletons in the rocks to be fossilized were in existence. This period is sometime prior to approximately 600 million years ago. The earth is believed to have taken its present form approximately 4700 million years ago. We have found in rocks whose age is about 1000 million years certain organic molecules which are closely related to the green pigment of plants, chlorophyll. This seems to establish that green plants were already fluorishing prior to that time. We have now found in rocks of still greater age, namely, 2500 million years, the same kinds of molecules mentioned above which can be attributed to the presence of living organisms. If these molecules are as old as the rocks, we have thus shortened the time available for the generation of the complex biosynthetic sequences which give rise to these specific hydrocarbons (polyisoprenoids) to less than 2000 million years.

  5. Plectasin, a Fungal Defensin, Targets the Bacterial Cell Wall Precursor Lipid II

    DEFF Research Database (Denmark)

    Schneider, Tanja; Kruse, Thomas; Wimmer, Reinhard

    2010-01-01

    that plectasin, a fungal defensin, acts by directly binding the bacterial cell-wall precursor Lipid II. A wide range of genetic and biochemical approaches identify cell-wall biosynthesis as the pathway targeted by plectasin. In vitro assays for cell-wall synthesis identified Lipid II as the specific cellular...

  6. Experimental evolution in biofilm populations.

    Science.gov (United States)

    Steenackers, Hans P; Parijs, Ilse; Foster, Kevin R; Vanderleyden, Jozef

    2016-05-01

    Biofilms are a major form of microbial life in which cells form dense surface associated communities that can persist for many generations. The long-life of biofilm communities means that they can be strongly shaped by evolutionary processes. Here, we review the experimental study of evolution in biofilm communities. We first provide an overview of the different experimental models used to study biofilm evolution and their associated advantages and disadvantages. We then illustrate the vast amount of diversification observed during biofilm evolution, and we discuss (i) potential ecological and evolutionary processes behind the observed diversification, (ii) recent insights into the genetics of adaptive diversification, (iii) the striking degree of parallelism between evolution experiments and real-life biofilms and (iv) potential consequences of diversification. In the second part, we discuss the insights provided by evolution experiments in how biofilm growth and structure can promote cooperative phenotypes. Overall, our analysis points to an important role of biofilm diversification and cooperation in bacterial survival and productivity. Deeper understanding of both processes is of key importance to design improved antimicrobial strategies and diagnostic techniques.

  7. Experimental evolution in biofilm populations

    Science.gov (United States)

    Steenackers, Hans P.; Parijs, Ilse; Foster, Kevin R.; Vanderleyden, Jozef

    2016-01-01

    Biofilms are a major form of microbial life in which cells form dense surface associated communities that can persist for many generations. The long-life of biofilm communities means that they can be strongly shaped by evolutionary processes. Here, we review the experimental study of evolution in biofilm communities. We first provide an overview of the different experimental models used to study biofilm evolution and their associated advantages and disadvantages. We then illustrate the vast amount of diversification observed during biofilm evolution, and we discuss (i) potential ecological and evolutionary processes behind the observed diversification, (ii) recent insights into the genetics of adaptive diversification, (iii) the striking degree of parallelism between evolution experiments and real-life biofilms and (iv) potential consequences of diversification. In the second part, we discuss the insights provided by evolution experiments in how biofilm growth and structure can promote cooperative phenotypes. Overall, our analysis points to an important role of biofilm diversification and cooperation in bacterial survival and productivity. Deeper understanding of both processes is of key importance to design improved antimicrobial strategies and diagnostic techniques. PMID:26895713

  8. Evolution of Star Formation in the UKIDSS Ultra Deep Survey Field - II. Star Formation as a Function of Stellar Mass Between z=1.46 and z=0.63

    CERN Document Server

    Drake, Alyssa B; Baldry, Ivan K; James, Phil A; Collins, Chris A; Ouchi, Masami; Yuma, Suraphong; Dunlop, James S; Smith, Daniel J B

    2015-01-01

    We present new results on the evolution of the cosmic star formation rate as a function of stellar mass in the SXDS-UDS field. We make use of narrow-band selected emission line galaxies in four redshift slices between z = 1.46 and z = 0.63, and compute stellar masses by fitting a series of templates to recreate each galaxy's star formation history. We determine mass-binned luminosity functions in each redshift slice, and derive the star formation rate density (rhoSFR) as a function of mass using the [OIII] or [OII] emission lines. We calculate dust extinction and metallicity as a function of stellar mass, and investigate the effect of these corrections on the shape of the overall rhoSFR(M). We find that both these corrections are crucial for determining the shape of the rhoSFR(M), and its evolution with redshift. The fully corrected rhoSFR(M) is a relatively flat distribution, with the normalisation moving towards lower values of rhoSFR with increasing cosmic time/decreasing redshift, and requiring star forma...

  9. Assimilation of ocean colour data into a Biochemical Flux Model of the Eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    G. Triantafyllou

    2006-09-01

    Full Text Available Within the framework of the European MFSTEP project, an advanced multivariate sequential data assimilation system has been implemented to assimilate real chlorophyll data from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS into a three-dimensional biochemical model of the Eastern Mediterranean. The physical ocean is described through the Princeton Ocean Model (POM while the biochemistry of the ecosystem is tackled with the Biochemical Flux Model (BFM. The assimilation scheme is based on the Singular Evolutive Extended Kalman (SEEK filter, in which the error statistics were parameterized by means of a suitable set of Empirical Orthogonal Functions (EOFs. A radius of influence was further selected around every data point to limit the range of the EOFs spatial correlations. The assimilation experiment was performed for one year over 1999 and forced with ECMWF 6 hour atmospheric fields. The accuracy of the ecological state identification by the assimilation system is assessed by the relevance of the system in fitting the data, and through the impact of the assimilation on non-observed biochemical processes. Assimilation of SeaWiFS data significantly improves the forecasting capability of the BFM model. Results, however, indicate the necessity of subsurface data to enhance the controllability of the ecosystem model in the deep layers.

  10. Felipe II

    Directory of Open Access Journals (Sweden)

    Carlos Restrepo Canal

    1962-04-01

    Full Text Available Como parte de la monumental Historia de España que bajo la prestante y acertadísima dirección de don Ramón Menéndez Pidal se comenzó a dar a la prensa desde 1954 por la Editorial Espasa Calpe S. A., aparecieron en 1958 dos tomos dedicados al reinado de Felipe II; aquella época en que el imperio español alcanzó su unidad peninsular juntamente con el dilatado poderío que le constituyó en la primera potencia de Europa.

  11. Hemoglobin variants: biochemical properties and clinical correlates.

    Science.gov (United States)

    Thom, Christopher S; Dickson, Claire F; Gell, David A; Weiss, Mitchell J

    2013-03-01

    Diseases affecting hemoglobin synthesis and function are extremely common worldwide. More than 1000 naturally occurring human hemoglobin variants with single amino acid substitutions throughout the molecule have been discovered, mainly through their clinical and/or laboratory manifestations. These variants alter hemoglobin structure and biochemical properties with physiological effects ranging from insignificant to severe. Studies of these mutations in patients and in the laboratory have produced a wealth of information on hemoglobin biochemistry and biology with significant implications for hematology practice. More generally, landmark studies of hemoglobin performed over the past 60 years have established important paradigms for the disciplines of structural biology, genetics, biochemistry, and medicine. Here we review the major classes of hemoglobin variants, emphasizing general concepts and illustrative examples.

  12. Simplifying biochemical models with intermediate species

    DEFF Research Database (Denmark)

    Feliu, Elisenda; Wiuf, Carsten

    2013-01-01

    canonical model that characterizes crucial dynamical properties, such as mono- and multistationarity and stability of steady states, of all models in the class. We show that if the core model does not have conservation laws, then the introduction of intermediates does not change the steady...... techniques, we study systematically the effects of intermediate, or transient, species in biochemical systems and provide a simple, yet rigorous mathematical classification of all models obtained from a core model by including intermediates. Main examples include enzymatic and post-translational modification...... systems, where intermediates often are considered insignificant and neglected in a model, or they are not included because we are unaware of their existence. All possible models obtained from the core model are classified into a finite number of classes. Each class is defined by a mathematically simple...

  13. On Biochemical Formation of Salt Deposits

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A water/salt system in an evaporative environment is both a physicochemical region and a biological one. All the parameters of the system, such as the salinity, temperature and CO2 partial pressure, are affected by halophilic bacteria. The system controls salt deposition but is modified by an accompanying ecological system; therefore it should be called a water/salt/biological system. Salt minerals result from accumulation of the remains of bacteria/algae, namely, bacteria/algae formation; whereas biological, biophysical and biochemical processes provide full evidence for organic involvement. Consequently, salt deposits should not be called purely chemical but biological/chemical ones. This new argument supplements and develops the traditional idea and helps perfect the mineralization theory of salts and even general deposits, thus giving guidance to prospecting for salt deposits.

  14. The biochemical basis of hereditary fructose intolerance.

    Science.gov (United States)

    Bouteldja, Nadia; Timson, David J

    2010-04-01

    Hereditary fructose intolerance is a rare, but potentially lethal, inherited disorder of fructose metabolism, caused by mutation of the aldolase B gene. Treatment currently relies solely on dietary restriction of problematic sugars. Biochemical study of defective aldolase B enzymes is key to revealing the molecular basis of the disease and providing a stronger basis for improved treatment and diagnosis. Such studies have revealed changes in enzyme activity, stability and oligomerisation. However, linking these changes to disease phenotypes has not always been straightforward. This review gives a general overview of the features of hereditary fructose intolerance, then concentrates on the biochemistry of the AP variant (Ala149Pro variant of aldolase B) and molecular pathological consequences of mutation of the aldolase B gene.

  15. Biochemically enhanced methane production from coal

    Science.gov (United States)

    Opara, Aleksandra

    For many years, biogas was connected mostly with the organic matter decomposition in shallow sediments (e.g., wetlands, landfill gas, etc.). Recently, it has been realized that biogenic methane production is ongoing in many hydrocarbon reservoirs. This research examined microbial methane and carbon dioxide generation from coal. As original contributions methane production from various coal materials was examined in classical and electro-biochemical bench-scale reactors using unique, developed facultative microbial consortia that generate methane under anaerobic conditions. Facultative methanogenic populations are important as all known methanogens are strict anaerobes and their application outside laboratory would be problematic. Additional testing examined the influence of environmental conditions, such as pH, salinity, and nutrient amendments on methane and carbon dioxide generation. In 44-day ex-situ bench-scale batch bioreactor tests, up to 300,000 and 250,000 ppm methane was generated from bituminous coal and bituminous coal waste respectively, a significant improvement over 20-40 ppm methane generated from control samples. Chemical degradation of complex hydrocarbons using environmentally benign reagents, prior to microbial biodegradation and methanogenesis, resulted in dissolution of up to 5% bituminous coal and bituminous coal waste and up to 25% lignite in samples tested. Research results confirm that coal waste may be a significant underutilized resource that could be converted to useful fuel. Rapid acidification of lignite samples resulted in low pH (below 4.0), regardless of chemical pretreatment applied, and did not generate significant methane amounts. These results confirmed the importance of monitoring and adjusting in situ and ex situ environmental conditions during methane production. A patented Electro-Biochemical Reactor technology was used to supply electrons and electron acceptor environments, but appeared to influence methane generation in a

  16. Thought Evolution

    Directory of Open Access Journals (Sweden)

    Shadrikov V.D.

    2015-08-01

    Full Text Available The thought evolution is studied by historical reconstruction method that is based on the propositions of the theory of culturalhistorical determination of the psyche development, and the data of the morphological analysis and child development, and the conception of the psyche neuroontogenesis. The grounds for advisability of protothinking are presented. The protothinking is understood as the use of objective thought in cases of awareness absence. It is shown that protothinking is a form of transition from animal thinking to human speech. The particular attention is paid to the process of the word producing and thought generation in that process. The conditions of word producing as cooccurring acoustic pattern served for though expression are discussed. It is emphasized that a word is produced by a particular person. The historical development of the language and the specificity of this development are pointed out

  17. Community Evolution

    CERN Document Server

    Bródka, Piotr; Kazienko, Przemysław

    2016-01-01

    The continuous interest in the social network area contributes to the fast development of this field. The new possibilities of obtaining and storing data facilitate deeper analysis of the entire social network, extracted social groups and single individuals as well. One of the most interesting research topic is the network dynamics and dynamics of social groups in particular, it means analysis of group evolution over time. It is the natural step forward after social community extraction. Having communities extracted, appropriate knowledge and methods for dynamic analysis may be applied in order to identify changes as well as to predict the future of all or some selected groups. Furthermore, knowing the most probably change of a given group some additional steps may be performed in order to change this predicted future according to specific needs. Such ability would be a powerful tool in the hands of human resource managers, personnel recruitment, marketing, telecommunication companies, etc.

  18. Biochemical and histological alterations in liver following sub chronic exposure of arsenic

    Directory of Open Access Journals (Sweden)

    Madhuri Mehta

    2015-07-01

    Full Text Available Objective: Contamination of groundwater with arsenic is of global concern. The present work was aimed to evaluate the biochemical and histological changes in liver of female rats induced by sodium arsenite at doses naturally found in groundwater of Punjab. Method: Twenty four female rats were divided into four groups of 6 animals each. Group I animals received distilled water and served as control; Group II-IV received arsenic at the dose of 10, 30 and 50 ppb (μg/L dissolved in distilled water ad libitum for 30 days. At the end of experiment, animals were sacrificed and liver was collected for biochemical and histological evaluation. Results: Biochemical analysis showed an increase in the activity of hepatic marker enzymes including transferases, phosphatases and lactate dehydrogenase (LDH. Also, the levels of antioxidant enzymes (catalase, reduced glutathione and glutathione-S-transferase decreased significantly (P<0.05 in treated animals when compared to control. A significant (P<0.05 dose dependent increase in the levels of lipid peroxidation and arsenic concentration in liver tissue was observed. Histological examination showed the presence of pyknotic bodies (necrosis and sinusoidal dilation in hepatocytes of treated groups. Conclusion: Sub chronic exposure of arsenic at these doses induces hepatotoxicity leading to oxidative stress.

  19. Hubble Space Telescope Hx Imaging of Star-forming Galaxies at z approximately equal to 1-1.5: Evolution in the Size and Luminosity of Giant H II Regions

    Science.gov (United States)

    Livermore, R. C.; Jones, T.; Richard, J.; Bower, R. G.; Ellis, R. S.; Swinbank, A. M.; Rigby, J. R.; Smail, Ian; Arribas, S.; Rodriguez-Zaurin, J.; Colina, L.; Ebeling, H.; Crain, R. A.

    2013-01-01

    We present Hubble Space Telescope/Wide Field Camera 3 narrow-band imaging of the Ha emission in a sample of eight gravitationally lensed galaxies at z = 1-1.5. The magnification caused by the foreground clusters enables us to obtain a median source plane spatial resolution of 360 pc, as well as providing magnifications in flux ranging from approximately 10× to approximately 50×. This enables us to identify resolved star-forming HII regions at this epoch and therefore study their Ha luminosity distributions for comparisons with equivalent samples at z approximately 2 and in the local Universe. We find evolution in the both luminosity and surface brightness of HII regions with redshift. The distribution of clump properties can be quantified with an HII region luminosity function, which can be fit by a power law with an exponential break at some cut-off, and we find that the cut-off evolves with redshift. We therefore conclude that 'clumpy' galaxies are seen at high redshift because of the evolution of the cut-off mass; the galaxies themselves follow similar scaling relations to those at z = 0, but their HII regions are larger and brighter and thus appear as clumps which dominate the morphology of the galaxy. A simple theoretical argument based on gas collapsing on scales of the Jeans mass in a marginally unstable disc shows that the clumpy morphologies of high-z galaxies are driven by the competing effects of higher gas fractions causing perturbations on larger scales, partially compensated by higher epicyclic frequencies which stabilize the disc.

  20. Spinal muscular atrophy type II (intermediary and III (Kugelberg-Welander: evolution of 50 patients with physiotherapy and hydrotherapy in a swimming pool Atrofia muscular espinhal tipo II (intermediária e III (Kugelberg-Welander: evolução de 50 pacientes com fisioterapia e hidroterapia em piscina

    Directory of Open Access Journals (Sweden)

    Márcia C. B. Cunha

    1996-09-01

    Full Text Available We added hydrotherapy to 50 patients with spinal muscular atrophy (SMA who were being treated with individual conventional physiotherapy. Hydrotherapy was performed at an approximate temperature of 30 degrees Celsius, twice a week, for thirty minutes in children and for forty-five minutes in adults during a 2-year period. The outcome derived from this combined modality of treatment was rated according to physiotherapeutic evaluations, the MMT (Manual Muscular Test, and the Barthel Ladder. Patients were reevaluated at 2-month intervals. After two years of ongoing treatment, we were able to observe that the deformities in hip, knee and foot were progressive in all SMA Type II patients, and in some Type III. Muscle strength stabilized in most SMA Type III patients, and improved in some. MMT was not done in SMA Type II. In all patients we were able to detect an improvement in the Barthel Ladder scale. This study suggests that a measurable improvement in the quality of daily living may be obtained in patients with SMA Types II and III subjected to conventional physiotherapy when associated with hydrotherapy.A hidroterapia foi realizada em SO pacientes com atrofia muscular espinhal, os quais foram também tratados com fisioterapia individual convencional. O tratamento hidroterápico foi realizado em piscina aquecida numa temperatura de aproximadamente 30° Celsius, duas vezes por semana, durante 30 minutos em crianças e 45 minutos em adultos num período de dois anos. Os benefícios deste tipo de tratamento foram avaliados de acordo com a evolução clínica, o MMT(Teste de Força Muscular e a Escala de Barthel. Os pacientes foram reavaliados a cada dois meses. Após dois anos de tratamento nós observamos que as deformidades nos quadris, joelhos e pés foram progressivas em todos os pacientes do Tipo II e em alguns do Tipo III. Houve estabilização da força muscular na maioria dos pacientes com SMA Tipo III, e melhora da força em alguns; nos

  1. Evaluation of the Quantum II yeast identification system.

    OpenAIRE

    Kiehn, T E; Edwards, F F; Tom, D; LIEBERMAN, G; Bernard, E M; Armstrong, D.

    1985-01-01

    We compared three methods for identifying clinical yeast isolates: Abbott Quantum II, API 20C, and a modified BBL Minitek system. The API 20C and modified Minitek systems agreed on the identification of 243 of 245 yeasts (99.2%). The Quantum II system correctly identified 197 (80.4%), incorrectly identified 19 (7.8%), and did not identify 29 (11.8%) of the yeasts. Most of the misidentifications with the Quantum II occurred because assimilation or biochemical results were false-positive. Sixte...

  2. A Biochemical Approach to the Problem of Dyslexia.

    Science.gov (United States)

    Baker, Sidney McDonald

    1985-01-01

    The paper presents the case of a sixth-grade boy, labeled dyslexic, who responded positively to a biochemical approach. Remedy of iron, zinc, and Vitamin B-6 deficiencies as well as an imbalance of fatty acids resulted in improvements in hair and skin and also in reading. A biochemical approach to behavior problems is proposed. (Author/CL)

  3. Local biochemical and morphological differences in human Achilles tendinopathy

    DEFF Research Database (Denmark)

    J, Pingel; Fredberg, Ulrich; K, Qvortrup;

    2012-01-01

    The incidence of Achilles tendinopathy is high and underlying etiology as well as biochemical and morphological pathology associated with the disease is largely unknown. The aim of the present study was to describe biochemical and morphological differences in chronic Achilles tendinopathy. The ex...

  4. The physiological and biochemical bases of functional brain imaging

    OpenAIRE

    2007-01-01

    Functional brain imaging is based on the display of computer-derived images of changes in physiological and/or biochemical functions altered by activation or depression of local functional activities in the brain. This article reviews the physiological and biochemical mechanisms involved.

  5. Biochemical evaluation of phenylketonuria (PKU: from diagnosis to treatment

    Directory of Open Access Journals (Sweden)

    Leticia Belmont-Martínez

    2014-07-01

    Besides periodical Phe and Tyr testing, biochemical follow-up includes the measurement of necessary elements that guarantee normal physical and intellectual development such as selenium, zinc, B12 vitamin, folates, iron and long chain fatty acids. Clinical context is as important as biochemical status so periodic evaluation of nutritional, medical, social and psychological aspects should be included.

  6. Biochemical diagnosis of pheochromocytoma: which test is best?

    NARCIS (Netherlands)

    Lenders, J.W.M.; Pacak, K.; Walther, M.M.; Linehan, W.M.; Mannelli, M.; Friberg, P.; Keiser, H.R.; Goldstein, D.S.; Eisenhofer, G.

    2002-01-01

    CONTEXT: Diagnosis of pheochromocytoma depends on biochemical evidence of catecholamine production by the tumor. However, the best test to establish the diagnosis has not been determined. OBJECTIVE: To determine the biochemical test or combination of tests that provides the best method for diagnosis

  7. Editorial: ESBES - European Society of Biochemical Engineering Sciences.

    Science.gov (United States)

    Ferreira, Guilherme; Jungbauer, Alois

    2013-06-01

    The latest ESBES special issue on "Biochemical Engineering Sciences" is edited by Prof. Guilherme Ferreira (Chairman, ESBES) and Prof. Alois Jungbauer (co-Editor-in-Chief, Biotechnology Journal). This special issue comprises the latest research in biochemical engineering science presented at the 9(th) ESBES Conference held in Istanbul, Turkey in 2012.

  8. Groupware requirements evolution patterns

    NARCIS (Netherlands)

    Pumareja, Dulce Trinidad

    2013-01-01

    Requirements evolution is a generally known problem in software development. Requirements are known to change all throughout a system's lifecycle. Nevertheless, requirements evolution is a poorly understood phenomenon. Most studies on requirements evolution focus on changes to written specifications

  9. Functional properties of the oxygen evolving complex of photosystem II.

    NARCIS (Netherlands)

    Vliet, van P.H.

    1996-01-01

    This Thesis presents the results of a study by electron paramagnetic resonance (EPR) and measurements of oxygen evolution of the Oxygen Evolving Complex of Photosystem 11 (PS-II) in PS-II enriched membranes from spinach.The experimental part of this Thesis is preceded by a general introduction (Chap

  10. Has Human Evolution Stopped?

    OpenAIRE

    TEMPLETON, Alan R

    2010-01-01

    It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important ...

