WorldWideScience

Sample records for stable tertiary structures

  1. Modelling the harmonized tertiary Institutions Salary Structure ...

    African Journals Online (AJOL)

    This paper analyses the Harmonized Tertiary Institution Salary Structure (HATISS IV) used in Nigeria. The irregularities in the structure are highlighted. A model that assumes a polynomial trend for the zero step salary, and exponential trend for the incremental rates, is suggested for the regularization of the structure.

  2. Structure of acid-stable carmine.

    Science.gov (United States)

    Sugimoto, Naoki; Kawasaki, Yoko; Sato, Kyoko; Aoki, Hiromitsu; Ichi, Takahito; Koda, Takatoshi; Yamazaki, Takeshi; Maitani, Tamio

    2002-02-01

    Acid-stable carmine has recently been distributed in the U.S. market because of its good acid stability, but it is not permitted in Japan. We analyzed and determined the structure of the major pigment in acid-stable carmine, in order to establish an analytical method for it. Carminic acid was transformed into a different type of pigment, named acid-stable carmine, through amination when heated in ammonia solution. The features of the structure were clarified using a model compound, purpurin, in which the orientation of hydroxyl groups on the A ring of the anthraquinone skeleton is the same as that of carminic acid. By spectroscopic means and the synthesis of acid-stable carmine and purpurin derivatives, the structure of the major pigment in acid-stable carmine was established as 4-aminocarminic acid, a novel compound.

  3. Dimensionality reduction in computational demarcation of protein tertiary structures.

    Science.gov (United States)

    Joshi, Rajani R; Panigrahi, Priyabrata R; Patil, Reshma N

    2012-06-01

    Predictive classification of major structural families and fold types of proteins is investigated deploying logistic regression. Only five to seven dimensional quantitative feature vector representations of tertiary structures are found adequate. Results for benchmark sample of non-homologous proteins from SCOP database are presented. Importance of this work as compared to homology modeling and best-known quantitative approaches is highlighted.

  4. Tertiary alphabet for the observable protein structural universe.

    Science.gov (United States)

    Mackenzie, Craig O; Zhou, Jianfu; Grigoryan, Gevorg

    2016-11-22

    Here, we systematically decompose the known protein structural universe into its basic elements, which we dub tertiary structural motifs (TERMs). A TERM is a compact backbone fragment that captures the secondary, tertiary, and quaternary environments around a given residue, comprising one or more disjoint segments (three on average). We seek the set of universal TERMs that capture all structure in the Protein Data Bank (PDB), finding remarkable degeneracy. Only ∼600 TERMs are sufficient to describe 50% of the PDB at sub-Angstrom resolution. However, more rare geometries also exist, and the overall structural coverage grows logarithmically with the number of TERMs. We go on to show that universal TERMs provide an effective mapping between sequence and structure. We demonstrate that TERM-based statistics alone are sufficient to recapitulate close-to-native sequences given either NMR or X-ray backbones. Furthermore, sequence variability predicted from TERM data agrees closely with evolutionary variation. Finally, locations of TERMs in protein chains can be predicted from sequence alone based on sequence signatures emergent from TERM instances in the PDB. For multisegment motifs, this method identifies spatially adjacent fragments that are not contiguous in sequence-a major bottleneck in structure prediction. Although all TERMs recur in diverse proteins, some appear specialized for certain functions, such as interface formation, metal coordination, or even water binding. Structural biology has benefited greatly from previously observed degeneracies in structure. The decomposition of the known structural universe into a finite set of compact TERMs offers exciting opportunities toward better understanding, design, and prediction of protein structure.

  5. Analysis of Management Practices in Lagos State Tertiary Institutions through Total Quality Management Structural Framework

    Science.gov (United States)

    AbdulAzeez, Abbas Tunde

    2016-01-01

    This research investigated total quality management practices and quality teacher education in public tertiary institutions in Lagos State. The study was therefore designed to analyse management practices in Lagos state tertiary institutions through total quality management structural framework. The selected public tertiary institutions in Lagos…

  6. How structurally stable are global socioeconomic systems?

    Science.gov (United States)

    Saavedra, Serguei; Rohr, Rudolf P; Gilarranz, Luis J; Bascompte, Jordi

    2014-11-06

    The stability analysis of socioeconomic systems has been centred on answering whether small perturbations when a system is in a given quantitative state will push the system permanently to a different quantitative state. However, typically the quantitative state of socioeconomic systems is subject to constant change. Therefore, a key stability question that has been under-investigated is how strongly the conditions of a system itself can change before the system moves to a qualitatively different behaviour, i.e. how structurally stable the systems is. Here, we introduce a framework to investigate the structural stability of socioeconomic systems formed by a network of interactions among agents competing for resources. We measure the structural stability of the system as the range of conditions in the distribution and availability of resources compatible with the qualitative behaviour in which all the constituent agents can be self-sustained across time. To illustrate our framework, we study an empirical representation of the global socioeconomic system formed by countries sharing and competing for multinational companies used as proxy for resources. We demonstrate that the structural stability of the system is inversely associated with the level of competition and the level of heterogeneity in the distribution of resources. Importantly, we show that the qualitative behaviour of the observed global socioeconomic system is highly sensitive to changes in the distribution of resources. We believe that this work provides a methodological basis to develop sustainable strategies for socioeconomic systems subject to constantly changing conditions. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  7. Structural Diversity in Tertiary Education. Go8 Backgrounder 18

    Science.gov (United States)

    Group of Eight (NJ1), 2010

    2010-01-01

    Projections of future population and tertiary education participation indicate that Australia needs soon to start planning for another surge in school leavers entering tertiary education from 2015, together with increased demand for greater skills deepening by adult workers. Hence it is necessary to find cost-effective supply solutions that…

  8. DFT computations of the lattice constant, stable atomic structure and ...

    African Journals Online (AJOL)

    This paper presents the most stable atomic structure and lattice constant of Fullerenes (C60). FHI-aims DFT code was used to predict the stable structure and the computational lattice constant of C60. These were compared with known experimental structures and lattice constants of C60. The results obtained showed that ...

  9. Structure optimization of energy supply systems in tertiary sector buildings

    Energy Technology Data Exchange (ETDEWEB)

    Lozano, Miguel A.; Ramos, Jose C.; Carvalho, Monica; Serra, Luis M. [Grupo GITSE - I3A, Department of Mechanical Engineering, Universidad de Zaragoza, 50018 Zaragoza (Spain)

    2009-10-15

    Trigeneration systems, also known as Combined Heat, Cooling and Power (CHCP) systems, are interesting alternatives to supply different energy services in urban districts and in large buildings, particularly in warm areas such as Mediterranean countries. These systems can provide substantial benefits from economic, energetic, and environmental viewpoints, since the cogenerated heat can be used for heating in winter as well as cooling in summer with an absorption refrigerator. This paper develops an optimization model using Mixed Integer Linear Programming (MILP) to determine the type, number and capacity of equipment in CHCP systems installed in the tertiary sector as well as to establish the optimal operation mode for the different plant components on an hour-by-hour basis throughout the year. The objective function to be minimized is the annual total cost. The optimization model considers the legal constraints imposed to feed the surplus autogenerated electricity into the grid at a regulated feed-in tariff. The optimization model is applied to design a system providing energy services for a hospital located in the city of Zaragoza (Spain). The effects of the financial market conditions and energy prices in the optimal structure of the system are analyzed. (author)

  10. Structure of a Stable G-Hairpin

    Czech Academy of Sciences Publication Activity Database

    Gajarský, M.; Zivkovic, M.L.; Stadlbauer, Petr; Pagano, B.; Fiala, R.; Amato, J.; Tomáška, L´.; Šponer, Jiří; Plavec, J.; Trantírek, L.

    2017-01-01

    Roč. 139, č. 10 (2017), s. 3591-3594 ISSN 0002-7863 R&D Projects: GA ČR GA13-28310S; GA ČR(CZ) GA16-13721S Institutional support: RVO:68081707 Keywords : g-quadruplex structures * human telomeric dna * single-stranded- dna * g-triplex Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 13.858, year: 2016

  11. High precision and stable structures for particle detectors

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude

    1999-01-01

    The central detectors used in High Energy Physics Experiments require the use of light and stable structures capable of supporting delicate and precise radiation detection elements. These structures need to be highly stable under environmental conditions where external vibrations, high radiation levels, temperature and humidity gradients should be taken into account. Their main design drivers are high dimension and dynamic stability, high stiffness to mass ratio and large radiation length. For most applications, these constraints lead us to choose Carbon Fiber Reinforced Plastics ( CFRP) as structural element. The construction of light and stable structures with CFRP for these applications can be achieved by careful design engineering and further confirmation at the prototyping phase. However, the experimental environment can influence their characteristics and behavior. In this case, theuse of adaptive structures could become a solution for this problem. We are studying structures in CFRP with bonded piezoel...

  12. Dynamics and control of twisting bi-stable structures

    Science.gov (United States)

    Arrieta, Andres F.; van Gemmeren, Valentin; Anderson, Aaron J.; Weaver, Paul M.

    2018-02-01

    Compliance-based morphing structures have the potential to offer large shape adaptation, high stiffness and low weight, while reducing complexity, friction, and scalability problems of mechanism based systems. A promising class of structure that enables these characteristics are multi-stable structures given their ability to exhibit large deflections and rotations without the expensive need for continuous actuation, with the latter only required intermittently. Furthermore, multi-stable structures exhibit inherently fast response due to the snap-through instability governing changes between stable states, enabling rapid configuration switching between the discrete number of programmed shapes of the structure. In this paper, the design and utilisation of the inherent nonlinear dynamics of bi-stable twisting I-beam structures for actuation with low strain piezoelectric materials is presented. The I-beam structure consists of three compliant components assembled into a monolithic single element, free of moving parts, and showing large deflections between two stable states. Finite element analysis is utilised to uncover the distribution of strain across the width of the flange, guiding the choice of positioning for piezoelectric actuators. In addition, the actuation authority is maximised by calculating the generalised coupling coefficient for different positions of the piezoelectric actuators. The results obtained are employed to tailor and test I-beam designs exhibiting desired large deflection between stable states, while still enabling the activation of snap-through with the low strain piezoelectric actuators. To this end, the dynamic response of the I-beams to piezoelectric excitation is investigated, revealing that resonant excitations are insufficient to dynamically trigger snap-through. A novel bang-bang control strategy, which exploits the nonlinear dynamics of the structure successfully triggers both single and constant snap-through between the stable states

  13. Pushing the frontiers of atomic models for protein tertiary structure ...

    Indian Academy of Sciences (India)

    Abstract. Protein folding, considered to be the holy grail of molecular biology, remains intractable even after six decades since the report of the first crystal structure. Over 70,000 X-ray and NMR structures are now available in protein structural repositories and no physico-chemical solution is in sight. Molecular simulation.

  14. Chemistry of Tertiary sediments in the surroundings of the Ries impact structure and moldavite formation revisited

    Czech Academy of Sciences Publication Activity Database

    Žák, Karel; Skála, Roman; Řanda, Zdeněk; Mizera, Jiří; Heissig, K.; Ackerman, Lukáš; Ďurišová, Jana; Jonášová, Šárka; Kameník, Jan; Magna, T.

    2016-01-01

    Roč. 179, 15 April (2016), s. 287-311 ISSN 0016-7037 R&D Projects: GA ČR GA13-22351S; GA MŠk(CZ) LM2011019 Institutional support: RVO:67985831 ; RVO:61389005 Keywords : sediments * Tertiary * tektites * moldavites * Ries impact structure Subject RIV: DB - Geology ; Mineralogy Impact factor: 4.609, year: 2016

  15. PROGRAM SYSTEM AND INFORMATION METADATA BANK OF TERTIARY PROTEIN STRUCTURES

    Directory of Open Access Journals (Sweden)

    T. A. Nikitin

    2013-01-01

    Full Text Available The article deals with the architecture of metadata storage model for check results of three-dimensional protein structures. Concept database model was built. The service and procedure of database update as well as data transformation algorithms for protein structures and their quality were presented. Most important information about entries and their submission forms to store, access, and delivery to users were highlighted. Software suite was developed for the implementation of functional tasks using Java programming language in the NetBeans v.7.0 environment and JQL to query and interact with the database JavaDB. The service was tested and results have shown system effectiveness while protein structures filtration.

  16. RNA tertiary structure prediction with ModeRNA.

    Science.gov (United States)

    Rother, Magdalena; Rother, Kristian; Puton, Tomasz; Bujnicki, Janusz M

    2011-11-01

    Noncoding RNAs perform important roles in the cell. As their function is tightly connected with structure, and as experimental methods are time-consuming and expensive, the field of RNA structure prediction is developing rapidly. Here, we present a detailed study on using the ModeRNA software. The tool uses the comparative modeling approach and can be applied when a structural template is available and an alignment of reasonable quality can be performed. We guide the reader through the entire process of modeling Escherichia coli tRNA(Thr) in a conformation corresponding to the complex with an aminoacyl-tRNA synthetase (aaRS). We describe the choice of a template structure, preparation of input files, and explore three possible modeling strategies. In the end, we evaluate the resulting models using six alternative benchmarks. The ModeRNA software can be freely downloaded from http://iimcb.genesilico.pl/moderna/ under the conditions of the General Public License. It runs under LINUX, Windows and Mac OS. It is also available as a server at http://iimcb.genesilico.pl/modernaserver/. The models and the script to reproduce the study from this article are available at http://www.genesilico.pl/moderna/examples/.

  17. Evolution of Tertiary Structure of Viral RNA Dependent Polymerases

    Czech Academy of Sciences Publication Activity Database

    Černý, Jiří; Černá, B.; Valdés, James J.; Grubhoffer, Libor; Růžek, Daniel

    2014-01-01

    Roč. 9, č. 5 (2014), e96070 E-ISSN 1932-6203 R&D Projects: GA ČR GAP502/11/2116; GA ČR GAP302/12/2490; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Q-BETA replicase * C virus RNA * crystal structure Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2014

  18. Testing for spatial clustering of amino acid replacements within protein tertiary structure

    DEFF Research Database (Denmark)

    Yu, Jiaye; Thorne, Jeffrey L

    2006-01-01

    Widely used models of protein evolution ignore protein structure. Therefore, these models do not predict spatial clustering of amino acid replacements with respect to tertiary structure. One formal and biologically implausible possibility is that there is no tendency for amino acid replacements...... to be spatially clustered during evolution. An alternative to this is that amino acid replacements are spatially clustered and this spatial clustering can be fully explained by a tendency for similar rates of amino acid replacement at sites that are nearby in protein tertiary structure. A third possibility...... is that the amount of clustering exceeds that which can be explained solely on the basis of independently evolving protein sites with spatially clustered replacement rates. We introduce two simple and not very parametric hypothesis tests that help distinguish these three possibilities. We then apply these tests...

  19. Recent developments in low cost stable structures for space

    International Nuclear Information System (INIS)

    Thompson, T.C.; Grastataro, C.; Smith, B.G.

    1994-01-01

    The Los Alamos National Laboratory (LANL) in partnership with Composite Optics Incorporated (COI) is advancing the development of low cost, lightweight, composite technology for use in spacecraft and stable structures. The use of advanced composites is well developed, but the application of an all-composite tracker structure has never been achieved. This paper investigates the application of composite technology to the design and fabrication of an all-composite spacecraft bus for small satellites, using technology directly applicable to central tracking in a high luminosity environment. The satellite program Fast On-Orbit Recording of Transient Events (FORTE) is the second in a series of satellites to be launched into orbit for the US Department of Energy (DOE). This paper will discuss recent developments in the area of low cost composites, used for either spacecraft or ultra stable applications in high energy physics (HEP) detectors. The use of advanced composites is a relatively new development in the area of HEP. The Superconducting Super Collider (SSC) spawned a new generation of Trackers which made extensive use of graphite fiber reinforced plastic (GFRP) composite systems. LANL has designed a structure employing new fabrication technology. This concept will lower the cost of composite structures to a point that they may now compete with conventional materials. This paper will discuss the design, analysis and proposed fabrication of a small satellite structure. Central tracking structures using advanced materials capable of operating in an adverse environment typical of that found in a high luminosity collider could use identical concepts

  20. Thermodynamics and kinetics of RNA tertiary structure formation in the junctionless hairpin ribozyme.

    Science.gov (United States)

    White, Neil A; Hoogstraten, Charles G

    2017-09-01

    The hairpin ribozyme consists of two RNA internal loops that interact to form the catalytically active structure. This docking transition is a rare example of intermolecular formation of RNA tertiary structure without coupling to helix annealing. We have used temperature-dependent surface plasmon resonance (SPR) to characterize the thermodynamics and kinetics of RNA tertiary structure formation for the junctionless form of the ribozyme, in which loops A and B reside on separate molecules. We find docking to be strongly enthalpy-driven and to be accompanied by substantial activation barriers for association and dissociation, consistent with the structural reorganization of both internal loops upon complex formation. Comparisons with the parallel analysis of a ribozyme variant carrying a 2'-O-methyl modification at the self-cleavage site and with published data in other systems reveal a surprising diversity of thermodynamic signatures, emphasizing the delicate balance of contributions to the free energy of formation of RNA tertiary structure. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Regional Comparisons of Oceanic Food Web Structure Using Stable Isotopes

    Science.gov (United States)

    Choy, A.; Drazen, J.; Popp, B. N.; Robison, B. H.

    2016-02-01

    Food chain length, or the number of trophic steps between primary producers and apex predators within an ecosystem, is a key determinant of ecosystem structure, including overall efficiency, stability, and productivity. Here, we quantitatively estimate food chain length for three pelagic ecosystems characterized by distinct biogeochemical and oceanographic regimes: the Northern California Current (NCC), the North Pacific Subtropical Gyre (NPSG), and the Gulf of California (GoC). From each region, ecologically equivalent organisms were selected from each of four successive trophic steps, including zooplankton (primary consumers), zooplanktivores (secondary consumers), piscivores (tertiary consumers), and higher order predators. Bulk tissue δ15N values of the organisms from all four trophic steps spanned ranges of approximately 9.8‰ (NCC), 1.4‰ (NPSG), and 2.1‰ (GoC). Regional variations in nitrogen biogeochemistry, however, can alter isotopic baselines and food web dynamics, ultimately complicating bulk isotope measurements across regions. Thus, we apply amino acid nitrogen isotope measurements to quantitatively measure and compare food chain length across consumers from the three regions, accounting for biogeochemical disparities in isotopic baseline. Implications for ecosystem production and efficiency are discussed, including the potential for these different ecosystems to withstand environmental change, including shifting oxygen levels and surface productivity.

  2. Determination of Trophic Structure in Selected Freshwater Ecosystems by using Stable Isotope Analysis.

    Science.gov (United States)

    Zainordin, 'Amila Faqhira; Ab Hamid, Suhaila

    2017-07-01

    Stable isotope analysis has been used extensively to establish trophic relationships in many ecosystems. Present study utilised stable isotope signatures of carbon and nitrogen to identify trophic structure of aquatic food web in river and rice field ecosystems in Perak, northern peninsular Malaysia. The mean δ 13 C values of all producers ranged from -35.29 ± 0.21 to -26.00 ± 0.050‰. The greatest δ 15 N values noted was in zenarchopterid fish with 9.68 ± 0.020‰. The δ 15 N values of aquatic insects ranged between 2.59 ± 0.107 in Elmidae (Coleoptera) and 8.11 ± 0.022‰ in Nepidae (Hemiptera). Correspondingly, with all the δ 13 C and δ 15 N values recorded, it can be deduced that there are four trophic levels existed in the freshwater ecosystems which started with the producer (plants), followed by primary consumer (aquatic insects and non-predatory fish), secondary consumer (invertebrate predators) and lastly tertiary consumer (vertebrate predators).

  3. Alteration of human serum albumin tertiary structure induced by glycation. Spectroscopic study.

    Science.gov (United States)

    Szkudlarek, A; Maciążek-Jurczyk, M; Chudzik, M; Równicka-Zubik, J; Sułkowska, A

    2016-01-15

    The modification of human serum albumin (HSA) structure by non-enzymatic glycation is one of the underlying factors that contribute to the development of complications of diabetes and neurodegenerative diseases. The aim of the present work was to estimate how glycation of HSA altered its tertiary structure. Changes of albumin conformation were investigated by comparison of glycated (gHSA) and non-glycated human serum albumin (HSA) absorption spectra, red edge excitation shift (REES) and synchronous spectra. Effect of glycation on human serum albumin tertiary structure was also investigated by (1)H NMR spectroscopy. Formation of gHSA Advanced Glycation End-products (AGEs) caused absorption of UV-VIS light between 310 nm and 400 nm while for non-glycated HSA in this region no absorbance has been registered. Analysis of red edge excitation shift effect allowed for observation of structural changes of gHSA in the hydrophobic pocket containing the tryptophanyl residue. Moreover changes in the microenvironment of tryptophanyl and tyrosyl residues brought about AGEs on the basis of synchronous fluorescence spectroscopy have been confirmed. The influence of glycation process on serum albumin binding to 5-dimethylaminonaphthalene-1-sulfonamide (DNSA), 2-(p-toluidino) naphthalene-6-sulfonic acid (TNS), has been studied. Fluorescence analysis showed that environment of both binding site I and II is modified by galactose glycation. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Highly stable thin film transistors using multilayer channel structure

    KAUST Repository

    Nayak, Pradipta K.

    2015-03-09

    We report highly stable gate-bias stress performance of thin film transistors (TFTs) using zinc oxide (ZnO)/hafnium oxide (HfO2) multilayer structure as the channel layer. Positive and negative gate-bias stress stability of the TFTs was measured at room temperature and at 60°C. A tremendous improvement in gate-bias stress stability was obtained in case of the TFT with multiple layers of ZnO embedded between HfO2 layers compared to the TFT with a single layer of ZnO as the semiconductor. The ultra-thin HfO2 layers act as passivation layers, which prevent the adsorption of oxygen and water molecules in the ZnO layer and hence significantly improve the gate-bias stress stability of ZnO TFTs.

  5. Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

    OpenAIRE

    Kimura, Yusuke

    2018-01-01

    F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface i...

  6. ProTSAV: A protein tertiary structure analysis and validation server.

    Science.gov (United States)

    Singh, Ankita; Kaushik, Rahul; Mishra, Avinash; Shanker, Asheesh; Jayaram, B

    2016-01-01

    Quality assessment of predicted model structures of proteins is as important as the protein tertiary structure prediction. A highly efficient quality assessment of predicted model structures directs further research on function. Here we present a new server ProTSAV, capable of evaluating predicted model structures based on some popular online servers and standalone tools. ProTSAV furnishes the user with a single quality score in case of individual protein structure along with a graphical representation and ranking in case of multiple protein structure assessment. The server is validated on ~64,446 protein structures including experimental structures from RCSB and predicted model structures for CASP targets and from public decoy sets. ProTSAV succeeds in predicting quality of protein structures with a specificity of 100% and a sensitivity of 98% on experimentally solved structures and achieves a specificity of 88%and a sensitivity of 91% on predicted protein structures of CASP11 targets under 2Å.The server overcomes the limitations of any single server/method and is seen to be robust in helping in quality assessment. ProTSAV is freely available at http://www.scfbio-iitd.res.in/software/proteomics/protsav.jsp. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Evaluation of correlation of BODE index with health-related quality of life among patients with stable COPD attending a tertiary care hospital.