  11. The Metal Abundance across Cosmic Time ($\\mathcal{MACT}$) Survey II: Evolution of the Mass-Metallicity Relation over 8 Billion Years, using [OIII]$\\lambda$4363\\AA-based Metallicities

    CERN Document Server

    Ly, Chun; Rigby, Jane; Nagao, Tohru

    2016-01-01

    [Abridged] We present the results of MMT and Keck spectroscopy for a large sample of $0.1\\leq z\\leq1$ emission-line galaxies selected from our narrow-band imaging in the Subaru Deep Field. In total, we have measured the weak [OIII]$\\lambda$4363 line for 164 galaxies (66 with at least 3$\\sigma$ detections, and 98 with significant upper limits). The strength of this nebular emission line is set by the electron temperature ($T_e$) for the ionized gas in these galaxies. Since the gas temperature is regulated by the metal content, an inverse relationship exists between gas-phase oxygen abundance and [OIII]$\\lambda$4363 line strength. Our $T_e$-based metallicity study is the first to span $\\approx$8 Gyr of cosmic time and $\\approx$3 dex in stellar mass for low-mass galaxies, $\\log{(M_{star}/M_{sun})}\\approx6.0-9.0$. Combined with extensive multi-wavelength photometry, we investigate the evolution of the stellar mass--gas metallicity relation, and its dependence on dust-corrected star formation rate. The latter is o...

  12. Calibration campaign against the international prototype of the kilogram in anticipation of the redefinition of the kilogram, part II: evolution of the BIPM as-maintained mass unit from the 3rd periodic verification to 2014

    Science.gov (United States)

    de Mirandés, Estefanía; Barat, Pauline; Stock, Michael; Milton, Martin J. T.

    2016-10-01

    In 2014 the Bureau International des Poids et Mesures (BIPM) carried out a calibration campaign using the international prototype of the kilogram (IPK). This is the second part in a series of publications describing the results of that campaign. As reported in [Metrologia 52 310–6] following the comparisons between the IPK and its official copies, it was found that the BIPM ‘as-maintained mass unit’ was offset by 35 mg from the mass of the IPK in 2014. We report here the results of an investigation into this offset that has considered all data available from internal BIPM mass comparisons carried out between 1992 and 2014. This has enabled us to model the evolution of the offset in the as-maintained mass unit and to identify some possible reasons why it has developed. We also report how the model has been used to estimate corrections to all 1 kg mass calibration certificates issued by the BIPM during this period.

  13. Structural visualization of the p53/RNA polymerase II assembly.

    Science.gov (United States)

    Singh, Sameer K; Qiao, Zhen; Song, Lihua; Jani, Vijay; Rice, William; Eng, Edward; Coleman, Robert A; Liu, Wei-Li

    2016-11-15

    The master tumor suppressor p53 activates transcription in response to various cellular stresses in part by facilitating recruitment of the transcription machinery to DNA. Recent studies have documented a direct yet poorly characterized interaction between p53 and RNA polymerase II (Pol II). Therefore, we dissected the human p53/Pol II interaction via single-particle cryo-electron microscopy, structural docking, and biochemical analyses. This study reveals that p53 binds Pol II via the Rpb1 and Rpb2 subunits, bridging the DNA-binding cleft of Pol II proximal to the upstream DNA entry site. In addition, the key DNA-binding surface of p53, frequently disrupted in various cancers, remains exposed within the assembly. Furthermore, the p53/Pol II cocomplex displays a closed conformation as defined by the position of the Pol II clamp domain. Notably, the interaction of p53 and Pol II leads to increased Pol II elongation activity. These findings indicate that p53 may structurally regulate DNA-binding functions of Pol II via the clamp domain, thereby providing insights into p53-regulated Pol II transcription.

  14. Central effects of angiotensin II, its fragment and analogues.

    Science.gov (United States)

    Georgiev, V P; Klousha, V E; Petkov, V D; Markovska, V L; Svirskis, S V; Mountsinietse, R K; Anouans, Z E

    1984-01-01

    The effects of the octapeptide angiotensin II (AT II), its fragment Ile8 AT3-8 and the analogues Sar1 Ala8 AT II, Ala8 AT II and Ile8 AT II were studied with respect to: the level of biogenic amines (DA, 5-HT and their metabolites HVA and 5-HIAA) in the forebrain; the behaviour of the animals--haloperidol catalepsy, apomorphine stereotypy, unconditioned jumping reaction (UJR), convulsive threshold. Good correlation was found between the biochemical and behavioural effects. The fragment of AT II where phenylalanine is substituted at the C-terminal by Ile reduces the haloperidol-increased content of HVA, potentiates apomorphine stereotypy and reduces catalepsy, whereas the AT II analogues (where the C-terminal phenylalanine is substituted by Ala, and the N-terminal--by Sar) potentiate the effect of haloperidol increasing the HVA content, reduce apomorphine stereotypy and potentiate catalepsy; saralasine independently applied induces brief catalepsy; AT II, its fragment and analogues inhibit UJR, in combination with amphetamine and PTZ this effect becomes deeper; the duration of hexobarbital sleep is increased. The peptides investigated increase the convulsive threshold. The results show that the hexapeptide fragment has preserved the effects of AT II, whereas in the analogues (with changed C- and N-terminals) they are changed. The results obtained may be explained with the modulating influence of AT II-receptors on the DA-ergic receptors in the brain structures with which AT II and its fragment and analogues enter in contact.

  15. BALL - biochemical algorithms library 1.3

    Directory of Open Access Journals (Sweden)

    Stöckel Daniel

    2010-10-01

    Full Text Available Abstract Background The Biochemical Algorithms Library (BALL is a comprehensive rapid application development framework for structural bioinformatics. It provides an extensive C++ class library of data structures and algorithms for molecular modeling and structural bioinformatics. Using BALL as a programming toolbox does not only allow to greatly reduce application development times but also helps in ensuring stability and correctness by avoiding the error-prone reimplementation of complex algorithms and replacing them with calls into the library that has been well-tested by a large number of developers. In the ten years since its original publication, BALL has seen a substantial increase in functionality and numerous other improvements. Results Here, we discuss BALL's current functionality and highlight the key additions and improvements: support for additional file formats, molecular edit-functionality, new molecular mechanics force fields, novel energy minimization techniques, docking algorithms, and support for cheminformatics. Conclusions BALL is available for all major operating systems, including Linux, Windows, and MacOS X. It is available free of charge under the Lesser GNU Public License (LPGL. Parts of the code are distributed under the GNU Public License (GPL. BALL is available as source code and binary packages from the project web site at http://www.ball-project.org. Recently, it has been accepted into the debian project; integration into further distributions is currently pursued.

  16. Robustness analysis of stochastic biochemical systems.

    Science.gov (United States)

    Ceska, Milan; Safránek, David; Dražan, Sven; Brim, Luboš

    2014-01-01

    We propose a new framework for rigorous robustness analysis of stochastic biochemical systems that is based on probabilistic model checking techniques. We adapt the general definition of robustness introduced by Kitano to the class of stochastic systems modelled as continuous time Markov Chains in order to extensively analyse and compare robustness of biological models with uncertain parameters. The framework utilises novel computational methods that enable to effectively evaluate the robustness of models with respect to quantitative temporal properties and parameters such as reaction rate constants and initial conditions. We have applied the framework to gene regulation as an example of a central biological mechanism where intrinsic and extrinsic stochasticity plays crucial role due to low numbers of DNA and RNA molecules. Using our methods we have obtained a comprehensive and precise analysis of stochastic dynamics under parameter uncertainty. Furthermore, we apply our framework to compare several variants of two-component signalling networks from the perspective of robustness with respect to intrinsic noise caused by low populations of signalling components. We have successfully extended previous studies performed on deterministic models (ODE) and showed that stochasticity may significantly affect obtained predictions. Our case studies demonstrate that the framework can provide deeper insight into the role of key parameters in maintaining the system functionality and thus it significantly contributes to formal methods in computational systems biology.

  17. Skin biochemical composition analysis by Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Patricia Karen; Tosato, Maira Gaspar; Alves, Rani de Souza; Martin, Airton Abrahao; Favero, Priscila Pereira; Raniero, Leandro, E-mail: amartin@univap.br [Laboratorio de Espectroscopia Vibracional Biomedica, Instituto de Pesquisa e Desenvolvimento - IP e D, Universidade do Vale do Paraiba - UniVap, Sao Jose dos Campos, SP (Brazil)

    2012-09-15

    Skin aging is characterized by cellular and molecular alterations. In this context, Confocal Raman spectroscopy was used in vivo to measure these biochemical changes as function of the skin depth. In this study we have tried to correlate spectra from pure amino acids to in vivo spectra from volunteers with different ages. This study was performed on 32 volunteers: 11 from Group A (20-23 years), 11 from Group B (39-42 years) and 10 from Group C (59-62 years). For each group, the Raman spectra were measured on the surface (0 mm), 30 +- 3 mm and 60 +- 3 {mu}m below the surface. The results from intergroup comparisons showed that the oldest group had a prevalence of the tyrosine band, but it also presented a decrease in the band centered at 875 cm{sup -1} of pyrrolidone acid. The amide I band centered at 1637 cm{sup -1} that is attributed to collagen, as well as other proteins and lipid, showed a smaller amount of these biomolecules for Group C, which can be explained by the decrease in collagen concentration as a function of age. (author)

  18. PHA bioplastics, biochemicals, and energy from crops.

    Science.gov (United States)

    Somleva, Maria N; Peoples, Oliver P; Snell, Kristi D

    2013-02-01

    Large scale production of polyhydroxyalkanoates (PHAs) in plants can provide a sustainable supply of bioplastics, biochemicals, and energy from sunlight and atmospheric CO(2). PHAs are a class of polymers with various chain lengths that are naturally produced by some microorganisms as storage materials. The properties of these polyesters make them functionally equivalent to many of the petroleum-based plastics that are currently in the market place. However, unlike most petroleum-derived plastics, PHAs can be produced from renewable feedstocks and easily degrade in most biologically active environments. This review highlights research efforts over the last 20 years to engineer the production of PHAs in plants with a focus on polyhydroxybutryrate (PHB) production in bioenergy crops with C(4) photosynthesis. PHB has the potential to be a high volume commercial product with uses not only in the plastics and materials markets, but also in renewable chemicals and feed. The major challenges of improving product yield and plant fitness in high biomass yielding C(4) crops are discussed in detail.

  19. The evolution of peptide hormones.

    Science.gov (United States)

    Niall, H D

    1982-01-01

    Despite limitations in our present knowledge it is already possible to discern the main features of peptide hormone evolution, since the same mechanisms (and indeed the same hormone molecules) function in many different ways. This underlying unity of organization has its basis in the tendency of biochemical networks, once established, to survive and diversify. The most surprising recent findings in endocrinology have been the discovery of vertebrate peptide hormones in multiple sites within the same organism, and the reports, persuasive but requiring confirmation, of vertebrate hormones in primitive unicellular organisms (20, 20a). Perhaps the major challenge for the future is to define the roles and interactions of the many peptide hormones identified in brain (18). The most primitive bacteria and the human brain, though an enormous evolutionary distance apart, may have more in common than we have recognized until now. As Axelrod & Hamilton have pointed out in a recent provocative article, "The Evolution of Cooperation" (1), bacteria, though lacking a brain, are capable of adaptive behavior that can be analysed in terms of game theory. It is clear that we can learn a great deal about the whole evolutionary process from a study of the versatile and durable peptide hormones molecules.

  20. Nudging Evolution?

    Directory of Open Access Journals (Sweden)

    Katharine N. Farrell

    2013-12-01

    Full Text Available This Special Feature, "Nudging Evolution? Critical Exploration of the Potential and Limitations of the Concept of Institutional Fit for the Study and Adaptive Management of Social-Ecological Systems," aims to contribute toward the development of social theory and social research methods for the study of social-ecological system dynamics. Our objective is to help strengthen the academic discourse concerning if, and if so, how, to what extent, and in what concrete ways the concept of institutional "fit" might play a role in helping to develop better understanding of the social components of interlinkages between the socioeconomic-cultural and ecological dynamics of social-ecological systems. Two clearly discernible patterns provide a map of this Special Feature: (1 One pattern is the authors' positions regarding the place and role of normativity within their studies and assessment of institutional fit. Some place this at the center of their studies, exploring phenomena endogenous to the process of defining what constitutes institutional fit, whereas others take the formation of norms as a phenomenon exogenous to their study. (2 Another pattern is the type of studies presented: critiques and elaborations of the theory, methods for judging qualities of fit, and/or applied case studies using the concept. As a body of work, these contributions highlight that self-understanding of social-ecological place, whether explicit or implicit, constitutes an important part of the study object, i.e., the role of institutions in social-ecological systems, and that this is, at the same time, a crucial point of reference for the scholar wishing to evaluate what constitutes institutional fit and how it might be brought into being.

  1. Synthesis, spectral characterization thermal stability, antimicrobial studies and biodegradation of starch–thiourea based biodegradable polymeric ligand and its coordination complexes with [Mn(II, Co(II, Ni(II, Cu(II, and Zn(II] metals

    Directory of Open Access Journals (Sweden)

    Nahid Nishat

    2016-09-01

    Full Text Available A biodegradable polymer was synthesized by the modification reaction of polymeric starch with thiourea which is further modified by transition metals, Mn(II, Co(II, Ni(II, Cu(II and Zn(II. All the polymeric compounds were characterized by (FT-IR spectroscopy, 1H NMR spectroscopy, 13C NMR spectroscopy, UV–visible spectra, magnetic moment measurements, thermogravimetric analysis (TGA and antibacterial activities. Polymer complexes of Mn(II, Co(II and Ni(II show octahedral geometry, while polymer complexes of Cu(II and Zn(II show square planar and tetrahedral geometry, respectively. The TGA revealed that all the polymer metal complexes are more thermally stable than their parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM-D-5338-93 standards of biodegradable polymers by CO2 evolution method which says that coordination decreases biodegradability. The antibacterial activity was screened with the agar well diffusion method against some selected microorganisms. Among all the complexes, the antibacterial activity of the Cu(II polymer–metal complex showed the highest zone of inhibition because of its higher stability constant.

  2. Four methods compared for measuring des-carboxy-prothrombin (PIVKA-II).

    Science.gov (United States)

    Widdershoven, J; van Munster, P; De Abreu, R; Bosman, H; van Lith, T; van der Putten-van Meyel, M; Motohara, K; Matsuda, I

    1987-11-01

    PIVKA-II (Protein Induced by Vitamin K Absence) is abnormal des-carboxylated prothrombin, which is present in vitamin K deficiency or in patients using warfarin. With a sensitive method for PIVKA-II, biochemical vitamin K deficiency can be established before clinical symptoms occur. We give an overview of methods used to detect PIVKA-II, and four selected methods are inter-compared: (a) measuring total factor II including PIVKA-II by using Echis carinatus snake venom as an activator of prothrombin; (b) measuring PIVKA-II by using snake venom as an activator of factor II after adsorption of functional factor II onto barium sulfate; (c) electrophoresis-immunofixation method; and (d) enzyme immunoassay. We found d to be the most sensitive and reliable method for PIVKA-II.

  3. [Tyrosinemia type II. Case report].

    Science.gov (United States)

    Benatiya, A I; Bouayed, M A; Touiza, E; Daoudi, K; Bhalil, S; Elmesbahi, I; Tahri, H

    2005-01-01

    Tyrosinemia type II or Richner-Hanhart syndrome is a rare hereditary disease characterized by the association of pseudoherpetiform corneal ulcerations and palmoplantar hyperkeratosis. We report the case of a 12 year-old young man presenting a superficial punctate keratitis and a corneal dystrophy in both eyes, associated with a palmoplantar hyperkeratosis. The dosage of the serum level of tyrosine is meaningfully raised to 1236 micromol/l. A dietary treatment restraining tyrosine and phenylalanine is started with favorable results after an evolution of 6 months. Tyrosinemia type II is an autosomal recessive disease, due to an enzymatic deficit in tyrosine aminotransferase. The diagnosis is based on the clinic and high level of serum and urinary tyrosine as well as of its urinary metabolites. This disease must be suspected in all cases of dentritic keratitis not reacting on the antiviral treatment, and more especially if it is associated with cutaneous lesions such as palmo-plantar keratosis.

  4. Predicting outcomes in organophosphate poisoning based on APACHE II and modified APACHE II scores.

    Science.gov (United States)

    Eizadi-Mood, N; Saghaei, M; Jabalameli, M

    2007-07-01

    The aim of this study was to evaluate the scores of the Acute Physiology and Chronic Health Evaluation (APACHE) II and a modified APACHE II system (MAS), without parameters of biochemical tests; and to find prognostic value of individual elements of the APACHE II and MAS in predicting outcomes in organophosphate (OP) poisoning. Data were collected from 131 patients. The median (25th-75th percentiles) of APACHE II score for survivors without intubation were found to be lower than those of non survivors or survivors with intubation and ventilation, [4 (1-7); versus 17.5 (7.8-29), and 13.5 (7.8-16.3)]. Logistic regression analysis identified white blood cell (WBC), potassium, Glasgow coma scale (GCS), age and sodium in APACHE II; GCS and mean arterial pressure in MAS system as prognostically valuable. There was no statistically significance difference between APACHE II and MAS scores in terms of area under Receiver Operating Characteristic Curve [(0.902, 95% confidence interval: (0.837-0.947) for APACHE II), and (0.892, 95% confidence interval: (0.826-0.940) for MAS); P=0.74) to predict need for intubation. It is concluded usage of MAS facilitates the prognostication of the OP poisoned patients due to simplicity, less time-consuming and effectiveness in an emergency situation.

  5. The Biochemical Prognostic Factors of Subclinical Hypothyroidism

    Directory of Open Access Journals (Sweden)

    Myung Won Lee

    2014-06-01

    Full Text Available BackgroundPatients with subclinical hypothyroidism (SHT are common in clinical practice. However, the clinical significance of SHT, including prognosis, has not been established. Further clarifying SHT will be critical in devising a management plan and treatment guidelines for SHT patients. Thus, the aim of this study was to investigate the prognostic factors of SHT.MethodsWe reviewed the medical records of Korean patients who visited the endocrinology outpatient clinic of Severance Hospital from January 2008 to September 2012. Newly-diagnosed patients with SHT were selected and reviewed retrospectively. We compared two groups: the SHT maintenance group and the spontaneous improvement group.ResultsThe SHT maintenance group and the spontaneous improvement group had initial thyroid-stimulating hormone (TSH levels that were significantly different (P=0.035. In subanalysis for subjects with TSH levels between 5 to 10 µIU/mL, the spontaneous improvement group showed significantly lower antithyroid peroxidase antibody (anti-TPO-Ab titer than the SHT maintenance group (P=0.039. Regarding lipid profiles, only triglyceride level, unlike total cholesterol and low density lipoprotein cholesterol, was related to TSH level, which is correlated with the severity of SHT. Diffuse thyroiditis on ultrasonography only contributed to the severity of SHT, not to the prognosis. High sensitivity C-reactive protein and urine iodine excretion, generally regarded as possible prognostic factors, did not show any significant relation with the prognosis and severity of SHT.ConclusionOnly initial TSH level was a definite prognostic factor of SHT. TPO-Ab titer was also a helpful prognostic factor for SHT in cases with mildly elevated TSH. Other than TSH and TPO-Ab, we were unable to validate biochemical prognostic factors in this retrospective study for Korean SHT patients.

  6. Biochemical Evolution and Histological Response of Patients with Hepatitis C Undergoing Antiviral Therapy.

    Directory of Open Access Journals (Sweden)

    Omar Julián Hernández Ojeda

    2011-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 Fundamento: la hepatitis C es uno de los principales problemas de salud a nivel mundial y la indicación más frecuente de transplante hepático en muchos países. Objetivo: determinar la evolución bioquímica y respuesta histológica de pacientes con hepatitis crónica tipo C bajo tratamiento con Interferón alfa 2b recombinante y ribavirina atendidos en consulta provincial de Hepatología. Métodos: estudio observacional y descriptivo, en 31 pacientes portadores del virus de la hepatitis C, remitidos a la consulta de Hepatología Provincial de Cienfuegos en el Hospital Universitario “Dr. Gustavo Aldereguía Lima”, entre enero de 2007 y junio de 2009; y tratados con interferon alfa 2b recombinante más ribavirina. Se estudiaron las variables: edad, sexo, posible vía de infección, valores séricos de alanito aminotransferasa, evaluación bioquímica (al concluir el tratamiento y al finalizar el seguimiento y respuesta histológica. Para la evaluación de la actividad histológica de las lesiones hepáticas crónicas se empleó el índice de Knodell. Para comparar los resultados (respuesta bioquímica y la respuesta histológica antes y después del tratamiento se empleó la Prueba de los Signos. Resultados: El sexo femenino predominó en la muestra (58,1 %. La edad promedio fue de 45,5±11,6 años. La vía posible de trasmisión no se pudo identificar en 51,6 % de los pacientes. El tratamiento quirúrgico fue identificado como vía de infección en el 22,6 %, seguido del tratamiento parenteral reiterado (16,1 %. Conclusión: al finalizar el tratamiento se obtuvo un mayor porcentaje de respuesta en cuanto a la evolución bioquímica y a la respuesta histológica.

  7. RESEARCES REGARDING THE SANGUINE CORTISOL EVOLUTION, AS BIOCHEMICAL INDEX, IN SPORT HORSES IN COMPLETE HORSE TRIAL

    Directory of Open Access Journals (Sweden)

    EUGENIA ŞOVĂREL

    2013-12-01

    Full Text Available Using the horse for sport activities needs a good training and an optimization ofphysical and psychical qualities, both contributing to achieve the wantedperformances. Physical effort impose to the horse in different competitions is a stresssituation, fact which induce an endocrine answer, materialised through increasingthe sanguine levels of some hormones and decreasing of others. The purpose of thisstudy was to verify if the training and the effort intensity is reflected in the sanguinecortisol behaviour in sport horses.

  8. SOME BIOCHEMICAL BLOOD CONSTANTS EVOLUTION IN REPORT TO THE TRAINING SCHEDULE STAGE IN SPORT HORSES

    Directory of Open Access Journals (Sweden)

    FLAVIA BOCHIS

    2013-12-01

    Full Text Available To determine whether a clinical examination was adequate to assess the fitness of horses in a fence course riding, and to characterize the relationship between a clinical assessment of the horse's fitness, training schedule stage and its blood biochemistry, 22 horses were monitored before (S1, during training, immediately after warming-up (S2 and after an E level fence obstacle course ride (S3. The blood samples were taken from the jugular vein in the above three mentioned phases, for the determination of total protein (g/dl, nitrogen (mg/dl, glucose (mg/dl, lactic acid (nmol/l, calcium (mg/dl, cholesterol (mg/dl and phosphorus (mg/dl. The intend of the paper is to present the obtained results as a reference study for the appropriate use by clinicians, sport horses owners and trainers in view to have a solid base in evaluation, for the adequate protection of health and welfare of the jumper horses competitors.

  9. Identification, Biochemical Characterization, and Evolution of the Rhizopus oryzae 99-880 Polygalacturonase Gene Family

    Science.gov (United States)

    A search of the recently sequenced Rhizopus oryzae strain 99-880 genome database uncovered 18 putative polygalacturonase genes with 2 genes being identical and only 1 with similarity to a previously reported R. oryzae polygalacturonase gene. The 17 different genes share 50% to greater than 90% iden...

  10. Guess-Work and Reasonings on Centennial Evolution of Surface Air Temperature in Russia. Part II: Is it Possible to Research Both Local Peculiarities and Regional Tendencies from the Bifurcation Analysis Viewpoint?

    Science.gov (United States)

    Kolokolov, Yury; Monovskaya, Anna

    analyze. Since only the historical data of the temperature observations are used, then the results approach as close as possible to the real events. We believe that our research seems to be interesting to estimate the theoretically possible latent abilities and evolution of the local climate dynamics.

  11. Small Diameter Bomb Increment II (SDB II)

    Science.gov (United States)

    2015-12-01

    Bomb Increment II (SDB II) DoD Component Air Force Joint Participants Department of the Navy Responsible Office References SAR Baseline ( Production ...Selected Acquisition Report (SAR) RCS: DD-A&T(Q&A)823-439 Small Diameter Bomb Increment II (SDB II) As of FY 2017 President’s Budget Defense...Funding 19 Low Rate Initial Production 31 Foreign Military Sales 32 Nuclear Costs 32 Unit Cost 33 Cost Variance 36 Contracts

  12. Role of cryptic genes in microbial evolution.

    Science.gov (United States)

    Hall, B G; Yokoyama, S; Calhoun, D H

    1983-12-01

    Cryptic genes are phenotypically silent DNA sequences, not normally expressed during the life cycle of an individual. They may, however, be activated in a few individuals of a large population by mutation, recombination, insertion elements, or other genetic mechanisms. A consideration of the microbial literature concerning biochemical evolution, physiology, and taxonomy provides the basis for a hypothesis of microbial adaptation and evolution by mutational activation of cryptic genes. Evidence is presented, and a mathematical model is derived, indicating that powerful and biologically important mechanisms exist to prevent the loss of cryptic genes. We propose that cryptic genes persist as a vital element of the genetic repertoire, ready for recall by mutational activation in future generations. Cryptic genes provide a versatile endogenous genetic reservoir that enhances the adaptive potential of a species by a mechanism that is independent of genetic exchange.

  13. Origins and Evolution of Life

    Science.gov (United States)

    Gargaud, Muriel; López-García, Purificación; Martin, Hervé

    2011-01-01

    Part I. What Is Life?: 1. Problems raised by a definition of life M. Morange; 2. Some remarks about uses of cosmological anthropic 'principles' D. Lambert; 3. Minimal cell: the biologist point of view C. Brochier-Armanet; 4. Minimal cell: the computer scientist point of view H. Bersini; 5. Origins of life: computing and simulation approaches B. Billoud; Part II. Astronomical and Geophysical Context of the Emergence of Life: 6. Organic molecules in interstellar medium C. Ceccarelli and C. Cernicharo; 7. Cosmochemical evolution and the origin of life: insights from meteorites S. Pizzarello; 8. Astronomical constraints on the emergence of life M. Gounelle and T. Montmerle; 9. Formation of habitable planets J. Chambers; 10. The concept of galactic habitable zone N. Prantzos; 11. The young Sun and its influence on planetary atmospheres M. Güdel and J. Kasting; 12. Climates of the Earth G. Ramstein; Part III. Role of Water in the Emergence of Life: 13. Liquid water: a necessary condition to all forms of life K. Bartik, G. Bruylants, E. Locci and J. Reisse; 14. The role of water in the formation and evolution of planets T. Encrenaz; 15. Water on Mars J. P. Bibring; Part IV. From Non-Living Systems to Life: 16. Energetic constraints on prebiotic pathways: application to the emergence of translation R. Pascal and L. Boiteau; 17. Comparative genomics and early cell evolution A. Lazcano; 18. Origin and evolution of metabolisms J. Peretó; Part V. Mechanisms for Life Evolution: 19. Molecular phylogeny: inferring the patterns of evolution E. Douzery; 20. Horizontal gene transfer: mechanisms and evolutionary consequences D. Moreira; 21. The role of symbiosis in eukaryotic evolution A. Latorre, A. Durbán, A. Moya and J. Peretó; Part VI. Life in Extreme Conditions: 22. Life in extreme conditions: Deinococcus radiodurans, an organism able to survive prolonged desiccation and high doses of ionising radiation S. Sommer and M. Toueille; 23. Molecular effects of UV and ionizing

  14. Elizabeth II uus kunstigalerii

    Index Scriptorium Estoniae

    1999-01-01

    Tähistamaks oma troonile asumise 50. aastapäeva, avab Elizabeth II 6. II 2002 Buckinghami palees uue kunstigalerii, mis ehitatakse palee tiibhoonena. Arhitekt John Simpson. Elizabeth II kunstikogust

  15. Diclofenac-induced biochemical and histopathological changes in white leghorn birds (Gallus domesticus

    Directory of Open Access Journals (Sweden)

    Jain Teenu

    2009-01-01

    Full Text Available Objective : Objective: To evaluate diclofenac-induced biochemical and histopathological changes in White Leghorn birds. Materials and Methods : Six-week-old birds were equally divided into three groups of six birds each. Group I served as control and received vehicle orally. The birds of Group II and III were orally administered with a single low (2 mg/kg and high dose (20 mg/kg of diclofenac sodium, respectively, and were observed for 7 days. The acute toxicity was assessed by observing the clinical signs and symptoms, mortality, alterations in blood biochemistry, and necropsy findings. Results : The birds of Group II showed only mild symptoms of diarrhea. In Group III, 50% of birds died in between 24 and 36 h post-treatment showing the symptoms of segregatory behavior, lethargy, terminal anorexia, and severe bloody diarrhea. The birds of Group II and the surviving birds of Group III showed a significantly (P< 0.05 increased plasma uric acid, creatinine and plasma glutamic pyruvic transaminase (PGPT, and decreased total protein and albumin at 12 and 24 h post-treatment which returned to the normal levels at 36 h post-treatment. The dead birds of the high-dose group also showed similar pattern of biochemical changes at 12 and 24 h post-treatment and revealed extensive visceral gout with characteristic histopathological lesions in liver, kidney, heart, spleen, and intestine on post-mortem. Conclusion : The results indicate that diclofenac sodium has hepatotoxic, nephrotoxic, and visceral gout inducing potentials in White Leghorn birds, especially at higher dose.

  16. Evolution prediction from tomography

    Science.gov (United States)

    Dominy, Jason M.; Venuti, Lorenzo Campos; Shabani, Alireza; Lidar, Daniel A.

    2017-03-01

    Quantum process tomography provides a means of measuring the evolution operator for a system at a fixed measurement time t. The problem of using that tomographic snapshot to predict the evolution operator at other times is generally ill-posed since there are, in general, infinitely many distinct and compatible solutions. We describe the prediction, in some "maximal ignorance" sense, of the evolution of a quantum system based on knowledge only of the evolution operator for finitely many times 0evolution at times away from the measurement times. Even if the original evolution is unitary, the predicted evolution is described by a non-unitary, completely positive map.

  17. EVALUATION OF THE EXTRACTS OF LEUCAS ASPERA ON BIOCHEMICAL PROFILES IN EXPERIMENTAL MODEL OF DIABETES MELLITUS (TYPE- I IN RATS

    Directory of Open Access Journals (Sweden)

    T.Tukaram

    2011-03-01

    Full Text Available The study was conducted to evaluate the effect of Leucas aspera leaves on experimental diabetes mellitus (type I in rats in terms of alterations in biochemical profiles. Thirty rats were randomly divided into six groups of 5 rats in each. Group-I were fed on basal diet without any treatment, group-II induced diabetic models (type-I (Alloxan monohydrate dissolved in sterile normal saline (150 mg/kgBW, ip, group-III, IV, V and VI were induced diabetics and treated with extract of Leucas aspera (30,100,150 and 300mg/kg BW respectively, PO twice daily in the morning and evening post prandially for thirty days respectively. The blood samples were collected on day 0, 10, 20 and 30 and were used for the analysis of biochemical profiles.The blood glucose (mg% were consistently increased significantly (P<0.01 in groups II,III, IV V and VI till day 20 while in groups V and VI there was a significant (P<0.01 decline in the values on day 30. There was found to have profound effect in lowering the blood glucose levels in dose dependent manner. The study revealed that experimental diabetes mellitus (type-I induced patho-biochemical changes were ameliorated more effectively by ethanolic extract of Leucas aspera in dose dependent manner.

  18. 40 CFR 158.2080 - Experimental use permit data requirements-biochemical pesticides.

    Science.gov (United States)

    2010-07-01

    ... requirements-biochemical pesticides. 158.2080 Section 158.2080 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical Pesticides § 158.2080 Experimental use permit data requirements—biochemical pesticides. (a) Sections...

  19. The diversity challenge in directed protein evolution.

    Science.gov (United States)

    Wong, Tuck Seng; Zhurina, Daria; Schwaneberg, Ulrich

    2006-05-01

    Over the past decade, we have witnessed a bloom in the field of evolutive protein engineering which is fueled by advances in molecular biology techniques and high-throughput screening technology. Directed protein evolution is a powerful algorithm using iterative cycles of random mutagenesis and screening for tailoring protein properties to our needs in industrial applications and for elucidating proteins' structure function relationships. This review summarizes, categorizes and discusses advantages and disadvantages of random mutagenesis methods used for generating genetic diversity. These random mutagenesis methods have been classified into four main categories depending on the method employed for nucleotide substitutions: enzyme based methods (Category I), synthetic chemistry based methods (Category II), whole cell methods (Category III) and combined methods (Category I-II, I-III and II-III). The basic principle of each method is discussed and varied mutagenic conditions are summarized in Tables and compared (benchmarked) to each other in terms of: mutational bias, controllable mutation frequency, ability to generate consecutive nucleotide substitutions and subset diversity, dependency on gene length, technical simplicity/robustness and cost-effectiveness. The latter comparison shows how highly-biased and limited current diversity creating methods are. Based on these limitations, strategies for generating diverse mutant libraries are proposed and discussed (RaMuS-Flowchart; KISS principle). We hope that this review provides, especially for researchers just entering the field of directed evolution, a guide for developing successful directed evolution strategies by selecting complementary methods for generating diverse mutant libraries.

  20. Study of interfacial phenomena for bio/chemical sensing applications

    Science.gov (United States)

    Min, Hwall

    This work presents the fundamental study of biological and chemical interfacial phenomena and (bio)chemical sensing applications using high frequency resonator arrays. To realize a versatile (bio)chemical sensing system for the fundamental study as well as their practical applications, the following three distinct components were studied and developed: i) detection platforms with high sensitivity, ii) novel innovative sensing materials with high selectivity, iii) analytical model for data interpretation. 8-pixel micromachined quartz crystal resonator (muQCR) arrays with a fundamental resonance frequency of 60 ¡V 90 MHz have been used to provide a reliable detection platform with high sensitivity. Room temperature ionic liquid (RTIL) has been explored and integrated into the sensing system as a smart chemical sensing material. The use of nanoporous gold (np-Au) enables the combination of the resonator and surface-enhanced Raman spectroscopy for both quantitative and qualitative measurement. A statistical model for the characterization of resonator behavior to study the protein adsorption kinetics is developed by random sequential adsorption (RSA) approach with the integration of an effective surface depletion theory. The investigation of the adsorption kinetics of blood proteins is reported as the fundamental study of biological phenomena using the proposed sensing system. The aim of this work is to study different aspects of protein adsorption and kinetics of adsorption process with blood proteins on different surfaces. We specifically focus on surface depletion effect in conjunction with the RSA model to explain the observed adsorption isotherm characteristics. A number of case studies on protein adsorption conducted using the proposed sensing system has been discussed. Effort is specifically made to understand adsorption kinetics, and the effect of surface on the adsorption process as well as the properties of the adsorbed protein layer. The second half of the

  1. Recent Advances in Shell Evolution with Shell-Model Calculations

    CERN Document Server

    Utsuno, Yutaka; Tsunoda, Yusuke; Shimizu, Noritaka; Honma, Michio; Togashi, Tomoaki; Mizusaki, Takahiro

    2014-01-01

    Shell evolution in exotic nuclei is investigated with large-scale shell-model calculations. After presenting that the central and tensor forces produce distinctive ways of shell evolution, we show several recent results: (i) evolution of single-particle-like levels in antimony and cupper isotopes, (ii) shape coexistence in nickel isotopes understood in terms of configuration-dependent shell structure, and (iii) prediction of the evolution of the recently established $N=34$ magic number towards smaller proton numbers. In any case, large-scale shell-model calculations play indispensable roles in describing the interplay between single-particle character and correlation.

  2. Co(II)1-xCo(0)x/3Mn(III)2x/3S Nanoparticles Supported on B/N-Codoped Mesoporous Nanocarbon as a Bifunctional Electrocatalyst of Oxygen Reduction/Evolution for High-Performance Zinc-Air Batteries.

    Science.gov (United States)

    Wang, Zilong; Xiao, Shuang; An, Yiming; Long, Xia; Zheng, Xiaoli; Lu, Xihong; Tong, Yexiang; Yang, Shihe

    2016-06-01

    Rechargeable Zn-air battery is an ideal type of energy storage device due to its high energy and power density, high safety, and economic viability. Its large-scale application rests upon the availability of active, durable, low-cost electrocatalysts for the oxygen reduction reaction (ORR) in the discharge process and oxygen evolution reaction (OER) in the charge process. Herein we developed a novel ORR/OER bifunctional electrocatalyst for rechargeable Zn-air batteries based on the codoping and hybridization strategies. The B/N-codoped mesoporous nanocarbon supported Co(II)1-xCo(0)x/3Mn(III)2x/3S nanoparticles exhibit a superior OER performance compared to that of IrO2 catalyst and comparable Zn-air battery performance to that of the Pt-based battery. The rechargeable Zn-air battery shows high discharge peak power density (over 250 mW cm(-2)) and current density (180 mA cm(-2) at 1 V), specific capacity (∼550 mAh g(-1)), small charge-discharge voltage gap of ∼0.72 V at 20 mA cm(-2) and even higher stability than the Pt-based battery. The advanced performance of the bifunctional catalysts highlights the beneficial role of the simultaneous formation of Mn(III) and Co(0) as well as the dispersed hybridization with the codoped nanocarbon support.

  3. 2011 Biomass Program Platform Peer Review: Biochemical Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Pezzullo, Leslie [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

    2012-02-01

    This document summarizes the recommendations and evaluations provided by an independent external panel of experts at the 2011 U.S. Department of Energy Biomass Program’s Biochemical Conversion Platform Review meeting.

  4. Biochemical methane potential (BMP) of solid organic materials

    DEFF Research Database (Denmark)

    Raposo, Francisco; Fernández-Cegrí, V.; De la Rubia, M.A.

    2010-01-01

    This paper describes the results obtained for different participating research groups in an interlaboratory study related to the biochemical methane potential (BMP). In this research work, the full experimental conditions influencing the test such as inoculum, substrate characteristics and experi...

  5. Approaches to Chemical and Biochemical Information and Signal Processing

    Science.gov (United States)

    Privman, Vladimir

    2012-02-01

    We outline models and approaches for error control required to prevent buildup of noise when ``gates'' and other ``network elements'' based on (bio)chemical reaction processes are utilized to realize stable, scalable networks for information and signal processing. We also survey challenges and possible future research. [4pt] [1] Control of Noise in Chemical and Biochemical Information Processing, V. Privman, Israel J. Chem. 51, 118-131 (2010).[0pt] [2] Biochemical Filter with Sigmoidal Response: Increasing the Complexity of Biomolecular Logic, V. Privman, J. Halamek, M. A. Arugula, D. Melnikov, V. Bocharova and E. Katz, J. Phys. Chem. B 114, 14103-14109 (2010).[0pt] [3] Towards Biosensing Strategies Based on Biochemical Logic Systems, E. Katz, V. Privman and J. Wang, in: Proc. Conf. ICQNM 2010 (IEEE Comp. Soc. Conf. Publ. Serv., Los Alamitos, California, 2010), pages 1-9.

  6. Assessment of biochemical concentrations of vegetation using remote sensing technology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The main biochemicals (such as lignin, protein, cellulose, sugar, starch, chlorophyll and water) of vegetation are directly or indirectly involved in major ecological processes, such as the functions of terrestrial ecosystems (i.e., nutrient-cycling processes, primary production, and decomposition). Remote sensing techniques provide a very convenient way of data acquisition capable of covering a large area several times during one season, so it can play a unique and essential role provided that we can relate remote sensing measurements to the biochemical characteristics of the Earth surface in a reliable and operational way. The application of remote sensing techniques for the estimation of canopy biochemicals was reviewed. Three methods of estimating biochemical concentrations of vegetation were included in this paper: index, stepwise multiple linear regression, and stepwise multiple linear regression based on a model of the forest crown. In addition, the vitality and potential applying value are stressed.

  7. Serum biochemical parameters of farmed carp (Cyprinus carpio

    Directory of Open Access Journals (Sweden)

    Tanţi Patriche

    2011-04-01

    Full Text Available Despite advances in ichthyo-pathology of recent years, interpretation of fish serum biochemical parameters is often difficult by lack of reference values. That is why to know the value of the serum biochemical parameters can be a useful tool for monitoring health status, detecting illnesses and responses to therapy. This paper provides data concerning biochemical composition of carp serum (Cyprinus carpio bred at Brateş Farm of Institute of Research and Development for Aquatic Ecology, Fishing and Aquaculture from Galaţi and Pleaşa Farm from Ploieşti, Romania. In research conducted onCyprinus carpio were determined following serum biochemical parameters: glucose (GLU, total proteins (TP, blood urea nitrogen (BUN, cholesterol (CHOL, triglyceride (TRIG, sodium (Na, potassium (K, calcium (Ca, magnesium (Mg, phosphorus (P, iron (Fe.

  8. Anatomical and biochemical investigation of primary brain tumours

    Energy Technology Data Exchange (ETDEWEB)

    Del Sole, A. [Univ. di Milano (Italy); Falini, A. [Univ. Vita e Salute (Italy). IRCCS; Ravasi, L.; Ottobrini, L.; Lucignani, G. [Univ. di Milano (Italy). Ist. di Scienze Radiologiche; De Marchis, D. [Univ. di Milano-Bicocca (Italy); Bombardieri, E. [Istituto Nazionale dei Tumori, Milano (Italy)

    2001-12-01

    Cancerous transformation entails major biochemical changes including modifications of the energy metabolism of the cell, e.g. utilisation of glucose and other substrates, protein synthesis, and expression of receptors and antigens. Tumour growth also leads to heterogeneity in blood flow owing to focal necrosis, angiogenesis and metabolic demands, as well as disruption of transport mechanisms of substrates across cell membranes and other physiological boundaries such as the blood-brain barrier. All these biochemical, histological and anatomical changes can be assessed with emission tomography, X-ray computed tomography (CT), magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS). Whereas anatomical imaging is aimed at the diagnosis of brain tumours, biochemical imaging is better suited for tissue characterisation. The identification of a tumoural mass and the assessment of its size and vascularisation are best achieved with X-ray CT and MRI, while biochemical imaging can provide additional information that is crucial for tumour classification, differential diagnosis and follow-up. As the assessment of variables such as water content, appearance of cystic lesions and location of the tumour are largely irrelevant for tissue characterisation, a number of probes have been employed for the assessment of the biochemical features of tumours. Since biochemical changes may be related to the growth rate of cancer cells, they can be thought of as markers of tumour cell proliferation. Biochemical imaging with radionuclides of processes that occur at a cellular level provides information that complements findings obtained by anatomical imaging aimed at depicting structural, vascular and histological changes. This review focusses on the clinical application of anatomical brain imaging and biochemical assessment with positron emission tomography, single-photon emission tomography and MRS in the diagnosis of primary brain tumours, as well as in follow-up. (orig.)

  9. Diabetes, Biochemical Markers of Bone Turnover, Diabetes Control, and Bone

    OpenAIRE

    Starup-Linde, Jakob

    2013-01-01

    Diabetes mellitus is known to have late complications including micro vascular and macro vascular disease. This review focuses on another possible area of complication regarding diabetes; bone. Diabetes may affect bone via bone structure, bone density, and biochemical markers of bone turnover. The aim of the present review is to examine in vivo from humans on biochemical markers of bone turnover in diabetics compared to non-diabetics. Furthermore, the effect of glycemic control on bone marker...

  10. Evolution of plant senescence

    Directory of Open Access Journals (Sweden)

    Young Mike

    2009-07-01

    characteristics of senescence-related genes allow a framework to be constructed of decisive events in the evolution of the senescence syndrome of modern land-plants. Combining phylogenetic, comparative sequence, gene expression and morphogenetic information leads to the conclusion that biochemical, cellular, integrative and adaptive systems were progressively added to the ancient primary core process of senescence as the evolving plant encountered new environmental and developmental contexts.

  11. [Fifty years of cooperation--FEBS and Polish Biochemical Society].

    Science.gov (United States)

    Barańska, Jolanta

    2014-01-01

    This year, the Federation of European Biochemical Societies (FEBS) celebrates its 50th anniversary. The Polish Biochemical Society, represented by the Society's President, Kazimierz Zakrzewski, was a founding member of the organization. The text presents a history of collaboration between FEBS and Polish Biochemical Society, the participation of Polish Biochemical Society members in different FEBS activities, as well as the role they played in running the Federation. Author describes FEBS Congresses which taken place in Warsaw, the first 3rd FEBS Meeting in 1966 and then 29th Congress in 2004. The profiles of Jakub Karol Parnas, the founding father of the Polish biochemistry and some crucial Presidents of the Society, are also presented. The text describes Parnas Conferences, organized jointly by Polish and Ukrainian Biochemical Societies from 1996, and growing from 2011 into three-nation event with participation of Ukrainian, Israeli and Polish scientists, largely due to significant help from FEBS. Summarizing the last few years, author judge the cooperation between the Federation and the Polish Biochemical Society as optimal.