    Science.gov (United States)

    Sarkar, Samir Kumar; Basuthakur, Sumitra; Das, Sibes K; Das, Anirban; Das, Soumya; Choudhury, Sabyasachi; Datta, Samadarshi

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is characterized by progressive deterioration of respiratory function along with systemic effects which have a great impact on health-related quality of life (HRQoL). Classification of severity of airflow limitation in COPD does not represent the clinical consequences of COPD. Hence, combined COPD assessment should be preferred. BODE index (Body mass index, Airflow obstruction, Dyspnea and Exercise capacity) has recently been proposed to provide useful prognostic information. To find out correlations between the BODE index and HRQoL, and between GOLD classification of COPD severity and HRQoL in stable COPD patients, and to compare between these two correlations. A longitudinal observational study was carried out with 114 stable COPD patients recruited over 10 months at the outpatient clinic of a tertiary care hospital in Kolkata, India. Patients were classified according to GOLD classification of severity of airflow limitation after performing spirometry. BODE index was calculated for each patient. Saint George's Respiratory Questionnaire (SGRQ) was used to assess the HRQoL. BODE scores were categorized into four quartiles, quartile one to four with scores of 0-2, 3-4, 5-6 and 7-10, respectively. Higher BODE quartiles were associated with higher total SGRQ scores and SGRQ subscale scores (symptom, activity and impact). Very strong correlations were found between BODE quartiles and total SGRQ scores (P = 0.914; P < 0.01). In contrast, GOLD classes showed moderate correlation with total SGRQ scores (P = 0.590; P < 0.01). BODE index was strongly correlated with the HRQoL in stable COPD patients and it was better than GOLD classes of COPD severity to reflect the health status in patients with stable COPD.

  8. Evaluation of correlation of BODE index with health-related quality of life among patients with stable COPD attending a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Samir Kumar Sarkar

    2015-01-01

    Full Text Available Background: Chronic obstructive pulmonary disease (COPD is characterized by progressive deterioration of respiratory function along with systemic effects which have a great impact on health-related quality of life (HRQoL. Classification of severity of airflow limitation in COPD does not represent the clinical consequences of COPD. Hence, combined COPD assessment should be preferred. BODE index (Body mass index, Airflow obstruction, Dyspnea and Exercise capacity has recently been proposed to provide useful prognostic information. Objectives: To find out correlations between the BODE index and HRQoL, and between GOLD classification of COPD severity and HRQoL in stable COPD patients, and to compare between these two correlations. Materials and Methods: A longitudinal observational study was carried out with 114 stable COPD patients recruited over 10 months at the outpatient clinic of a tertiary care hospital in Kolkata, India. Patients were classified according to GOLD classification of severity of airflow limitation after performing spirometry. BODE index was calculated for each patient. Saint George′s Respiratory Questionnaire (SGRQ was used to assess the HRQoL. Results: BODE scores were categorized into four quartiles, quartile one to four with scores of 0-2, 3-4, 5-6 and 7-10, respectively. Higher BODE quartiles were associated with higher total SGRQ scores and SGRQ subscale scores (symptom, activity and impact. Very strong correlations were found between BODE quartiles and total SGRQ scores (P = 0.914; P < 0.01. In contrast, GOLD classes showed moderate correlation with total SGRQ scores (P = 0.590; P < 0.01. Conclusions: BODE index was strongly correlated with the HRQoL in stable COPD patients and it was better than GOLD classes of COPD severity to reflect the health status in patients with stable COPD.

  9. Application of Divide and Conquer Extended Genetic Algorithm to Tertiary Protein Structure of Chymotrypsin Inhibitor-2

    Directory of Open Access Journals (Sweden)

    A. Alfaro

    2006-01-01

    Full Text Available Determining the method by which a protein thermodynamically folds and unfolds in three-dimension is one of the most complex and least understood problems in modern biochemistry. Misfolded proteins have been recently linked to diseases including Amyotrophic Lateral Sclerosis and Alzheimer's disease. Because of the large number of parameters involved in defining the tertiary structure of proteins, based on free energy global minimisation, we have developed a new Divide and Conquer (DAC Extended Genetic Algorithm. The approach was applied to explore and verify the energy landscape of protein chymotrypsin inhibitor-2.

  10. Stable structural color patterns displayed on transparent insect wings.

    Science.gov (United States)

    Shevtsova, Ekaterina; Hansson, Christer; Janzen, Daniel H; Kjærandsen, Jostein

    2011-01-11

    Color patterns play central roles in the behavior of insects, and are important traits for taxonomic studies. Here we report striking and stable structural color patterns--wing interference patterns (WIPs)--in the transparent wings of small Hymenoptera and Diptera, patterns that have been largely overlooked by biologists. These extremely thin wings reflect vivid color patterns caused by thin film interference. The visibility of these patterns is affected by the way the insects display their wings against various backgrounds with different light properties. The specific color sequence displayed lacks pure red and matches the color vision of most insects, strongly suggesting that the biological significance of WIPs lies in visual signaling. Taxon-specific color patterns are formed by uneven membrane thickness, pigmentation, venation, and hair placement. The optically refracted pattern is also stabilized by microstructures of the wing such as membrane corrugations and spherical cell structures that reinforce the pattern and make it essentially noniridescent over a large range of light incidences. WIPs can be applied to map the micromorphology of wings through direct observation and are useful in several fields of biology. We demonstrate their usefulness as identification patterns to solve cases of cryptic species complexes in tiny parasitic wasps, and indicate their potentials for research on the genetic control of wing development through direct links between the transregulatory wing landscape and interference patterns we observe in Drosophila model species. Some species display sexually dimorphic WIPs, suggesting sexual selection as one of the driving forces for their evolution.

  11. An All-Atom Force Field for Tertiary Structure Prediction of Helical Proteins

    Science.gov (United States)

    Herges, T.; Wenzel, W.

    2004-01-01

    We have developed an all-atom free-energy force field (PFF01) for protein tertiary structure prediction. PFF01 is based on physical interactions and was parameterized using experimental structures of a family of proteins believed to span a wide variety of possible folds. It contains empirical, although sequence-independent terms for hydrogen bonding. Its solvent-accessible surface area solvent model was first fit to transfer energies of small peptides. The parameters of the solvent model were then further optimized to stabilize the native structure of a single protein, the autonomously folding villin headpiece, against competing low-energy decoys. Here we validate the force field for five nonhomologous helical proteins with 20–60 amino acids. For each protein, decoys with 2–3 Å backbone root mean-square deviation and correct experimental Cβ–Cβ distance constraints emerge as those with the lowest energy. PMID:15507688

  12. Network structure and concentration fluctuations in a series of elemental, binary, and tertiary liquids and glasses.

    Science.gov (United States)

    Soper, Alan K

    2010-10-13

    Liquids and glasses continue to produce a lively debate about the nature of the disordered structure in these materials, and whether it is driven by longer range concentration or density fluctuations. One factor often lacking in these studies is an overview of a wide range of structures from which common features of and differences between materials can be identified. Here I examine the structure of a wide range of chain and network, elemental, binary and tertiary liquids and glasses, using available x-ray and neutron diffraction data and combining them with empirical potential structure refinement. Calculation of the Bhatia-Thornton number-number and concentration-concentration structure factors and distribution functions highlights common structural motifs that run through many of the series. It is found that the greatest structural overlap occurs where the nearest-neighbour and second-neighbour coordination numbers are similar for different materials. As these coordination numbers increase, so the structures undergo a sequence of characteristic changes involving increasingly bent bond angle distributions and increased packing fractions. In these regards liquid and amorphous phosphorus appear to be in a structural class of their own, combining both chain-like and network-like characteristics.

  13. Protein Tertiary Structure Prediction Based on Main Chain Angle Using a Hybrid Bees Colony Optimization Algorithm

    Science.gov (United States)

    Mahmood, Zakaria N.; Mahmuddin, Massudi; Mahmood, Mohammed Nooraldeen

    Encoding proteins of amino acid sequence to predict classified into their respective families and subfamilies is important research area. However for a given protein, knowing the exact action whether hormonal, enzymatic, transmembranal or nuclear receptors does not depend solely on amino acid sequence but on the way the amino acid thread folds as well. This study provides a prototype system that able to predict a protein tertiary structure. Several methods are used to develop and evaluate the system to produce better accuracy in protein 3D structure prediction. The Bees Optimization algorithm which inspired from the honey bees food foraging method, is used in the searching phase. In this study, the experiment is conducted on short sequence proteins that have been used by the previous researches using well-known tools. The proposed approach shows a promising result.

  14. Thermally-Stable High Strain Deployable Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is for the development of a thermally-stable composite made of carbon fibers and elastomeric resin. This combination of materials will allow...

  15. An analytical framework for assessing drug and therapeutics committee structure and work processes in tertiary Brazilian hospitals.

    Science.gov (United States)

    Lima-Dellamora, Elisangela da Costa; Caetano, Rosângela; Gustafsson, Lars L; Godman, Brian B; Patterson, Ken; Osorio-de-Castro, Claudia Garcia Serpa

    2014-09-01

    University teaching hospitals usually provide tertiary care and are subject to early adoption of new technologies, which may compromise healthcare systems when uncritically adopted. Knowledge on the decision-making process - drug selection by drug selection committees or DTCs - is crucial to improve the quality of care. There are no models for studying the selection of drugs in Brazilian healthcare services. This study aims to discuss DTC structure and the processes regarding adoption of medicines in tertiary university hospitals in Brazil and to propose an analytical structure for providing direction for the future. State of the art content regarding drug selection processes and DTC procedures was reviewed in three databases. Information on the medicine selection process in a Brazilian gold standard teaching hospital was collected through observations and a review of existing procedures. A structured discussion on medicine selection and DTC procedures in tertiary hospitals ensued. This discussion resulted in findings that were organized in three dimensions, composing an analytical framework for the application in tertiary Brazilian hospitals (i) motivations for the adoption of drugs; (ii) necessary structural and organizational aspects for decision-making; and (iii) criteria and methods employed by the decision-making process. We believe that the suggested framework is compatible with tertiary Brazilian hospitals, because a gold standard in the country was able to conduct all its procedures in the light of WHO and international recommendations. We hope to contribute in producing knowledge which may hopefully be adopted in tertiary hospitals across Brazil. © 2014 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  16. Tertiary Lymphoid Structures in Cancer: Drivers of Antitumor Immunity, Immunosuppression, or Bystander Sentinels in Disease?

    Science.gov (United States)

    Colbeck, Emily Jayne; Ager, Ann; Gallimore, Awen; Jones, Gareth Wyn

    2017-01-01

    Secondary lymphoid organs are integral to initiation and execution of adaptive immune responses. These organs provide a setting for interactions between antigen-specific lymphocytes and antigen-presenting cells recruited from local infected or inflamed tissues. Secondary lymphoid organs develop as a part of a genetically preprogrammed process during embryogenesis. However, organogenesis of secondary lymphoid tissues can also be recapitulated in adulthood during de novo lymphoid neogenesis of tertiary lymphoid structures (TLSs). These ectopic lymphoid-like structures form in the inflamed tissues afflicted by various pathological conditions, including cancer, autoimmunity, infection, or allograft rejection. Studies are beginning to shed light on the function of such structures in different disease settings, raising important questions regarding their contribution to progression or resolution of disease. Data show an association between the tumor-associated TLSs and a favorable prognosis in various types of human cancer, attracting the speculation that TLSs support effective local antitumor immune responses. However, definitive evidence for the role for TLSs in fostering immune responses in vivo are lacking, with current data remaining largely correlative by nature. In fact, some more recent studies have even demonstrated an immunosuppressive, tumor-promoting role for cancer-associated TLSs. In this review, we will discuss what is known about the development of cancer-associated TLSs and the current understanding of their potential role in the antitumor immune response. PMID:29312327

  17. Interaction Of Calcium Phosphate Nanoparticles With Human Chorionic Gonadotropin Modifies Secondary And Tertiary Protein Structure

    Directory of Open Access Journals (Sweden)

    Al-Hakeim Hussein K

    2015-12-01

    Full Text Available Calcium phosphate nanoparticles (CaPNP have good biocompatibility and bioactivity inside human body. In this study, the interaction between CaPNP and human chorionic gonadotropin (hCG was analyzed to determine the changes in the protein structure in the presence of CaPNP and the quantity of protein adsorbed on the CaPNP surface. The results showed a significant adsorption of hCG on the CaPNP nanoparticle surface. The optimal fit was achieved using the Sips isotherm equation with a maximum adsorption capacity of 68.23 µg/mg. The thermodynamic parameters, including ∆H° and ∆G°, of the adsorption process are positive, whereas ∆S° is negative. The circular dichroism results of the adsorption of hCG on CaPNP showed the changes in its secondary structure; such changes include the decomposition of α-helix strand and the increase in β-pleated sheet and random coil percentages. Fluorescence study indicated minimal changes in the tertiary structure near the microenvironment of the aromatic amino acids such as tyrosine and phenyl alanine caused by the interaction forces between the CaPNP and hCG protein. The desorption process showed that the quantity of the hCG desorbed significantly increases as temperature increases, which indicates the weak forces between hCG and the surface.

  18. Two novel ceramides with a phytosphingolipid and a tertiary amide structure from Zephyranthes candida.

    Science.gov (United States)

    Wu, Zhi-Ping; Chen, Yu; Xia, Bing; Wang, Ming; Dong, Yun-Fa; Feng, Xu

    2009-01-01

    Two novel ceramides, Candidamide A (1) with a phytosphingolipid structure, and Candidamide B (2) with a tertiary amide structure, together with 12 known compounds (3-14) have been isolated from the bulbs of Zephyranthes candida, The structures of 1 and 2 have been elucidated to be 1,3,5,6-tetrahydroxy-2-(2'-hydroxytetracosanoyl amino)-8-(E)-octadecadiene (1) and (2S,3S,4R,8E,2'R)-2-[N-(2'-hydroxyoctadecanoyl)-N-(1'',2''-dihydroxyethyl)-amino]-8-hexacosene-1,3,4-triol (2) on the basis of spectroscopic evidence including IR, MS, NMR ((1)H-NMR, (13)C-NMR, DEPT, (1)H-(1)H COSY, HSQC, HMBC). The known compounds were identified as (2S)-3',7-dihydroxy-4'-methoxyflavan (3), (2S)-4'-hydroxy-7-methoxyflavan (4), (2S)-4',7-dihydroxyflavan (5), 7-hydroxy-3', 4'-methylenedioxyflavan (6), ambrettolide (7), beta-sitostero1 (8), beta-daucosterin (9), rutin (10), pancratistatin (11), lycorine (12), haemanthidine (13), and haemanthamine (14). In the antimicrobial assay, candidamide A (1) and candidamide B (2) displayed moderate activities against bacteria Staphylococcus aureus and Escherichia coli, and fungi Aspergillus niger, Candida albicans and Trichophyton rubrum.

  19. Gain of local structure in an amphipathic peptide does not require a specific tertiary framework.

    Science.gov (United States)

    Roman, Ernesto A; Rosi, Pablo; González Lebrero, Mariano C; Wuilloud, Rodolfo; González Flecha, F Luis; Delfino, José M; Santos, Javier

    2010-10-01

    In this work, we studied how an amphipathic peptide of the surface of the globular protein thioredoxin, TRX94-108, acquires a native-like structure when it becomes involved in an apolar interaction network. We designed peptide variants where the tendency to form alpha-helical conformation is modulated by replacing each of the leucine amino acid residues by an alanine. The induction of structure caused by sodium dodecyl sulfate (SDS) binding was studied by capillary zone electrophoresis, circular dichroism, DOSY-NMR, and molecular dynamics simulations (MDS). In addition, we analyzed the strength of the interaction between a C18 RP-HPLC matrix and the peptides. The results presented here reveal that (a) critical elements in the sequence of the wild-type peptide stabilize a SDS/peptide supramolecular cluster; (b) the hydrophobic nature of the interaction between SDS molecules and the peptide constrains the ensemble of conformations; (c) nonspecific apolar surfaces are sufficient to stabilize peptide secondary structure. Remarkably, MDS shed light on a contact network formed by a limited number of SDS molecules that serves as a structural scaffold preserving the helical conformation of this module. This mechanism might prevail when a peptide with low helical propensity is involved in structure consolidation. We suggest that folding of peptides sharing this feature does not require a preformed tightly-packed protein core. Thus, the formation of specific tertiary interactions would be the consequence of peptide folding and not its cause. In this scenario, folding might be thought of as a process that includes unspecific rounds of structure stabilization guiding the protein to the native state. 2010 Wiley-Liss, Inc.

  20. The tertiary structure of an i-type lysozyme isolated from the common orient clam (Meretrix lusoria).

    Science.gov (United States)

    Kuwano, Yuko; Yoneda, Kazunari; Kawaguchi, Yuya; Araki, Tomohiro

    2013-11-01

    To evaluate the structure-function relationships of invertebrate lysozymes, a new invertebrate-type (i-type) lysozyme was isolated from the common orient clam (Meretrix lusoria) and the tertiary structure of this enzyme was determined. Comparison of the tertiary structure of this enzyme with those of chicken and Venerupi philippinarum lysozymes revealed that the location of the side chain of the second catalytic residue, an aspartic acid, and the N-acetylglucosamine trimer bound at subsites A-C were different. Furthermore, the amino acid electrostatically interacting with Asp30 in V. philippinarum lysozyme, Lys108, was substituted by Gly in M. lusoria lysozyme and no other possible amino acid that could contribute to this interaction was found in M. lusoria lysozyme. It therefore seems that the substitutions of the amino acids at the interface of the V. philippinarum lysozyme dimer are likely to change the oligomeric state of the M. lusoria lysozyme.

  1. Tertiary Lymphoid Structures Associate with Tumour Stage in Urothelial Bladder Cancer.

    Science.gov (United States)

    Koti, Madhuri; Xu, Amanda Shou; Ren, Kevin Yi Mi; Visram, Kash; Ren, Runhan; Berman, David M; Siemens, D Robert

    2017-10-27

    Urothelial bladder cancer (UBC) is a highly prevalent disease in North America, however its optimal management remains elusive. The contribution of B cell associated responses is poorly understood in bladder cancer. Lymphoid neogenesis is a hallmark of an active immune response at tumor sites that sometimes leads to formation of tertiary lymphoid structures (TLS) that resemble germinal centers formed in secondary lymphoid organs. This study was conducted with an aim to investigate the presence and characteristics of TLS in UBC with a focus to compare and contrast the TLS formation in treatment naive low grade non-muscle invasive (NMIBC) and muscle invasive bladder cancers (MIBC). The study cohort consisted of transurethral bladder resection tumour (TURBT) specimens from 28 patients. Sections showing lymphoid aggregates in hematoxylin and eosin (H&E) stained TURBT specimens were further subjected to multi-color immunohistochemistry using immune cell markers specific to CD20 + B cells, CD3 + and CD8 + T cells, PNAd + high endothelial venules, CD208 + mature dendritic cells, CD21 + follicular dendritic cells to confirm the hallmarks of classical germinal centers. Our pilot study investigating the presence of TLS in bladder cancer patients is the first to demonstrate that well-formed TLS are more common in aggressive high grade MIBC tumors compared to low grade NIMBC. These novel findings suggest B cell mediated anti-tumour humoral immune responses in bladder cancer progression.

  2. Stratigraphic structure of the B1 Tertiary tectonostratigraphic unit in eastern Slovenia

    Directory of Open Access Journals (Sweden)

    Bogomir Jelen

    2002-06-01

    Full Text Available High inconsistency and incoherence in the stratigraphy of the Slovenian upper Paleogene and lower Miocene have remained unsolved in the past 150 years. To solve the problem, we tried to rigorously conduct the authentic Galilei’s scientific method. Steps of logical and empirical verification confirmed the existence of the posited B1 Tertiary tectonostratigraphic unit, and a general chronostratigraphic model of new positional relationships of lithologic units resulted from rather good biochronostratigraphic resolution achieved by nannoplankton and planktonic foraminifera biostratigraphy. The application of principles of newly developed fields in science helped us to avoid errors in transmission of messages (to reduce noise from the source (rock to the concept formation,which had been done previously. This in turn has strongly reduced inconsistency andincoherence (high information entropy = uncertainty. The released amount of information enabled us to answer also questions that reached beyond the original difficulty, e.g.: is the tectonostratigraphic structure of eastern Slovenia a manifestation of plate tectonics processes, and of which ones, are theories of continental escape in the Alps and associated dissection and offset of the formerly uniform Slovenian-Hungarian Paleogene basin tenableor not, are then there in the B1 stratigraphic equivalents of the Hungarian Paleogene basin formations, where are the important Eocene / Oligocene, Paleogene / Neogene, Rupelian / Chattian and Kiscellian / Egerian boundaries in Slovenia, and is there acontinuation of the B1 in Croatia and in the Mid-Hungarian tectonic zone?

  3. Hygro-Thermal Transient Analysis for Highly Stable Structures

    CERN Document Server

    Da Mota Silva, S; Hauviller, Claude; Kanoute, P; Ribeiro, R

    1999-01-01

    This paper presents the results obtained with the simulations of a sandwich rectangular plate made of carbon/epoxy composite when subjected to temperature and humidity cycles. Fickian diffusion process, moisture transport along the interfaces and damage caused by slipping and debonding between the components of the microscopic structure are considered. The application of the design methodology to a real structure is shown.

  4. Facilities management: Structuring a body of knowledge for continuing and tertiary education in South Africa

    Directory of Open Access Journals (Sweden)

    A. C. Hauptfleisch

    2010-01-01

    is exacerbated by the fact that very little is being done at the level of continuing education and formal tertiary education in South Africa. The limited attempts in this regard are furthermore taking place in isolation, with practically no dialogue between the limited facilities management industry and the providers of the limited education that is available.Although the study that was undertaken did not have the objective to create comprehensive interaction between the existing role-players, the stated problems were addressed by involving the industry, participants in continuing education programmes and other role-players in the condensed research problem as stated below. The problem at hand is firstly to extract, from the present practice of facilities management, a knowledge framework and secondly to formulate the results in terms of suitable continuing and tertiary education programmes to address the shortcomings in South Africa. Research was therefore undertaken to address the structuring of educational programmes. The methodology applied comprised a comprehensive literature survey and three quantified and qualified data surveys, the latter conducted amongst facilities management practitioners, primarily the perceived beneficiaries of such programmes. These surveys provided information that led to the resultant educational activities stated below. The most important aspects that were determined were the following: It was possible to create and test amongst facilities management practitioners a diagrammatic presentation that contextualised facilities management. The literature survey, including international and South African sources, contributed towards compiling a primary knowledge framework for facilities management. The perceived value of the contents of a continuing education programme that had been attended by numerous groups of delegates over a number of years was established. A proposed tertiary education programme was presented to practitioners

  5. Periodontal status affects C-reactive protein and lipids in patients with stable heart disease from a tertiary care cardiovascular clinic.