  12. Analysis of clinical and biochemical spectrum of Wilson Disease patients

    Directory of Open Access Journals (Sweden)

    Sumreena Mansoor

    2012-01-01

    Full Text Available Background and Aims: Wilson disease (WD is autosomal recessive disorder of copper metabolism. Wilson disease patients usually suffer from hepatic or neuropsychiatric complications. The symptoms appear between ages five to 35 but it can vary from two years to 72 years. Materials and Methods : Study was carried out from June 2008 to November 2010. This study included nine families with eleven cases of WD to determine clinical presentation, diagnostic findings (including laboratory results and liver histology. It included 11 patients who presented with hepatic manifestations and/or Neuropsychiatric manifestations and/or family history suggesting features of WD. Patients with hepatitis B and C and those with history of taking antipsychotic drugs were excluded from the study. Patient′s data was included in a well designed performa. Liver function test, serum ceruloplasmin, serum copper, 24 hour urinary copper, blood complete picture were analyzed. Quantitative data such as age, hemoglobin etc were expressed as mean with ± SD and quantitative variables such as sex, movement disorders, hepatic involvement etc were expressed as frequency and percentage. Results: There were five male and six female patients with evidence of various manifestations here (i hepatic in which they had only liver dysfunction (ii hepatic and neurological (iii neurological. The mean age of presentation was 8.7±3.92 years (range 4-19 years and 45% were male patients. Decreased serum ceruloplasmin, enhanced 24-h urinary copper excretion and signs of chronic liver damage were confirmed in all patients and Kayser-Fleischer rings (KF rings in 72% of patients. In severe WD patients, serum prothrombin activity was less than 50%, serum ceruloplasmin were low and serum copper levels were high than those in non-severe WD patients. High degree of suspicion leads to early treatment with good outcome. Conclusions: The WD is rare but important cause of chronic liver disease. Clinical and

  13. DNA strand generation for DNA computing by using a multi-objective differential evolution algorithm.

    Science.gov (United States)

    Chaves-González, José M; Vega-Rodríguez, Miguel A

    2014-02-01

    In this paper, we use an adapted multi-objective version of the differential evolution (DE) metaheuristics for the design and generation of reliable DNA libraries that can be used for computation. DNA sequence design is a very relevant task in many recent research fields, e.g. nanotechnology or DNA computing. Specifically, DNA computing is a new computational model which uses DNA molecules as information storage and their possible biological interactions as processing operators. Therefore, the possible reactions and interactions among molecules must be strictly controlled to prevent incorrect computations. The design of reliable DNA libraries for bio-molecular computing is an NP-hard combinatorial problem which involves many heterogeneous and conflicting design criteria. For this reason, we modelled DNA sequence design as a multiobjective optimization problem and we solved it by using an adapted multi-objective version of DE metaheuristics. Seven different bio-chemical design criteria have been simultaneously considered to obtain high quality DNA sequences which are suitable for molecular computing. Furthermore, we have developed the multiobjective standard fast non-dominated sorting genetic algorithm (NSGA-II) in order to perform a formal comparative study by using multi-objective indicators. Additionally, we have also compared our results with other relevant results published in the literature. We conclude that our proposal is a promising approach which is able to generate reliable real-world DNA sequences that significantly improve other DNA libraries previously published in the literature.

  14. [Biochemical and molecular characterization of gliadins].

    Science.gov (United States)

    Qi, P F; Wei, Y M; Yue, Y W; Yan, Z H; Zheng, Y L

    2006-01-01

    Gliadins account for about 40-50% of the total proteins in wheat seeds and play an important role on the nutritional and processing quality of flour. Usually, gliadins could be divided into alpha- (alpha/beta-), gamma- and omega-groups, whereas the low-molecular-weigh (LMW) gliadins were novel seed storage proteins. The low-molecular-weight glutenin subunits (LMW-GSs) were also designated as gliadins in a few literatures. The genes encoding gliadins were mainly located on the short arms of group 6 and group 1 chromosomes, and not evenly distributed. Repetitive sequences covered most of un-coding regions, which attributed greatly to the evolution of wheat genome. Primary structure of each gliadin has been divided into several domains, and the long repetitive domains consisted of peptide motifs. Conserved cysteine residues mainly formed intramolecular disulphide bonds. The rare potential intermolecular disulphide bonds and the long repetitive domains played an important role in the wheat flour quality. There was a general idea that gliadin genes, even prolamin genes, have a common origin and subsequent divergence lead to the gene polymorphism. The gamma-gliadins have been considered to be the most ancient of the wheat prolamin family. Several elements in the 5'-flanking (e.g. CAAT and TATA box) and the 3'-flanking sequences had been detected, which had been shown necessary for the proper expression of gliadins.

  15. Systems biology solutions for biochemical production challenges

    DEFF Research Database (Denmark)

    Hansen, Anne Sofie Lærke; Lennen, Rebecca M; Sonnenschein, Nikolaus

    2017-01-01

    There is an urgent need to significantly accelerate the development of microbial cell factories to produce fuels and chemicals from renewable feedstocks in order to facilitate the transition to a biobased society. Methods commonly used within the field of systems biology including omics character......There is an urgent need to significantly accelerate the development of microbial cell factories to produce fuels and chemicals from renewable feedstocks in order to facilitate the transition to a biobased society. Methods commonly used within the field of systems biology including omics...... characterization, genome-scale metabolic modeling, and adaptive laboratory evolution can be readily deployed in metabolic engineering projects. However, high performance strains usually carry tens of genetic modifications and need to operate in challenging environmental conditions. This additional complexity...... compared to basic science research requires pushing systems biology strategies to their limits and often spurs innovative developments that benefit fields outside metabolic engineering. Here we survey recent advanced applications of systems biology methods in engineering microbial production strains...

  16. The Ancient Gamete Fusogen HAP2 Is a Eukaryotic Class II Fusion Protein.

    Science.gov (United States)

    Fédry, Juliette; Liu, Yanjie; Péhau-Arnaudet, Gérard; Pei, Jimin; Li, Wenhao; Tortorici, M Alejandra; Traincard, François; Meola, Annalisa; Bricogne, Gérard; Grishin, Nick V; Snell, William J; Rey, Félix A; Krey, Thomas

    2017-02-23

    Sexual reproduction is almost universal in eukaryotic life and involves the fusion of male and female haploid gametes into a diploid cell. The sperm-restricted single-pass transmembrane protein HAP2-GCS1 has been postulated to function in membrane merger. Its presence in the major eukaryotic taxa-animals, plants, and protists (including important human pathogens like Plasmodium)-suggests that many eukaryotic organisms share a common gamete fusion mechanism. Here, we report combined bioinformatic, biochemical, mutational, and X-ray crystallographic studies on the unicellular alga Chlamydomonas reinhardtii HAP2 that reveal homology to class II viral membrane fusion proteins. We further show that targeting the segment corresponding to the fusion loop by mutagenesis or by antibodies blocks gamete fusion. These results demonstrate that HAP2 is the gamete fusogen and suggest a mechanism of action akin to viral fusion, indicating a way to block Plasmodium transmission and highlighting the impact of virus-cell genetic exchanges on the evolution of eukaryotic life.

  17. Early evolution stage of AGN

    Science.gov (United States)

    Kunert-Bajraszewska, M.; Labiano, A.; Siemiginowska, A.; Guainazzi, M.; Gawroński, M.

    2015-03-01

    Radio sources are divided into two distinct morphological groups of objects: Fanaroff-Riley type I and type II sources. There is a relatively sharp luminosity boundary between these at low frequency. The nature of the FR division is still an open issue, as are the details of the evolutionary process in which younger and smaller GHz-peaked spectrum (GPS) and compact steep spectrum (CSS) sources become large-scale radio structures. It is still unclear whether FRII objects evolve to become FRIs, or whether a division has already occurred amongst CSS sources and some of these then become FRIs and some FRIIs. We explored evolution scenarios of AGNs using new radio, optical and X-ray data of unstudied so far Low Luminosity Compact (LLC) sources. We suggest that the determining factors of the further evolution of compact radio objects could occur at subgalactic (or even nuclear) scales, or they could be related to the radio jet - interstellar medium (ISM) interactions and evolution. Our studies show that the evolutionary track could be related to the interaction, strength of the radio source and excitation levels of the ionized gas instead of the radio morphology of the young radio source.

  18. Biochemical investigations of yield-limitations in potatoes (Solanum tuberosum L. ) under warm tropical conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mohabir, G.

    1988-01-01

    An important factor that limits potato yields in the lowland tropics is the continuously high soil temperatures. The biochemical basis of this limitation has been investigated. A sharp temperature optimum is observed in Arrhenius plots at 21.5/degrees/C when the incorporation of (/sup 14/C) sucrose into starch is measured with discs cut from developing tubers of potato. Over the same temperature range evolution of (/sup 14/C) CO/sub 2/ and apoplastic uptake show positive linearity while ethanol-soluble uptake displays a broad optimum above 25/degrees/C. By comparison starch synthesis in discs from corms of cocoyam (Colocasia esculenta (L) Schott.) is increased linearly by raising the temperature from 15/degrees/C to 35/degrees/C. The significance of a relatively low temperature optimum for starch synthesis in potato is discussed in relation to the yield limitation imposed by continuously high soil temperatures.

  19. Biochemical and genetic engineering strategies to enhance hydrogen production in photosynthetic algae and cyanobacteria.

    Science.gov (United States)

    Srirangan, Kajan; Pyne, Michael E; Perry Chou, C

    2011-09-01

    As an energy carrier, hydrogen gas is a promising substitute to carbonaceous fuels owing to its superb conversion efficiency, non-polluting nature, and high energy content. At present, hydrogen is predominately synthesized via chemical reformation of fossil fuels. While various biological methods have been extensively explored, none of them is justified as economically feasible. A sustainable platform for biological production of hydrogen will certainly impact the biofuel market. Among a selection of biological systems, algae and cyanobacteria have garnered major interests as potential cell factories for hydrogen production. In conjunction with photosynthesis, these organisms utilize inexpensive inorganic substrates and solar energy for simultaneous biosynthesis and hydrogen evolution. However, the hydrogen yield associated with these organisms remains far too low to compete with the existing chemical systems. This article reviews recent advances of biochemical, bioprocess, and genetic engineering strategies in circumventing technological limitations to hopefully improve the applicative potential of these photosynthetic hydrogen production systems.

  20. Biochemical evaluation of the renin-angiotensin system: the good, bad, and absolute?

    Science.gov (United States)

    Chappell, Mark C

    2016-01-15

    The renin-angiotensin system (RAS) constitutes a key hormonal system in the physiological regulation of blood pressure through peripheral and central mechanisms. Indeed, dysregulation of the RAS is considered a major factor in the development of cardiovascular pathologies, and pharmacological blockade of this system by the inhibition of angiotensin-converting enzyme (ACE) or antagonism of the angiotensin type 1 receptor (AT1R) offers an effective therapeutic regimen. The RAS is now defined as a system composed of different angiotensin peptides with diverse biological actions mediated by distinct receptor subtypes. The classic RAS comprises the ACE-ANG II-AT1R axis that promotes vasoconstriction; water intake; sodium retention; and increased oxidative stress, fibrosis, cellular growth, and inflammation. In contrast, the nonclassical RAS composed primarily of the ANG II/ANG III-AT2R and the ACE2-ANG-(1-7)-AT7R pathways generally opposes the actions of a stimulated ANG II-AT1R axis. In lieu of the complex and multifunctional aspects of this system, as well as increased concerns on the reproducibility among laboratories, a critical assessment is provided on the current biochemical approaches to characterize and define the various components that ultimately reflect the status of the RAS.

  1. Biochemical and histological characterization of tomato mutants

    Directory of Open Access Journals (Sweden)

    Carolina C. Monteiro

    2012-06-01

    Full Text Available Biochemical responses inherent to antioxidant systems as well morphological and anatomical properties of photomorphogenic, hormonal and developmental tomato mutants were investigated. Compared to the non-mutant Micro-Tom (MT, we observed that the malondialdehyde (MDA content was enhanced in the diageotropica (dgt and lutescent (l mutants, whilst the highest levels of hydrogen peroxide (H2O2 were observed in high pigment 1 (hp1 and aurea (au mutants. The analyses of antioxidant enzymes revealed that all mutants exhibited reduced catalase (CAT activity when compared to MT. Guaiacol peroxidase (GPOX was enhanced in both sitiens (sit and notabilis (not mutants, whereas in not mutant there was an increase in ascorbate peroxidase (APX. Based on PAGE analysis, the activities of glutathione reductase (GR isoforms III, IV, V and VI were increased in l leaves, while the activity of superoxide dismutase (SOD isoform III was reduced in leaves of sit, epi, Never ripe (Nr and green flesh (gf mutants. Microscopic analyses revealed that hp1 and au showed an increase in leaf intercellular spaces, whereas sit exhibited a decrease. The au and hp1 mutants also exhibited a decreased in the number of leaf trichomes. The characterization of these mutants is essential for their future use in plant development and ecophysiology studies, such as abiotic and biotic stresses on the oxidative metabolism.Neste trabalho, analisamos as respostas bioquímicas inerentes ao sistema antioxidante, assim como propriedades morfológicas e anatômicas de mutantes fotomorfogenéticos e hormonais de tomateiro. Comparados ao não mutante Micro-Tom (MT, observamos que o conteúdo de malondialdeído (MDA aumentou nos mutantes diageotropica (dgt e lutescent (l, enquanto os maiores níveis de H2O2 foram encontrados nos mutantes high pigment 1 (hp1 e aurea (au. Análises de enzimas antioxidantes mostraram que todos os mutantes reduziram a atividade de catalase (CAT quando comparado a MT. A

  2. BIOCHEMICAL STUDIES ON NIGERIAN MONODORA TENUIFOLIA SEED

    Directory of Open Access Journals (Sweden)

    Ekeanyanwu Raphael Chukwuma

    2013-01-01

    Full Text Available The nutritive constituents of the seeds of Monodora tenuifolia were analyzed to augment the available information on Monodora tenuifolia research. Blood glucose and lipid profile were investigated on the flavonoid rich fraction of M. tenuifolia in rats. The composition (gkg-1 of alkaloids, cyanogenic glycosides, tannins and flavonoids were 13.3±0.1, 21.2×10-2±0.6, 1.3±0.1, 1.7±0.1 and 11.7±1.1 respectively. The proximate composition (gkg-1 of M. tenuifolia seed were crude fibre (262.3±1.2, crude protein (82.6±1.0, crude fat (349.9±1.9, ash (49.9±0.6, moisture (190.0±0.00 and carbohydrate (65.5±4.7. Analysis of the minerals content (gkg-1 yielded calcium (864.0±29.38, sodium (2752.0±140.35, iron (3.34±0.06, zinc (5.26±0.08, potassium (326.4±13.06, magnesium (342.9±13.71 and phosphorus (9.52±0.17, while vitamin analysis yielded vitamin A (10.05±0.17 iu/100 g, C (56.40±0.14 gkg-1 and E (11.71±0.87 iu /100 g, thiamine (0.11±0.01 gkg-1, niacin (0.46±0.32 gkg-1 and riboflavin (0.04±0.01 gkg-1. The results of amino acid analysis showed the total amino acid of M. tenuifolia seed was 71.78 of crude protein. The total essential amino acid with Histidine was calculated to be 29.24 of the crude protein. The antinutrient analysis of M. tenuifolia shows it contained total phenol (0.8±0.0 gkg-1, oxalates (4.09±1.17 gkg-1, phytates (0.012±0.42 gkg-1 and trypsin inhibitor (0.230±0.42 iu/g. The main fatty acids of the seed oil are linoleic acid (401.7 g kg-1, oleic acid (346.1 g kg-1 and palmitic acid (122.61 g kg-1. The LD50 of the flavonoid-rich fraction was found to be above 5000 mg kg-1 b.w. After the day 14 study, biochemical markers such as triacylglycerol, very low density lipoprotein increased significantly (p0.05 effect was observed on the blood glucose and lipid profile of wistar albino rats compared with the control. The result shows that M. tenuifolia seed is rich

  3. Development of a system for characterizing biomass quality of lignocellulosic feedstocks for biochemical conversion

    Science.gov (United States)

    Murphy, Patrick Thomas

    The purpose of this research was twofold: (i) to develop a system for screening lignocellulosic biomass feedstocks for biochemical conversion to biofuels and (ii) to evaluate brown midrib corn stover as feedstock for ethanol production. In the first study (Chapter 2), we investigated the potential of corn stover from bm1-4 hybrids for increased ethanol production and reduced pretreatment intensity compared to corn stover from the isogenic normal hybrid. Corn stover from hybrid W64A X A619 and respective isogenic bm hybrids was pretreated by aqueous ammonia steeping using ammonium hydroxide concentrations from 0 to 30%, by weight, and the resulting residues underwent simultaneous saccharification and cofermentation (SSCF) to ethanol. Dry matter (DM) digested by SSCF increased with increasing ammonium hydroxide concentration across all genotypes (P>0.0001) from 277 g kg-1 DM in the control to 439 g kg-1 DM in the 30% ammonium hydroxide pretreatment. The bm corn stover materials averaged 373 g kg-1 DM of DM digested by SSCF compared with 335 g kg-1 DM for the normal corn stover (Pcell-wall carbohydrate hydrolysis of corn stover, (ii) the lowest initial cell-wall carbohydrate concentration, (iii) the lowest dry matter remaining after pretreatment, and (iv) the highest amount of monosaccharides released during enzymatic hydrolysis. However, bm corn stover did not reduce the severity of aqueous ammonia steeping pretreatment needed to maximize DM hydrolysis during SSCF compared with normal corn stover. In the remaining studies (Chapters 3 thru 5), a system for analyzing the quality of lignocellulosic biomass feedstocks for biochemical conversion to biofuels (i.e., pretreatment, enzymatic hydrolysis, and fermentation) was developed. To accomplish this, a carbohydrate availability model was developed to characterize feedstock quality. The model partitions carbohydrates within a feedstock material into fractions based on their availability to be converted to fermentable

  4. Lymphocytic thyroiditis: a correlation of cytological grades with clinical, biochemical and ultrasound findings

    Directory of Open Access Journals (Sweden)

    P. Uma

    2013-08-01

    Full Text Available Background: Hashimoto’s thyroiditis sometimes referred to as goitrous thyroiditis is a synonym of chronic lymphocytic thyroiditis or autoimmune thyroiditis. Chronic lymphocytic thyroiditis (Hashimoto’s thyroiditis is one of the most common cause of goiter and hypothyroidism, it is found most commonly in middle aged and young female, but can also occur in other age groups, including children. Chronic lymphocytic thyroiditis can be graded based on cytomorphology. In this study an attempt has been made to correlate the grades with clinical findings, biochemical levels and ultrasonography findings. Methods: This is a prospective study conducted on 309 patients in the Department of Pathology, Andhra Medical College, Visakhapatnam. The various parameters like patient’s clinical presentation, biochemical levels and thyroid ultrasound were studied. Fine needle aspiration of thyroid gland and grading of thyroiditis was done on smears. The grades were correlated with above parameters and the correlation indices were evaluated statistically. Chi-square tests were used for statistical correlation and p value of <0.05 was considered significant. Results: Most of the patients were females (297, 96.11% who commonly presented with a diffuse goiter (263, 85.11%. Asymptomatic cases (193, 62.46% and elevated TSH (194, 62.78% were common. Most of the cases had grade I/II disease (299, 96.76% by cytology. Conclusion: FNAC is a simple, safe and cost effective procedure and is a sensitive and specific diagnostic tool in diagnosing chronic lymphocytic thyroiditis. Cytological grading of chronic lymphocytic thyroiditis helps in assessing the severity of the disease and can predict the thyroid functional status. A combined approach of cytological grading of chronic lymphocytic thyroiditis along with ultrasonography and biochemical levels can detect subclinical hypothyroid states and provide a guide to therapy. [Int J Res Med Sci 2013; 1(4.000: 523-531

  5. Sperm quality and selected biochemical parameters of seminal fluid in dogs with benign prostatic hyperplasia.

    Science.gov (United States)

    Krakowski, L; Wąchocka, A; Brodzki, P; Wrona, Z; Piech, T; Wawron, W; Chałabis-Mazurek, A

    2015-09-01

    Benign prostatic hyperplasia (BPH) in dogs is most commonly associated with age and increasing concentrations of dihydrotesterone, a hormone that stimulates growth and secretion of the prostatic epithelial cells. During this process, the biochemical composition of prostatic secretion changes, which can affect the quality of semen and limit the ability of the sperm to contribute to fertilization. Therefore, the present study was conducted to examine possible correlation between BPH and biological quality of semen. The study was performed in 11 sexually mature dogs of various breeds. Animals were divided into two groups: healthy dogs (Group I; n = 5; mean age 4.32; SEM = 1.28) and dogs with BPH (Group II n = 6; mean age 6.16; SEM = 0.65). Semen and prostate secretions were collected and evaluated in this study. Standard semen examinations were conducted in the ejaculates collected; moreover, the extent of apoptosis and DNA defragmentation was determined. The selected biochemical parameters were determined in the prostate secretion. According to the examination results, there were no significant differences in standard semen parameters between the two groups of dogs. Nevertheless, morphological tests of semen in dogs with BPH demonstrated elevated percentages of primary defects in spermatozoa. A significant increase (P = 0.01) in DNA defragmentation of sperm was found in dogs with BPH. Moreover, changes in the biochemical composition of prostate secretion were demonstrated. In dogs with BPH, pH of prostate secretions was greater (P = 0.03), concentrations of cholesterol increased while concentrations of Zn and Cu decreased. The study findings reveal that BPH does not change semen quality in dogs.

  6. [Effects of diets on growth, serum biochemical indices and lipid metabolism in Coilia nasus].

    Science.gov (United States)

    Wei, Guang-Lian; Xu, Gang-Chun; Gu, Ruo-Bo; Xu, Pao

    2013-12-01

    Effects of diets on growth, serum biochemical indices, and enzyme activities related to lipid metabolism in fingerlings Coilia nasus at age of 6 months were investigated during 60-day experiment in this study. Fingerlings with similar body length and mass were fed with one of 3 types of diets (diet 1: soft pellet; diet 2: soft pellet mixed with fish oil; diet 3: slow-sinking hard pellet). Fish fed with diets 2 or 3 had significantly higher total body mass, rate of mass gain, specific growth rate, and fullness coefficient than those fed with diet 1. Fish fed with diet 3 exhibited the lower food coefficient compared to those fed with diets 1 or 2. Growth traits (length, length to mass ratio, length to width ratio, hepatopancreas somatic indices and viscera somatic index) and serum biochemical indices (total protein, albumin, blood glucose, cholesterol and triglycerides) in all three treatments were not significantly different. Fish fed with diet 1 exhibited significantly higher carnitine palmitoyltransferase-I than those fed with diets 2 or 3, while fish fed with diet 2 exhibited significantly lower carnitine palmitoyltransferase-II. However, amylase, pepsin, lipase activity, lipoprotein lipase and acetyl-coa carboxylase had no significant difference in fish body among all groups. Results suggested that fish oil as a diet supplement highly facilitated fish growing. The slow-sinking pellet had the highest utilization efficiency and was suitable to feed fish fingerlings of C. nasus.