    Science.gov (United States)

    Flores, Manuela F; Montenegro, Marlon M; Furtado, Mariana V; Polanczyk, Carisi A; Rösing, Cassiano K; Haas, Alex N

    2014-04-01

    There are scarce data on the impact of the periodontal condition in the control of biomarkers in patients with cardiovascular disease (CVD). The aim of this study is to assess whether periodontal inflammation and tissue breakdown are associated with C-reactive protein (CRP) and lipids in patients with stable heart disease. This cross-sectional study included 93 patients with stable coronary artery disease (57 males; mean age: 63.5 ± 9.8 years) who were in outpatient care for at least 6 months. After applying a structured questionnaire, periodontal examinations were performed by two calibrated periodontists in six sites per tooth at all teeth. Blood samples were collected from patients on the day of periodontal examination to determine levels of CRP, lipids, and glycated hemoglobin. Multiple linear regression models were fitted to evaluate the association among different periodontal and blood parameters controlling for sex, body mass index, glycated hemoglobin, use of oral hypoglycemic drugs, and smoking. Overall, the sample presented high levels of periodontal inflammation and tissue breakdown. Unadjusted mean concentrations of triglycerides (TGs), very-low-density lipoprotein cholesterol, and glucose were significantly higher in individuals with severe periodontitis. When multiple linear regression models were applied, number of teeth with clinical attachment loss ≥6 mm and presence of severe periodontitis were significantly associated with higher CRP concentrations. Bleeding on probing was significantly associated with TGs, total cholesterol, and non-high-density lipoprotein cholesterol. In this sample of patients with stable CVD, current periodontal inflammation and tissue breakdown are associated with cardiovascular inflammatory markers, such as CRP and lipid profile.

  6. Active structural control with stable fuzzy PID techniques

    CERN Document Server

    Yu, Wen

    2016-01-01

    This book presents a detailed discussion of intelligent techniques to measure the displacement of buildings when they are subjected to vibration. It shows how these techniques are used to control active devices that can reduce vibration 60–80% more effectively than widely used passive anti-seismic systems. After introducing various structural control devices and building-modeling and active structural control methods, the authors propose offset cancellation and high-pass filtering techniques to solve some common problems of building-displacement measurement using accelerometers. The most popular control algorithms in industrial settings, PD/PID controllers, are then analyzed and then combined with fuzzy compensation. The stability of this combination is proven with standard weight-training algorithms. These conditions provide explicit methods for selecting PD/PID controllers. Finally, fuzzy-logic and sliding-mode control are applied to the control of wind-induced vibration. The methods described are support...

  7. An Energy stable Monolithic Eulerian Fluid-Structure Numerical Scheme *

    OpenAIRE

    Pironneau , Olivier

    2017-01-01

    The conservation laws of continuum mechanic written in an Eulerian frame make no difference between fluids and solids except in the expression of the stress tensors, usually with Newton's hypothesis for the fluids and Helmholtz potentials of energy for hyperelastic solids. By taking the velocities as unknown , monolithic methods for fluid structure interactions (FSI) are built. In this article such a formulation is analyzed when the fluid is compressible and the fluid is incompressible. The i...

  8. Crystalline mesoporous zirconia catalysts having stable tetragonal pore wall structure

    Science.gov (United States)

    Sachtler, Wolfgang M. H.; Huang, Yin-Yan

    1998-01-01

    Methods for the preparation of new sulfated mesoporous zirconia materials/catalysts with crystalline pore walls of predominantly tetragonal crystal structure, characterized by nitrogen physisorption measurement, X-ray diffraction, transmission electron microscopy and catalytic tests using n-butane isomerization to iso-butane and alkylation of 1-naphthol with 4-tert-butylstyrene as probe reactions. Sulfate deposition is preferred for the transformation of a mesoporous precursor with amorphous pore walls into a material with crystalline pore walls maintaining the mesoporous characteristics.

  9. Numerically stable fluid–structure interactions between compressible flow and solid structures

    KAUST Repository

    Grétarsson, Jón Tómas

    2011-04-01

    We propose a novel method to implicitly two-way couple Eulerian compressible flow to volumetric Lagrangian solids. The method works for both deformable and rigid solids and for arbitrary equations of state. The method exploits the formulation of [11] which solves compressible fluid in a semi-implicit manner, solving for the advection part explicitly and then correcting the intermediate state to time tn+1 using an implicit pressure, obtained by solving a modified Poisson system. Similar to previous fluid-structure interaction methods, we apply pressure forces to the solid and enforce a velocity boundary condition on the fluid in order to satisfy a no-slip constraint. Unlike previous methods, however, we apply these coupled interactions implicitly by adding the constraint to the pressure system and combining it with any implicit solid forces in order to obtain a strongly coupled, symmetric indefinite system (similar to [17], which only handles incompressible flow). We also show that, under a few reasonable assumptions, this system can be made symmetric positive-definite by following the methodology of [16]. Because our method handles the fluid-structure interactions implicitly, we avoid introducing any new time step restrictions and obtain stable results even for high density-to-mass ratios, where explicit methods struggle or fail. We exactly conserve momentum and kinetic energy (thermal fluid-structure interactions are not considered) at the fluid-structure interface, and hence naturally handle highly non-linear phenomenon such as shocks, contacts and rarefactions. © 2011 Elsevier Inc.

  10. Spatial variations in food web structures with alternative stable states: evidence from stable isotope analysis in a large eutrophic lake

    Science.gov (United States)

    Li, Yunkai; Zhang, Yuying; Xu, Jun; Zhang, Shuo

    2017-05-01

    Food web structures are well known to vary widely among ecosystems. Moreover, many food web studies of lakes have generally attempted to characterize the overall food web structure and have largely ignored internal spatial and environmental variations. In this study, we hypothesize that there is a high degree of spatial heterogeneity within an ecosystem and such heterogeneity may lead to strong variations in environmental conditions and resource availability, in turn resulting in different trophic pathways. Stable carbon and nitrogen isotopes were employed for the whole food web to describe the structure of the food web in different sub-basins within Taihu Lake. This lake is a large eutrophic freshwater lake that has been intensively managed and highly influenced by human activities for more than 50 years. The results show significant isotopic differences between basins with different environmental characteristics. Such differences likely result from isotopic baseline differences combining with a shift in food web structure. Both are related to local spatial heterogeneity in nutrient loading in waters. Such variation should be explicitly considered in future food web studies and ecosystem-based management in this lake ecosystem.

  11. Tertiary Students ’ Entrepreneurship Learning Socialization : Factor Analysis and Structural Equation Modeling

    OpenAIRE

    Chun- Mei Chou; Chien- Hua Shen

    2015-01-01

    This study examines 728 tertiary students’ entrepreneurship learning socialization and its influencing factors to serve as a school reference for the development of internship and entrepreneurship education. The results show that students’ internship experience has a significant direct effect on entrepreneurship learning socialization, and entrepreneurship intention has a significant effect on entrepreneurship learning...

  12. Tertiary Students ’ Entrepreneurship Learning Socialization : Factor Analysis and Structural Equation Modeling

    Directory of Open Access Journals (Sweden)

    Chun- Mei Chou

    2015-09-01

    Full Text Available This study examines 728 tertiary students’ entrepreneurship learning socialization and its influencing factors to serve as a school reference for the development of internship and entrepreneurship education. The results show that students’ internship experience has a significant direct effect on entrepreneurship learning socialization, and entrepreneurship intention has a significant effect on entrepreneurship learning socialization through internship experience. The influence pattern and empirical data of entrepreneurship intention and internship experience on entrepreneurship learning socialization has a good fit. This paper gives an insight from Taiwan tertiary institutions about entrepreneurial learning socialization of students and contributions to them. We describe the development of the influencing factors, discuss its implications for entrepreneurship and internship education, and finally offer suggestions for further entrepreneurship education development.

  13. Major structural controls on the distribution of pre-Tertiary rocks, Nevada Test Site vicinity, southern Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J.C.

    1998-10-23

    The lateral and vertical distributions of Proterozoic and Paleozoic sedimentary rocks in southern Nevada are the combined products of original stratigraphic relationships and post-depositional faults and folds. This map compilation shows the distribution of the pre-Tertiary rocks in the region including and surrounding the Nevada Test Site. It is based on considerable new evidence from detailed geologic mapping, biostratigraphic control, sedimentological analysis, and a review of regional map relationships. Proterozoic and Paleozoic rocks of the region record paleogeographic transitions between continental shelf depositional environments on the east and deeper-water slope-facies depositional environments on the west. Middle Devonian and Mississippian sequences, in particular, show strong lateral facies variations caused by contemporaneous changes in the western margin of North America during the Antler orogeny. Sections of rock that were originally deposited in widely separated facies localities presently lie in close proximity. These spatial relationships chiefly result from major east- and southeast-directed thrusts that deformed the region in Permian or later time. Somewhat younger contractional structures are identified within two irregular zones that traverse the region. These folds and thrusts typically verge toward the west and northwest and overprint the relatively simple pattern of the older contractional terranes. Local structural complications are significant near these younger structures due to the opposing vergence and due to irregularities in the previously folded and faulted crustal section. Structural and stratigraphic discontinuities are identified on opposing sides of two north-trending fault zones in the central part of the compilation region north of Yucca Flat. The origin and significance of these zones are enigmatic because they are largely covered b Tertiary and younger deposits. These faults most likely results from significant lateral

  14. TGP, an extremely stable, non-aggregating fluorescent protein created by structure-guided surface engineering

    OpenAIRE

    Close, Devin W.; Don Paul, Craig; Langan, Patricia S.; Wilce, Matthew C.J.; Traore, Daouda A.K.; Halfmann, Randal; Rocha, Reginaldo C.; Waldo, Geoffery S.; Payne, Riley J.; Rucker, Joseph B.; Prescott, Mark; Bradbury, Andrew R.M.

    2015-01-01

    In this paper we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP....

  15. Structure of stable degeneration of K3 surfaces into pairs of rational elliptic surfaces

    Science.gov (United States)

    Kimura, Yusuke

    2018-03-01

    F-theory/heterotic duality is formulated in the stable degeneration limit of a K3 fibration on the F-theory side. In this note, we analyze the structure of the stable degeneration limit. We discuss whether stable degeneration exists for pairs of rational elliptic surfaces. We demonstrate that, when two rational elliptic surfaces have an identical complex structure, stable degeneration always exists. We provide an equation that systematically describes the stable degeneration of a K3 surface into a pair of isomorphic rational elliptic surfaces. When two rational elliptic surfaces have different complex structures, whether their sum glued along a smooth fiber admits deformation to a K3 surface can be determined by studying the structure of the K3 lattice. We investigate the lattice theoretic condition to determine whether a deformation to a K3 surface exists for pairs of extremal rational elliptic surfaces. In addition, we discuss the configurations of singular fibers under stable degeneration. The sum of two isomorphic rational elliptic surfaces glued together admits a deformation to a K3 surface, the singular fibers of which are twice that of the rational elliptic surface. For special situations, singular fibers of the resulting K3 surface collide and they are enhanced to a fiber of another type. Some K3 surfaces become attractive in these situations. We determine the complex structures and the Weierstrass forms of these attractive K3 surfaces. We also deduce the gauge groups in F-theory compactifications on these attractive K3 surfaces times a K3. E 6, E 7, E 8, SU(5), and SO(10) gauge groups arise in these compactifications.

  16. Novel stable structure of Li3PS4 predicted by evolutionary algorithm under high-pressure

    Directory of Open Access Journals (Sweden)

    S. Iikubo

    2018-01-01

    Full Text Available By combining theoretical predictions and in-situ X-ray diffraction under high pressure, we found a novel stable crystal structure of Li3PS4 under high pressures. At ambient pressure, Li3PS4 shows successive structural transitions from γ-type to β-type and from β-type to α type with increasing temperature, as is well established. In this study, an evolutionary algorithm successfully predicted the γ-type crystal structure at ambient pressure and further predicted a possible stable δ-type crystal structures under high pressure. The stability of the obtained structures is examined in terms of both static and dynamic stability by first-principles calculations. In situ X-ray diffraction using a synchrotron radiation revealed that the high-pressure phase is the predicted δ-Li3PS4 phase.

  17. Stable preparations of tyrosine hydroxylase provide the solution structure of the full-length enzyme

    Science.gov (United States)

    Bezem, Maria T.; Baumann, Anne; Skjærven, Lars; Meyer, Romain; Kursula, Petri; Martinez, Aurora; Flydal, Marte I.

    2016-01-01

    Tyrosine hydroxylase (TH) catalyzes the rate-limiting step in the biosynthesis of catecholamine neurotransmitters. TH is a highly complex enzyme at mechanistic, structural, and regulatory levels, and the preparation of kinetically and conformationally stable enzyme for structural characterization has been challenging. Here, we report on improved protocols for purification of recombinant human TH isoform 1 (TH1), which provide large amounts of pure, stable, active TH1 with an intact N-terminus. TH1 purified through fusion with a His-tagged maltose-binding protein on amylose resin was representative of the iron-bound functional enzyme, showing high activity and stabilization by the natural feedback inhibitor dopamine. TH1 purified through fusion with a His-tagged ZZ domain on TALON is remarkably stable, as it was partially inhibited by resin-derived cobalt. This more stable enzyme preparation provided high-quality small-angle X-ray scattering (SAXS) data and reliable structural models of full-length tetrameric TH1. The SAXS-derived model reveals an elongated conformation (Dmax = 20 nm) for TH1, different arrangement of the catalytic domains compared with the crystal structure of truncated forms, and an N-terminal region with an unstructured tail that hosts the phosphorylation sites and a separated Ala-rich helical motif that may have a role in regulation of TH by interacting with binding partners. PMID:27462005

  18. Embodied memory: effective and stable perception by combining optic flow and image structure.

    Science.gov (United States)

    Pan, Jing Samantha; Bingham, Ned; Bingham, Geoffrey P

    2013-12-01

    Visual perception studies typically focus either on optic flow structure or image structure, but not on the combination and interaction of these two sources of information. Each offers unique strengths in contrast to the other's weaknesses. Optic flow yields intrinsically powerful information about 3D structure, but is ephemeral. It ceases when motion stops. Image structure is less powerful in specifying 3D structure, but is stable. It remains when motion stops. Optic flow and image structure are intrinsically related in vision because the optic flow carries one image to the next. This relation is especially important in the context of progressive occlusion, in which optic flow provides information about the location of targets hidden in subsequent image structure. In four experiments, we investigated the role of image structure in "embodied memory" in contrast to memory that is only in the head. We found that either optic flow (Experiment 1) or image structure (Experiment 2) alone were relatively ineffective, whereas the combination was effective and, in contrast to conditions requiring reliance on memory-in-the-head, much more stable over extended time (Experiments 2 through 4). Limits well documented for visual short memory (that is, memory-in-the-head) were strongly exceeded by embodied memory. The findings support J. J. Gibson's (1979/1986, The Ecological Approach to Visual Perception, Boston, MA, Houghton Mifflin) insights about progressive occlusion and the embodied nature of perception and memory.

  19. Prediction of Stable Ruthenium Silicides from First-Principles Calculations: Stoichiometries, Crystal Structures, and Physical Properties.

    Science.gov (United States)

    Zhang, Chuanzhao; Kuang, Xiaoyu; Jin, Yuanyuan; Lu, Cheng; Zhou, Dawei; Li, Peifang; Bao, Gang; Hermann, Andreas

    2015-12-09

    We present results of an unbiased structure search for stable ruthenium silicide compounds with various stoichiometries, using a recently developed technique that combines particle swarm optimization algorithms with first-principles calculations. Two experimentally observed structures of ruthenium silicides, RuSi (space group P2(1)3) and Ru2Si3 (space group Pbcn), are successfully reproduced under ambient pressure conditions. In addition, a stable RuSi2 compound with β-FeSi2 structure type (space group Cmca) was found. The calculations of the formation enthalpy, elastic constants, and phonon dispersions demonstrate the Cmca-RuSi2 compound is energetically, mechanically, and dynamically stable. The analysis of electronic band structures and densities of state reveals that the Cmca-RuSi2 phase is a semiconductor with a direct band gap of 0.480 eV and is stabilized by strong covalent bonding between Ru and neighboring Si atoms. On the basis of the Mulliken overlap population analysis, the Vickers hardness of the Cmca structure RuSi2 is estimated to be 28.0 GPa, indicating its ultra-incompressible nature.

  20. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J.; Cross, T.A.; Unkefer, C.J. [eds.

    1994-12-01

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database.

  1. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    International Nuclear Information System (INIS)

    Trewhella, J.; Cross, T.A.; Unkefer, C.J.

    1994-12-01

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database

  2. Dipolar Quinoidal Acene Analogues as Stable Isoelectronic Structures of Pentacene and Nonacene

    KAUST Repository

    Shi, Xueliang

    2015-10-08

    Quinoidal thia-acene analogues, as the respective isoelectronic structures of pentacene and nonacene, were synthesized and an unusual 1,2-sulfur migration was observed during the Friedel-Crafts alkylation reaction. The analogues display a closed-shell quinoidal structure in the ground state with a distinctive dipolar character. In contrast to their acene isoelectronic structures, both compounds are stable because of the existence of more aromatic sextet rings, a dipolar character, and kinetic blocking. They exhibit unique packing in single crystals resulting from balanced dipole-dipole and [C-H⋯π]/[C-H⋯S] interactions.

  3. Stable algorithm for the computation of the electromagnetic field distribution of eigenmodes of periodic diffraction structures.

    Science.gov (United States)

    Bezus, Evgeni A; Doskolovich, Leonid L

    2012-11-01

    In the present work, a stable algorithm for the calculation of the electromagnetic field distributions of the eigenmodes of one-dimensional diffraction gratings is presented. The proposed approach is based on the method for the computation of the propagation constants of Bloch waves of such structures previously presented by Cao et al.[J. Opt. Soc. Am. A 19, 335 (2002)] and uses a modified S-matrix algorithm to ensure numerical stability.

  4. Muon-Substituted Malonaldehyde: Transforming a Transition State into a Stable Structure by Isotope Substitution.

    Science.gov (United States)

    Goli, Mohammad; Shahbazian, Shant

    2016-02-12

    Isotope substitutions are usually conceived to play a marginal role on the structure and bonding pattern of molecules. However, a recent study [Angew. Chem. Int. Ed. 2014, 53, 13706-13709; Angew. Chem. 2014, 126, 13925-13929] further demonstrates that upon replacing a proton with a positively charged muon, as the lightest radioisotope of hydrogen, radical changes in the nature of the structure and bonding of certain species may take place. The present report is a primary attempt to introduce another example of structural transformation on the basis of the malonaldehyde system. Accordingly, upon replacing the proton between the two oxygen atoms of malonaldehyde with the positively charged muon a serious structural transformation is observed. By using the ab initio nuclear-electronic orbital non-Born-Oppenheimer procedure, the nuclear configuration of the muon-substituted species is derived. The resulting nuclear configuration is much more similar to the transition state of the proton transfer in malonaldehyde rather than to the stable configuration of malonaldehyde. The comparison of the "atoms in molecules" (AIM) structure of the muon-substituted malonaldehyde and the AIM structure of the stable and the transition-state configurations of malonaldehyde also unequivocally demonstrates substantial similarities of the muon-substituted malonaldehyde to the transition state. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Making the Bend: DNA Tertiary Structure and Protein-DNA Interactions

    OpenAIRE

    Sabrina Harteis; Sabine Schneider

    2014-01-01

    DNA structure functions as an overlapping code to the DNA sequence. Rapid progress in understanding the role of DNA structure in gene regulation, DNA damage recognition and genome stability has been made. The three dimensional structure of both proteins and DNA plays a crucial role for their specific interaction, and proteins can recognise the chemical signature of DNA sequence (“base readout”) as well as the intrinsic DNA structure (“shape recognition”). These recognition mechanisms do not e...

  6. Structure and Dynamics of Thin Ionomer Films: a Key to A Stable Fuel Cell Membrane.

    Science.gov (United States)

    Perahia, Dvora

    2000-03-01

    The technology for solid polymeric electrolytic membranes for a fuel cells, calls for the thinnest film which is electrochemically stable. At present, none supported polymeric solid state fuel cell membranes, thinner than 50 microns, fail mechanically during fuel cell operation. When approaching the thin film limits, interfacial effects become significant to structure dynamics and consequently, the stability of the membranes. Our work focuses on understanding the interfacial effects on thin per-fluorinated ionomer films, including interfacial effects on the thin films themselves and nanotubes-thin film complexes, mimicking the catalyst-ionomer complexes. In particular we investigated the dynamics and structure in 500 angstrom and less, films made by several perfluorinated ionomers, cast on a solid support. Both the films and their parent solutions were investigated with the goal of resolving the factors that affect the stability in the ultra thin regime. AFM/STM and X-ray and neutron reflectivity were used to investigate the thin films and small angle neutron scattering was utilized to the study of the solutions. Films were both spin-coated and self assembles from solutions on a model oxidized single crystal silicon wafer, treated with HF. When coated from molecular solutions, the films tend to dewet on a time scale of minutes to hours. With increasing concentrations, above the critical micellar concentration of the ionomers in water/alcohol, stable films on the order of 200-500 angstroms were formed. While self-assembled films were found to be stable at temperatures close to Tg of the ionomer, spin-coated ones partially dewet. The surface structure obtained, exhibit periodicity on different length scales, depending on the concentration of the polymer in the solution from which the film was assembled. In the ultra dilute regime, micelles were detected at the solid interface. Films formed from dilute solutions exhibit fractal nature with a fractal dimension varying

  7. Evidence for the residual tertiary structure in the urea-unfolded form of bacteriophage T5 endolysin.

    Science.gov (United States)

    Kutyshenko, Victor P; Prokhorov, Dmitry A; Mikoulinskaia, Galina V; Molochkov, Nikolai V; Paskevich, Svetlana I; Uversky, Vladimir N

    2017-05-01

    Using high-resolution NMR spectroscopy, we studied peculiarities of the unfolding process of the bacteriophage T5 endolysin (EndoT5) by strong denaturants. It was shown that in the absence of zinc ions this protein is mostly unfolded in the solution of 8 M urea or 6 M guanidine hydrochloride. However, in the presence of zinc ions EndoT5 unfolding can be achieved only in acidic solutions (at pH  4.0 NMR spectra of the metal-bound protein (Zn 2+ -Ca 2+ -EndoT5 or Zn 2+ -EndoT5 complexes) exhibit a few chemical shifts characteristic of the native or native-like proteins. Our data, including the pH-titration curve with the pK of ~5, suggested involvement of the zinc-binding histidines in the stabilization of this protein. Up-field signals that appear in the NMR spectra of apo-EndoT5 in the presence of high concentrations of strong denaturants are probably derived from the amino acid residues included in the formation of structured hydrophobic cluster, which likely corresponds to the 81-93 region of EndoT5 and contains some residual tertiary structure. It is possible also that this hydrophobic fragment serves as a foundation for the formation of structured cluster in the unfolded state.

  8. Stable Encoding of Task Structure Coexists With Flexible Coding of Task Events in Sensorimotor Striatum

    Science.gov (United States)

    Kubota, Yasuo; Liu, Jun; Hu, Dan; DeCoteau, William E.; Eden, Uri T.; Smith, Anne C.

    2009-01-01

    The sensorimotor striatum, as part of the brain's habit circuitry, has been suggested to store fixed action values as a result of stimulus-response learning and has been contrasted with a more flexible system that conditionally assigns values to behaviors. The stability of neural activity in the sensorimotor striatum is thought to underlie not only normal habits but also addiction and clinical syndromes characterized by behavioral fixity. By recording in the sensorimotor striatum of mice, we asked whether neuronal activity acquired during procedural learning would be stable even if the sensory stimuli triggering the habitual behavior were altered. Contrary to expectation, both fixed and flexible activity patterns appeared. One, representing the global structure of the acquired behavior, was stable across changes in task cuing. The second, a fine-grain representation of task events, adjusted rapidly. Such dual forms of representation may be critical to allow motor and cognitive flexibility despite habitual performance. PMID:19625536

  9. TGP, an extremely stable, non-aggregating fluorescent protein created by structure-guided surface engineering

    Science.gov (United States)

    Close, Devin W.; Don Paul, Craig; Langan, Patricia S.; Wilce, Matthew C.J.; Traore, Daouda A.K.; Halfmann, Randal; Rocha, Reginaldo C.; Waldo, Geoffery S.; Payne, Riley J.; Rucker, Joseph B.; Prescott, Mark; Bradbury, Andrew R.M.

    2014-01-01

    In this paper we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization. PMID:25287913

  10. Thermal green protein, an extremely stable, nonaggregating fluorescent protein created by structure-guided surface engineering.

    Science.gov (United States)

    Close, Devin W; Paul, Craig Don; Langan, Patricia S; Wilce, Matthew C J; Traore, Daouda A K; Halfmann, Randal; Rocha, Reginaldo C; Waldo, Geoffery S; Payne, Riley J; Rucker, Joseph B; Prescott, Mark; Bradbury, Andrew R M

    2015-07-01

    In this article, we describe the engineering and X-ray crystal structure of Thermal Green Protein (TGP), an extremely stable, highly soluble, non-aggregating green fluorescent protein. TGP is a soluble variant of the fluorescent protein eCGP123, which despite being highly stable, has proven to be aggregation-prone. The X-ray crystal structure of eCGP123, also determined within the context of this paper, was used to carry out rational surface engineering to improve its solubility, leading to TGP. The approach involved simultaneously eliminating crystal lattice contacts while increasing the overall negative charge of the protein. Despite intentional disruption of lattice contacts and introduction of high entropy glutamate side chains, TGP crystallized readily in a number of different conditions and the X-ray crystal structure of TGP was determined to 1.9 Å resolution. The structural reasons for the enhanced stability of TGP and eCGP123 are discussed. We demonstrate the utility of using TGP as a fusion partner in various assays and significantly, in amyloid assays in which the standard fluorescent protein, EGFP, is undesirable because of aberrant oligomerization. © 2014 Wiley Periodicals, Inc.

  11. The search for the most stable structures of silicon-carbon monolayer compounds.

    Science.gov (United States)

    Li, Pengfei; Zhou, Rulong; Zeng, Xiao Cheng

    2014-10-21

    The most stable structures of two-dimensional (2D) silicon-carbon monolayer compounds with different stoichiometric compositions (i.e., Si : C ratio = 2 : 3, 1 : 3 and 1 : 4) are predicted for the first time based on the particle-swarm optimization (PSO) technique combined with density functional theory optimization. Although the 2D Si-C monolayer compounds considered here are rich in carbon, many of the low-energy metastable and the lowest-energy silicon-carbon structures are not graphene (carbon monolayer) like. Phonon-spectrum calculations and ab initio molecular dynamics simulations were also performed to confirm the dynamical stability of the predicted most stable 2D silicon-carbon structures as well their thermal stability at elevated temperature. The computed electronic band structures show that all three predicted silicon-carbon compounds are semiconductors with direct or indirect bandgaps. Importantly, their bandgaps are predicted to be close to those of bulk silicon or bulk germanium. If confirmed in the laboratory, these 2D silicon-carbon compounds with different stoichiometric compositions may be exploited for future applications in nanoelectronic devices.

  12. Structural insights into methanol-stable variants of lipase T6 from Geobacillus stearothermophilus.

    Science.gov (United States)

    Dror, Adi; Kanteev, Margarita; Kagan, Irit; Gihaz, Shalev; Shahar, Anat; Fishman, Ayelet

    2015-11-01

    Enzymatic production of biodiesel by transesterification of triglycerides and alcohol, catalyzed by lipases, offers an environmentally friendly and efficient alternative to the chemically catalyzed process while using low-grade feedstocks. Methanol is utilized frequently as the alcohol in the reaction due to its reactivity and low cost. However, one of the major drawbacks of the enzymatic system is the presence of high methanol concentrations which leads to methanol-induced unfolding and inactivation of the biocatalyst. Therefore, a methanol-stable lipase is of great interest for the biodiesel industry. In this study, protein engineering was applied to substitute charged surface residues with hydrophobic ones to enhance the stability in methanol of a lipase from Geobacillus stearothermophilus T6. We identified a methanol-stable variant, R374W, and combined it with a variant found previously, H86Y/A269T. The triple mutant, H86Y/A269T/R374W, had a half-life value at 70 % methanol of 324 min which reflects an 87-fold enhanced stability compared to the wild type together with elevated thermostability in buffer and in 50 % methanol. This variant also exhibited an improved biodiesel yield from waste chicken oil compared to commercial Lipolase 100L® and Novozyme® CALB. Crystal structures of the wild type and the methanol-stable variants provided insights regarding structure-stability correlations. The most prominent features were the extensive formation of new hydrogen bonds between surface residues directly or mediated by structural water molecules and the stabilization of Zn and Ca binding sites. Mutation sites were also characterized by lower B-factor values calculated from the X-ray structures indicating improved rigidity.

  13. Folding of RNA tertiary structure: Linkages between backbone phosphates, ions, and water.

    Science.gov (United States)

    Draper, David E

    2013-12-01

    The functional forms of many RNAs have compact architectures. The placement of phosphates within such structures must be influenced not only by the strong electrostatic repulsion between phosphates, but also by networks of interactions between phosphates, water, and mobile ions. This review first explores what has been learned of the basic thermodynamic constraints on these arrangements from studies of hydration and ions in simple DNA molecules, and then gives an overview of what is known about ion and water interactions with RNA structures. A brief survey of RNA crystal structures identifies several interesting architectures in which closely spaced phosphates share hydration shells or phosphates are buried in environments that provide intramolecular hydrogen bonds or site-bound cations. Formation of these structures must require strong coupling between the uptake of ions and release of water. Copyright © 2013 Wiley Periodicals, Inc.

  14. Structurally stable gel bead containing entrapped enzyme and method for manufacture thereof

    Science.gov (United States)

    Woodward, J.

    1998-12-08

    This research provides a structurally stable gel bead containing an entrapped enzyme and a method for its manufacture. The enzyme is covalently cross-linked to gelatin in the presence of glutaraldehyde prior to the formation of the gel bead, to prevent leakage of the enzyme. Propylene glycol alginate is then added to the mixture. Once the gel beads are formed, they are then soaked in glutaraldehyde, which imparts structural stability to the gel beads. This method can be used with many types of enzymes, such as proteases, carbohydrases, proteases, ligases, isomerases, oxidoreductases, and specialty enzymes. These and other enzymes can be immobilized in the gel beads and utilized in a number of enzymatic processes. Exogenously added ions are not required to maintain the structural stability of these gel beads. 7 figs.

  15. Rich stoichiometries of stable Ca-Bi system: Structure prediction and superconductivity

    Science.gov (United States)

    Dong, Xu; Fan, Changzeng

    2015-03-01

    Using a variable-composition ab initio evolutionary algorithm implemented in the USPEX code, we have performed a systematic search for stable compounds in the Ca-Bi system at different pressures. In addition to the well-known tI12-Ca2Bi and oS12-CaBi2, a few more structures were found by our calculations, among which phase transitions were also predicted in Ca2Bi (tI12 --> oI12 --> hP6), Ca3Bi2 (hP5 --> mC20 --> aP5) and CaBi (tI2 --> tI8), as well as a new phase (Ca3Bi) with a cF4 structure. All the newly predicted structures can be both dynamically and thermodynamically stable with increasing pressure. The superconductive properties of cF4-CaBi3, tI2-CaBi and cF4-Ca3Bi were studied and the superconducting critical temperature Tc can be as high as 5.16, 2.27 and 5.25 K, respectively. Different superconductivity behaviors with pressure increasing have been observed by further investigations.

  16. Entropy stable high order discontinuous Galerkin methods for ideal compressible MHD on structured meshes

    Science.gov (United States)

    Liu, Yong; Shu, Chi-Wang; Zhang, Mengping

    2018-02-01

    We present a discontinuous Galerkin (DG) scheme with suitable quadrature rules [15] for ideal compressible magnetohydrodynamic (MHD) equations on structural meshes. The semi-discrete scheme is analyzed to be entropy stable by using the symmetrizable version of the equations as introduced by Godunov [32], the entropy stable DG framework with suitable quadrature rules [15], the entropy conservative flux in [14] inside each cell and the entropy dissipative approximate Godunov type numerical flux at cell interfaces to make the scheme entropy stable. The main difficulty in the generalization of the results in [15] is the appearance of the non-conservative "source terms" added in the modified MHD model introduced by Godunov [32], which do not exist in the general hyperbolic system studied in [15]. Special care must be taken to discretize these "source terms" adequately so that the resulting DG scheme satisfies entropy stability. Total variation diminishing / bounded (TVD/TVB) limiters and bound-preserving limiters are applied to control spurious oscillations. We demonstrate the accuracy and robustness of this new scheme on standard MHD examples.

  17. Use of systematics in the interpretation of nuclear structure far from the beta-stable region

    International Nuclear Information System (INIS)

    Wood, J.L.

    1979-01-01

    The use of systematics in the interpretation of nuclear structure far from the beta-stable region is discussed. In particular, a set of rules for the use of systematics is presented together with some experimental criteria that need to be fulfilled for radioactive decay scheme studies in order that all states up to a given spin-parity and energy are located. Illustrative examples are taken from the region 180 < A < 210, with particular emphasis on the odd-mass Au and Hg nuclei. 6 figures

  18. Stable isotopes provide insight into population structure and segregation in eastern North Atlantic sperm whales

    DEFF Research Database (Denmark)

    Borrell, Asunción; Velásquez Vacca, Adriana; Pinela, Ana M.

    2013-01-01

    highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we...... measured oxygen-isotope ratios (delta O-18) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (delta N-15: delta C-13) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in delta N-15 and delta O-18 values...

  19. Incorporation of crystallographic temperature factors in the statistical analysis of protein tertiary structures.

    Science.gov (United States)

    Bott, R; Frane, J

    1990-08-01

    A method to identify statistically significant differences between equivalent atoms in two closely related protein X-ray crystallographic structures is described. This method uses the linear relationship found between the logarithm of the distance between equivalent atoms and their mean temperature factor to determine, by linear regression, the expected difference and variance.

  20. Tertiary Structures of the Escherichia coli and Human Chromosome 21 Molecules of DNA

    Czech Academy of Sciences Publication Activity Database

    Hanzálek, Petr; Kypr, Jaroslav

    2001-01-01

    Roč. 283, č. 1 (2001), s. 219-223 ISSN 0006-291X R&D Projects: GA AV ČR IAA5004802 Institutional research plan: CEZ:AV0Z5004920 Keywords : DNA crystal structures * phosphorus atom representation * genomic DNA molecules Subject RIV: BO - Biophysics Impact factor: 2.946, year: 2001

  1. Structure-Guided Redesign Increases the Propensity of HIV Env To Generate Highly Stable Soluble Trimers.

    Science.gov (United States)

    Guenaga, Javier; Dubrovskaya, Viktoriya; de Val, Natalia; Sharma, Shailendra K; Carrette, Barbara; Ward, Andrew B; Wyatt, Richard T

    2015-12-30

    Due to high viral diversity, an effective HIV-1 vaccine will likely require Envs derived from multiple subtypes to generate broadly neutralizing antibodies (bNAbs). Soluble Env mimics, like the native flexibly linked (NFL) and SOSIP trimers, derived from the subtype A BG505 Env, form homogeneous, stable native-like trimers. However, other Env sequences, such as JRFL and 16055 from subtypes B and C, do so to a lesser degree. The high-resolution BG505 SOSIP crystal structures permit the identification and redesign of Env elements involved in trimer stability. Here, we identified structure trimer-derived (TD) residues that increased the propensity of the subtype B JRFL and subtype C 16055 Env sequences to form well-ordered, homogenous, and highly stable soluble trimers. The generation of these spike mimics no longer required antibody-based selection, positive or negative. Using the redesigned subtype B and C trimer representatives as respective foundations, we further stabilized the NFL TD trimers by engineering an intraprotomer disulfide linkage in the prebridging sheet, I201C-A433C (CC), that locks the gp120 in the receptor nontriggered state. We demonstrated that this disulfide pair prevented CD4 induced-conformational rearrangements in NFL trimers derived from the prototypic subtype A, B, and C representatives. Coupling the TD-based design with the engineered disulfide linkage, CC, increased the propensity of Env to form soluble highly stable spike mimics that are resistant to CD4-induced changes. These advances will allow testing of the hypothesis that such stabilized immunogens will more efficiently elicit neutralizing antibodies in small-animal models and primates. HIV-1 displays unprecedented global diversity circulating in the human population. Since the envelope glycoprotein (Env) is the target of neutralizing antibodies, Env-based vaccine candidates that address such diversity are needed. Soluble well-ordered Env mimics, typified by NFL and SOSIP trimers

  2. Phocid seal leptin: tertiary structure and hydrophobic receptor binding site preservation during distinct leptin gene evolution.

    Directory of Open Access Journals (Sweden)

    John A Hammond

    Full Text Available The cytokine hormone leptin is a key signalling molecule in many pathways that control physiological functions. Although leptin demonstrates structural conservation in mammals, there is evidence of positive selection in primates, lagomorphs and chiropterans. We previously reported that the leptin genes of the grey and harbour seals (phocids have significantly diverged from other mammals. Therefore we further investigated the diversification of leptin in phocids, other marine mammals and terrestrial taxa by sequencing the leptin genes of representative species. Phylogenetic reconstruction revealed that leptin diversification was pronounced within the phocid seals with a high dN/dS ratio of 2.8, indicating positive selection. We found significant evidence of positive selection along the branch leading to the phocids, within the phocid clade, but not over the dataset as a whole. Structural predictions indicate that the individual residues under selection are away from the leptin receptor (LEPR binding site. Predictions of the surface electrostatic potential indicate that phocid seal leptin is notably different to other mammalian leptins, including the otariids. Cloning the grey seal leptin binding domain of LEPR confirmed that this was structurally conserved. These data, viewed in toto, support a hypothesis that phocid leptin divergence is unlikely to have arisen by random mutation. Based upon these phylogenetic and structural assessments, and considering the comparative physiology and varying life histories among species, we postulate that the unique phocid diving behaviour has produced this selection pressure. The Phocidae includes some of the deepest diving species, yet have the least modified lung structure to cope with pressure and volume changes experienced at depth. Therefore, greater surfactant production is required to facilitate rapid lung re-inflation upon surfacing, while maintaining patent airways. We suggest that this additional

  3. Salt-influenced structures in the mesozoic-tertiary cover of the southern North Sea, U.K.

    Energy Technology Data Exchange (ETDEWEB)

    Coward, M. [Imperial College, London (United Kingdom); Stewart, S. [Amerada Hess Ltd., London (United Kingdom)

    1996-12-31

    A structural model encompassing the southern North Sea Basin west of the Central Graben has been developed that combines gravity gliding of the postsalt cover with basement tectonics. The basin differs from many salt basins in that it forms a closed system. Section construction and balancing through the cover of the North Sea need to take into account thin-skinned and thick-skinned extensions and contractions. The North Sea salt formed in Permian time in two large oval basins separated by the Mid North Sea High. The shape of these basins reflects variable patterns of thermal subsidence. Subsequent salt tectonics was governed by local graben structures and by regional uplift and subsidence. Rifting initiated during the Triassic and allowed reactive and locally passive diapirs to develop in the post-salt cover. In the southern North Sea, the Dowsing graben system in the cover is offset from the Dowsing fault zone below the salt. This offset in extensional structures probably relates to the salt thickness and to the position of the surface hinge line that controlled the onset of gravity gliding in the postsalt section. Gravity gliding of the cover into the Triassic-Jurassic Sole Pit trough and away from zones of rift flank uplift was associated with Late Jurassic-Early Cretaceous extension in the Central North Sea; gliding caused asymmetric compressional pillows to develop downslope. Gravity spreading of the cover during the Late Cretaceous-early Tertiary was associated with tilting during thermal subsidence of the southern North Sea Basin, enhanced by pulses of tectonic inversion in the southern North Sea basement. The resultant glide tectonics formed new small grabens upslope and compressional pillows downslope. Where the compressional pillows were eroded sufficiently or faulted later, the salt broke through the thinned cover to produce new active and then passive diapirs, which drained the pillows to produce new rim synclines.

  4. Trophic structure in a seabird host-parasite food web: insights from stable isotope analyses.

    Directory of Open Access Journals (Sweden)

    Elena Gómez-Díaz

    2010-05-01

    Full Text Available Ecological studies on food webs rarely include parasites, partly due to the complexity and dimensionality of host-parasite interaction networks. Multiple co-occurring parasites can show different feeding strategies and thus lead to complex and cryptic trophic relationships, which are often difficult to disentangle by traditional methods. We analyzed stable isotope ratios of C ((13C/(12C, delta(13C and N ((15N/(14N, delta(15N of host and ectoparasite tissues to investigate trophic structure in 4 co-occurring ectoparasites: three lice and one flea species, on two closely related and spatially segregated seabird hosts (Calonectris shearwaters. delta(13C isotopic signatures confirmed feathers as the main food resource for the three lice species and blood for the flea species. All ectoparasite species showed a significant enrichment in delta(15N relatively to the host tissue consumed (discrimination factors ranged from 2 to 5 per thousand depending on the species. Isotopic differences were consistent across multiple host-ectoparasite locations, despite of some geographic variability in baseline isotopic levels. Our findings illustrate the influence of both ectoparasite and host trophic ecology in the isotopic structuring of the Calonectris ectoparasite community. This study highlights the potential of stable isotope analyses in disentangling the nature and complexity of trophic relationships in symbiotic systems.

  5. Ultra-Stable Zero-CTE HoneySiC and H2CMN Mirror Support Structures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA MSFC, GSFC and JPL are interested in Ultra-Stable Mirror Support Structures for Exoplanet Missions. Telescopes with Apertures of 4-meters or larger and using an...

  6. Ultra-Stable Zero-CTE HoneySiC and H2CMN Mirror Support Structures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA MSFC, GSFC and JPL are interested in Ultra-Stable Mirror Support Structures for Exoplanet Missions. Telescopes with Apertures of 4-meters or larger and using an...

  7. Morphology, molecular structure, and stable carbon isotopic composition of black carbon (BC) in urban topsoils.

    Science.gov (United States)

    Zong, Yutong; Xiao, Qing; Lu, Shenggao

    2018-02-01

    Urban soils contain significant amounts of black carbon (BC) from biomass and fossil fuel combustion and regard to be a pool of BC. BC in urban soils has multiple effects on environmental processes in urban system, such as global climate change, air quality, and public health. Urban topsoil samples (0-10 cm) were collected from Anshan, Liaoning Province, northeast China, which is one of the most important old steel industrial bases in China. The BC in urban topsoils was extracted using the density method. Their chemical composition, morphology, molecular structure, and stable carbon isotopic composition were examined using elemental analysis, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and stable carbon isotope (δ 13 C). Elemental analysis shows that carbon content in the BC of studied soils ranged from 64.5 to 78.4%, with the average more than 70%. The O/C atomic ratio of BC is on average 0.18. The BC particle displays different morphology, including porous spherical, irregular porous fragmentary, and blocky shapes. The porous spherical BC particles has atomic molar O/C ratio determined by SEM-EDS ranging from 0.04 to 0.37. XRD indicates that BC exists in mainly combining with mineral phases hematite (Fe 2 O 3 ), kaolinite (Al 2 Si 2 O 5 (OH) 4 ), quartz (SiO 2 ), and calcite (CaCO 3 ). The FTIR spectra of BC particles show major bands at approximately 3400 cm -1 (O-H), 2920 cm -1 (C = H), 1600 cm -1 (C = C), 1230 cm -1 (C = O), and 1070 cm -1 (C = O). The stable carbon isotope (δ 13 C) of BC ranges from -24.48 to -23.18‰ with the average of -23.79 ± 0.39‰. The concentration of BC in the industrial area is significantly (p fuel combustion. Results indicated that a combination of atomic O/C ratio, porous structure, and stable carbon isotopic (δ 13 C) of BC could reflect effectively the origin of BC

  8. Defining proximity relationships in the tertiary structure of the dopamine transporter. Identification of a conserved glutamic acid as a third coordinate in the endogenous Zn(2+)-binding site

    DEFF Research Database (Denmark)

    Løland, Claus Juul; Norregaard, L; Gether, U

    1999-01-01

    Recently, we have described a distance constraint in the unknown tertiary structure of the human dopamine transporter (hDAT) by identification of two histidines, His(193) in the second extracellular loop and His(375) at the top of transmembrane (TM) 7, that form two coordinates in an endogenous....... Summarized, our data define an important set of proximity relationships in hDAT that should prove an important template for further exploring the molecular architecture of Na(+)/Cl(-)-dependent neurotransmitter transporters....

  9. Effect of surface texture and structure on the development of stable fluvial armors

    Science.gov (United States)

    Bertin, Stephane; Friedrich, Heide

    2018-04-01

    Stable fluvial armors are found in river systems under conditions of partial sediment transport and limited sediment supply, a common occurrence in nature. Stable armoring is also readily recreated in experimental flumes. Initially, this bed stabilizing phenomenon was examined for different flow discharges and solely related to surface coarsening and bedload transport reduction. The models developed suggest a specific armor composition (i.e., texture) dependent on the parent bed material and formative discharge. Following developments in topographic remote sensing, recent research suggests that armor structure is an important control on bed stability and roughness. In this paper, replicated flume runs during which digital elevation models (DEMs) were collected from both exposed and flooded gravel beds are used to interpret armoring manifestations and to assess their replicability. A range of methodologies was used for the analysis, providing information on (i) surface grain size and orientation, (ii) bed-elevation distributions, (iii) the spatial coherence of the elevations at the grain-scale, (iv) surface slope and aspect, (v) grain imbrication and (vi) the spatial variability in DEM properties. The bed-surface topography was found to be more responsive than bed-material size to changes in flow strength. Our experimental results also provide convincing evidence that gravel-beds' response to water-work during parallel degradation is unique (i.e., replicable) given the formative parameters. Based on this finding, relationships between the armors' properties and formative parameters are proposed, and are supported by adding extensive data from previous research.