  7. Chemical Evolution of the Juvenile Universe

    CERN Document Server

    Wasserburg, G J

    2009-01-01

    Only massive stars contribute to the chemical evolution of the juvenile universe corresponding to [Fe/H]-0.32. Recent observations show that there are stars with [Sr/Fe]<-2 and [Fe/H]<-3. This proves that the two-component model is not correct and that a third component is necessary to explain the observations. This leads to a simple three-component model including low-mass and normal SNe II and hypernovae (HNe), which gives a good description of essentially all the data for stars with [Fe/H]<-1.5. We conclude that HNe are more important than normal SNe II in the chemical evolution of the low-A elements, in sharp distinction to earlier models. (Abridged)

  8. Haemato-biochemical alterations induced by lead acetate toxicity in wistar rats

    Directory of Open Access Journals (Sweden)

    S. G. Suradkar

    Full Text Available An experiment was conducted to study the haemato-biochemical alterations induced by lead acetate toxicity in 48 Wistar rats of either sex, divided uniformly into four different groups. The rats of group I received only deionised water as control while, group II, III and IV were given lead acetate @ 1 PPM, 100 PPM and 1000 PPM, in drinking deionised water respectively for 28 days. In group III and IV dose dependant significant (P<0.05 reductions in TEC, Hb, PCV and TLC were observed. No significant change was observed in neutrophil, eosinophil, basophil and monocyte count in any treatment groups, whereas the lymphocyte count decreased significantly (P<0.05 in group III and IV. A dose dependant significant (P<0.05 increase in AST, ALP, AKP, GGT, BUN and creatinine was experiential while TP and albumin levels were decreased in group III and IV. [Vet World 2009; 2(11.000: 429-431

  9. Insect Cells Encode a Class II α-Mannosidase with Unique Properties*

    OpenAIRE

    Kawar, Ziad; Karaveg, Khanita; Moremen, Kelley W.; Jarvis, Donald L.

    2001-01-01

    Previously, we cloned and characterized an insect (Sf9) cell cDNA encoding a class II α-mannosidase with amino acid sequence and biochemical similarities to mammalian Golgi α-mannosidase II. Since then, it has been demonstrated that other mammalian class II α-mannosidases can participate in N-glycan processing. Thus, the present study was performed to evaluate the catalytic properties of the Sf9 class II α-mannosidase and to more clearly determine its relationship to mammalian Golgi α-mannosi...

  10. Impact of recombination on bacterial evolution

    OpenAIRE

    2010-01-01

    Genetic exchange plays a defining role in the evolution of many bacteria. The recent accumulation of nucleotide sequence data from multiple members of diverse bacterial genera has facilitated comparative studies that have revealed many features of this process. Here we focus on genetic exchange that has involved homologous recombination and illustrate how nucleotide sequence data have furthered our understanding of: (i) the frequency of recombination; (ii) the impact of recombination in diffe...

  11. Effects of Training Load on Some Hormonal, Hematological and Biochemical Profile of Male Cyclists

    Directory of Open Access Journals (Sweden)

    Pralay Majumdar

    2014-07-01

    Full Text Available Hematological profiles of cyclists fluctuates are based on the volume/frequency/intensity of training. The present study examined the effects of training load on the cyclist’s biochemical profile which may be associated with over training. Twelve male cyclists volunteered to participate in this study. The participants completed a systematic training program which was divided into four phases i.e. phase I (560 km, continuous aerobic training, II (680 km, continuous aerobic training, III (720 km, aerobic and anaerobic interval training and IV (560 km, continuous aerobic training. Blood samples were collected at the end of each phase. The hemoglobin level of the cyclists increased throughout the training cycle whereas iron level increased till the third phase and decreased in the fourth phase due to alteration in training. Hemoglobin level was high during the IV phase and this was due to the lowest volume/frequency of training given to the cyclists in final phase. Total Iron Binding Capacity (TIBC level was elevated during the competitive phase, due to the high volume / intensity during III phase. The depletion of ferritin was high during phase II which was associated with a 21% increase in training volume after the first phase. The highest intensity, volume and frequency of E2S training (phase III were associated with a large increase in Creatine Phosphokinase (CPK, Lactate Dehydrogenase (LDH and cortisol levels, demonstrating a significant decrease in testosterone that showed the over-trained state. Hence, these biochemical markers are important in monitoring athlete’s training load as these parameters are altered with the training intensity, frequency and volume of training given to the cyclist.

  12. Biochemical characterisation during seed development of oil palm (Elaeis guineensis).

    Science.gov (United States)

    Kok, Sau-Yee; Namasivayam, Parameswari; Ee, Gwendoline Cheng-Lian; Ong-Abdullah, Meilina

    2013-07-01

    Developmental biochemical information is a vital base for the elucidation of seed physiology and metabolism. However, no data regarding the biochemical profile of oil palm (Elaeis guineensis Jacq.) seed development has been reported thus far. In this study, the biochemical changes in the developing oil palm seed were investigated to study their developmental pattern. The biochemical composition found in the seed differed significantly among the developmental stages. During early seed development, the water, hexose (glucose and fructose), calcium and manganese contents were present in significantly high levels compared to the late developmental stage. Remarkable changes in the biochemical composition were observed at 10 weeks after anthesis (WAA): the dry weight and sucrose content increased significantly, whereas the water content and hexose content declined. The switch from a high to low hexose/sucrose ratio could be used to identify the onset of the maturation phase. At the late stage, dramatic water loss occurred, whereas the content of storage reserves increased progressively. Lauric acid was the most abundant fatty acid found in oil palm seed starting from 10 WAA.

  13. A critical appraisal of the phene-plate biochemical fingerprinting system for epidemiological subtyping of Salmonella typhimurium

    DEFF Research Database (Denmark)

    On, S.L.W.; Baggesen, Dorte Lau

    1996-01-01

    The efficacy and reproducibility of the Phene-Plate (PhP) system (Biosys Inova, Stockholm, Sweden) for biochemical fingerprinting of Salmonella typhimurium was investigated. Duplicate and replicate assays on 40 epidemiologically related and unrelated strains were performed in two batches of PhP-48......P-types which are epidemiologically unjustified, (ii) tests currently recommended for PhP-typing S. typhimurium may be somewhat unstable and not satisfactory for fingerprinting purposes, (iii) caution must be exercised when comparing data from different batches of PhP-48 plates, and (iv) best results...

  14. Small Diameter Bomb Increment II (SDB II)

    Science.gov (United States)

    2013-12-01

    been further delays to the F-35 System Development and Demonstration ( SDD ) program. As a result, the SDB II integration will be accomplished as a...follow-on integration to the F-35 SDD . SDB II OT&E on the F-35 will not be completed by the FRP threshold of October 2019, thus delaying the FRP decision

  15. Chemical Evolution models of Local Group galaxies

    CERN Document Server

    Tosi, M P

    2003-01-01

    Status quo and perspectives of standard chemical evolution models of Local Group galaxies are summarized, discussing what we have learnt from them, what we know we have not learnt yet, and what I think we will learn in the near future. It is described how Galactic chemical evolution models have helped showing that: i) stringent constraints on primordial nucleosynthesis can be derived from the observed Galactic abundances of the light elements, ii) the Milky Way has been accreting external gas from early epochs to the present time, iii) the vast majority of Galactic halo stars have formed quite rapidly at early epochs. Chemical evolution models for the closest dwarf galaxies, although still uncertain so far, are expected to become extremely reliable in the nearest future, thanks to the quality of new generation photometric and spectroscopic data which are currently being acquired.

  16. Click Chemistry-Mediated Nanosensors for Biochemical Assays.

    Science.gov (United States)

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanoprobes based on click chemistry. Nanoprobes including gold nanoparticles, quantum dots, magnetic nanoparticles and carbon nanomaterials are covered. We discuss the advantages of click chemistry-mediated nanosensors for biochemical assays, and give perspectives on the development of click chemistry-mediated approaches for clinical diagnosis and other biomedical applications.

  17. Click Chemistry-Mediated Nanosensors for Biochemical Assays

    Science.gov (United States)

    Chen, Yiping; Xianyu, Yunlei; Wu, Jing; Yin, Binfeng; Jiang, Xingyu

    2016-01-01

    Click chemistry combined with functional nanoparticles have drawn increasing attention in biochemical assays because they are promising in developing biosensors with effective signal transformation/amplification and straightforward signal readout for clinical diagnostic assays. In this review, we focus on the latest advances of biochemical assays based on Cu (I)-catalyzed 1, 3-dipolar cycloaddition of azides and alkynes (CuAAC)-mediated nanosensors, as well as the functionalization of nanoprobes based on click chemistry. Nanoprobes including gold nanoparticles, quantum dots, magnetic nanoparticles and carbon nanomaterials are covered. We discuss the advantages of click chemistry-mediated nanosensors for biochemical assays, and give perspectives on the development of click chemistry-mediated approaches for clinical diagnosis and other biomedical applications. PMID:27217831

  18. SABRE: A Tool for Stochastic Analysis of Biochemical Reaction Networks

    CERN Document Server

    Didier, Frederic; Mateescu, Maria; Wolf, Verena

    2010-01-01

    The importance of stochasticity within biological systems has been shown repeatedly during the last years and has raised the need for efficient stochastic tools. We present SABRE, a tool for stochastic analysis of biochemical reaction networks. SABRE implements fast adaptive uniformization (FAU), a direct numerical approximation algorithm for computing transient solutions of biochemical reaction networks. Biochemical reactions networks represent biological systems studied at a molecular level and these reactions can be modeled as transitions of a Markov chain. SABRE accepts as input the formalism of guarded commands, which it interprets either as continuous-time or as discrete-time Markov chains. Besides operating in a stochastic mode, SABRE may also perform a deterministic analysis by directly computing a mean-field approximation of the system under study. We illustrate the different functionalities of SABRE by means of biological case studies.

  19. The Development of a Biochemical Profile of Acacia Honey by Identifying Biochemical Determinants of its Quality

    Directory of Open Access Journals (Sweden)

    Liviu Alexandru MARGHITAS

    2010-09-01

    Full Text Available Codex Alimentarius Standard, EU Legislation and National Standards state honey authenticity. Authenticity in respect of production (to prevent adulteration and authenticity in respect of geographical and botanical origin are the two main aspects of general honey authenticity. Quality of honey depends on the plant source, the chemical composition of these plants as well, as on the climatic conditions and soil mineral composition. Romanian acacia (Robinia pseudoacacia honey that came from the most important Transylvanian massif (Valea lui Mihai, Bihor County, Romania was evaluated for authenticity by pollen-analysis, several physico-chemical analyses, including sugar profile and mineral content. As polyphenolic content could be also an important factor for botanical authentification, HPLC-DAD-MS analyses were performed to assess the fingerprint of this important secondary plant metabolite. Statistical data were processed in order to develop a biochemical profile of this type of honey and the main quality categories identification. The results of physico-chemical analysis demonstrated that the tested honey samples could be framed into monofloral type of acacia honeys. The analysis of acacia honeys originating from Valea lui Mihai, Romania, showed that polyphenolic profile (phenolic acids and flavonoids could be used as a complementary method for authenticity determination together with pollen analysis and other physico-chemical analysis.

  20. ROMANIAN BANKING SYSTEM EVOLUTION AND BASEL II REQUIREMENTS

    Directory of Open Access Journals (Sweden)

    Mihaela NICOLAU

    2006-01-01

    Full Text Available Before 1989, Romanian Banking System was structured in the specific way of a centralized economy. Restructuring of the banking system took its first step at the end of 1990 when the newly- established bank, Banca Comercială Română, took over retail operations performed previously by the NBR. Simultaneously, some privately-owned banking companies were established and foreign banks’ branches were integrated into the domestic banking activity, the number of banks almost trebling. The unfriendly economic environment, the poor quality of bank managers and shareholders and cumbersome legal procedures led to an increase in tensions, the poor quality of credit portfolio representing the major difficulty of the banking sector. In the past years, NBR tried to control more thebanking activity by implementing international settlements. More over, since Romania is one of the European Union countries, it is absolutely necessary the harmonization of entire economic and financial system to EU regulations. The paper try to present the position of Romanian banking system in the framework of all these transformations.

  1. Physiological and biochemical basis of salmon young ifshes migratory behavior

    Institute of Scientific and Technical Information of China (English)

    Vladimir Ivanovich Martemyanov

    2016-01-01

    The review presents data on structural changes, physiological and biochemical reactions occurring at salmon young fishes during smoltification. It is shown, that young salmon fishes located in fresh water, in the process of smoltification undergo a complex of structural, physiological and biochemical changes directed on preparation of the organism for living in the sea. These changes cause stress reaction which excites young fishes to migrate down the river towards the sea. Measures to improve reproduction of young salmon fishes at fish farms are offered.

  2. The Biochemical Properties of Antibodies and Their Fragments.

    Science.gov (United States)

    Hnasko, Robert M

    2015-01-01

    Immunoglobulins (Ig) or antibodies are powerful molecular recognition tools that can be used to identify minute quantities of a given target analyte. Their antigen-binding properties define both the sensitivity and selectivity of an immunoassay. Understanding the biochemical properties of this class of protein will provide users with the knowledge necessary to select the appropriate antibody composition to maximize immunoassay results. Here we define the general biochemical properties of antibodies and their similarities and differences, explain how these properties influence their functional relationship to an antigen target, and describe a method for the enzymatic fragmentation of antibodies into smaller functional parts.

  3. Factor II deficiency

    Science.gov (United States)

    ... if one or more of these factors are missing or are not functioning like they should. Factor II is one such coagulation factor. Factor II deficiency runs in families (inherited) and is very rare. Both parents must ...

  4. Multiplicity in Early Stellar Evolution

    CERN Document Server

    Reipurth, Bo; Boss, Alan P; Goodwin, Simon P; Rodriguez, Luis Felipe; Stassun, Keivan G; Tokovinin, Andrei; Zinnecker, Hans

    2014-01-01

    Observations from optical to centimeter wavelengths have demonstrated that multiple systems of two or more bodies is the norm at all stellar evolutionary stages. Multiple systems are widely agreed to result from the collapse and fragmentation of cloud cores, despite the inhibiting influence of magnetic fields. Surveys of Class 0 protostars with mm interferometers have revealed a very high multiplicity frequency of about 2/3, even though there are observational difficulties in resolving close protobinaries, thus supporting the possibility that all stars could be born in multiple systems. Near-infrared adaptive optics observations of Class I protostars show a lower binary frequency relative to the Class 0 phase, a declining trend that continues through the Class II/III stages to the field population. This loss of companions is a natural consequence of dynamical interplay in small multiple systems, leading to ejection of members. We discuss observational consequences of this dynamical evolution, and its influenc...

  5. Lymphocytic Thyroiditis - is cytological grading significant? A correlation of grades with clinical, biochemical, ultrasonographic and radionuclide parameters

    Directory of Open Access Journals (Sweden)

    Bhatia Alka

    2007-01-01

    Full Text Available Background: Clinical, biochemical, ultrasonographic, radionuclide and cytomorphological observations in Lymphocytic thyroiditis (LT, to define the cytological grading criteria on smears and correlation of grades with above parameters. Methods: This prospective study was conducted on 76 patients attending the Fine needle aspiration cytology clinic of a tertiary care institute in North India. The various parameters like patients′ clinical presentation, thyroid antimicrosomal antibodies, hormonal profiles, radionuclide thyroid scan and thyroid ultrasound were studied. Fine needle aspiration of thyroid gland and grading of thyroiditis was done on smears. The grades were correlated with above parameters and the correlation indices were evaluated statistically. Results: Most of the patients were females (70, 92.11% who presented with a diffuse goiter (68, 89.47%. Hypothyroid features (56, 73.68% and elevated TSH (75, 98.68% were common, but radioiodide uptake was low or normal in majority of patients. Thyroid antimicrosomal antibody was elevated in 46/70 (65.71% patients. Cytomorphology in fine needle aspirates was diagnostic of lymphocytic thyroiditis in 75 (98.68% patients. Most of them had grade I/II disease by cytology. No correlation was observed between grades of cytomorphology and clinical, biochemical, ultrasonographic and radionuclide parameters. Conclusion: Despite the availability of several tests for diagnosis of LT, FNAC remains the gold standard. The grades of thyroiditis at cytology however do not correlate with clinical, biochemical, radionuclide and ultrasonographic parameters.

  6. Lymphocytic Thyroiditis – is cytological grading significant? A correlation of grades with clinical, biochemical, ltrasonographic and radionuclide parameters

    Directory of Open Access Journals (Sweden)

    Dash Radharaman

    2007-01-01

    Full Text Available Abstract Background Clinical, biochemical, ultrasonographic, radionuclide and cytomorphological observations in Lymphocytic thyroiditis (LT, to define the cytological grading criteria on smears and correlation of grades with above parameters. Methods This prospective study was conducted on 76 patients attending the Fine needle aspiration cytology clinic of a tertiary care institute in North India. The various parameters like patients' clinical presentation, thyroid antimicrosomal antibodies, hormonal profiles, radionuclide thyroid scan and thyroid ultrasound were studied. Fine needle aspiration of thyroid gland and grading of thyroiditis was done on smears. The grades were correlated with above parameters and the correlation indices were evaluated statistically. Results Most of the patients were females (70, 92.11% who presented with a diffuse goiter (68, 89.47%. Hypothyroid features (56, 73.68% and elevated TSH (75, 98.68% were common, but radioiodide uptake was low or normal in majority of patients. Thyroid antimicrosomal antibody was elevated in 46/70 (65.71% patients. Cytomorphology in fine needle aspirates was diagnostic of lymphocytic thyroiditis in 75 (98.68% patients. Most of them had grade I/II disease by cytology. No correlation was observed between grades of cytomorphology and clinical, biochemical, ultrasonographic and radionuclide parameters. Conclusion Despite the availability of several tests for diagnosis of LT, FNAC remains the gold standard. The grades of thyroiditis at cytology however do not correlate with clinical, biochemical, radionuclide and ultrasonographic parameters.

  7. Effects of intermittent hydrostatic pressure magnitude on the chondrogenesis of MSCs without biochemical agents under 3D co-culture.

    Science.gov (United States)

    Jeong, Jae Young; Park, So Hee; Shin, Ji Won; Kang, Yun Gyeong; Han, Ki-Ho; Shin, Jung-Woog

    2012-11-01

    Without using biochemical agents, in this study, we sought to investigate the potential of controlling the differentiation of mesenchymal stem cells (MSCs) into a specific cell type through the use of 3D co-culturing and mechanical stimuli. MSCs and primary cultured chondrocytes were separately encapsulated into alginate beads, and the two types of beads were separated by a membrane. For the investigation a computer-controllable bioreactor was designed and used to engage intermittent hydrostatic pressure (IHP). Five different magnitudes (0.20, 0.10, 0.05, 0.02 MPa and no stimulation) of IHP were applied. The stimulation pattern was the same for all groups: 2 h/day for 7 days starting at 24 h after seeding; 2 and 15 min cycles of stimulating and resting, respectively. Biochemical (DNA and GAG contents), histological (Alcian blue), and RT-PCR (Col II, SOX9, AGC) analyses were performed on days 1, 5, 10, and 20. The results from these analyses showed that stimulation with higher magnitudes of IHP (≥0.10 MPa) were more effective on the proliferation and differentiation of co-cultured MSCs. Together, these data demonstrate the potential of using mechanical stimulation and co-culturing for the proliferation and differentiation of MSCs, even without biochemical agents.

  8. Has Human Evolution Stopped?

    Directory of Open Access Journals (Sweden)

    Alan R. Templeton

    2010-07-01

    Full Text Available It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important implications for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the human gene pool, thereby enhancing the potential for human evolution. The increase in human population size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual heterozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences.

  9. Has human evolution stopped?

    Science.gov (United States)

    Templeton, Alan R

    2010-07-01

    It has been argued that human evolution has stopped because humans now adapt to their environment via cultural evolution and not biological evolution. However, all organisms adapt to their environment, and humans are no exception. Culture defines much of the human environment, so cultural evolution has actually led to adaptive evolution in humans. Examples are given to illustrate the rapid pace of adaptive evolution in response to cultural innovations. These adaptive responses have important implications for infectious diseases, Mendelian genetic diseases, and systemic diseases in current human populations. Moreover, evolution proceeds by mechanisms other than natural selection. The recent growth in human population size has greatly increased the reservoir of mutational variants in the human gene pool, thereby enhancing the potential for human evolution. The increase in human population size coupled with our increased capacity to move across the globe has induced a rapid and ongoing evolutionary shift in how genetic variation is distributed within and among local human populations. In particular, genetic differences between human populations are rapidly diminishing and individual heterozygosity is increasing, with beneficial health effects. Finally, even when cultural evolution eliminates selection on a trait, the trait can still evolve due to natural selection on other traits. Our traits are not isolated, independent units, but rather are integrated into a functional whole, so selection on one trait can cause evolution to occur on another trait, sometimes with mildly maladaptive consequences.