  10. Stable anilinyl radicals coordinated to nickel: X-ray crystal structure and characterization.

    Science.gov (United States)

    Kochem, Amélie; Gellon, Gisèle; Leconte, Nicolas; Baptiste, Benoit; Philouze, Christian; Jarjayes, Olivier; Orio, Maylis; Thomas, Fabrice

    2013-12-02

    Two anilinosalen and a mixed phenol-anilinosalen ligands involving sterically hindered anilines moieties were synthesized. Their nickel(II) complexes 1, 2, and 3 were prepared and characterized. They could be readily one-electron oxidized (E(1/2)=-0.30, -0.26 and 0.10 V vs. Fc(+)/Fc, respectively) into anilinyl radicals species [1](+), [2](+), and [3](+), respectively. The radical complexes are extremely stable and were isolated as single crystals. X-ray crystallographic structures reveal that the changes in bond length resulting from oxidation do not exceed 0.02 Å within the ligand framework in the symmetrical [1](+) and [2](+). No quinoid bond pattern was present. In contrast, larger structural rearrangements were evidenced for the unsymmetrical [3](+), with shortening of one C(ortho)-C(meta) bond. Radical species [1](+) and [2](+) exhibit a strong absorption band at around 6000 cm(-1) (class III mixed valence compounds). This band is significantly less intense than [3](+), consistent with a rather localized anilinyl radical character, and thus a classification of this species as class II mixed-valence compound. Magnetic and electronic properties, as well as structural parameters, have been computed by DFT methods. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Highly active and stable oxaloacetate decarboxylase Na⁺ pump complex for structural analysis.

    Science.gov (United States)

    Inoue, Michio; Li, Xiaodan

    2015-11-01

    The oxaloacetate decarboxylase primary Na(+) pump (Oad) produces energy for the surviving of some pathogenic bacteria under anaerobic conditions. Oad composes of three subunits: Oad-α, a biotinylated soluble subunit and catalyzes the decarboxylation of oxaloacetate; Oad-β, a transmembrane subunit and functions as a Na(+) pump; and Oad-γ, a single transmembrane α-helical anchor subunit and assembles Oad-α/β/γ complex. The molecular mechanism of Oad complex coupling the exothermic decarboxylation to generate the Na(+) electrochemical gradient remains unsolved. Our biophysical and biochemical studies suggested that the stoichiometry of Oad complex from Vibrio cholerae composed of α, β, γ in 4:2:2 stoichiometry not that of 4:4:4. The high-resolution structure determination of the Oad complex would reveal the energetic transformation mechanism from the catalytical soluble α subunit to membrane β subunit. Sufficient amount stable, conformational homogenous and active Oad complex with the right stoichiometry is the prerequisite for structural analysis. Here we report an easy and reproducible protocol to obtain high quantity and quality Oad complex protein for structural analysis. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Aedes aegypti has spatially structured and seasonally stable populations in Yogyakarta, Indonesia.

    Science.gov (United States)

    Rašić, Gordana; Endersby-Harshman, Nancy; Tantowijoyo, Warsito; Goundar, Anjali; White, Vanessa; Yang, Qiong; Filipović, Igor; Johnson, Petrina; Hoffmann, Ary A; Arguni, Eggi

    2015-12-01

    Dengue fever, the most prevalent global arboviral disease, represents an important public health problem in Indonesia. Control of dengue relies on the control of its main vector, the mosquito Aedes aegypti, yet nothing is known about the population history and genetic structure of this insect in Indonesia. Our aim was to assess the spatio-temporal population genetic structure of Ae. aegypti in Yogyakarta, a densely populated region on Java with common dengue outbreaks. We used multiple marker systems (microsatellites, nuclear and mitochondrial genome-wide single nucleotide polymorphisms generated via Restriction-site Associated DNA sequencing) to analyze 979 Ae. aegypti individuals collected from the Yogyakarta city and the surrounding hamlets during the wet season in 2011 and the following dry season in 2012. We employed individual- and group-based approaches for inferring genetic structure. We found that Ae. aegypti in Yogyakarta has spatially structured and seasonally stable populations. The spatial structuring was significant for the nuclear and mitochondrial markers, while the temporal structuring was non-significant. Nuclear markers identified three main genetic clusters, showing that hamlets have greater genetic isolation from each other and from the inner city sites. However, one hamlet experienced unrestricted mosquito interbreeding with the inner city, forming a single genetic cluster. Genetic distance was poorly correlated with the spatial distance among mosquito samples, suggesting stronger influence of human-assisted gene flow than active mosquito movement on spatial genetic structure. A star-shaped mitochondrial haplotype network and a significant R(2) test statistic (R(2) = 0.0187, P = 0.001) support the hypothesis that Ae. aegypti in Yogyakarta originated from a small or homogeneous source and has undergone a relatively recent demographic expansion. We report the first insights into the spatio-temporal genetic structure and the underlying

  13. Expansion of highly stable bla OXA-10 β-lactamase family within diverse host range among nosocomial isolates of Gram-negative bacilli within a tertiary referral hospital of Northeast India.

    Science.gov (United States)

    Maurya, Anand Prakash; Dhar, Debadatta; Basumatary, Mridul Kumar; Paul, Deepjyoti; Ingti, Birson; Choudhury, Debarati; Talukdar, Anupam Das; Chakravarty, Atanu; Mishra, Shweta; Bhattacharjee, Amitabha

    2017-04-04

    The current study reports dissemination of highly stable bla OXA-10 family of beta lactamases among diverse group of nosocomial isolates of Gram-negative bacilli within a tertiary referral hospital of the northern part of India. In the current study, a total number of 590 Gram negative isolates were selected for a period of 1 year (i.e. 1st November 2011-31st October 2012). Members of Enterobacteriaceae and non fermenting Gram negative rods were obtained from Silchar Medical College and Hospital, Silchar, India. Screening and molecular characterization of β-lactamase genes was done. Integrase gene PCR was performed for detection and characterization of integrons and cassette PCR was performed for study of the variable regions of integron gene cassettes carrying bla OXA-10 . Gene transferability, stability and replicon typing was also carried out. Isolates were typed by ERIC as well as REP PCR. Twenty-four isolates of Gram-negative bacilli that were harboring bla OXA-10 family (OXA-14, and OXA16) with fact that resistance was to the extended cephalosporins. The resistance determinant was located within class I integron in five diverse genetic contexts and horizontally transferable in Enterobacteriaceae, was carried through IncY type plasmid. MIC values were above break point for all the tested cephalosporins. Furthermore, co-carriage of bla CMY-2 was also observed. Multiple genetic environment of bla OXA-10 in this geographical region must be investigated to prevent dissemination of these gene cassettes within bacterial population within hospital settings.

  14. A Fundamental Approach to Developing Aluminium based Bulk Amorphous Alloys based on Stable Liquid Metal Structures and Electronic Equilibrium - 154041

    Science.gov (United States)

    2017-03-28

    AFRL-AFOSR-JP-TR-2017-0027 A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal Structures and...to 16 Dec 2016 4.  TITLE AND SUBTITLE A Fundamental Approach to Developing Aluminium -based Bulk Amorphous Alloys based on Stable Liquid-Metal...Air Force Research Laboratory for accurately predicting compositions of new amorphous alloys specifically based on aluminium with properties superior

  15. Structural information from OH stretching frequencies—V. On the presence of different rotamers in substituted tertiary cyclohexanol compounds

    NARCIS (Netherlands)

    Lutz, E.T.G.; Maas, J.H. van der

    1980-01-01

    The presence of different hydroxyl rotamers in a number of saturated aequatorial and axial tertiary cyclohexanols has been studied by means of the i.r. spectra of the OH stretching band. Band resolving experiments indicate that an OH positioned over a cyclohexylring contributes appreciably to the

  16. Structure of stable binary neutron star merger remnants: Role of initial spin

    Science.gov (United States)

    Kastaun, W.; Ciolfi, R.; Endrizzi, A.; Giacomazzo, B.

    2017-08-01

    We present general relativistic numerical simulations of binary neutron star (BNS) mergers with different initial spin configurations. We focus on models with stars of mass 1.4 M⊙ each, which employ the equation of state (EOS) by Shen, Horowitz, and Teige, and which result in stable NSs as merger remnants. For comparison, we consider two irrotational equal mass (M =1.35 M⊙) and unequal mass (M =1.29 , 1.42 M⊙ ) BNS models using the APR4 EOS, which result in a supramassive merger remnant. We present visualizations of the fluid flow and temperature distribution and find a strong impact of the spin on vortex structure and nonaxisymmetric deformation. We compute the radial mass distribution and the rotation profile in the equatorial plane using recently developed measures independent of spatial gauge, revealing slowly rotating cores that can be well approximated by the cores of spherical stars. We also study the influence of the spin on the inspiral phase and the gravitational wave (GW) signal. Using a newly developed analysis method, we further show that gravitational waveforms from BNS mergers can exhibit one or more phase jumps after merger, which occur together with minima of the strain amplitude. We provide a natural explanation in terms of the remnant's quadrupole moment, and show that cancellation effects due to phase jumps can have a strong impact on the GW power spectrum. Finally, we discuss the impact of the spin on the amount of ejected matter.

  17. Exploration of stable compounds, crystal structures, and superconductivity in the Be-H system

    Directory of Open Access Journals (Sweden)

    Shuyin Yu

    2014-10-01

    Full Text Available Using first-principles variable-composition evolutionary methodology, we explored the high-pressure structures of beryllium hydrides between 0 and 400 GPa. We found that BeH2 remains the only stable compound in this pressure range. The pressure-induced transformations are predicted as I b a m → P 3 ̄ m 1 → R 3 ̄ m → C m c m → P 4 / n m m , which occur at 24, 139, 204 and 349 GPa, respectively. P 3 ̄ m 1 and R 3 ̄ m structures are layered polytypes based on close packings of H atoms with Be atoms filling all octahedral voids in alternating layers. Cmcm and P4/nmm contain two-dimensional triangular networks with each layer forming a kinked slab in the ab-plane. P 3 ̄ m 1 and R 3 ̄ m are semiconductors while Cmcm and P4/nmm are metallic. We have explored superconductivity of both metal phases, and found large electron-phonon coupling parameters of λ = 0.63 for Cmcm with a Tc of 32.1-44.1 K at 250 GPa and λ = 0.65 for P4/nmm with a Tc of 46.1-62.4 K at 400 GPa. The dependence of Tc on pressure indicates that Tc initially increases to a maximum of 45.1 K for Cmcm at 275 GPa and 97.0 K for P4/nmm at 365 GPa, and then decreases with increasing pressure for both phases.

  18. Structure of stable binary neutron star merger remnants: A case study

    Science.gov (United States)

    Kastaun, W.; Ciolfi, R.; Giacomazzo, B.

    2016-08-01

    In this work, we study the merger of two neutron stars with a gravitational mass of 1.4 M⊙ each, employing the Shen-Horowitz-Teige equation of state. This equation of state is a corner case, allowing the formation of a stable neutron star with the given total baryonic mass of 3.03 M⊙. We investigate in unprecedented detail the structure of the remnant, in particular the mass distribution, the thermal structure, and the rotation profile. We also compute fluid trajectories both inside the remnant and those relevant for the formation of the disk. We find a peanut-shaped fluid flow inside the remnant following a strong m =2 perturbation. Moreover, the flow is locally compressive, causing the appearance of dynamic hot spots. Further, we introduce new diagnostic measures that are easy to implement in numeric simulations and that allow one to quantify mass and compactness of merger remnants in a well-defined way. As in previous studies of supra- and hypermassive stars, we find a remnant with a slowly rotating core and an outer envelope rotating at nearly Keplerian velocity. We compute a Tolman-Oppenheimer-Volkoff star model which agrees well with that of the remnant in the core, while the latter possesses extensive outer layers rotating close to Kepler velocity. Finally, we extract the gravitational wave signal and discuss the detectability with modern observatories. This study has implications for the interpretation of gravitational wave detections from the postmerger phase and is relevant for short gamma-ray burst models.

  19. Preliminary examination of food web structure of Nicola Lake (Taim Hydrological System, south Brazil using dual C and N stable isotope analyses

    Directory of Open Access Journals (Sweden)

    Alexandre M. Garcia

    Full Text Available Taim Ecological Reserve is located within the Taim Hydrological System and was created to protect a heterogeneous and productive landscape harboring exceptional biological diversity in southern Brazil. Using stable isotope ratio analyses of carbon (delta13C and nitrogen (delta15N, we provide a preliminary description of the food web structure, including estimates of production sources supporting fish populations and vertical trophic structure, within a representative lake of this system. A total of 21 organisms (5 macrophytes, 3 mollusks and 13 adult fishes representing 16 species were collected for isotope analysis. Fishes had delta13C values ranging from -24.30º/oo to -28.31º/oo , showing concordance with the range of values observed for macrophytes (-25.49 to -27.10º/oo, and suggesting that these plants could be a major carbon source supporting these fishes. delta13C signatures of Corbicula (-30.81º/oo and Pomacea (-24.26º/oo indirectly suggest that phytoplankton and benthic algae could be alternative carbon sources for some consumers. Nitrogen isotope ratios indicated approximately three consumer trophic levels. The pearl cichlid Geophagus brasiliensis was a primary consumer. Two catfishes (Trachelyopterus lucenai and Loricariichthys anus were secondary consumers. Two congeneric pike cichclids (Crenicichla lepidota and C. punctata, a catfish (Pimelodus maculatus and the characids Astyanax fasciatus and Oligosarcus robustus were tertiary consumers. Further studies including additional primary producers and consumers and greater sample numbers should be conducted to provide a more complete and detailed description of food web structure and dynamics within the reserve.

  20. The use of protein structure/activity relationships in the rational design of stable particulate delivery systems

    Directory of Open Access Journals (Sweden)

    M.H.B. Costa

    2002-06-01

    Full Text Available The recombinant heat shock protein (18 kDa-hsp from Mycobacterium leprae was studied as a T-epitope model for vaccine development. We present a structural analysis of the stability of recombinant 18 kDa-hsp during different processing steps. Circular dichroism and ELISA were used to monitor protein structure after thermal stress, lyophilization and chemical modification. We observed that the 18 kDa-hsp is extremely resistant to a wide range of temperatures (60% of activity is retained at 80ºC for 20 min. N-Acylation increased its ordered structure by 4% and decreased its ß-T1 structure by 2%. ELISA demonstrated that the native conformation of the 18 kDa-hsp was preserved after hydrophobic modification by acylation. The recombinant 18 kDa-hsp resists to a wide range of temperatures and chemical modifications without loss of its main characteristic, which is to be a source of T epitopes. This resistance is probably directly related to its lack of organization at the level of tertiary and secondary structures.

  1. Molecular identification of aiiA homologous gene from endophytic Enterobacter species and in silico analysis of putative tertiary structure of AHL-lactonase.

    Science.gov (United States)

    Rajesh, P S; Rai, V Ravishankar

    2014-01-03

    The aiiA homologous gene known to encode AHL- lactonase enzyme which hydrolyze the N-acylhomoserine lactone (AHL) quorum sensing signaling molecules produced by Gram negative bacteria. In this study, the degradation of AHL molecules was determined by cell-free lysate of endophytic Enterobacter species. The percentage of quorum quenching was confirmed and quantified by HPLC method (pEnterobacter asburiae VT65, Enterobacter aerogenes VT66 and Enterobacter ludwigii VT70 strains. Sequence alignment analysis revealed the presence of two zinc binding sites, "HXHXDH" motif as well as tyrosine residue at the position 194. Based on known template available at Swiss-Model, putative tertiary structure of AHL-lactonase was constructed. The result showed that novel endophytic strains of Enterobacter genera encode the novel aiiA homologous gene and its structural importance for future study. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. DNA-based stable isotope probing: a link between community structure and function

    Czech Academy of Sciences Publication Activity Database

    Uhlík, Ondřej; Ječná, K.; Leigh, M. B.; Macková, Martina; Macek, Tomáš

    2009-01-01

    Roč. 407, č. 12 (2009), s. 3611-3619 ISSN 0048-9697 Grant - others:GA MŠk(CZ) 2B08031 Program:2B Institutional research plan: CEZ:AV0Z40550506 Keywords : DNA-based stable isotope probing * microbial diversity * bioremediation Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.905, year: 2009

  3. A chemically stable electrolyte with a novel sandwiched structure for proton-conducting solid oxide fuel cells (SOFCs)

    KAUST Repository

    Bi, Lei

    2013-11-01

    A chemically stable electrolyte structure was developed for proton-conducting SOFCs by using two layers of stable BaZr0.7Pr 0.1Y0.2O3 -δ to sandwich a highly-conductive but unstable BaCe0.8Y0.2O 3 -δ electrolyte layer. The sandwiched electrolyte structure showed good chemical stability in both CO2 and H2O atmosphere, indicating that the BZPY layers effectively protect the inner BCY electrolyte, while the BCY electrolyte alone decomposed completely under the same conditions. Fuel cell prototypes fabricated with the sandwiched electrolyte achieved a relatively high performance of 185 mW cm- 2 at 700 C, with a high electrolyte film conductivity of 4 × 10- 3 S cm- 1 at 600 C. © 2013 Elsevier B.V.

  4. Closed Pore Structured NiCo2O4-Coated Nickel Foams for Stable and Effective Oil/Water Separation.

    Science.gov (United States)

    Li, Yan; Zheng, Xi; Yan, Zhanheng; Tian, Dongliang; Ma, Jianmin; Zhang, Xiaofang; Jiang, Lei

    2017-08-30

    To solve the serious problem caused by oily wastewater pollution, unique interface designs, for example, membranes with superwetting properties such as superhydrophobicity/superoleophilicity and superhydrophilicity/underwater superoleophobicity, provide a good way to achieve oil/water separation. Here, inspired by the liquid storage property of the honeycomb structure, we propose a strategy to fabricate NiCo 2 O 4 -coated nickel foams for stable and efficient oil/water separation. NiCo 2 O 4 with a closed-pore structure was formed by assembling nanoflakes with a micro/nanoscale hierarchical structure. Compared with nickel foam coated by NiCo 2 O 4 with an open-pore structure (NiCo 2 O 4 nanowires), the enclosed nanostructure of NiCo 2 O 4 nanoflakes can firmly hold water for a more stable superhydrophilic/underwater superoleophobic interface. As a consequence, the NiCo 2 O 4 -nanoflake-coated nickel foam has a larger oil breakthrough pressure than the NiCo 2 O 4 -nanowire-coated nickel foam because of a slightly larger oil advancing angle and a lower underwater oil adhesion force, which makes it more stable and efficient for oil/water separation. Moreover, the NiCo 2 O 4 -coated nickel foams have excellent chemical and mechanical stability, and they are reusable for oil-water separation. This work will be beneficial for the design and development of stable underwater superoleophobic self-cleaning materials and related device applications, such as oil/water separation.

  5. Finding the Stable Structures of WxN1-x with an ab-initio High-Throughput Approach

    Science.gov (United States)

    2014-03-13

    properties must be energetically stable against decomposition into other compounds. This stability can only be found after the determination of the...polarized. However, in every structure the self-consistent magnetic moment was negligible, and the final calculations were all done assuming no moment. The...of NaCl) we looked at all 255 combinations. We found 34 unique structures, including NbO itself, CsCl, S3U4, ReO3,[59] cubic perovskite (with formula

  6. Social media use profile, social skills, and nurse-patient interaction among Registered Nurses in tertiary hospitals: A structural equation model analysis.

    Science.gov (United States)

    Mariano, Micah Celine O; Maniego, John Christian M; Manila, Hariette Lou Marie D; Mapanoo, Ram Cedrick C; Maquiran, Kerwin Miguel A; Macindo, John Rey B; Tejero, Lourdes Marie S; Torres, Gian Carlo S

    2018-04-01

    Social media has become increasingly important over the past decades and has been integrated in various environments, including the healthcare setting. Yet, the influence of social media use on the social skills and nurse-patient interaction of nurses is an area in nursing that requires further studies. This study determined the interrelationships among social media use profile, social skills, and nurse-patient interaction of Registered Nurses in tertiary hospitals. Employing structural equation modeling, a descriptive-correlational study was conducted among 212 consecutively-selected nurses from two tertiary hospitals. Consenting respondents completed a two-part survey composed of the respondent profile sheet and the Social Skills Inventory. The respondent profile sheet assessed demographic profile and social media use profile in terms of the mode, frequency, and duration of utilization. Three trained team members observed each nurse-patient dyad and completed the Nurse-Patient Bonding Instrument. A good fit model illustrated the negative effects of frequent social media use to patient openness (β = -0.18, p social media on a daily basis, however, positively affected both dimensions of social skills. Accessing social media platforms using non-handheld devices showed the most influential positive effects to social skills and nurse-patient interaction. Additionally, although verbal social skills positively affected most dimensions of nurse-patient interaction, non-verbal social skills negatively influenced patient engagement (β = -0.19, p = 0.019) and nurse openness (β = -0.38, p ≤ 0.05). The structural model illustrates the effects of using social media on the social skills and nurse-patient interaction of nurses and emphasizes the need for implementing institutional policies on the judicious use and application of social media in the workplace. Further, social skills development programs geared toward having a balanced social skill must

  7. Stable feature selection for clinical prediction: exploiting ICD tree structure using Tree-Lasso.

    Science.gov (United States)

    Kamkar, Iman; Gupta, Sunil Kumar; Phung, Dinh; Venkatesh, Svetha

    2015-02-01

    Modern healthcare is getting reshaped by growing Electronic Medical Records (EMR). Recently, these records have been shown of great value towards building clinical prediction models. In EMR data, patients' diseases and hospital interventions are captured through a set of diagnoses and procedures codes. These codes are usually represented in a tree form (e.g. ICD-10 tree) and the codes within a tree branch may be highly correlated. These codes can be used as features to build a prediction model and an appropriate feature selection can inform a clinician about important risk factors for a disease. Traditional feature selection methods (e.g. Information Gain, T-test, etc.) consider each variable independently and usually end up having a long feature list. Recently, Lasso and related l1-penalty based feature selection methods have become popular due to their joint feature selection property. However, Lasso is known to have problems of selecting one feature of many correlated features randomly. This hinders the clinicians to arrive at a stable feature set, which is crucial for clinical decision making process. In this paper, we solve this problem by using a recently proposed Tree-Lasso model. Since, the stability behavior of Tree-Lasso is not well understood, we study the stability behavior of Tree-Lasso and compare it with other feature selection methods. Using a synthetic and two real-world datasets (Cancer and Acute Myocardial Infarction), we show that Tree-Lasso based feature selection is significantly more stable than Lasso and comparable to other methods e.g. Information Gain, ReliefF and T-test. We further show that, using different types of classifiers such as logistic regression, naive Bayes, support vector machines, decision trees and Random Forest, the classification performance of Tree-Lasso is comparable to Lasso and better than other methods. Our result has implications in identifying stable risk factors for many healthcare problems and therefore can

  8. Amphibian and reptile road-kills on tertiary roads in relation to landscape structure: using a citizen science approach with open-access land cover data.