  10. Imminent Cardiac Risk Assessment via Optical Intravascular Biochemical Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, D.; Wetzel, L; Wetzel, M; Lodder, R

    2009-01-01

    Heart disease is by far the biggest killer in the United States, and type II diabetes, which affects 8% of the U.S. population, is on the rise. In many cases, the acute coronary syndrome and/or sudden cardiac death occurs without warning. Atherosclerosis has known behavioral, genetic and dietary risk factors. However, our laboratory studies with animal models and human post-mortem tissue using FT-IR microspectroscopy reveal the chemical microstructure within arteries and in the arterial walls themselves. These include spectra obtained from the aortas of ApoE-/- knockout mice on sucrose and normal diets showing lipid deposition in the former case. Also pre-aneurysm chemical images of knockout mouse aorta walls, and spectra of plaque excised from a living human patient are shown for comparison. In keeping with the theme of the SPEC 2008 conference Spectroscopic Diagnosis of Disease this paper describes the background and potential value of a new catheter-based system to provide in vivo biochemical analysis of plaque in human coronary arteries. We report the following: (1) results of FT-IR microspectroscopy on animal models of vascular disease to illustrate the localized chemical distinctions between pathological and normal tissue, (2) current diagnostic techniques used for risk assessment of patients with potential unstable coronary syndromes, and (3) the advantages and limitations of each of these techniques illustrated with patent care histories, related in the first person, by the physician coauthors. Note that the physician comments clarify the contribution of each diagnostic technique to imminent cardiac risk assessment in a clinical setting, leading to the appreciation of what localized intravascular chemical analysis can contribute as an add-on diagnostic tool. The quality of medical imaging has improved dramatically since the turn of the century. Among clinical non-invasive diagnostic tools, laboratory tests of body fluids, EKG, and physical examination are

  11. Biosensors and bioelectronics on smartphone for portable biochemical detection.

    Science.gov (United States)

    Zhang, Diming; Liu, Qingjun

    2016-01-15

    Smartphone has been widely integrated with sensors, such as test strips, sensor chips, and hand-held detectors, for biochemical detections due to its portability and ubiquitous availability. Utilizing built-in function modules, smartphone is often employed as controller, analyzer, and displayer for rapid, real-time, and point-of-care monitoring, which can significantly simplify design and reduce cost of the detecting systems. This paper presents a review of biosensors and bioelectronics on smartphone for portable biochemical detections. The biosensors and bioelectronics based on smartphone can mainly be classified into biosensors using optics, surface plasmon resonance, electrochemistry, and near-field communication. The developments of these biosensors and bioelectronics on smartphone are reviewed along with typical biochemical detecting cases. Sensor strategies, detector attachments, and coupling methods are highlighted to show designs of the compact, lightweight, and low-cost sensor systems. The performances and advantages of these designs are introduced with their applications in healthcare diagnosis, environment monitoring, and food evaluation. With advances in micro-manufacture, sensor technology, and miniaturized electronics, biosensor and bioelectronic devices on smartphone can be used to perform biochemical detections as common and convenient as electronic tag readout in foreseeable future.

  12. Polynomial analysis of canopy spectra and biochemical component content inversion

    Institute of Scientific and Technical Information of China (English)

    YAN Chunyan; LIU Qiang; NIU Zheng; WANG Jihua; HUANG Wenjiang; LIU Liangyun

    2005-01-01

    A polynomial expression model was developed in this paper to describe directional canopy spectra, and the decomposition of the polynomial expression was used as a tool for retrieving biochemical component content from canopy multi-angle spectra. First, the basic formula of the polynomial expression was introduced and the physical meaning of its terms and coefficients was discussed. Based on this analysis, a complete polynomial expression model and its decomposition method were given. By decomposing the canopy spectra simulated with SAILH model, it shows that the polynomial expression can not only fit well the canopy spectra, but also show the contribution of every order scattering to the whole reflectance. Taking the first scattering coefficients a10 and a01 for example, the test results show that the polynomial coefficients reflect very well the hot spot phenomenon and the effects of viewing angles, LAI and leaf inclination angle on canopy spectra. By coupling the polynomial expression with leaf model PROSPECT, a canopy biochemical component content inversion model was given. In the simulated test, the canopy multi-angle spectra were simulated by two different models, SAILH and 4-SCALE respectively, then the biochemical component content was retrieved by inverting the coupled polynomial expression + PROSPECT model. Results of the simulated test are promising, and when applying the algorithm to measured corn canopy multi-angle spectra, we also get relatively accurate chlorophyll content. It shows that the polynomial analysis provides a new method to get biochemical component content independent of any specific canopy model.

  13. Saliva as research material: Biochemical, physicochemical and practical aspects

    NARCIS (Netherlands)

    Schipper, R.G.; Silletti, E.; Vingerhoeds, M.H.

    2007-01-01

    Whole saliva is a complex mixture of proteins and other molecules which originate from several sources. The biochemical and physicochemical properties of saliva contribute to the numerous functions of saliva in, e.g., speech, maintaining oral and general health, and food processing. Interest in sali

  14. MATLAB-Based Teaching Modules in Biochemical Engineering

    Science.gov (United States)

    Lee, Kilho; Comolli, Noelle K.; Kelly, William J.; Huang, Zuyi

    2015-01-01

    Mathematical models play an important role in biochemical engineering. For example, the models developed in the field of systems biology have been used to identify drug targets to treat pathogens such as Pseudomonas aeruginosa in biofilms. In addition, competitive binding models for chromatography processes have been developed to predict expanded…

  15. Biochemical aspects of pressure tolerance in marine mammals.

    Science.gov (United States)

    Castellini, Michael A; Rivera, Patricia M; Castellini, Judith M

    2002-11-01

    Some marine mammals can dive to depths approaching 2000 m. At these hydrostatic pressures (200 atm), some fish species show alterations in enzyme structure and function that make them pressure-tolerant. Do marine mammals also possess biochemical adaptations to withstand such pressures? In theory, biochemical alterations might occur at the control of enzymatic pathways, by impacting cell membrane fluidity changes or at a higher level, such as cellular metabolism. Studies of marine mammal tissues show evidence of all of these changes, but the results are not consistent across species or diving depth. This review discusses whether the elevated body temperature of marine mammals imparts pressure tolerance at the biochemical level, whether there are cell membrane structural differences in marine mammals and whether whole, living cells from marine mammals alter their metabolism when pressure stressed. We conclude that temperature alone is probably not protective against pressure and that cell membrane composition data are not conclusive. Whole cell studies suggest that marine mammals either respond positively to pressure or are not impacted by pressure. However, the range of tissue types and enzyme systems that have been studied is extremely limited and needs to be expanded before more general conclusions about how these mammals tolerate elevated pressures on a biochemical level can be drawn.

  16. The Stereochemistry of Biochemical Molecules: A Subject to Revisit

    Science.gov (United States)

    Centelles, Josep J.; Imperial, Santiago

    2005-01-01

    Although Fischer's convention for stereoisomers is useful for simple molecules, the stereochemistry of complex biochemical molecules is often poorly indicated in textbooks. This article reports on errors in stereochemistry of complex hydrosoluble vitamin B12 molecule. Twenty-five popular biochemistry textbooks were examined for their treatment of…

  17. [Experiments using rats on Kosmos biosatellites: morphologic and biochemical studies].

    Science.gov (United States)

    Il'in, E A; Kaplanskiĭ, A S; Savina, E A

    1989-01-01

    Results of morphological and biochemical investigations of rats flown on Cosmos biosatellites are discussed. It is emphasized that most changes occurring during exposure to microgravity are directly or indirectly related to lower musculoskeletal loads which in turn produce deconditioning of different physiological systems and organism as a whole. It is concluded that this deconditioning is associated with both metabolic and structural changes.

  18. Biochemical Parameters of Orienteers Competing in a Long Distance Race.

    Science.gov (United States)

    Mikan, Vladimir; And Others

    1992-01-01

    Measured important biochemical parameters in a group of orienteers two hours before beginning and immediately after an orienteering marathon. Found levels of dehydration. Suggests a drinking regimen which is designed for orienteering races. Concludes that no runner having kidney or liver abnormalities or changes in the urine should be allowed to…

  19. Model Based Monitoring and Control of Chemical and Biochemical Processes

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted

    This presentation will give an overview of the work performed at the department of Chemical and Biochemical Engineering related to process control. A research vision is formulated and related to a number of active projects at the department. In more detail a project describing model estimation...

  20. Evaluation of biological and biochemical quality of whey protein.

    Science.gov (United States)

    Haraguchi, Fabiano Kenji; Pedrosa, Maria Lucia; Paula, Heberth de; Santos, Rinaldo Cardoso dos; Silva, Marcelo Eustáquio

    2010-12-01

    Nutritional and biochemical properties of noncommercial whey protein have been described since 1950. However, comparisons between commercial whey protein for human consumption and casein are rarely found. The aim of this study was to compare biological quality of a commercial whey protein with casein and its effect on biochemical parameters of rats. Thirty-two weanling Fisher rats were divided into three groups and given the following diets: casein group, standard diet (AOAC); whey protein group, modified AOAC diet with whey protein instead of casein; and casein:whey group, modified AOAC diet with 70%:30% casein:whey. A protein-free group was used for determination of endogenous nitrogen losses. Net protein ratio, protein efficiency ratio, and true digestibility were determined, and blood was collected for biochemical analysis. When compared with casein, whey protein showed significant differences for all biological parameters evaluated, as well as for albumin, total protein, total cholesterol, and glucose concentrations. Replacing 30% of casein with whey protein did not affect these parameters. A positive relation among whey protein, high-density lipoprotein-cholesterol, and paraoxonase activity was found. Hepatic or renal dysfunctions were not observed. In conclusion, in comparison with casein, commercial whey protein had higher values of biological parameters, and biochemical evaluation revealed it improved glycemic homeostasis, lipid status, and paraoxonase activity in rats.

  1. Development of a new first-aid biochemical detector

    Science.gov (United States)

    Hu, Jingfei; Liao, Haiyang; Su, Shilin; Ding, Hao; Liu, Suquan

    2016-10-01

    The traditional biochemical detector exhibits poor adaptability, inconvenient carrying and slow detection, which can't meet the needs of first-aid under field condition like natural or man-made disasters etc. Therefore a scheme of first-aid biochemical detector based on MOMES Micro Spectrometer, UV LED and Photodiode was proposed. An optical detection structure combined continuous spectrum sweep with fixed wavelength measurement was designed, which adopted mobile detection optical path consisting of Micro Spectrometer and Halogen Lamp to detect Chloride (Cl-), Creatinine (Cre), Glucose (Glu), Hemoglobin (Hb). The UV LED and Photodiode were designed to detect Potassium (K-), Carbon dioxide (CO2), Sodium (Na+). According to the field diagnosis and treatment requirements, we designed the embedded control hardware circuit and software system, the prototype of first-aid biochemical detector was developed and the clinical trials were conducted. Experimental results show that the sample's absorbance repeatability is less than 2%, the max coefficient of variation (CV) in the batch repeatability test of all 7 biochemical parameters in blood samples is 4.68%, less than the clinical requirements 10%, the correlation coefficient (R2) in the clinical contrast test with AU5800 is almost greater than 0.97. To sum up, the prototype meets the requirements of clinical application.

  2. Integrating Carbon Nanotubes into Microfluidic Chip for Separating Biochemical Compounds

    DEFF Research Database (Denmark)

    Chen, Miaoxiang Max; Mogensen, Klaus Bo; Bøggild, Peter

    2012-01-01

    We present a new type of device to separate biochemical compounds wherein carbon nanotubes (CNTs) are integrated as chromatographic stationary phase. The CNTs were directly grown on the bottom of microfluidic channels on Si/SiO2 substrates by chemical vapor deposition (CVD). Acetylene was used...

  3. Physicochemical and biochemical characterization of biosurfactants released by Lactobacillus strains

    NARCIS (Netherlands)

    Velraeds, MMC; vanderMei, HC; Reid, G; Busscher, HJ

    1996-01-01

    Biosurfactants from Lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54 and Lactobacillus acidophilus RC14 were isolated from bacteria in their mid-exponential (4-5 h) and stationary growth phases (18 h) and physicochemical and biochemical properties of the freeze-drie

  4. Metstoich--Teaching Quantitative Metabolism and Energetics in Biochemical Engineering

    Science.gov (United States)

    Wong, Kelvin W. W.; Barford, John P.

    2010-01-01

    Metstoich, a metabolic calculator developed for teaching, can provide a novel way to teach quantitative metabolism to biochemical engineering students. It can also introduce biochemistry/life science students to the quantitative aspects of life science subjects they have studied. Metstoich links traditional biochemistry-based metabolic approaches…

  5. Thermodynamically consistent Bayesian analysis of closed biochemical reaction systems

    Directory of Open Access Journals (Sweden)

    Goutsias John

    2010-11-01

    Full Text Available Abstract Background Estimating the rate constants of a biochemical reaction system with known stoichiometry from noisy time series measurements of molecular concentrations is an important step for building predictive models of cellular function. Inference techniques currently available in the literature may produce rate constant values that defy necessary constraints imposed by the fundamental laws of thermodynamics. As a result, these techniques may lead to biochemical reaction systems whose concentration dynamics could not possibly occur in nature. Therefore, development of a thermodynamically consistent approach for estimating the rate constants of a biochemical reaction system is highly desirable. Results We introduce a Bayesian analysis approach for computing thermodynamically consistent estimates of the rate constants of a closed biochemical reaction system with known stoichiometry given experimental data. Our method employs an appropriately designed prior probability density function that effectively integrates fundamental biophysical and thermodynamic knowledge into the inference problem. Moreover, it takes into account experimental strategies for collecting informative observations of molecular concentrations through perturbations. The proposed method employs a maximization-expectation-maximization algorithm that provides thermodynamically feasible estimates of the rate constant values and computes appropriate measures of estimation accuracy. We demonstrate various aspects of the proposed method on synthetic data obtained by simulating a subset of a well-known model of the EGF/ERK signaling pathway, and examine its robustness under conditions that violate key assumptions. Software, coded in MATLAB®, which implements all Bayesian analysis techniques discussed in this paper, is available free of charge at http://www.cis.jhu.edu/~goutsias/CSS%20lab/software.html. Conclusions Our approach provides an attractive statistical methodology for

  6. FeII/MgII, [Fe/Mg] Ratios and High-z Quasars

    CERN Document Server

    Korista, K; Corbin, M R; Freudling, W; Korista, Kirk; Kodituwakku, Nalaka; Corbin, Michael; Freudling, Wolfram

    2003-01-01

    It has been suggested in the literature that the (Fe/alpha) abundance ratio may be used as a chronometer, due to a delay in this ratio reaching its solar value as predicted by galactic chemical evolution models. Using grids of photoionization models along a sequence of the (Fe/Mg) abundance ratio vs.\\ metallicity with time in a giant elliptical starburst scenario, we investigate the relationship between the (Fe/Mg) abundance ratio and the FeII/MgII emission line flux ratio under the assumption that these lines originate in photoionized clouds within the broad emission line regions of quasars.

  7. CELib: Software library for simulations of chemical evolution

    Science.gov (United States)

    Saitoh, Takayuki R.

    2016-12-01

    CELib (Chemical Evolution Library) simulates chemical evolution of galaxy formation under the simple stellar population (SSP) approximation and can be used by any simulation code that uses the SSP approximation, such as particle-base and mesh codes as well as semi-analytical models. Initial mass functions, stellar lifetimes, yields from type II and Ia supernovae, asymptotic giant branch stars, and neutron star mergers components are included and a variety of models are available for use. The library allows comparisons of the impact of individual models on the chemical evolution of galaxies by changing control flags and parameters of the library.

  8. Functional evolution of quantum cylindrical waves

    CERN Document Server

    Cho, D H J; Cho, Demian H.J.; Varadarajan, Madhavan

    2006-01-01

    Kucha{\\v{r}} showed that the quantum dynamics of (1 polarization) cylindrical wave solutions to vacuum general relativity is determined by that of a free axially-symmetric scalar field along arbitrary axially-symmetric foliations of a fixed flat 2+1 dimensional spacetime. We investigate if such a dynamics can be defined {\\em unitarily} within the standard Fock space quantization of the scalar field. Evolution between two arbitrary slices of an arbitrary foliation of the flat spacetime can be built out of a restricted class of evolutions (and their inverses). The restricted evolution is from an initial flat slice to an arbitrary (in general, curved) slice of the flat spacetime and can be decomposed into (i) `time' evolution in which the spatial Minkowskian coordinates serve as spatial coordinates on the initial and the final slice, followed by (ii) the action of a spatial diffeomorphism of the final slice on the data obtained from (i). We show that although the functional evolution of (i) is unitarily implemen...

  9. Chemical Evolution Library for Galaxy Formation Simulation

    Science.gov (United States)

    Saitoh, Takayuki R.

    2017-02-01

    We have developed a software library for chemical evolution simulations of galaxy formation under the simple stellar population (SSP) approximation. In this library, all of the necessary components concerning chemical evolution, such as initial mass functions, stellar lifetimes, yields from Type II and Type Ia supernovae, asymptotic giant branch stars, and neutron star mergers, are compiled from the literature. Various models are pre-implemented in this library so that users can choose their favorite combination of models. Subroutines of this library return released energy and masses of individual elements depending on a given event type. Since the redistribution manner of these quantities depends on the implementation of users’ simulation codes, this library leaves it up to the simulation code. As demonstrations, we carry out both one-zone, closed-box simulations and 3D simulations of a collapsing gas and dark matter system using this library. In these simulations, we can easily compare the impact of individual models on the chemical evolution of galaxies, just by changing the control flags and parameters of the library. Since this library only deals with the part of chemical evolution under the SSP approximation, any simulation codes that use the SSP approximation—namely, particle-base and mesh codes, as well as semianalytical models—can use it. This library is named “CELib” after the term “Chemical Evolution Library” and is made available to the community.

  10. Oxygen evolution reaction catalysis

    Science.gov (United States)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  11. INVESTIGATIONS ON BIOCHEMICAL PURIFICATION OF GROUND WATER FROM HYDROGEN SULFIDE

    Directory of Open Access Journals (Sweden)

    Yu. P. Sedlukho

    2015-01-01

    Full Text Available The paper considers problems and features of biochemical removal of hydrogen sulfide from ground water. The analysis of existing methods for purification of ground water from hydrogen sulfide has been given in the paper. The paper has established shortcomings of physical and chemical purification of ground water. While using aeration methods for removal of hydrogen sulfide formation of colloidal sulfur that gives muddiness and opalescence to water occurs due to partial chemical air oxidation. In addition to this violation of sulfide-carbonate equilibrium taking place in the process of aeration due to desorption of H2S and CO2, often leads to clogging of degasifier nozzles with formed CaCO3 that causes serious operational problems. Chemical methods require relatively large flow of complex reagent facilities, storage facilities and transportation costs.In terms of hydrogen sulfide ground water purification the greatest interest is given to the biochemical method. Factors deterring widespread application of the biochemical method is its insufficient previous investigation and necessity to execute special research in order to determine optimal process parameters while purifying groundwater of a particular water supply source. Biochemical methods for oxidation of sulfur compounds are based on natural biological processes that ensure natural sulfur cycle. S. Vinogradsky has established a two-stage mechanism for oxidation of hydrogen sulfide with sulfur bacteria (Beggiatoa. The first stage presupposes oxidation of hydrogen sulphide to elemental sulfur which is accumulating in the cytoplasm in the form of globules. During the second stage sulfur bacteria begin to oxidize intracellular sulfur to sulfuric acid due to shortage of hydrogen sulfide.The paper provides the results of technological tests of large-scale pilot plants for biochemical purification of groundwater from hydrogen sulfide in semi-industrial conditions. Dependences of water quality

  12. Accurate atom-mapping computation for biochemical reactions.

    Science.gov (United States)

    Latendresse, Mario; Malerich, Jeremiah P; Travers, Mike; Karp, Peter D

    2012-11-26

    The complete atom mapping of a chemical reaction is a bijection of the reactant atoms to the product atoms that specifies the terminus of each reactant atom. Atom mapping of biochemical reactions is useful for many applications of systems biology, in particular for metabolic engineering where synthesizing new biochemical pathways has to take into account for the number of carbon atoms from a source compound that are conserved in the synthesis of a target compound. Rapid, accurate computation of the atom mapping(s) of a biochemical reaction remains elusive despite significant work on this topic. In particular, past researchers did not validate the accuracy of mapping algorithms. We introduce a new method for computing atom mappings called the minimum weighted edit-distance (MWED) metric. The metric is based on bond propensity to react and computes biochemically valid atom mappings for a large percentage of biochemical reactions. MWED models can be formulated efficiently as Mixed-Integer Linear Programs (MILPs). We have demonstrated this approach on 7501 reactions of the MetaCyc database for which 87% of the models could be solved in less than 10 s. For 2.1% of the reactions, we found multiple optimal atom mappings. We show that the error rate is 0.9% (22 reactions) by comparing these atom mappings to 2446 atom mappings of the manually curated Kyoto Encyclopedia of Genes and Genomes (KEGG) RPAIR database. To our knowledge, our computational atom-mapping approach is the most accurate and among the fastest published to date. The atom-mapping data will be available in the MetaCyc database later in 2012; the atom-mapping software will be available within the Pathway Tools software later in 2012.

  13. Museums teach evolution.

    Science.gov (United States)

    Diamond, Judy; Evans, E Margaret

    2007-06-01

    Natural history museums play a significant role in educating the general public about evolution. This article describes Explore Evolution, one of the largest evolution education projects funded by the National Science Foundation. A group of regional museums from the Midwestern United States worked with leading evolutionary scientists to create multiple permanent exhibit galleries and a curriculum book for youth. This program invites the public to experience current evolutionary research on organisms that range in size from HIV to whales. Learning research is being conducted on museum visitors to understand how they reason about evolution and to determine what influences the process of conceptual change.

  14. Industrial dust sulphate and its effects on biochemical and morphological characteristics of Morus (Morus alba) plant in NCR Delhi.

    Science.gov (United States)

    Gupta, Gyan Prakash; Singh, Sudha; Kumar, Bablu; Kulshrestha, U C

    2015-03-01

    Abundance of CaCO3 rich soil dust is a typical feature of atmospheric environment in the Indian region. During prevailing dry weather conditions, dustfall is deposited onto the foliar surfaces of plant affecting their morphology, stomata and the levels of biochemical constituents. This study reports the chemical characteristics of dustfall, its effect on foliar morphology and biochemical constituents of a medicinal plant (Morus alba) at two sites which are differentiated on the basis of landuse pattern, viz., (i) residential, Jawaharlal Nehru University (JNU), and (ii) industrial, Sahibabad (SB), located in the National Capital Region (NCR) of Delhi. Dustfall was characterized for major anions (F(-), Cl(-), NO3 (-) and SO4 (--)) and cations (Na(+), NH4 (+), K(+), Mg(++) and Ca(++)). Biochemical parameters such as chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, proline and ascorbic acid were determined in foliar samples. The results showed that the dustfall fluxes of all the major ions were found to be higher at the industrial site (SB) as compared to the residential site (JNU). Foliar analysis revealed that the levels of biochemical parameters were more affected at SB site due to higher levels of dust SO4 (--) contributed by various anthropogenic sources resulting in more stressful conditions affecting the biochemistry of the plant. The possible entry pathways for dust SO4 (--) into foliar cells are also discussed in the paper. It was noticed that the deposition of urban dust was responsible for the damage of trichome, epidermis, cuticle and stomatal guard cells significantly affecting foliar morphology. SB exhibited more damage to these morphological parts suggesting that industrial dust is harmful to the plants.