    Science.gov (United States)

    Heigl, Florian; Horvath, Kathrin; Laaha, Gregor; Zaller, Johann G

    2017-06-26

    Amphibians and reptiles are among the most endangered vertebrate species worldwide. However, little is known how they are affected by road-kills on tertiary roads and whether the surrounding landscape structure can explain road-kill patterns. The aim of our study was to examine the applicability of open-access remote sensing data for a large-scale citizen science approach to describe spatial patterns of road-killed amphibians and reptiles on tertiary roads. Using a citizen science app we monitored road-kills of amphibians and reptiles along 97.5 km of tertiary roads covering agricultural, municipal and interurban roads as well as cycling paths in eastern Austria over two seasons. Surrounding landscape was assessed using open access land cover classes for the region (Coordination of Information on the Environment, CORINE). Hotspot analysis was performed using kernel density estimation (KDE+). Relations between land cover classes and amphibian and reptile road-kills were analysed with conditional probabilities and general linear models (GLM). We also estimated the potential cost-efficiency of a large scale citizen science monitoring project. We recorded 180 amphibian and 72 reptile road-kills comprising eight species mainly occurring on agricultural roads. KDE+ analyses revealed a significant clustering of road-killed amphibians and reptiles, which is an important information for authorities aiming to mitigate road-kills. Overall, hotspots of amphibian and reptile road-kills were next to the land cover classes arable land, suburban areas and vineyards. Conditional probabilities and GLMs identified road-kills especially next to preferred habitats of green toad, common toad and grass snake, the most often found road-killed species. A citizen science approach appeared to be more cost-efficient than monitoring by professional researchers only when more than 400 km of road are monitored. Our findings showed that freely available remote sensing data in combination with a

  9. Sonochemical synthesis, structure and magnetic properties of air-stable Fe3O4/Au nanoparticles

    International Nuclear Information System (INIS)

    Wu Wei; He Quanguo; Chen Hong; Tang Jianxin; Nie Libo

    2007-01-01

    Air-stable nanoparticles of Fe 3 O 4 /Au were prepared via sonolysis of a solution mixture of hydrogen tetrachloroaureate(III) trihydrate (HAuCl 4 ) and (3-aminopropyl)triethoxysilane (APTES)-coated Fe 3 O 4 nanoparticles with further drop-addition of sodium citrate. The Fe 3 O 4 /Au nanoparticles were characterized by x-ray powder diffraction (XRD), ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS) and superconducting quantum interference device (SQUID) magnetometry. Nanoparticles of Fe 3 O 4 /Au obtained under appropriate conditions possess a very high saturation magnetization of about 63 emu g -1 and their average diameter is about 30 nm

  10. Benthic Food Web Structure across the Canadian Arctic Ocean: Insights from stable isotopes and the IP25 biomarker

    Science.gov (United States)

    Friscourt, N.; Archambault, P.; Masse, G.; Nozais, C.

    2016-02-01

    In recent decades, the Arctic Ocean has undergone unprecedented changes, such as an increase in the surface temperature and a reduction of sea ice cover. These changes may cause variations in the intensity and spatial distribution of primary production and the nature of pelagic-benthic coupling. This could affect the amount and quality of organic matter that settles onto the seafloor, and the benthic communities that feed upon it. The objectives of this study were i) to describe the trophic structure and resilience of regional benthic food webs using stable carbon and nitrogen isotope analyses and ii) to evaluate the significance of ice algae in the diet of benthic communities using the sea ice proxy IP25. The study area extends from the North Water Polynya to the Chukchi Sea across five geographic regions (North Water Polynya, Canadian Archipelago, Amundsen Gulf, Beaufort Sea and Chukchi Sea) based on environmental factors. To reach these objectives, we collected particulate organic matter (POM), sediments and zoobenthic samples from July to October 2014 aboard the CCGS Amundsen. Stable isotope and IP25 data, the trophic structure within regions and comparison between regions will be presented. Potential impacts of climate change and human activities on benthic ecosystems in the Arctic are still difficult to assess because of the lack of baseline data. The baseline data once provided will enable us to make further predictions on how these changes may affect benthic food web structure.

  11. Soil structure stability and distribution of carbon in water-stable aggregates in different tilled and fertilized Haplic Luvisol

    Directory of Open Access Journals (Sweden)

    Vladimír Šimanský

    2012-01-01

    Full Text Available The influence of tillage and fertilization on soil structure stability and the distribution of carbon in water-stable aggregates of loamy Haplic Luvisol were studied. Soil samples from the locality of Dolná Malanta (experimental station of SUA Nitra were collected (in 2007–2009 from a depth of 0–0.2 m in two tillage variants: (1. conventional tillage, 2. minimal tillage and three treatments of fertilization: (1. without fertilization, 2. crop residues and NPK fertilizers, 3. NPK fertilizers. The minimal tillage system has a positive effect on both the aggregation processes and sequestration of carbon in size fractions of water-stable aggregates, as well as ploughing of crop residues together with NPK fertilizers. On the other hand, application of only NPK fertilizers had a negative effect on SOM content. Under the minimal tillage system and in treatment with crop residues together with NPK fertilizers, what has been observed is a statistically significant increase in the total organic carbon contents by increasing size fractions of water-stable aggregates. Organic carbon did not influence the aggregation processes with dependence on tillage systems. Under conventional tillage as well as in treatment with ploughing crop residues with NPK fertilizers, a very important effect on aggregation had bivalent cations Ca2+ and Mg2+.

  12. Apolipoprotein AI tertiary structures determine stability and phospholipid-binding activity of discoidal high-density lipoprotein particles of different sizes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bin; Ren, Xuefeng; Neville, Tracey; Jerome, W. Gray; Hoyt, David W.; Sparks, Daniel L.; Ren, Gang; Wang, Jianjun

    2009-05-18

    Human high-density lipoprotein (HDL) plays a key role in the reverse cholesterol transport pathway that delivers excess cholesterol back to the liver for clearance. In vivo, HDL particles vary in size, shape and biological function. The discoidal HDL is a 140-240 kDa, disk-shaped intermediate of mature HDL. During mature spherical HDL formation, discoidal HDLs play a key role in loading cholesterol ester onto the HDL particles by activating the enzyme, lecithin:cholesterol acyltransferase (LCAT). One of the major problems for high-resolution structural studies of discoidal HDL is the difficulty in obtaining pure and, foremost, homogenous sample. We demonstrate here that the commonly used cholate dialysis method for discoidal HDL preparation usually contains 5-10% lipid-poor apoAI that significantly interferes with the high-resolution structural analysis of discoidal HDL using biophysical methods. Using an ultracentrifugation method, we quickly removed lipid-poor apoAI. We also purified discoidal reconstituted HDL (rHDL) into two pure discoidal HDL species of different sizes that are amendable for high-resolution structural studies. A small rHDL has a diameter of 7.6 nm, and a large rHDL has a diameter of 9.8 nm. We show that these two different sizes of discoidal HDL particles display different stability and phospholipid-binding activity. Interestingly, these property/functional differences are independent from the apoAI -helical secondary structure, but are determined by the tertiary structural difference of apoAI on different discoidal rHDL particles, as evidenced by two-dimensional NMR and negative stain electron microscopy data. Our result further provides the first high-resolution NMR data, demonstrating a promise of structural determination of discoidal HDL at atomic resolution using a combination of NMR and other biophysical techniques.

  13. Location and extent of Tertiary structures in Cook Inlet Basin, Alaska, and mantle dynamics that focus deformation and subsidence

    Science.gov (United States)

    Haeussler, Peter J.; Saltus, Richard W.

    2011-01-01

    This report is a new compilation of the location and extent of folds and faults in Cook Inlet Basin, Alaska. Data sources are previously published maps, well locations, and seismic-reflection data. We also utilize interpretation of new aeromagnetic data and some proprietary seismic-reflection data. Some structures are remarkably well displayed on frequency-filtered aeromagnetic maps, which are a useful tool for constraining the length of some structures. Most anticlines in and around the basin have at least shows of oil or gas, and some structures are considered to be seismically active. The new map better displays the pattern of faulting and folding. Deformation is greatest in upper Cook Inlet, where structures are oriented slightly counterclockwise of the basin bounding faults. The north ends of these structures bend to the northeast, which gives a pattern consistent with right-transpressional deformation.

  14. DNA-based stable isotope probing: a link between community structure and function

    International Nuclear Information System (INIS)

    Uhlik, Ondrej; Jecna, Katerina; Leigh, Mary Beth; Mackova, Martina; Macek, Tomas

    2009-01-01

    DNA-based molecular techniques permit the comprehensive determination of microbial diversity but generally do not reveal the relationship between the identity and the function of microorganisms. The first direct molecular technique to enable the linkage of phylogeny with function is DNA-based stable isotope probing (DNA-SIP). Applying this method first helped describe the utilization of simple compounds, such as methane, methanol or glucose and has since been used to detect microbial communities active in the utilization of a wide variety of compounds, including various xenobiotics. The principle of the method lies in providing 13C-labeled substrate to a microbial community and subsequent analyses of the 13C-DNA isolated from the community. Isopycnic centrifugation permits separating 13C-labeled DNA of organisms that utilized the substrate from 12C-DNA of the inactive majority. As the whole metagenome of active populations is isolated, its follow-up analysis provides successful taxonomic identification as well as the potential for functional gene analyses. Because of its power, DNA-SIP has become one of the leading techniques of microbial ecology research. But from other point of view, it is a labor-intensive method that requires careful attention to detail during each experimental step in order to avoid misinterpretation of results.

  15. Conjugated organic framework with three-dimensionally ordered stable structure and delocalized π clouds

    Science.gov (United States)

    Guo, Jia; Xu, Yanhong; Jin, Shangbin; Chen, Long; Kaji, Toshihiko; Honsho, Yoshihito; Addicoat, Matthew A.; Kim, Jangbae; Saeki, Akinori; Ihee, Hyotcherl; Seki, Shu; Irle, Stephan; Hiramoto, Masahiro; Gao, Jia; Jiang, Donglin

    2013-01-01

    Covalent organic frameworks are a class of crystalline organic porous materials that can utilize π–π-stacking interactions as a driving force for the crystallization of polygonal sheets to form layered frameworks and ordered pores. However, typical examples are chemically unstable and lack intrasheet π-conjugation, thereby significantly limiting their applications. Here we report a chemically stable, electronically conjugated organic framework with topologically designed wire frameworks and open nanochannels, in which the π conjugation-spans the two-dimensional sheets. Our framework permits inborn periodic ordering of conjugated chains in all three dimensions and exhibits a striking combination of properties: chemical stability, extended π-delocalization, ability to host guest molecules and hole mobility. We show that the π-conjugated organic framework is useful for high on-off ratio photoswitches and photovoltaic cells. Therefore, this strategy may constitute a step towards realizing ordered semiconducting porous materials for innovations based on two-dimensionally extended π systems. PMID:24220603

  16. Optimized multi-step NMR-crystallography approach for structural characterization of a stable quercetin solvate.

    Science.gov (United States)

    Filip, Xenia; Miclaus, Maria; Martin, Flavia; Filip, Claudiu; Grosu, Ioana Georgeta

    2017-05-10

    Herein we report the preparation and solid state structural investigation of the 1,4-dioxane-quercetin solvate. NMR crystallography methods were employed for crystal structure determination of the solvate from microcrystalline powder. The stability of the compound relative to other reported quercetin solvates is discussed and found to be in perfect agreement with the hydrogen bonding networks/supra-molecular architectures formed in each case. It is also clearly shown that NMR crystallography represents an ideal analytical tool in such cases when hydrogen-bonding networks are required to be constrained at a high accuracy level. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. A hypoplastic constitutive model for clays with meta-stable structure

    Czech Academy of Sciences Publication Activity Database

    Mašín, David

    2007-01-01

    Roč. 44, č. 3 (2007), s. 363-375 ISSN 0008-3674 R&D Projects: GA AV ČR(CZ) IAA200710605 Institutional research plan: CEZ:AV0Z20710524 Keywords : constitutive relations * hypoplasticity * clays * structure of soils Subject RIV: JM - Building Engineering Impact factor: 0.542, year: 2007

  18. Structurally stable design of output regulation for a class of nonlinear systems

    Czech Academy of Sciences Publication Activity Database

    Villanueva-Novelo, C.; Čelikovský, Sergej; Castillo-Toledo, B.

    2001-01-01

    Roč. 37, č. 5 (2001), s. 517-561 ISSN 0023-5954 R&D Projects: GA ČR GA102/99/1368 Institutional research plan: AV0Z1075907 Keywords : nonlinear systems * structural stability * output regulation Subject RIV: BC - Control Systems Theory Impact factor: 0.316, year: 2001

  19. Using molecular principal axes for structural comparison: determining the tertiary changes of a FAB antibody domain induced by antigenic binding

    Directory of Open Access Journals (Sweden)

    Silverman B David

    2007-11-01

    Full Text Available Abstract Background Comparison of different protein x-ray structures has previously been made in a number of different ways; for example, by visual examination, by differences in the locations of secondary structures, by explicit superposition of structural elements, e.g. α-carbon atom locations, or by procedures that utilize a common symmetry element or geometrical feature of the structures to be compared. Results A new approach is applied to determine the structural changes that an antibody protein domain experiences upon its interaction with an antigenic target. These changes are determined with the use of two different, however comparable, sets of principal axes that are obtained by diagonalizing the second-order tensors that yield the moments-of-geometry as well as an ellipsoidal characterization of domain shape, prior to and after interaction. Determination of these sets of axes for structural comparison requires no internal symmetry features of the domains, depending solely upon their representation in three-dimensional space. This representation may involve atomic, Cα, or residue centroid coordinates. The present analysis utilizes residue centroids. When the structural changes are minimal, the principal axes of the domains, prior to and after interaction, are essentially comparable and consequently may be used for structural comparison. When the differences of the axes cannot be neglected, but are nevertheless slight, a smaller relatively invariant substructure of the domains may be utilized for comparison. The procedure yields two distance metrics for structural comparison. First, the displacements of the residue centroids due to antigenic binding, referenced to the ellipsoidal principal axes, are noted. Second, changes in the ellipsoidal distances with respect to the non-interacting structure provide a direct measure of the spatial displacements of the residue centroids, towards either the interior or exterior of the domain

  20. Atomic-scale structure and properties of highly stable antiphase boundary defects in Fe3O4.

    Science.gov (United States)

    McKenna, Keith P; Hofer, Florian; Gilks, Daniel; Lazarov, Vlado K; Chen, Chunlin; Wang, Zhongchang; Ikuhara, Yuichi

    2014-12-10

    The complex and intriguing properties of the ferrimagnetic half metal magnetite (Fe 3 O 4 ) are of continuing fundamental interest as well as being important for practical applications in spintronics, magnetism, catalysis and medicine. There is considerable speculation concerning the role of the ubiquitous antiphase boundary (APB) defects in magnetite, however, direct information on their structure and properties has remained challenging to obtain. Here we combine predictive first principles modelling with high-resolution transmission electron microscopy to unambiguously determine the three-dimensional structure of APBs in magnetite. We demonstrate that APB defects on the {110} planes are unusually stable and induce antiferromagnetic coupling between adjacent domains providing an explanation for the magnetoresistance and reduced spin polarization often observed. We also demonstrate how the high stability of the {110} APB defects is connected to the existence of a metastable bulk phase of Fe 3 O 4 , which could be stabilized by strain in films or nanostructures.

  1. Structural changes, market concentration and vertical integration: would they lead to more stable markets

    International Nuclear Information System (INIS)

    Tahmassebi, H.

    1991-01-01

    This communication is concerned with three major developments that are likely to have significant impact on the future structure of world oil markets: oil company mergers and acquisitions, shift of exploration and production activity from the United States to overseas, and joint venture agreements between producing countries and oil companies aimed at further downstream integration by OPEC. The last two developments are likely to contribute substantially to price and market stability in the future

  2. Stable isotope evidence of long-term changes in North Sea food web structure

    DEFF Research Database (Denmark)

    Richardson, Katherine; Christensen, Jens Tang

    2008-01-01

    coast. Porpoises collected after ~1960 had significantly lower d15N than porpoises collected earlier. This change in d15N implies that fundamental changes in food web structure in, or nutrient availability to, the North Sea have taken place over the last ~150 yr and that most of the change occurred over...... reported here may be a reflection of a change in the isotope signature of nitrogen entering the food web. Regardless of its underlying cause, the recorded change in isotopic signature in harbour porpoises is noteworthy as it represents the first fisheries-independent documentation of a long-term temporal...

  3. Bacterioplankton communities of Crater Lake, OR: Dynamic changes with euphotic zone food web structure and stable deep water populations

    Science.gov (United States)

    Urbach, E.; Vergin, K.L.; Larson, G.L.; Giovannoni, S.J.

    2007-01-01

    The distribution of bacterial and archaeal species in Crater Lake plankton varies dramatically over depth and with time, as assessed by hybridization of group-specific oligonucleotides to RNA extracted from lakewater. Nonmetric, multidimensional scaling (MDS) analysis of relative bacterial phylotype densities revealed complex relationships among assemblages sampled from depth profiles in July, August and September of 1997 through 1999. CL500-11 green nonsulfur bacteria (Phylum Chloroflexi) and marine Group I crenarchaeota are consistently dominant groups in the oxygenated deep waters at 300 and 500 m. Other phylotypes found in the deep waters are similar to surface and mid-depth populations and vary with time. Euphotic zone assemblages are dominated either by ??-proteobacteria or CL120-10 verrucomicrobia, and ACK4 actinomycetes. MDS analyses of euphotic zone populations in relation to environmental variables and phytoplankton and zooplankton population structures reveal apparent links between Daphnia pulicaria zooplankton population densities and microbial community structure. These patterns may reflect food web interactions that link kokanee salmon population densities to community structure of the bacterioplankton, via fish predation on Daphnia with cascading consequences to Daphnia bacterivory and predation on bacterivorous protists. These results demonstrate a stable bottom-water microbial community. They also extend previous observations of food web-driven changes in euphotic zone bacterioplankton community structure to an oligotrophic setting. ?? 2007 Springer Science+Business Media B.V.

  4. Pyridine and phosphonate containing ligands for stable lanthanide complexation. An experimental and theoretical study to assess the solution structure.

    Science.gov (United States)

    Mato-Iglesias, Marta; Balogh, Edina; Platas-Iglesias, Carlos; Tóth, Eva; de Blas, Andrés; Rodríguez Blas, Teresa

    2006-12-07

    We report an experimental and theoretical study of the stability and solution structure of lanthanide complexes with two novel ligands containing pyridine units and phosphonate pendant arms on either ethane-1,2-diamine (L2) or cyclohexane-1,2-diamine (L3) backbones. Potentiometric studies have been carried out to determine the protonation constants of the ligands and the stability constants of the complexes with Gd(III) and the endogenous metal ions Zn(II) and Cu(II). While the stability constant of the GdL2 complex is too high to be determined by direct pH-potentiometric titrations, the cyclohexyl derivative GdL3 has a lower and assessable stability (log K(GdL3)=17.62). Due to the presence of the phosphonate groups, various protonated species can be detected up to pH approximately 8 for both ligands and all metal ions studied. The molecular clusters [Ln(L)(H2O)](3-).19H2O (Ln=La, Nd, Ho or Lu; L=L2 or L3) were characterized by theoretical calculations at the HF level. Our calculations provide two minimum energy geometries where the ligand adopts different conformations: twist-wrap (tw), in which the ligand wraps around the metal ion by twisting the pyridyl units relative to each other, and twist-fold (tf), where the slight twisting of the pyridyl units is accompanied by an overall folding of the two pyridine units towards one of the phosphonate groups. The relative free energies of the tw and tf conformations of [Ln(L)(H2O)]3- (L=L2, L3) complexes calculated in aqueous solution (C-PCM) by using the B3LYP model indicate that the tw form is the most stable one along the whole lanthanide series for the complexes of L3, while for those of L2 only the Gd(III) complex is more stable in the tf conformation by ca. 0.5 kcal mol-1. 1H NMR studies of the Eu(III) complex of L3 show the initial formation of the tf complex in aqueous solution, which slowly converts to the thermodynamically stable tw form. The structures calculated for the Nd(III) complexes are in reasonably

  5. Role of Tertiary Lymphoid Structures (TLS) in Anti-Tumor Immunity: Potential Tumor-Induced Cytokines/Chemokines that Regulate TLS Formation in Epithelial-Derived Cancers

    Energy Technology Data Exchange (ETDEWEB)

    Pimenta, Erica M. [Rutgers Biomedical and Health Sciences, New Jersey Medical School-Cancer Center, Newark, NJ 07103 (United States); Barnes, Betsy J., E-mail: barnesbe@njms.rutgers.edu [Department of Biochemistry and Molecular Biology, Rutgers Biomedical and Health Sciences, New Jersey Medical School-Cancer Center, Newark, NJ 07103 (United States)

    2014-04-23

    Following the successes of monoclonal antibody immunotherapies (trastuzumab (Herceptin{sup ®}) and rituximab (Rituxan{sup ®})) and the first approved cancer vaccine, Provenge{sup ®} (sipuleucel-T), investigations into the immune system and how it can be modified by a tumor has become an exciting and promising new field of cancer research. Dozens of clinical trials for new antibodies, cancer and adjuvant vaccines, and autologous T and dendritic cell transfers are ongoing in hopes of identifying ways to re-awaken the immune system and force an anti-tumor response. To date, however, few consistent, reproducible, or clinically-relevant effects have been shown using vaccine or autologous cell transfers due in part to the fact that the immunosuppressive mechanisms of the tumor have not been overcome. Much of the research focus has been on re-activating or priming cytotoxic T cells to recognize tumor, in some cases completely disregarding the potential roles that B cells play in immune surveillance or how a solid tumor should be treated to maximize immunogenicity. Here, we will summarize what is currently known about the induction or evasion of humoral immunity via tumor-induced cytokine/chemokine expression and how formation of tertiary lymphoid structures (TLS) within the tumor microenvironment may be used to enhance immunotherapy response.

  6. Role of Tertiary Lymphoid Structures (TLS) in Anti-Tumor Immunity: Potential Tumor-Induced Cytokines/Chemokines that Regulate TLS Formation in Epithelial-Derived Cancers

    International Nuclear Information System (INIS)

    Pimenta, Erica M.; Barnes, Betsy J.

    2014-01-01

    Following the successes of monoclonal antibody immunotherapies (trastuzumab (Herceptin ® ) and rituximab (Rituxan ® )) and the first approved cancer vaccine, Provenge ® (sipuleucel-T), investigations into the immune system and how it can be modified by a tumor has become an exciting and promising new field of cancer research. Dozens of clinical trials for new antibodies, cancer and adjuvant vaccines, and autologous T and dendritic cell transfers are ongoing in hopes of identifying ways to re-awaken the immune system and force an anti-tumor response. To date, however, few consistent, reproducible, or clinically-relevant effects have been shown using vaccine or autologous cell transfers due in part to the fact that the immunosuppressive mechanisms of the tumor have not been overcome. Much of the research focus has been on re-activating or priming cytotoxic T cells to recognize tumor, in some cases completely disregarding the potential roles that B cells play in immune surveillance or how a solid tumor should be treated to maximize immunogenicity. Here, we will summarize what is currently known about the induction or evasion of humoral immunity via tumor-induced cytokine/chemokine expression and how formation of tertiary lymphoid structures (TLS) within the tumor microenvironment may be used to enhance immunotherapy response

  7. Role of Tertiary Lymphoid Structures (TLS in Anti-Tumor Immunity: Potential Tumor-Induced Cytokines/Chemokines that Regulate TLS Formation in Epithelial-Derived Cancers

    Directory of Open Access Journals (Sweden)

    Erica M. Pimenta

    2014-04-01

    Full Text Available Following the successes of monoclonal antibody immunotherapies (trastuzumab (Herceptin® and rituximab (Rituxan® and the first approved cancer vaccine, Provenge® (sipuleucel-T, investigations into the immune system and how it can be modified by a tumor has become an exciting and promising new field of cancer research. Dozens of clinical trials for new antibodies, cancer and adjuvant vaccines, and autologous T and dendritic cell transfers are ongoing in hopes of identifying ways to re-awaken the immune system and force an anti-tumor response. To date, however, few consistent, reproducible, or clinically-relevant effects have been shown using vaccine or autologous cell transfers due in part to the fact that the immunosuppressive mechanisms of the tumor have not been overcome. Much of the research focus has been on re-activating or priming cytotoxic T cells to recognize tumor, in some cases completely disregarding the potential roles that B cells play in immune surveillance or how a solid tumor should be treated to maximize immunogenicity. Here, we will summarize what is currently known about the induction or evasion of humoral immunity via tumor-induced cytokine/chemokine expression and how formation of tertiary lymphoid structures (TLS within the tumor microenvironment may be used to enhance immunotherapy response.