  15. PROGNOSTIC FACTORS OF BIOCHEMICAL RELAPSE FREE SURVIVAL FOLLOWING SALVAGE RADIOTHERAPY IN MEN WITH BIOCHEMICAL RECURRENCE AFTER RADICAL PROSTATECTOMY

    Directory of Open Access Journals (Sweden)

    P. D. Demeshko

    2014-07-01

    Full Text Available Purpose. To evaluate influence of clinical, biochemical and histological factors to biochemical relapse free survival (BRFS following salvage radiotherapy (RT in men with biochemical recurrence after radical prostatectomy.Material and methods. 77 patients with newly diagnosed biochemical recurrence (BR after RPE were included into retrospective study. All of them underwent local salvage RT. Сlinical variables (age, serum prostate-specific antigen [PSA] level and PSA kinetics, time RPE-BR, Gleason grade, stage after RPE and clinical findings were evaluated using Cox proportional hazards regression analysis.Results. The median, 1- and 3-year BRFS were 19,9 months, 63,8 ± 6,5 % and 24,7 ± 8,5 % respectively. Significant variables in the multivariable model were age, PSA level before RT, prostatectomy T3b stage, PSA doubling time and positive digital rectal examination findings (p < 0,05. Several clinical parameters help predict the outcomes of men with PSA elevation after radical prostatectomy. These data may be useful in counseling men regarding the timing of administration of adjuvant therapies.

  16. Programmed evolution for optimization of orthogonal metabolic output in bacteria.

    Directory of Open Access Journals (Sweden)

    Todd T Eckdahl

    Full Text Available Current use of microbes for metabolic engineering suffers from loss of metabolic output due to natural selection. Rather than combat the evolution of bacterial populations, we chose to embrace what makes biological engineering unique among engineering fields - evolving materials. We harnessed bacteria to compute solutions to the biological problem of metabolic pathway optimization. Our approach is called Programmed Evolution to capture two concepts. First, a population of cells is programmed with DNA code to enable it to compute solutions to a chosen optimization problem. As analog computers, bacteria process known and unknown inputs and direct the output of their biochemical hardware. Second, the system employs the evolution of bacteria toward an optimal metabolic solution by imposing fitness defined by metabolic output. The current study is a proof-of-concept for Programmed Evolution applied to the optimization of a metabolic pathway for the conversion of caffeine to theophylline in E. coli. Introduced genotype variations included strength of the promoter and ribosome binding site, plasmid copy number, and chaperone proteins. We constructed 24 strains using all combinations of the genetic variables. We used a theophylline riboswitch and a tetracycline resistance gene to link theophylline production to fitness. After subjecting the mixed population to selection, we measured a change in the distribution of genotypes in the population and an increased conversion of caffeine to theophylline among the most fit strains, demonstrating Programmed Evolution. Programmed Evolution inverts the standard paradigm in metabolic engineering by harnessing evolution instead of fighting it. Our modular system enables researchers to program bacteria and use evolution to determine the combination of genetic control elements that optimizes catabolic or anabolic output and to maintain it in a population of cells. Programmed Evolution could be used for applications in

  17. Biochemical aspects of overtraining in endurance sports : the metabolism alteration process syndrome.

    Science.gov (United States)

    Petibois, Cyril; Cazorla, Georges; Poortmans, Jacques-Rémi; Déléris, Gérard

    2003-01-01

    Recent studies have shown that endurance overtraining could result from successive and cumulative alterations in metabolism, which become chronic during training. The onset of this process is a biochemical alteration in carbohydrate (saccharide) metabolism. During endurance exercises, the amount of saccharide chains from two blood glycoproteins (alpha(2)-macroglobulin and alpha(1)-acid glycoprotein) was found to have decreased, i.e. concentrations of these proteins remained unchanged but their quality changed. These saccharide chains were probably used for burning liver glycogen stores during exercise. This step was followed by alterations in lipid metabolism. The most relevant aspect of this step was that the mean chain length of blood fatty acids decreased, i.e. the same amount of fatty acids were found within the blood, but overtrained individuals presented shorter fatty acids than well-trained individuals. This suggests that alterations appeared in the liver synthesis of long-chain fatty acids or that higher peroxidation of blood lipoparticles occurred. For the final step of this overtraining process, it was found that these dysfunctions in carbohydrate/lipid metabolism led to the higher use of amino acids, which probably resulted from protein catabolism. The evolution of three protein concentrations (alpha(1)-acid glycoprotein, alpha(2)-macroglobulin and IgG(3)) correlated with this amino acid concentration increase, suggesting a specific catabolism of these proteins. At this time only, overtraining was clinically diagnosed through conventional symptoms. Therefore, this process described successive alterations in exercise metabolism that shifted from the main energetic stores of exercise (carbohydrates and lipids) towards molecular pools (proteins) normally not substantially used for the energetic supply of skeletal muscles. Now, a general biochemical model of the overtraining process may be proposed which includes most of the previously identified metabolic

  18. Framing Evolution Discussion Intellectually

    Science.gov (United States)

    Oliveira, Alandeom W.; Cook, Kristin; Buck, Gayle A.

    2011-01-01

    This study examines how a first-year biology teacher facilitates a series of whole-class discussions about evolution during the implementation of a problem-based unit. A communicative theoretical perspective is adopted wherein evolution discussions are viewed as social events that the teacher can frame intellectually (i.e., present or organize as…

  19. Evolution for Young Victorians

    Science.gov (United States)

    Lightman, Bernard

    2012-01-01

    Evolution was a difficult topic to tackle when writing books for the young in the wake of the controversies over Darwin's "Origin of Species." Authors who wrote about evolution for the young experimented with different ways of making the complex concepts of evolutionary theory accessible and less controversial. Many authors depicted presented…

  20. Software evolution with XVCL

    DEFF Research Database (Denmark)

    Zhang, Weishan; Jarzabek, Stan; Zhang, Hongyu

    2004-01-01

    This chapter introduces software evolution with XVCL (XML-based Variant Configuration Language), which is an XML-based metaprogramming technique. As the software evolves, a large number of variants may arise, especially whtn such kinds of evolutions are related to multiple platforms as shown in o...

  1. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  2. Kognition, evolution og Bibel

    DEFF Research Database (Denmark)

    Jensen, Hans Jørgen Lundager

    2012-01-01

    En opfordring til, at Bibelvidneskaberne oprienterer sig i retning af aktuelle teorier om bio-kulturel evolution (Merlin Donald, aksetids-teori hos fx Robert Bellah)......En opfordring til, at Bibelvidneskaberne oprienterer sig i retning af aktuelle teorier om bio-kulturel evolution (Merlin Donald, aksetids-teori hos fx Robert Bellah)...

  3. Self and Evolution.

    Science.gov (United States)

    Csikszentmihalyi, Mihaly

    1998-01-01

    Suggests the time has come for humans to direct their own individual evolution and the evolution of the entire species. Argues that ways must be found to encourage individuals, families, and cultures to discover and develop their differentiating characteristics and help these groups integrate with other cultures, customs, and belief systems.…

  4. Evolution of Constructivism

    Science.gov (United States)

    Liu, Chu Chih; Chen, I Ju

    2010-01-01

    The contrast between social constructivism and cognitive constructivism are depicted in different ways in many studies. The purpose of this paper is to summarize the evolution of constructivism and put a focus on social constructivism from the perception of Vygotsky. This study provides a general idea of the evolution of constructivism for people…

  5. Biochemical studies on Francisella tularensis RelA in (p)ppGpp biosynthesis.

    Science.gov (United States)

    Wilkinson, Rachael C; Batten, Laura E; Wells, Neil J; Oyston, Petra C F; Roach, Peter L

    2015-10-08

    The bacterial stringent response is induced by nutrient deprivation and is mediated by enzymes of the RSH (RelA/SpoT homologue; RelA, (p)ppGpp synthetase I; SpoT, (p)ppGpp synthetase II) superfamily that control concentrations of the 'alarmones' (p)ppGpp (guanosine penta- or tetra-phosphate). This regulatory pathway is present in the vast majority of pathogens and has been proposed as a potential anti-bacterial target. Current understanding of RelA-mediated responses is based on biochemical studies using Escherichia coli as a model. In comparison, the Francisella tularensis RelA sequence contains a truncated regulatory C-terminal region and an unusual synthetase motif (EXSD). Biochemical analysis of F. tularensis RelA showed the similarities and differences of this enzyme compared with the model RelA from Escherichia coli. Purification of the enzyme yielded a stable dimer capable of reaching concentrations of 10 mg/ml. In contrast with other enzymes from the RelA/SpoT homologue superfamily, activity assays with F. tularensis RelA demonstrate a high degree of specificity for GTP as a pyrophosphate acceptor, with no measurable turnover for GDP. Steady state kinetic analysis of F. tularensis RelA gave saturation activity curves that best fitted a sigmoidal function. This kinetic profile can result from allosteric regulation and further measurements with potential allosteric regulators demonstrated activation by ppGpp (5',3'-dibisphosphate guanosine) with an EC50 of 60±1.9 μM. Activation of F. tularensis RelA by stalled ribosomal complexes formed with ribosomes purified from E. coli MRE600 was observed, but interestingly, significantly weaker activation with ribosomes isolated from Francisella philomiragia.

  6. Listening to PS II: enthalpy, entropy, and volume changes.

    Science.gov (United States)

    Hou, Harvey J M; Mauzerall, David

    2011-01-01

    Photosystem II, located in the thylakoid membranes of green plants, algae, and cyanobacteria, uses sunlight to split water into protons, electrons, and a dioxygen molecule. The mechanism of its electron transfers and oxygen evolution including the structure of the protein and rates of the S-state cycle has been extensively investigated. Substantial progress has been made; however, the thermodynamics of PS II electron transfer and of the oxygen cycle are poorly understood. Recent progress in thermodynamic measurements in photosynthesis provides novel insights on the enthalpic and entropic contribution to electron transfer in proteins. In this review the thermodynamic parameters including quantum yield, enthalpy, entropy, and volume changes of PS II photochemistry determined by photoacoustics and other laser techniques are summarized and evaluated. Light-driven volume changes via electrostriction are directly related to the photoreaction in PS II and thus can be a useful measurement of PS II activity and function. The enthalpy changes of the reactions observed can be directly measured by photoacoustics. The apparent reaction entropy can also be estimated when the free energy is known. Dissecting the free energy of a photoreaction into enthalpic and entropic components provides critical information about mechanisms of PS II function. Potential limitations and future direction of the study of the thermodynamics of PS II electron transfer and oxygen evolution are presented.

  7. Quininium tetrachloridozinc(II

    Directory of Open Access Journals (Sweden)

    Li-Zhuang Chen

    2009-10-01

    Full Text Available The asymmetric unit of the title compound {systematic name: 2-[hydroxy(6-methoxyquinolin-1-ium-4-ylmethyl]-8-vinylquinuclidin-1-ium tetrachloridozinc(II}, (C20H26N2O2[ZnCl4], consists of a double protonated quininium cation and a tetrachloridozinc(II anion. The ZnII ion is in a slightly distorted tetrahedral coordination environment. The crystal structure is stabilized by intermolecular N—H...Cl and O—H...Cl hydrogen bonds.

  8. Hydrosol II Project; El Proyecto Hydrosol II

    Energy Technology Data Exchange (ETDEWEB)

    Lopez Martinez, A.

    2008-07-01

    At present energy production is based on the combustion of fossil fuels and is the main cause of greenhouse gas emissions, which is to say it is the main cause of the climate change that is affecting the planet. On a worldwide scale, the use of solar concentration systems with systems capable of dissociating water is considered, from both an energy and an economic standpoint, as the most important long-term goal in the production of solar fuels to reduce the costs of hydrogen and to ensure practically zero carbon dioxide emissions. The Hydrosol II project has the largest pilot plant of its kind, and the Hydrosol II reactors will be capable of breaking up the water molecule on the basis of thermochemical cycles at moderate temperatures. The Hydrosol II project pilot plant is now a reality, located in the SSPS heliostats field of the Almeria Solar Platform. (Author)

  9. Structural Basis for Ubiquitin Recognition by the Human ESCRT-II EAP45 GLUE Domain

    Energy Technology Data Exchange (ETDEWEB)

    Alam,S.; Langelier, C.; Whitby, F.; Koirala, S.; Robinson, H.; Hill, C.; Sundquist, W.

    2006-01-01

    ESCRT-IESCRT-IIGLUEEAP45VPS36The ESCRT-I and ESCRT-II complexes help sort ubiquitinated proteins into vesicles that accumulate within multivesicular bodies (MVBs). Crystallographic and biochemical analyses reveal that the GLUE domain of the human ESCRT-II EAP45 (also called VPS36) subunit is a split pleckstrin-homology domain that binds ubiquitin along one edge of the {beta}-sandwich. The structure suggests how human ESCRT-II can couple recognition of ubiquitinated cargoes and endosomal phospholipids during MVB protein sorting.

  10. Burkina Faso - BRIGHT II

    Data.gov (United States)

    Millennium Challenge Corporation — Millennium Challenge Corporation hired Mathematica Policy Research to conduct an independent evaluation of the BRIGHT II program. The three main research questions...

  11. 40 CFR 158.2084 - Experimental use permit biochemical pesticides nontarget organisms and environmental fate data...

    Science.gov (United States)

    2010-07-01

    ... pesticides nontarget organisms and environmental fate data requirements table. 158.2084 Section 158.2084 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS DATA REQUIREMENTS FOR PESTICIDES Biochemical Pesticides § 158.2084 Experimental use permit biochemical...

  12. Polyamines as salinity biochemical marker in callus of eucalyptus urograndis

    Directory of Open Access Journals (Sweden)

    Giuseppina Lima Pace Pereira

    2003-01-01

    Full Text Available Biochemical markers have been used for the analysis of plant cells submitted to several types of stress, among them salinity. This work aimed at analyzing the effect of saline stress in callus of Eucalyptus urograndis on polyamine contents. Explants (hypocotyls obtained from seeds were inoculated in callus inductive medium, submitted to different levels of NaCl and analyzed at 10, 20 and 30 days after the inoculation. The free polyamines were extracted, isolated and quantified using TLC (Thin-Layer Chromatography. Putrescine content was higher and a fall in the spermidine content was observed in callus submitted to salinity condition. The results showed that polyamine accumulation is related to NaCl exposure in callus of Eucalyptus urograndis. The decrease in spermine content could be used as a biochemical marker for Eucalyptus callus subjected to salinity.

  13. Biochemical functionalization of peptide nanotubes with phage displayed peptides

    Science.gov (United States)

    Swaminathan, Swathi; Cui, Yue

    2016-09-01

    The development of a general approach for the biochemical functionalization of peptide nanotubes (PNTs) could open up existing opportunities in both fundamental studies as well as a variety of applications. PNTs are spontaneously assembled organic nanostructures made from peptides. Phage display has emerged as a powerful approach for identifying selective peptide binding motifs. Here, we demonstrate for the first time the biochemical functionalization of PNTs via peptides identified from a phage display peptide library. The phage-displayed peptides are shown to recognize PNTs. These advances further allow for the development of bifunctional peptides for the capture of bacteria and the self-assembly of silver particles onto PNTs. We anticipate that these results could provide significant opportunities for using PNTs in both fundamental studies and practical applications, including sensors and biosensors nanoelectronics, energy storage devices, drug delivery, and tissue engineering.

  14. The application of information theory to biochemical signaling systems.

    Science.gov (United States)

    Rhee, Alex; Cheong, Raymond; Levchenko, Andre

    2012-08-01

    Cell signaling can be thought of fundamentally as an information transmission problem in which chemical messengers relay information about the external environment to the decision centers within a cell. Due to the biochemical nature of cellular signal transduction networks, molecular noise will inevitably limit the fidelity of any messages received and processed by a cell's signal transduction networks, leaving it with an imperfect impression of its environment. Fortunately, Shannon's information theory provides a mathematical framework independent of network complexity that can quantify the amount of information that can be transmitted despite biochemical noise. In particular, the channel capacity can be used to measure the maximum number of stimuli a cell can distinguish based upon the noisy responses of its signaling systems. Here, we provide a primer for quantitative biologists that covers fundamental concepts of information theory, highlights several key considerations when experimentally measuring channel capacity, and describes successful examples of the application of information theoretic analysis to biological signaling.

  15. The free energy cost of accurate biochemical oscillations

    CERN Document Server

    Cao, Yuansheng; Ouyang, Qi; Tu, Yuhai

    2015-01-01

    Oscillation is an important cellular process that regulates timing of different vital life cycles. However, in the noisy cellular environment, oscillations can be highly inaccurate due to phase fluctuations. It remains poorly understood how biochemical circuits suppress phase fluctuations and what is the incurred thermodynamic cost. Here, we study four different types of biochemical oscillations representing three basic oscillation motifs shared by all known oscillatory systems. We find that the phase diffusion constant follows the same inverse dependence on the free energy dissipation per period for all systems studied. This relationship between the phase diffusion and energy dissipation is shown analytically in a model of noisy oscillation. Microscopically, we find that the oscillation is driven by multiple irreversible cycles that hydrolyze the fuel molecules such as ATP; the number of phase coherent periods is proportional to the free energy consumed per period. Experimental evidence in support of this un...

  16. BIOCHEMICAL PROCESSES IN CHERNOZEM SOIL UNDER DIFFERENT FERTILIZATION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Ecaterina Emnova

    2012-06-01

    Full Text Available The paper deals with the evaluation of the intensity of certain soil biochemical processes (e.g. soil organic C mineralization at Organic and mixed Mineral+Organic fertilization of typical chernozem in crop rotation dynamics (for 6 years by use of eco-physiological indicators of biological soil quality: microbial biomass carbon, basal soil respiration, as well as, microbial and metabolic quotients. Soil sampling was performed from a long-term field crop experiment, which has been established in 1971 at the Balti steppe (Northern Moldova. The crop types had a more considerable impact on the soil microbial biomass accumulation and community biochemical activity compared to long-term Organic or mixed Mineral + Organic fertilizers amendments. The Org fertilization system doesn’t make it possible to avoid the loss of organic C in arable typical chernozem. The organic fertilizer (cattle manure is able to mitigate the negative consequences of long-term mineral fertilization.

  17. Electrolyte-Gated Graphene Ambipolar Frequency Multipliers for Biochemical Sensing.

    Science.gov (United States)

    Fu, Wangyang; Feng, Lingyan; Mayer, Dirk; Panaitov, Gregory; Kireev, Dmitry; Offenhäusser, Andreas; Krause, Hans-Joachim

    2016-04-13

    In this Letter, the ambipolar properties of an electrolyte-gated graphene field-effect transistor (GFET) have been explored to fabricate frequency-doubling biochemical sensor devices. By biasing the ambipolar GFETs in a common-source configuration, an input sinusoidal voltage at frequency f applied to the electrolyte gate can be rectified to a sinusoidal wave at frequency 2f at the drain electrode. The extraordinary high carrier mobility of graphene and the strong electrolyte gate coupling provide the graphene ambipolar frequency doubler an unprecedented unity gain, as well as a detection limit of ∼4 pM for 11-mer single strand DNA molecules in 1 mM PBS buffer solution. Combined with an improved drift characteristics and an enhanced low-frequency 1/f noise performance by sampling at doubled frequency, this good detection limit suggests the graphene ambipolar frequency doubler a highly promising biochemical sensing platform.

  18. Biomphalaria prona (Gastropoda: Planorbidae: a morphological and biochemical study

    Directory of Open Access Journals (Sweden)

    W. Lobato Paraense

    1992-06-01

    Full Text Available Two samples of Biomphalaria prona (Martens, 1873 from Lake Valencia (type locality and seven from other Venezuelan localities were studied morphologically (shell and reproductive system and biochemically (allozyme electrophoresis. In spite of marked differences in shell characters, all of them proved indistinguishable under the anatomic and biochemical criteria. So far B. prona has been considered an endemic species, restricted to Lake Valencia. It is now demonstrated that the extralacustrine populations refered to Biomphalaria havanensis (Pfeiffer, 1839 by several authors correspond in shell characters to an extreme variant of B. prona from the Lake and really belong to the last*mentioned species. They may be regarded as the result of a process of directional selection favoring a shell phenotype other than those making up the modal class in the Lake.

  19. The Metabolic Syndrome and Biochemical Recurrence following Radical Prostatectomy

    Directory of Open Access Journals (Sweden)

    Jennifer M. Post

    2011-01-01

    Full Text Available Metabolic syndrome refers to a set of conditions that increases the risk of cardiovascular disease and has been associated with an increased risk of prostate cancer, particularly among African American men. This study aimed to estimate the association of metabolic syndrome with biochemical recurrence (BCR in a racially diverse population. Among 383 radical prostatectomy patients, 67 patients had documented biochemical recurrence. Hypertension was significantly, positively associated with the rate of BCR (hazard ratio (HR = 2.1; 95%  CI = 1.1, 3.8. There were distinct racial differences in the prevalence of individual metabolic syndrome components; however, the observed associations with BCR did not differ appreciably by race. We conclude that hypertension may contribute to a poorer prognosis in surgically treated prostate cancer patients. Our findings suggest that targeting components of the metabolic syndrome which are potentially modifiable through lifestyle interventions may be a viable strategy to reduce risk of BCR in prostate cancer.

  20. Experimental evolution in silico: a custom-designed mathematical model for virulence evolution of Bacillus thuringiensis.

    Science.gov (United States)

    Strauß, Jakob Friedrich; Crain, Philip; Schulenburg, Hinrich; Telschow, Arndt

    2016-08-01

    Most mathematical models on the evolution of virulence are based on epidemiological models that assume parasite transmission follows the mass action principle. In experimental evolution, however, mass action is often violated due to controlled infection protocols. This "theory-experiment mismatch" raises the question whether there is a need for new mathematical models to accommodate the particular characteristics of experimental evolution. Here, we explore the experimental evolution model system of Bacillus thuringiensis as a parasite and Caenorhabditis elegans as a host. Recent experimental studies with strict control of parasite transmission revealed that one-sided adaptation of B. thuringiensis with non-evolving hosts selects for intermediate or no virulence, sometimes coupled with parasite extinction. In contrast, host-parasite coevolution selects for high virulence and for hosts with strong resistance against B. thuringiensis. In order to explain the empirical results, we propose a new mathematical model that mimics the basic experimental set-up. The key assumptions are: (i) controlled parasite transmission (no mass action), (ii) discrete host generations, and (iii) context-dependent cost of toxin production. Our model analysis revealed the same basic trends as found in the experiments. Especially, we could show that resistant hosts select for highly virulent bacterial strains. Moreover, we found (i) that the evolved level of virulence is independent of the initial level of virulence, and (ii) that the average amount of bacteria ingested significantly affects the evolution of virulence with fewer bacteria ingested selecting for highly virulent strains. These predictions can be tested in future experiments. This study highlights the usefulness of custom-designed mathematical models in the analysis and interpretation of empirical results from experimental evolution.

  1. Biochemical recurrence of prostate cancer: the controversial recognition and management

    Institute of Scientific and Technical Information of China (English)

    XIA Shu-jie; JING Yi-feng

    2011-01-01

    @@ Over the past decaade, more and more patients diagnosed as prostate cancer have received radical management attributing to the advent of prostate-specific antigen (PSA) based medical screening.Radical prostatectomy (RP) and radiation therapy (RT) are the most commonly used forms of definitive therapy for clinically localized prostate cancer.However, despite these technique advances, biochemical recurrence (BCR),as determined by subsequent rises in the serum PSA level,is still a challenge that urologists face.

  2. Biochemical Changes During Seed Germination of Sterculia urens Roxb.

    OpenAIRE

    Botcha SATYANARAYANA; Prattipati Subhashini DEVI; Atluru ARUNDATHI

    2011-01-01

    The present study describes biochemical changes taking place during seed germination of Sterculia urens. The levels of proteins, total amino acids, reducing sugars, total soluble sugars and lipids were studied during various stages of seed germination (0-15 days). Total protein content was decreased in cotyledons during seed germination while free amino acid content increased to its maximum extent by 9th day of germination and reverse trend thereafter. The levels of reducing sugars and total ...

  3. Biological and biochemical properties in evaluation of forest soil quality

    OpenAIRE

    Błońska Ewa; Lasota Jarosław

    2014-01-01

    The aim of this study was to assess the possibility of using biological and biochemical parameters in the evaluation of forest soil quality and changes caused by land use. The study attempted to determine a relationship between the enzymatic activity of soil, the number of earthworms and soil physico-chemical properties. The study was carried out in central Poland in adjoining Forest Districts (Przedbórz and Smardzewice). In soil samples taken from 12 research plots, basic physico-chemical pr...

  4. Biological and biochemical properties in evaluation of forest soil quality

    OpenAIRE

    Błońska, Ewa; Lasota, Jarosław

    2014-01-01

    The aim of this study was to assess the possibility of using biological and biochemical parameters in the evaluation of forest soil quality and changes caused by land use. The study attempted to determine a relationship between the enzymatic activity of soil, the number of earthworms and soil physico-chemical properties. The study was carried out in central Poland in adjoining Forest Districts (Przedbórz and Smardzewice). In soil samples taken from 12 research plots, basic physico-chem...

  5. Molecular and biochemical studies on bovine ephemeral fever

    Directory of Open Access Journals (Sweden)

    Nahed S. Thabet; Emad W. Ghazy; Mohamed A. Nayel; Mohamed Abo-Elkhair

    2011-05-01

    Full Text Available Bovine ephemeral fever (BEF in cattle has been reported to be associated with a range of biochemical changes which are similar to those seen in milk fever. This study aimed to clarify the biochemical alterations that associate infection of cattle with BEF with special references to the mechanisms involved in the development of hypocalcemia. The study was conducted on 30 cases of cattle infected with BEF based on the characteristic clinical signs which were confirmed by isolation of virus and RT-PCR. Another 6 healthy cows were used in the study as control. The evaluated parameters included biochemical variables such as serum values of total protein (TP, albumin (Alb, glucose (Glu, total calcium (tCa, ionized calcium (iCa, inorganic phosphorus (P, magnesium (Mg, sodium (Na, potassium (K, chloride (Cl, creatinine (Cr, blood urea nitrogen (BUN and serum activity of alkaline phosphatase (ALP. Hormonal profile included parathyroid hormone (PTH, insulin (Ins, and cortisol (Cor. The results showed that BEF-infected animals demonstrated a significant decrease (P<0.05 in serum concentrations of TP, Glo, iCa, P, Na, K, BUN and ALP while the mean values of serum levels of Glu and Cl were significantly increased (P<0.05. The mean values of serum levels of PTH were significantly decreased (P<0.05 while serum concentrations of Ins and Cor showed a significant increase. It was concluded that the clinical signs of bovine ephemeral fever are related to the hypocalcemia resulting from suppression of parathyroid hormone which seems to be mediated by respiratory alkalosis caused by the disease. This explanation needs future studies to provide a direct link between measurement of blood indicators of acid-base status, blood biochemical parameters and urine analysis. However, this work can provide a good knowledge about the pathogenesis of the disease that can lead to better management and proper treatment.

  6. Accelerated maximum likelihood parameter estimation for stochastic biochemical systems

    Directory of Open Access Journals (Sweden)

    Daigle Bernie J

    2012-05-01

    Full Text Available Abstract Background A prerequisite for the mechanistic simulation of a biochemical system is detailed knowledge of its kinetic parameters. Despite recent experimental advances, the estimation of unknown parameter values from observed data is still a bottleneck for obtaining accurate simulation results. Many methods exist for parameter estimation in deterministic biochemical systems; methods for discrete stochastic systems are less well developed. Given the probabilistic nature of stochastic biochemical models, a natural approach is to choose parameter values that maximize the probability of the observed data with respect to the unknown parameters, a.k.a. the maximum likelihood parameter estimates (MLEs. MLE computation for all but the simplest models requires the simulation of many system trajectories that are consistent with experimental data. For models with unknown parameters, this presents a computational challenge, as the generation of consistent trajectories can be an extremely rare occurrence. Results We have developed Monte Carlo Expectation-Maximization with Modified Cross-Entropy Method (MCEM2: an accelerated method for calculating MLEs that combines advances in rare event simulation with a computationally efficient version of the Monte Carlo expectation-maximization (MCEM algorithm. Our method requires no prior knowledge regarding parameter values, and it automatically provides a multivariate parameter uncertainty estimate. We applied the method to five stochastic systems of increasing complexity, progressing from an analytically tractable pure-birth model to a computationally demanding model of yeast-polarization. Our results demonstrate that MCEM2 substantially accelerates MLE computation on all tested models when compared to a stand-alone version of MCEM. Additionally, we show how our method identifies parameter values for certain classes of models more accurately than two recently proposed computationally efficient methods

  7. Supplementation with carnitine for weight loss: a biochemical approach

    Directory of Open Access Journals (Sweden)

    José Henry Osorio

    2011-11-01

    Full Text Available Carnitine is a molecule involved in transporting activated fatty acids among different cellular compartments, which is mostlikely present in all animal species, and in numerous microorganisms and plants. Recently the trend in the field of weightcontrol is to include carnitine in the diet as an agent responsible for weight loss. In the present review, some findings arediscussed from a biochemical point of view to illustrate if the use of carnitine for weight loss can be considered fiction orreality.

  8. Supplementation with carnitine for weight loss: a biochemical approach

    OpenAIRE

    José Henry Osorio

    2011-01-01

    Carnitine is a molecule involved in transporting activated fatty acids among different cellular compartments, which is mostlikely present in all animal species, and in numerous microorganisms and plants. Recently the trend in the field of weightcontrol is to include carnitine in the diet as an agent responsible for weight loss. In the present review, some findings arediscussed from a biochemical point of view to illustrate if the use of carnitine for weight loss can be considered fiction orre...

  9. CLINICAL AND BIOCHEMICAL CHARACTERISTICS AT THE CIRRHOSIS OF VARIOUS GENESIS

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    A. R. Bilalova

    2016-01-01

    Full Text Available Purpose of the study. To carry out a comparative description of the clinical and biochemical parameters at patients with cirrhosis of an alcoholic genesis (CP-HGA and cirrhosis of mixed etiologies — CP-HGM (HСV+ alcohol.Materials and methods. The study involved 62 patients with cirrhosis of different etiologies, who carries out clinical, immunogenetic and biochemical studies.Results. Patients with the 3d genotype and low viral load were registered with cirrhosis of mixed etiologies (HСV+ alcohol. At the cirrhosis Class B for Child-Pugh basic data biochemical parameters were similar in patients with CP-HGA and CP-HGM, but ALT and AST activity, which are significantly higher than observed in patients with CP-HGM. At dismissal, ALT and GGT activities were detected significantly higher in patients with CP-HGM than the CP-HGA. At the cirrhosis Class C for Child-Pugh the baseline, reflecting cholestasis — is total bilirubin, GGT and alkaline phosphatase and were detected significantly higher in the CP-HGA, than with CP-HGM significantly reduced, and thore is no differences between the groups to be discharged from the hospital, in addition to the activity of GGT, which it remained significantly higher in the CP-HGA, than with CP-HGM. Cytolytic activity of enzymes (ALT, AST during the entire period of the disease was observed significantly higher normal values and did not depend on the CP etiology.Conclusion decision. The maximum rate of change of the basic biochemical parameters is observed in patients with cirrhosis of mixed etiologies Class B for Child-Pugh and at the cirrhosis of an alcoholic genesis — in patients with cirrhosis Class C.

  10. The evolution and molecular mechanism of the function of the cytokine system in vertebrates

    DEFF Research Database (Denmark)

    Siupka, Piotr

    Cytokines are small signaling molecules involved in many processes in vertebrates. The most prominent role of class I and II cytokines is connected with vertebrate immunology. Piotr studied the evolution of the class II cytokine system. By resolving the crystal structure of interleukin-22 from...

  11. Complete integrability of information processing by biochemical reactions

    Science.gov (United States)

    Agliari, Elena; Barra, Adriano; Dello Schiavo, Lorenzo; Moro, Antonio

    2016-11-01

    Statistical mechanics provides an effective framework to investigate information processing in biochemical reactions. Within such framework far-reaching analogies are established among (anti-) cooperative collective behaviors in chemical kinetics, (anti-)ferromagnetic spin models in statistical mechanics and operational amplifiers/flip-flops in cybernetics. The underlying modeling - based on spin systems - has been proved to be accurate for a wide class of systems matching classical (e.g. Michaelis-Menten, Hill, Adair) scenarios in the infinite-size approximation. However, the current research in biochemical information processing has been focusing on systems involving a relatively small number of units, where this approximation is no longer valid. Here we show that the whole statistical mechanical description of reaction kinetics can be re-formulated via a mechanical analogy - based on completely integrable hydrodynamic-type systems of PDEs - which provides explicit finite-size solutions, matching recently investigated phenomena (e.g. noise-induced cooperativity, stochastic bi-stability, quorum sensing). The resulting picture, successfully tested against a broad spectrum of data, constitutes a neat rationale for a numerically effective and theoretically consistent description of collective behaviors in biochemical reactions.

  12. Polyphenol Oxidase as a Biochemical Seed Defense Mechanism

    Directory of Open Access Journals (Sweden)

    E. Patrick Fuerst

    2014-12-01

    Full Text Available Seed dormancy and resistance to decay are fundamental survival strategies, which allow a population of seeds to germinate over long periods of time. Seeds have physical, chemical, and biological defense mechanisms that protect their food reserves from decay-inducing organisms and herbivores. Here, we hypothesize that seeds also possess enzyme-based biochemical defenses, based on induction of the plant defense enzyme, polyphenol oxidase (PPO, when wild oat (Avena fatua L. caryopses and seeds were challenged with seed-decaying Fusarium fungi. These studies suggest that dormant seeds are capable of mounting a defense response to pathogens. The pathogen-induced PPO activity from wild oat was attributed to a soluble isoform of the enzyme that appeared to result, at least in part, from proteolytic activation of a latent PPO isoform. PPO activity was also induced in wild oat hulls (lemma and palea, non-living tissues that cover and protect the caryopsis. These results are consistent with the hypothesis that seeds possess inducible enzyme-based biochemical defenses arrayed on the exterior of seeds and these defenses represent a fundamental mechanism of seed survival and longevity in the soil. Enzyme-based biochemical defenses may have broader implications since they may apply to other defense enzymes as well as to a diversity of plant species and ecosystems.

  13. BIOCHEMICAL NUTRITIONAL PROFILE OF LIVER CIRRHOSIS PATIENTS WITH HEPATOCELLULAR CARCINOMA

    Directory of Open Access Journals (Sweden)

    Gabriela Zanatta PORT

    2014-03-01

    Full Text Available Context Liver cirrhosis patients with hepatocellular carcinoma present nutritional alterations and metabolic disorders that negatively impact the prognosis. Objective The objective is to identify alterations in the metabolism of macro and micronutrients among liver cirrhosis patients with and without hepatocellular carcinoma and their relation to the Child-Turcote-Pugh score and Barcelona Clinic Liver Cancer staging. Methods Analytical transversal study, with 31 hepatocellular carcinoma patients and 48 liver cirrhosis patients. Laboratorial exams were carried out. The existence of an association between the biochemical parameters and the disease severity as well as the presence of hepatocellular carcinoma was assessed. Results The metabolic-nutritional profile of liver cirrhosis patients caused by the hepatitis C virus and hepatocellular carcinoma showed alterations, specifically the lipid (total cholesterol, HDL and triglycerides, protein (albumin, creatinine and uric acid, iron (transferrin, iron and ferritin saturation, hematocrit and hemoglobin, zinc and B12 vitamin profiles. There is a relation between nutritional biochemical markers and the Child-Turcote-Pugh, as well as Barcelona Clinic Liver Cancer staging. Conclusions Considering the existence of alterations in the metabolism of nutrients in liver cirrhosis patients with and without hepatocellular carcinoma, and also that conventional nutritional assessment methods present limitations for this population, the biochemical laboratorial exams are valid to complement the diagnosis of the nutritional state in a quick and practical manner.

  14. Ethylmalonic encephalopathy: application of improved biochemical and molecular diagnostic approaches.

    Science.gov (United States)

    Drousiotou, A; DiMeo, I; Mineri, R; Georgiou, Th; Stylianidou, G; Tiranti, V

    2011-04-01

    Ethylmalonic encephalopathy (EE, OMIM # 602473) is an autosomal recessive metabolic disorder of infancy affecting the brain, the gastrointestinal tract and peripheral vessels. It is caused by a defect in the ETHE1 gene product, which was recently shown to be part of a metabolic pathway devoted to sulphide detoxification. We report the application of improved biochemical and molecular approaches to the diagnosis of three cases of EE from two unrelated Cypriot families. The children presented all the typical biochemical hallmarks of the disease including elevated lactate and butyrylcarnitine in blood and elevated urinary excretion of ethylmalonic acid, 2-methylsuccinate, isobutyrylglycine and isovalerylglycine. We also detected an elevated level of thiosulphate in urine, which we propose as an additional biochemical marker of the disease. The proband of the first family was shown to be a compound heterozygote for a missense mutation in exon 5, L185R, and a deletion of exon 4. The deletion was identified using quantitative real-time polymerase chain reaction (qRT-PCR). Using the same technique, the proband of the second family was found to be homozygous for the exon 4 deletion. A prenatal diagnosis was performed for the second family using qRT-PCR, thus establishing the usefulness of RT-PCR in prenatal diagnosis.

  15. Importance of Biochemical Markers in Postmenopausal and Senile Osteoporosis

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    Deniz Evcik

    2002-12-01

    Full Text Available Recently, the biochemical markers are widely used in order to evaluate the bone turnover. This study was planned to investigate the role of biochemical markers and Bone Mineral Density(BMD in postmenopausal (PMO and senile osteoporosis (SO patients. A total of 86 patients( 44 PMO, 42 SO, ages ranged between 39-79 were included in this study. Alkaline phosphatase (ALP and osteocalcin levels were determined from blood samples. Urinary deoxypyridinoline(Dpd and creatinine(cr concentration were examined and the ratio of Dpd/cr was calculated. Also BMD of the patients were measured from L1-L4 and proximal femur and t score were determined. There was no statistical difference in ALP levels between two groups. Osteocalcine and Dpd/cr levels were statistically increased in PMO group(p<0.001. According to BMD t score which was measured from proximal femur was significantly higher in SO patients(p<0.05. Our results show that biochemical markers are useful for the assessment of high-turnover osteoporosis.

  16. ASSESMENT OF BIOCHEMICAL ATTRIBUTES OF PRAECITRULLUS FISTULOSUS TREATED WITH MUTAGENS

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    Mehreen Khan

    2016-02-01

    Full Text Available Plants are well known to have certain primary and secondary metabolites collectively are known as biochemicals that plays an important role for human health as their medicinal properties. The aim of present study was to enhance and evaluate biochemical profile of Praecitrullus fistulosus by induced mutagenesis to cause genetic variations, plant leaves were treated with different chemical and physical mutagens. Colchicine and Ethidium bromide were used as chemical mutagens. While Ultraviolet (UV rays and X- rays were used as physical mutagens for the treatment of seeds. After the eleventh week of their growth, methanol extracts of dried leaves were prepared and further analyzed for the estimation of biochemicals. It was observed that total carbohydrates, total Proteins, phenolic compounds, antioxidant activity, reducing power, ascorbic Acid  and Chlorophyll a, were found significantly (p<0.05 higher in Colchicine 0.02% treated plants, while reducing sugars were significantly (p<0.05  increases in Colchicine 0.01% treated plants as compared to control plants. Total flavonoids, total flavonol, Chlorophyll b and Carotenoids were increases significantly (p<0.05 in plants treated with 0.05% Ethidium bromide while tannin content was increased significantly (p<0.05 in 0.10% Ethidium bromide treated plants as compared to the  control plants.

  17. Human choline dehydrogenase: medical promises and biochemical challenges.

    Science.gov (United States)

    Salvi, Francesca; Gadda, Giovanni

    2013-09-15

    Human choline dehydrogenase (CHD) is located in the inner membrane of mitochondria primarily in liver and kidney and catalyzes the oxidation of choline to glycine betaine. Its physiological role is to regulate the concentrations of choline and glycine betaine in the blood and cells. Choline is important for regulation of gene expression, the biosynthesis of lipoproteins and membrane phospholipids and for the biosynthesis of the neurotransmitter acetylcholine; glycine betaine plays important roles as a primary intracellular osmoprotectant and as methyl donor for the biosynthesis of methionine from homocysteine, a required step for the synthesis of the ubiquitous methyl donor S-adenosyl methionine. Recently, CHD has generated considerable medical attention due to its association with various human pathologies, including male infertility, homocysteinuria, breast cancer and metabolic syndrome. Despite the renewed interest, the biochemical characterization of the enzyme has lagged behind due to difficulties in the obtainment of purified, active and stable enzyme. This review article summarizes the medical relevance and the physiological roles of human CHD, highlights the biochemical knowledge on the enzyme, and provides an analysis based on the comparison of the protein sequence with that of bacterial choline oxidase, for which structural and biochemical information is available.

  18. Weighting schemes in metabolic graphs for identifying biochemical routes.

    Science.gov (United States)

    Ghosh, S; Baloni, P; Vishveshwara, S; Chandra, N

    2014-03-01

    Metabolism forms an integral part of all cells and its study is important to understand the functioning of the system, to understand alterations that occur in disease state and hence for subsequent applications in drug discovery. Reconstruction of genome-scale metabolic graphs from genomics and other molecular or biochemical data is now feasible. Few methods have also been reported for inferring biochemical pathways from these networks. However, given the large scale and complex inter-connections in the networks, the problem of identifying biochemical routes is not trivial and some questions still remain open. In particular, how a given path is altered in perturbed conditions remains a difficult problem, warranting development of improved methods. Here we report a comparison of 6 different weighting schemes to derive node and edge weights for a metabolic graph, weights reflecting various kinetic, thermodynamic parameters as well as abundances inferred from transcriptome data. Using a network of 50 nodes and 107 edges of carbohydrate metabolism, we show that kinetic parameter derived weighting schemes [Formula: see text] fare best. However, these are limited by their extent of availability, highlighting the usefulness of omics data under such conditions. Interestingly, transcriptome derived weights yield paths with best scores, but are inadequate to discriminate the theoretical paths. The method is tested on a system of Escherichia coli stress response. The approach illustrated here is generic in nature and can be used in the analysis for metabolic network from any species and perhaps more importantly for comparing condition-specific networks.

  19. Considerations on the biochemical composition of some freshwater zooplankton species.

    Directory of Open Access Journals (Sweden)

    Nicoletta RICCARDI

    1999-02-01

    Full Text Available The mean elemental (C, H, N and biochemical composition (lipids, carbohydrates and proteins of some abundant crustacean zooplankton species of Italian insubric lakes has been estimated by the analysis of samples collected at different seasons from various environments (Lake Maggiore, Lake Varese, Lake Comabbio, Lake Monate. From each sample an adequate number of specimens of each abundant species was sorted and analyzed by a CHN elemental analyzer. The percentage of lipids, carbohydrates and proteins and the calorific content were calculated from the elemental composition according to Gnaiger & Bitterlich (1984. Inter- and intraspecific variability of biochemical composition was quite high, while elemental composition and calorific content were less variable. An estimate of the mean elemental and biochemical composition of each species was obtained by pooling the data. These mean values have been used to estimate the pools of elements and compounds in the crustacean zooplankton of Lake Comabbio to provide an example of the importance of a multiple approach in zooplankton studies.

  20. Modelling biochemical reaction systems by stochastic differential equations with reflection.

    Science.gov (United States)

    Niu, Yuanling; Burrage, Kevin; Chen, Luonan

    2016-05-07

    In this paper, we gave a new framework for modelling and simulating biochemical reaction systems by stochastic differential equations with reflection not in a heuristic way but in a mathematical way. The model is computationally efficient compared with the discrete-state Markov chain approach, and it ensures that both analytic and numerical solutions remain in a biologically plausible region. Specifically, our model mathematically ensures that species numbers lie in the domain D, which is a physical constraint for biochemical reactions, in contrast to the previous models. The domain D is actually obtained according to the structure of the corresponding chemical Langevin equations, i.e., the boundary is inherent in the biochemical reaction system. A variant of projection method was employed to solve the reflected stochastic differential equation model, and it includes three simple steps, i.e., Euler-Maruyama method was applied to the equations first, and then check whether or not the point lies within the domain D, and if not perform an orthogonal projection. It is found that the projection onto the closure D¯ is the solution to a convex quadratic programming problem. Thus, existing methods for the convex quadratic programming problem can be employed for the orthogonal projection map. Numerical tests on several important problems in biological systems confirmed the efficiency and accuracy of this approach.