  8. Isotopic and anatomical evidence of an herbivorous diet in the Early Tertiary giant bird Gastornis. Implications for the structure of Paleocene terrestrial ecosystems

    Science.gov (United States)

    Angst, D.; Lécuyer, C.; Amiot, R.; Buffetaut, E.; Fourel, F.; Martineau, F.; Legendre, S.; Abourachid, A.; Herrel, A.

    2014-04-01

    The mode of life of the early Tertiary giant bird Gastornis has long been a matter of controversy. Although it has often been reconstructed as an apex predator feeding on small mammals, according to other interpretations, it was in fact a large herbivore. To determine the diet of this bird, we analyze here the carbon isotope composition of the bone apatite from Gastornis and contemporaneous herbivorous mammals. Based on 13C-enrichment measured between carbonate and diet of carnivorous and herbivorous modern birds, the carbonate δ13C values of Gastornis bone remains, recovered from four Paleocene and Eocene French localities, indicate that this bird fed on plants. This is confirmed by a morphofunctional study showing that the reconstructed jaw musculature of Gastornis was similar to that of living herbivorous birds and unlike that of carnivorous forms. The herbivorous Gastornis was the largest terrestrial tetrapod in the Paleocene biota of Europe, unlike the situation in North America and Asia, where Gastornis is first recorded in the early Eocene, and the largest Paleocene animals were herbivorous mammals. The structure of the Paleocene terrestrial ecosystems of Europe may have been similar to that of some large islands, notably Madagascar, prior to the arrival of humans.

  9. Volumetric contributions of loop regions of G-quadruplex DNA to the formation of the tertiary structure.

    Science.gov (United States)

    Takahashi, Shuntaro; Sugimoto, Naoki

    2017-12-01

    DNA guanine-quadruplexes (G-quadruplexes) are unique DNA structures formed by guanine-rich sequences. The loop regions of G-quadruplexes play key roles in stability and topology of G-quadruplexes. Here, we investigated volumetric changes induced by pressure in the folding of the G-quadruplex formed by the thrombin binding aptamer (TBA) with mutations within the loop regions. The change of partial molar volume in the transition from coil to G-quadruplex, ∆V tr , of TBA with a mutation from T to A in the 5' most loop (TBA T3A) was 75.5cm 3 mol -1 , which was larger than that of TBA (54.6cm 3 mol -1 ). TBA with a G to T mutation in the central loop (TBA G8T) had thermal stability similar to TBA T3A but a smaller ∆V tr of 41.1cm 3 mol -1 . In the presence of poly(ethylene)glycol 200 (PEG200), ∆V tr values were 14.7cm 3 mol -1 for TBA T3A and 13.2cm 3 mol -1 for TBA G8T. These results suggest that the two mutations destabilize the G-quadruplex structure differently. Thus, volumetric data obtained using pressure-based thermodynamic analyses provides information about the dynamics of the loop regions and the roles of loops in the stabilities and folding of G-quadruplex structures. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Global population structure of the stable fly (Stomoxys calcitrans) inferred by mitochondrial and nuclear sequence data.

    Science.gov (United States)

    Dsouli-Aymes, N; Michaux, J; De Stordeur, E; Couloux, A; Veuille, M; Duvallet, G

    2011-03-01

    Stomoxys calcitrans (Diptera: Muscidae: Stomoxyini), a synanthropic fly with a worldwide distribution, is recognized to have an important medical and veterinary impact. We conducted a phylogeographic analysis based on several populations from five major zoogeographic regions of the world in order to analyse population genetic structure of S. calcitrans and to trace its global dispersion. Results from mitochondrial (COI, Cyt-b and ND1-16S) and nuclear (ITS2) DNA show a substantial differentiation of Oriental populations (first lineage) from the Afrotropical, Palearctic, Nearctic, Neotropical and Oceanian populations (second lineage). The divergence time analyses suggest the separation between the two lineages approximately in mid-Pleistocene. Oriental populations are isolated and would not have participated in the colonization of other regions, unlike the Afrotropical one which seems to be the source of S. calcitrans dispersion towards other regions. Demographic analyses indicate that Oriental, Afrotropical and Palearctic regions have undergone a population expansion during late Pleistocene-early Holocene. The expansion time of this cosmopolitan species could have been influenced by continental human expansions and by animal domestication. Copyright © 2010 Elsevier B.V. All rights reserved.

  11. Peculiarities of the fundamental mode structure in stable-resonator lasers upon spatially inhomogeneous amplification

    International Nuclear Information System (INIS)

    Gorbunkov, Mikhail V; Kostryukov, P V; Telegin, L S; Tunkin, V G; Yakovlev, D V

    2007-01-01

    The structure of the fundamental mode of a laser is calculated by the iteration Fox-Li method in the case of inhomogeneous unsaturated amplification produced by axially symmetric longitudinal pumping. The calculation is performed for different parameters g 1 and g 2 of the resonator within the entire stability region. It is shown that in the case of inhomogeneous amplification, the fundamental mode considerably deviates from the Gaussian mode of an empty resonator only in the so-called critical configurations of the resonator, when the quantity [arccos(g 1 g 2 ) 1/2 ]/π is zero or takes a number of values expressed by irreducible fractions m/n. For the Fresnel number N F = 9, configurations with m/n = 1/2, 2/5, 3/8, 1/3, 3/10, 1/4, 1/5, 1/6, 1/8, and 1/10 are pronounced. As N F increases, the number of critical configurations increases. The expansion in a system of Laguerre-Gaussian beams shows that the fundamental mode in critical configurations is formed by a set of beams with certain radial indices p phased in the active medium. (resonators. modes)

  12. The structure of mAG, a monomeric mutant of the green fluorescent protein Azami-Green, reveals the structural basis of its stable green emission

    International Nuclear Information System (INIS)

    Ebisawa, Tatsuki; Yamamura, Akihiro; Kameda, Yasuhiro; Hayakawa, Kou; Nagata, Koji; Tanokura, Masaru

    2010-01-01

    The crystal structure of a monomeric mutant of Azami-Green (mAG) from G. fascicularis was determined at 2.2 Å resolution. Monomeric Azami-Green (mAG) from the stony coral Galaxea fascicularis is the first known monomeric green-emitting fluorescent protein that is not a variant of Aequorea victoria green fluorescent protein (avGFP). These two green fluorescent proteins are only 27% identical in their amino-acid sequences. mAG is more similar in its amino-acid sequence to four fluorescent proteins: Dendra2 (a green-to-red irreversibly photoconverting fluorescent protein), Dronpa (a bright-and-dark reversibly photoswitchable fluorescent protein), KikG (a tetrameric green-emitting fluorescent protein) and Kaede (another green-to-red irreversibly photoconverting fluorescent protein). To reveal the structural basis of stable green emission by mAG, the 2.2 Å crystal structure of mAG has been determined and compared with the crystal structures of avGFP, Dronpa, Dendra2, Kaede and KikG. The structural comparison revealed that the chromophore formed by Gln62-Tyr63-Gly64 (QYG) and the fixing of the conformation of the imidazole ring of His193 by hydrogen bonds and van der Waals contacts involving His193, Arg66 and Thr69 are likely to be required for the stable green emission of mAG. The crystal structure of mAG will contribute to the design and development of new monomeric fluorescent proteins with faster maturation, brighter fluorescence, improved photostability, new colours and other preferable properties as alternatives to avGFP and its variants

  13. Synthesis, structure and topological analysis of glycine templated highly stable cadmium sulfate framework: A New Lewis Acid catalyst

    Science.gov (United States)

    Paul, Avijit Kumar

    2018-04-01

    One new open-framework two-dimensional layer, [Cd(NH3CH2COO)(SO4)], I, has been synthesized using amino acid as templating agent. Single crystal structural analysis shows that the compound crystallizes in monoclinic cell with non-centrosymmetric space group P21, a = 4.9513(1) Å, b = 7.9763(2) Å, c = 8.0967(2) Å, β = 105.917(1)° and V = 307.504(12) Å3. The compound has connectivity between the Cd-centers and the sulfate units forming a two-dimensional layer structure. Sulfate unit is coordinated to metal center with η3, μ4 mode possessing a coordination free oxygen atom. The zwitterionic form of glycine molecule is present in the structure bridging with two metal centers through μ2-mode by carboxylate oxygens. The topological analysis reveals that the two-dimensional network is formed with a novel 4- and 6-connected binodal net of (32,42,52)(34,44,54,63) topology. Although one end of the glycine molecule is free from coordination, the structure is highly stable up to 350 °C. Strong N-H⋯ O hydrogen bonding interactions play an important role in the stabilization and formation of three-dimensional supramolecular structure. The cyanosilylation of imines using the present compounds as heterogeneous catalyst indicates good catalytic behavior. The present study illustrates the usefulness of the amino acid for the structure building in less studied sulfate based framework materials as well as designing of new heterogeneous catalysts for the broad application. The compound has also been characterized through elemental analysis, PXRD, IR, SEM and TG-DT studies.

  14. The effect of temperature on generic stable periodic structures in the parameter space of dissipative relativistic standard map

    Science.gov (United States)

    Horstmann, Ana C. C.; Albuquerque, Holokx A.; Manchein, Cesar

    2017-05-01

    In this work, we have characterized changes in the dynamics of a two-dimensional relativistic standard map in the presence of dissipation and specially when it is submitted to thermal effects modeled by a Gaussian noise reservoir. By the addition of thermal noise in the dissipative relativistic standard map (DRSM) it is possible to suppress typical stable periodic structures (SPSs) embedded in the chaotic domains of parameter space for large enough temperature strengths. Smaller SPSs are first affected by thermal effects, starting from their borders, as a function of temperature. To estimate the necessary temperature strength capable to destroy those SPSs we use the largest Lyapunov exponent to obtain the critical temperature (TC) diagrams. For critical temperatures the chaotic behavior takes place with the suppression of periodic motion, although the temperature strengths considered in this work are not so large to convert the deterministic features of the underlying system into a stochastic ones.

  15. Stable isotopes indicate population structuring in the southwest Atlantic population of right whales (Eubalaena australis.

    Directory of Open Access Journals (Sweden)

    Morgana Vighi

    Full Text Available From the early 17th century to the 1970s southern right whales, Eubalaena australis, were subject to intense exploitation along the Atlantic coast of South America. Catches along this coast recorded by whalers originally formed a continuum from Brazil to Tierra del Fuego. Nevertheless, the recovery of the population has apparently occurred fragmentarily, and with two main areas of concentration, one off southern Brazil (Santa Catarina and another off central Argentina (Peninsula Valdés. This pattern suggests some level of heterogeneity amongst the population, which is apparently contradicted by records that traced individuals moving throughout the whole geographical extension covered by the species in the Southwest Atlantic. To test the hypothesis of the potential occurrence of discrete subpopulations exploiting specific habitats, we investigated N, C and O isotopic values in 125 bone samples obtained from whaling factories operating in the early 1970s in southern Brazil (n=72 and from contemporary and more recent strandings occurring in central Argentina (n=53. Results indicated significant differences between the two sampling areas, being δ13C and δ18O values significantly higher in samples from southern Brazil than in those from central Argentina. This variation was consistent with isotopic baselines from the two areas, indicating the occurrence of some level of structure in the Southwest Atlantic right whale population and equally that whales more likely feed in areas commonly thought to exclusively serve as nursing grounds. Results aim at reconsidering of the units currently used in the management of the southern right whale in the Southwest Atlantic Ocean. In the context of the current die-off affecting the species in Peninsula Valdés, these results also highlight the necessity to better understand movements of individuals and precisely identify their feeding areas.

  16. Stable isotopes indicate population structuring in the southwest Atlantic population of right whales (Eubalaena australis).

    Science.gov (United States)

    Vighi, Morgana; Borrell, Asunción; Crespo, Enrique A; Oliveira, Larissa R; Simões-Lopes, Paulo C; Flores, Paulo A C; García, Néstor A; Aguilar, Alex; Aguilar, Alejandro

    2014-01-01

    From the early 17th century to the 1970s southern right whales, Eubalaena australis, were subject to intense exploitation along the Atlantic coast of South America. Catches along this coast recorded by whalers originally formed a continuum from Brazil to Tierra del Fuego. Nevertheless, the recovery of the population has apparently occurred fragmentarily, and with two main areas of concentration, one off southern Brazil (Santa Catarina) and another off central Argentina (Peninsula Valdés). This pattern suggests some level of heterogeneity amongst the population, which is apparently contradicted by records that traced individuals moving throughout the whole geographical extension covered by the species in the Southwest Atlantic. To test the hypothesis of the potential occurrence of discrete subpopulations exploiting specific habitats, we investigated N, C and O isotopic values in 125 bone samples obtained from whaling factories operating in the early 1970s in southern Brazil (n=72) and from contemporary and more recent strandings occurring in central Argentina (n=53). Results indicated significant differences between the two sampling areas, being δ13C and δ18O values significantly higher in samples from southern Brazil than in those from central Argentina. This variation was consistent with isotopic baselines from the two areas, indicating the occurrence of some level of structure in the Southwest Atlantic right whale population and equally that whales more likely feed in areas commonly thought to exclusively serve as nursing grounds. Results aim at reconsidering of the units currently used in the management of the southern right whale in the Southwest Atlantic Ocean. In the context of the current die-off affecting the species in Peninsula Valdés, these results also highlight the necessity to better understand movements of individuals and precisely identify their feeding areas.

  17. Tertiary Education in Poland

    OpenAIRE

    World Bank

    2004-01-01

    The polish tertiary education report was undertaken by the World Bank and the European Investment Bank in consultation with the Ministry of National Education and Sports of Poland (MoNES). The modernization of higher education and other tertiary education services has become an increasing focus of public concern in Poland. A major purpose of the report is to discuss important issues in Pol...

  18. Assessment of a structured management pathway for patients referred to the Emergency Department for syncope: results in a tertiary hospital.

    Science.gov (United States)

    Ungar, Andrea; Tesi, Francesca; Chisciotti, Valentina Maddalena; Pepe, Giuseppe; Vanni, Simone; Grifoni, Stefano; Balzi, Daniela; Rafanelli, Martina; Marchionni, Niccolò; Brignole, Michele

    2016-03-01

    High hospitalization rates (39-58% in the literature) of patients admitted to Emergency Department (ED) for transient loss of consciousness (T-LOC) suspected for syncope are still an unresolved issue. The presence of an Observation Unit has reduced hospital admissions and the duration of hospitalization in controlled studies, and a Syncope Unit (SU) in the hospital may reduce hospitalization and increase the number of diagnoses in patients with T-LOC. We assessed the effect of a structured organization on hospitalization rate and outcome. Consecutive patients referred to the ED for a T-LOC of a suspected syncopal nature as the main diagnosis were included. The ED physician was trained to choose between: hospital admission (directly or after short observation); discharge after short (cause occurred in 72 (24%) patients; re-admission rates were 45.9, 19.3, 11.5, and 18.0% among admitted, observation, SU, and ED-discharged patients, respectively. The availability of short observation and a SU seems to reduce the hospitalization rate compared with previous reported historical reports from our and other centres. Most deaths during follow-up occurred in patients who had been hospitalized. High rates of re-admission to the ED within 1 year are still an issue. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

  19. In silico Prediction and Docking of Tertiary Structure of LuxI, an Inducer Synthase of Vibrio fischeri

    Directory of Open Access Journals (Sweden)

    Mohammed Zaghlool Saeed Al-Khayyat

    2016-05-01

    Full Text Available Background: LuxI is a component of the quorum sensing signaling pathway in Vibrio fischeri responsible for the inducer synthesis that is essential for bioluminescence. Methods: Homology modeling of LuxI was carried out using Phyre2 and refined with the GalaxyWEB server. Five models were generated and evaluated by ERRAT, ANOLEA, QMEAN6, and Procheck. Results: Five refined models were generated by the GalaxyWEB server, with Model 4 having the greatest quality based on the QMEAN6 score of 0.732. ERRAT analysis revealed an overall quality of 98.9%, while the overall quality of the initial model was 54%. The mean force potential energy, as analyzed by ANOLEA, were better compared to the initial model. Sterochemical quality estimation by Procheck showed that the refined Model 4 had a reliable structure, and was therefore submitted to the protein model database. Drug Discovery Workbench V.2 was used to screen 2700 experimental compounds from the DrugBank database to identify inhibitors that can bind to the active site between amino acids 24 and 110. Ten compounds with high negative scores were selected as the best in binding. Conclusion: The model produced, and the predicted acteyltransferase binding site, could be useful in modeling homologous sequences from other microorganisms and the design of new antimicrobials.

  20. Cross-Disciplinary Perceptions of Structured Interprofessional Rounds in Promoting Teamwork Within an Academic Tertiary Care Obstetric Unit.

    Science.gov (United States)

    Chau, Anthony; Vijjeswarapu, Mary A; Hickey, Margaret; Acker, David; Huang, Chuan-Chin; Tsen, Lawrence C

    2017-06-01

    In 2005, physician and nursing leaders at Brigham and Women's Hospital initiated structured interprofessional rounds (SIPRs) on the labor and delivery (L&D) suite to improve team communication. We performed a cross-sectional analysis of providers' perceptions of SIPRs and their effectiveness in improving teamwork. We hypothesized that on average, providers would perceive SIPRs as being effective in promoting teamwork, but ratings would differ among professional groups. After a factor analysis and internal consistency assessment, a 19-item paper-based questionnaire was used to evaluate providers' perceptions using a 5-point Likert scale. Respondents included L&D nurses, midwives, obstetricians, and anesthesiologists who participate in SIPRs. The primary aim was to evaluate the providers' perceptions of SIPRs and their association with professional roles. The outcome was total response score for each provider, ranging from 19 to 95; perception of SIPRs as being effective in promoting teamwork was defined as having a total response score of >66.5 (mean score, >3.5 per question). A univariable linear regression model was performed, followed by a multivariable analysis adjusting for predictors that modified the outcome; predictors included years of professional practice, years of experience on the L&D suite, number of clinical work hours worked weekly, and principal shift assignment among nurses. The associations between these predictors and providers' perceptions were assessed as a secondary aim. A total of 234 practitioners responded (100% response rate). The mean total response score (SD) for all providers was 73.3 (9.5). After multivariable adjustment, the mean total response scores were significantly higher for obstetric providers than for anesthesia (Δ mean, 6.5, 95% CI, 0.3, 12.7 P = .036) and midwifery (Δ mean, 12.5, 95% CI, 2.0, 23.0, P = .009) providers. Providers scored significantly lower if they worked >60 clinical hours per week compared with ≤20 (

  1. Stable phase CdS nanoparticles for optoelectronics: a study on surface morphology, structural and optical characterization

    Directory of Open Access Journals (Sweden)

    Kumar Suresh

    2016-06-01

    Full Text Available This work presents a study on the surface morphology, structure and optical behavior of stable phase cadmium sulphide (CdS nanoparticles synthesized via co-precipitation technique. Scanning electron microscopy (SEM analysis has been employed to study a cluster formation in the aggregated nanoparticles. An image analysis approach using ImageJ has been used to measure the size of nanoparticles from the SEM micrographs. Fourier transform infrared spectroscopic (FT-IR analysis identified absorption peaks of Cd–S stretching along with moisture content. X-ray diffraction (XRD analysis showed that CdS nanoparticles crystallized in wurtzite structure with a preferential orientation along (0 0 2 plane. The particle size, microstrain and lattice constants have been evaluated using XRD data. The lattice parameters of these nanoparticles were found to be shorter than the bulk value which led to lattice contraction. The optical absorption study showed a blue shift in the fundamental absorption edge indicating a quantum size effect.

  2. Impact of forest harvesting on trophic structure of eastern Canadian Boreal Shield lakes: insights from stable isotope analyses.

    Directory of Open Access Journals (Sweden)

    Patricia Glaz

    Full Text Available Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes. We measured carbon and nitrogen stable isotopes values for aquatic primary producers, terrestrial detritus, benthic macroinvertebrates, zooplankton and brook trout (Salvelinus fontinalis over a three-year period in eight eastern Boreal Shield lakes. Four lakes were studied before, one and two years after forest harvesting (perturbed lakes and compared with four undisturbed reference lakes (unperturbed lakes sampled at the same time. Stable isotope mixing models showed leaf-litter to be the main food source for benthic primary consumers in both perturbed and unperturbed lakes, suggesting no logging impact on allochthonous subsidies to the littoral food web. Brook trout derived their food mainly from benthic predatory macroinvertebrates in unperturbed lakes. However, in perturbed lakes one year after harvesting, zooplankton appeared to be the main contributor to brook trout diet. This change in brook trout diet was mitigated two years after harvesting. Size-related diet shift were also observed for brook trout, indicating a diet shift related to size. Our study suggests that carbon from terrestrial habitat may be a significant contribution to the food web of oligotrophic Canadian Boreal Shield lakes. Forest harvesting did not have an impact on the diet of benthic primary consumers. On the other hand, brook trout diet composition was affected by logging with greater zooplankton contribution in perturbed lakes, possibly induced by darker-colored environment in these lakes one year after logging.

  3. Impact of forest harvesting on trophic structure of eastern Canadian Boreal Shield lakes: insights from stable isotope analyses.

    Science.gov (United States)

    Glaz, Patricia; Sirois, Pascal; Archambault, Philippe; Nozais, Christian

    2014-01-01

    Perturbations on ecosystems can have profound immediate effects and can, accordingly, greatly alter the natural community. Land-use such as forestry activities in the Canadian Boreal region have increased in the last decades, raising concerns about their potential impact on aquatic ecosystems. The objective of this study was to evaluate the impact of forest harvesting on trophic structure in eastern Canadian Boreal Shield lakes. We measured carbon and nitrogen stable isotopes values for aquatic primary producers, terrestrial detritus, benthic macroinvertebrates, zooplankton and brook trout (Salvelinus fontinalis) over a three-year period in eight eastern Boreal Shield lakes. Four lakes were studied before, one and two years after forest harvesting (perturbed lakes) and compared with four undisturbed reference lakes (unperturbed lakes) sampled at the same time. Stable isotope mixing models showed leaf-litter to be the main food source for benthic primary consumers in both perturbed and unperturbed lakes, suggesting no logging impact on allochthonous subsidies to the littoral food web. Brook trout derived their food mainly from benthic predatory macroinvertebrates in unperturbed lakes. However, in perturbed lakes one year after harvesting, zooplankton appeared to be the main contributor to brook trout diet. This change in brook trout diet was mitigated two years after harvesting. Size-related diet shift were also observed for brook trout, indicating a diet shift related to size. Our study suggests that carbon from terrestrial habitat may be a significant contribution to the food web of oligotrophic Canadian Boreal Shield lakes. Forest harvesting did not have an impact on the diet of benthic primary consumers. On the other hand, brook trout diet composition was affected by logging with greater zooplankton contribution in perturbed lakes, possibly induced by darker-colored environment in these lakes one year after logging.

  4. Population-Level Metrics of Trophic Structure Based on Stable Isotopes and Their Application to Invasion Ecology

    Science.gov (United States)

    Jackson, Michelle C.; Donohue, Ian; Jackson, Andrew L.; Britton, J. Robert; Harper, David M.; Grey, Jonathan

    2012-01-01

    Biological invasions are a significant driver of human-induced global change and many ecosystems sustain sympatric invaders. Interactions occurring among these invaders have important implications for ecosystem structure and functioning, yet they are poorly understood. Here we apply newly developed metrics derived from stable isotope data to provide quantitative measures of trophic diversity within populations or species. We then use these to test the hypothesis that sympatric invaders belonging to the same functional feeding group occupy a smaller isotopic niche than their allopatric counterparts. Two introduced, globally important, benthic omnivores, Louisiana swamp crayfish (Procambarus clarkii) and carp (Cyprinus carpio), are sympatric in Lake Naivasha, Kenya. We applied our metrics to an 8-year data set encompassing the establishment of carp in the lake. We found a strong asymmetric interaction between the two invasive populations, as indicated by inverse correlations between carp abundance and measures of crayfish trophic diversity. Lack of isotopic niche overlap between carp and crayfish in the majority of years indicated a predominantly indirect interaction. We suggest that carp-induced habitat alteration reduced the diversity of crayfish prey, resulting in a reduction in the dietary niche of crayfish. Stable isotopes provide an integrated signal of diet over space and time, offering an appropriate scale for the study of population niches, but few isotope studies have retained the often insightful information revealed by variability among individuals in isotope values. Our population metrics incorporate such variation, are robust to the vagaries of sample size and are a useful additional tool to reveal subtle dietary interactions among species. Although we have demonstrated their applicability specifically using a detailed temporal dataset of species invasion in a lake, they have a wide array of potential ecological applications. PMID:22363724

  5. A high density of tertiary lymphoid structure B cells in lung tumors is associated with increased CD4+ T cell receptor repertoire clonality.

    Science.gov (United States)

    Zhu, Wei; Germain, Claire; Liu, Zheng; Sebastian, Yinong; Devi, Priyanka; Knockaert, Samantha; Brohawn, Philip; Lehmann, Kim; Damotte, Diane; Validire, Pierre; Yao, Yihong; Valge-Archer, Viia; Hammond, Scott A; Dieu-Nosjean, Marie-Caroline; Higgs, Brandon W

    2015-12-01

    T and B cell receptor (TCR and BCR, respectively) Vβ or immunoglobulin heavy chain complementarity-determining region 3 sequencing allows monitoring of repertoire changes through recognition, clonal expansion, affinity maturation, and T or B cell activation in response to antigen. TCR and BCR repertoire analysis can advance understanding of antitumor immune responses in the tumor microenvironment. TCR and BCR repertoires of sorted CD4 + , CD8 + or CD19 + cells in tumor, non-tumoral distant tissue (NT), and peripheral compartments (blood/draining lymph node [P]) from 47 non-small cell lung cancer (NSCLC) patients (age median = 68 y) were sequenced. The clonotype spectra were assessed among different tissues and correlated with clinical and immunological parameters. In all tissues, CD4 + and CD8 + TCR repertoires had greater clonality relative to CD19 + BCR. CD4 + T cells exhibited greater clonality in NT compared to tumor ( p = 0.002) and P ( p 68). Younger patients exhibited greater CD4 + T cell diversity in P compared to older patients ( p = 0.05), and greater CD4 + T cell clonality in tumor relative to P ( p cell clonality in tumor and P, respectively (both p = 0.05), correlated with high density of tumor-associated tertiary lymphoid structure (TLS) B cells, a biomarker of higher overall survival in NSCLC. Results indicate distinct adaptive immune responses in NSCLC, where peripheral T cell diversity is modulated by age, and tumor T cell clonal expansion is favored by the presence of TLSs in the tumor microenvironment.

  6. Interrupted hydrogen/deuterium exchange reveals the stable core of the remarkably helical molten globule of alpha-beta parallel protein flavodoxin.

    NARCIS (Netherlands)

    Nabuurs, S.M.; Mierlo, C.P. van

    2010-01-01

    Kinetic intermediates that appear early during protein folding often resemble the relatively stable molten globule intermediates formed by several proteins under mildly denaturing conditions. Molten globules have a substantial amount of secondary structure but lack virtually all tertiary side-chain

  7. Interrupted hydrogen/deuterium exchange reveals the stable core of the remarkably helical molten globule of a-ß parallel protein flavodoxin

    NARCIS (Netherlands)

    Nabuurs, S.M.; Mierlo, van C.P.M.

    2010-01-01

    Kinetic intermediates that appear early during protein folding often resemble the relatively stable molten globule intermediates formed by several proteins under mildly denaturing conditions. Molten globules have a substantial amount of secondary structure but lack virtually all tertiary side-chain

  8. Trophic structure of mesopelagic fishes in the Gulf of Mexico revealed by gut content and stable isotope analyses

    Science.gov (United States)

    McClain-Counts, Jennifer P.; Demopoulos, Amanda W.J.; Ross, Steve W.

    2017-01-01

    Mesopelagic fishes represent an important component of the marine food web due to their global distributions, high abundances and ability to transport organic material throughout a large part of the water column. This study combined stable isotope (SIAs) and gut content analyses (GCAs) to characterize the trophic structure of mesopelagic fishes in the North-Central Gulf of Mexico. Additionally, this study examined whether mesopelagic fishes utilized chemosynthetic energy from cold seeps. Specimens were collected (9–25 August 2007) over three deep (>1,000 m) cold seeps at discrete depths (surface to 1,503 m) over the diurnal cycle. GCA classified 31 species (five families) of mesopelagic fishes into five feeding guilds: piscivores, large crustacean consumers, copepod consumers, generalists and mixed zooplanktivores. However, these guilds were less clearly defined based on stable isotope mixing model (MixSIAR) results, suggesting diets may be more mixed over longer time periods (weeks–months) and across co-occurring species. Copepods were likely important for the majority of mesopelagic fishes, consistent with GCA (this study) and previous literature. MixSIAR results also identified non-crustacean prey items, including salps and pteropods, as potentially important prey items for mesopelagic fishes, including those fishes not analysed in GCA (Sternoptyx spp. and Melamphaidae). Salps and other soft-bodied species are often missed in GCAs. Mesopelagic fishes had δ13C results consistent with particulate organic matter serving as the baseline organic carbon source, fueling up to three trophic levels. Fishes that undergo diel vertical migration were depleted in 15N relative to weak migrators, consistent with depth-specific isotope trends in sources and consumers, and assimilation of 15N-depleted organic matter in surface waters. Linear correlations between fish size and δ15N values suggested ontogenetic changes in fish diets for several species. While there was

  9. Étude expérimentale de structures stables en turbulence bidimensionnelle, comparaison avec une théorie de mécanique statistique

    OpenAIRE

    DENOIX , Marie-Alice

    1992-01-01

    We create two-dimensional flows within a thin layer of mercury, horizontal and subjected to a vertical uniform magnetic field. The fluid is set in motion by injecting electrical currents. We are interested in the inertial organization into stable structures of two-dimensional turbulence. With the experimental conditions in two areas of initial vorticity, we get axisymmetric structures, elliptical, or eccentric. We study these structures using visualizations and also measurements by potential ...

  10. Ontogeny in Tertiary Frogs

    Czech Academy of Sciences Publication Activity Database

    Roček, Zbyněk

    2004-01-01

    Roč. 260, č. 3 (2004), s. 322-323 ISSN 0362-2525. [International Congress of Vertebrate Morphology /7./. 27.07.2004-01.08.2004, Boca Raton] Keywords : Anura * Tertiary * Czech Republic Subject RIV: EA - Cell Biology

  11. Secondary and tertiary hyperparathyroidism.

    Science.gov (United States)

    Jamal, Sophie A; Miller, Paul D

    2013-01-01

    We reviewed the etiology and management of secondary and tertiary hyperparathyroidism. Secondary hyperparathyroidism is characterized by an increase in parathyroid hormone (PTH) that is appropriate and in response to a stimulus, most commonly low serum calcium. In secondary hyperparathyroidism, the serum calcium is normal and the PTH level is elevated. Tertiary hyperparathyroidism is characterized by excessive secretion of PTH after longstanding secondary hyperparathyroidism, in which hypercalcemia has ensued. Tertiary hyperparathyroidism typically occurs in men and women with chronic kidney disease usually after kidney transplant. The etiology and treatment of secondary hyperparathyroidism is relatively straightforward whereas data on the management of tertiary hyperparathyroidism is limited to a few small trials with short follow-up. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  12. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction.

    Science.gov (United States)

    Chen, Yen-Chang; Lu, Ang-Yu; Lu, Ping; Yang, Xiulin; Jiang, Chang-Ming; Mariano, Marina; Kaehr, Bryan; Lin, Oliver; Taylor, André; Sharp, Ian D; Li, Lain-Jong; Chou, Stanley S; Tung, Vincent

    2017-11-01

    The emerging molybdenum disulfide (MoS 2 ) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS 2 (ce-MoS 2 ) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Structural, physiological, and stable carbon isotopic evidence that the enigmatic Paleozoic fossil Prototaxites formed from rolled liverwort mats.

    Science.gov (United States)

    Graham, Linda E; Cook, Martha E; Hanson, David T; Pigg, Kathleen B; Graham, James M

    2010-02-01

    New structural, nutritional, and stable carbon isotope data may resolve a long-standing mystery-the biological affinities of the fossil Prototaxites, the largest organism on land during the Late Silurian to Late Devonian (420-370 Ma). The tree trunk-shaped specimens, of varying dimensions but consistent tubular anatomy, first formed prior to vascular plant dominance. Hence, Prototaxites has been proposed to represent giant algae, fungi, or lichens, despite incompatible biochemical and anatomical observations. Our comparative analyses instead indicate that Prototaxites formed from partially degraded, wind-, gravity-, or water-rolled mats of mixotrophic liverworts having fungal and cyanobacterial associates, much like the modern liverwort genus Marchantia. We propose that the fossil body is largely derived from abundant, highly degradation-resistant, tubular rhizoids of marchantioid liverworts, intermixed with tubular microbial elements. Our concept explains previously puzzling fossil features and is consistent with evidence for liverworts and microbial associates in Ordovician-Devonian deposits, extensive ancient and modern marchantioid mats, and modern associations of liverworts with cyanobacteria and diverse types of fungi. Our interpretation indicates that liverworts were important components of Devonian ecosystems, that some macrofossils and microfossils previously attributed to "nematophytes" actually represent remains of ancient liverworts, and that mixotrophy and microbial associations were features of early land plants.

  14. Structurally Deformed MoS2 for Electrochemically Stable, Thermally Resistant, and Highly Efficient Hydrogen Evolution Reaction

    KAUST Repository

    Chen, Yen-Chang

    2017-10-12

    The emerging molybdenum disulfide (MoS2) offers intriguing possibilities for realizing a transformative new catalyst for driving the hydrogen evolution reaction (HER). However, the trade-off between catalytic activity and long-term stability represents a formidable challenge and has not been extensively addressed. This study reports that metastable and temperature-sensitive chemically exfoliated MoS2 (ce-MoS2) can be made into electrochemically stable (5000 cycles), and thermally robust (300 °C) while maintaining synthetic scalability and excellent catalytic activity through physical-transformation into 3D structurally deformed nanostructures. The dimensional transition enabled by a high throughput electrohydrodynamic process provides highly accessible, and electrochemically active surface area and facilitates efficient transport across various interfaces. Meanwhile, the hierarchically strained morphology is found to improve electronic coupling between active sites and current collecting substrates without the need for selective engineering the electronically heterogeneous interfaces. Specifically, the synergistic combination of high strain load stemmed from capillarity-induced-self-crumpling and sulfur (S) vacancies intrinsic to chemical exfoliation enables simultaneous modulation of active site density and intrinsic HER activity regardless of continuous operation or elevated temperature. These results provide new insights into how catalytic activity, electrochemical-, and thermal stability can be concurrently enhanced through the physical transformation that is reminiscent of nature, in which properties of biological materials emerge from evolved dimensional transitions.

  15. Highly transparent, stable, and superhydrophobic coatings based on gradient structure design and fast regeneration from physical damage

    Science.gov (United States)

    Chen, Zao; Liu, Xiaojiang; Wang, Yan; Li, Jun; Guan, Zisheng

    2015-12-01

    Optical transparency, mechanical flexibility, and fast regeneration are important factors to expand the application of superhydrophobic surfaces. Herein, we fabricated highly transparent, stable, and superhydrophobic coatings through a novel gradient structure design by versatile dip-coating of silica colloid particles (SCPs) and diethoxydimethysiliane cross-linked silica nanoparticles (DDS-SNPs) on polyethylene terephthalate (PET) film and glass, followed by the modification of octadecyltrichlorosiliane (OTCS). When the DDS concentration reached 5 wt%, the modified SCPs/DDS-SNPs coating exhibited a water contact angle (WCA) of 153° and a sliding angle (SA) superhydrophobic coating on PET film and glass was increased by 2.7% and 1% in the visible wavelength, respectively. This superhydrophobic coating also showed good robustness and stability against water dropping impact, ultrasonic damage, and acid solution. Moreover, the superhydrophobic PET film after physical damage can quickly regain the superhydrophobicity by one-step spray regenerative solution of dodecyltrichlorosilane (DTCS) modified silica nanoparticles at room temperature. The demonstrated method for the preparation and regeneration of superhydrophobic coating is available for different substrates and large-scale production at room temperature.

  16. Microbial communities of the Lemon Creek Glacier show subtle structural variation yet stable phylogenetic composition over space and time

    Directory of Open Access Journals (Sweden)

    Cody Springer Sheik

    2015-05-01

    Full Text Available Glaciers are geologically important yet transient ecosystems that support diverse, biogeochemically significant microbial communities. During the melt season glaciers undergo dramatic physical, geochemical and biological changes that exert great influence on downstream biogeochemical cycles. Thus, we sought to understand the temporal melt-season dynamics of microbial communities and associated geochemistry at the terminus of Lemon Creek Glacier (LCG in coastal southern Alaska. Due to late season snowfall, sampling of LCG occurred in three interconnected areas: proglacial Lake Thomas, the lower glacial outflow stream and the glacier’s terminus. LCG associated microbial communities were phylogenetically diverse and varied by sampling location. However, Betaproteobacteria, Alphaproteobacteria and Bacteroidetes dominated communities at all sampling locations. Strict anaerobic groups such as methanogens, SR1, and OP11 were also recovered from glacier outflows, indicating anoxic conditions in at least some portions of the LCG subglacial environment. Microbial community structure was significantly correlated with sampling location and sodium concentrations. Microbial communities sampled from terminus outflow waters exhibited day-to-day fluctuation in taxonomy and phylogenetic similarity. However, these communities were not significantly different from randomly constructed communities from all three sites. These results indicate that glacial outflows share a large proportion of phylogenetic overlap with downstream environments and that the observed significant shifts in community structure are driven by changes in relative abundance of different taxa, and not complete restructuring of communities. We conclude that LCG glacial discharge hosts a diverse and relatively stable microbiome that shifts at fine taxonomic scales in response to geochemistry and likely water residence time.

  17. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  18. Stable and High OSNR Compound Linear-Cavity Single-Longitudinal-Mode Erbium-Doped Silica Fiber Laser Based on an Asymmetric Four-Cavity Structure

    International Nuclear Information System (INIS)

    Feng Ting; Yan Feng-Ping; Li Qi; Peng Wan-Jing; Feng Su-Chun; Wen Xiao-Dong; Tan Si-Yu; Liu Peng

    2012-01-01

    We propose a stable and high optical signal-to-noise ratio (OSNR) compound linear-cavity single-longitudinal-mode (SLM) erbium-doped silica fiber laser. It consists of three uniform fiber Bragg gratings (FBGs) and two fiber couplers to form a simple asymmetric four-cavity structure to select the longitudinal mode. The stable SLM operation at the wavelength of 1544.053 nm with a 3 dB bandwidth of 0.014 nm and an OSNR of ∼60 dB was verified experimentally. Under laboratory conditions, a power fluctuation performance of less than 0.05 dB for 5 h and wavelength variation of less than 0.01 nm for about 150 min is demonstrated. Finally, the characteristic of laser output power as a function of pump power is investigated. The proposed system provides a simple and cost-effective approach to realize a stable SLM fiber laser

  19. This paper investigates the attitudes of some university and tertiary ...

    African Journals Online (AJOL)

    tertiary institution students to codeswitching. Respondents were drawn from four tertiary institutions located in the Southwestern part of Nigeria. A structured questionnaire ... attitude to code switching, and therefore the high representation of Yoruba ... utterance, conversation or writing has been extensively researched by.

  20. Development of Tertiary Basins of SE Asia from the South China Sea to the Andaman Sea region ; a comparative view on structure and timing

    Science.gov (United States)

    Pubellier, Manuel; Sautter, Benjamin

    2016-04-01

    Basins of SE Asia have developed since the end of Cretaceous times to the detriment of a Mesozoic andean arc which surrounded Sundaland. The arc was broader in the Eastern part along the Pacific Subduction Zone including theSouth China Sea (SCS), than in the Western part along the Sumatra Subduction Zone (Myanmar, Andaman Sea (AS), Malay Peninsula). By the end of the Upper Cretaceous, this arc died out and a widespread rifting with astonishing resemblances started in the whole Sundaland. We compare and discuss the basins similarities and differences in structure and timing between the two sides. A relaxation stage is evidenced in Western Sunda, represented by poorly exposed Late Cretaceous red beds filling the pre-existing morphostructures without clear fault-controlled basins. These deposits are also observed on seismic data offshore in the Gulf of Thailand and AS). On the opposite side along the Chinese margin, thick molasse-type deposits of Late Cretaceous age are on the contrary well expressed offshore and restricted to narrow valleys, indicating that stretching had already begun. There, the Paleogene is marked by strong extension with large crustal blocks rotated by often counter-regional normal faults creating half grabens. Crust was extended and extremely thinned particularly around the SCS. Basins reached the spreading stage in the Celebes Sea, the North Makassar basin and the SCS. On the western side, this period corresponds to narrow deep grabens (e.g. Mergui basins and part of western Malacca) with continental deposits, meaning that the stretching was localized. There, thinning of the crust took place during the Oligocene up to the Middle Miocene where large basins develop mostly to the outer edges of the Yenshanian Arc. Extension resumed in the Pliocene with the opening of the Andaman basin in an even more external position. To the eastern side the uppermost Miocene and the Pliocene were marked mostly by a deepening of the margins and the SCS ocean

  1. 2,6,10-Tris(dialkylamino)-trioxatriangulenium Ions. Synthesis, Structure, and Properties of Exceptionally Stable Carbenium Ions

    DEFF Research Database (Denmark)

    Laursen, Bo W.; Krebs, Frederik C; Nielsen, Merete F.

    1998-01-01

    is expressed as the pK(R+) value, which is determined in strongly basic nonaqueous solution on-the basis of a new acidity function C-. The pK(R+) value of 5a is measured to be 19.7, which is 10 orders of magnitude higher than the values found for the most stable carbenium ions previously reported...

  2. Acousto-optical and SAW propagation characteristics of temperature stable multilayered structures based on LiNbO3 and diamond

    International Nuclear Information System (INIS)

    Shandilya, Swati; Sreenivas, K; Gupta, Vinay

    2008-01-01

    Theoretical studies on the surface acoustic wave (SAW) properties of c-axis oriented LiNbO 3 /IDT/diamond and diamond/IDT/128 0 rotated Y-X cut LiNbO 3 multilayered structures have been considered. Both layered structures exhibit a positive temperature coefficient of delay (TCD) characteristic, and a zero TCD device is obtained after integrating with an over-layer of either tellurium dioxide (TeO 2 ) or silicon dioxide (SiO 2 ). The presence of a TeO 2 over-layer enhanced the electromechanical coupling coefficients of both multilayered structures, which acts as a better temperature compensation layer than SiO 2 . The temperature stable TeO 2 /LiNbO 3 /IDT/diamond layered structure exhibits good electromechanical coefficient and higher phase velocity for SAW device applications. On the other hand, a high acousto-optical (AO) figure of merit (30-37) x 10 -15 s 3 kg -1 has been obtained for the temperature stable SiO 2 /diamond/IDT/LiNbO 3 layered structure indicating a promising device structure for AO applications

  3. Stable structures of Al510–800 clusters and lowest energy sequence of truncated octahedral Al clusters up to 10,000 atoms

    International Nuclear Information System (INIS)

    Wu, Xia; He, Chengdong

    2012-01-01

    Highlights: ► The stable structures of Al 510–800 clusters are obtained with the NP-B potential. ► Al 510–800 clusters adopt truncated octahedral (TO) growth pattern based on complete TOs at Al 405 , Al 586 , and Al 711 . ► The lowest energy sequence of complete TOs up to the size 10,000 is proposed. -- Abstract: The stable structures of Al 510–800 clusters are obtained using dynamic lattice searching with constructed cores (DLSc) method by the NP-B potential. According to the structural growth rule, octahedra and truncated octahedra (TO) configurations are adopted as the inner cores in DLSc method. The results show that in the optimized structures two complete TO structures are found at Al 586 and Al 711 . Furthermore, Al 510–800 clusters adopt TO growth pattern on complete TOs at Al 405 , Al 586 , and Al 711 , and the configurations of the surface atoms are investigated. On the other hand, Al clusters with complete TO motifs are studied up to the size 10,000 by the geometrical construction method. The structural characteristics of complete TOs are denoted by the term “family”, and the growth sequence of Al clusters is investigated. The lowest energy sequence of complete TOs is proposed.

  4. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  5. Application of Nitrogen and Carbon Stable Isotopes (δ15N and δ13C) to Quantify Food Chain Length and Trophic Structure

    OpenAIRE

    Perkins, Matthew J.; McDonald, Robbie A.; van Veen, F. J. Frank; Kelly, Simon D.; Rees, Gareth; Bearhop, Stuart

    2014-01-01

    Increasingly, stable isotope ratios of nitrogen (δ(15)N) and carbon (δ(13)C) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using δ(15)N, and carbon range (CR) using δ(13)C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of kn...

  6. Language and Literature in Tertiary Education: The Case for Stylistics.

    Science.gov (United States)

    Buckledee, Steve

    2002-01-01

    Advocates the use of stylistics for teaching English-as-a-Foreign-Language at the tertiary level. Describes stylistics, discusses discourse conventions and grammatical structure, and examines stylistic analysis of a Shakespearian sonnet and a poem. (Author/VWL)

  7. Synthesis and characterization of highly efficient and stable Pr6O11/Ag3PO4/Pt ternary hybrid structure

    International Nuclear Information System (INIS)

    Deng, Jiatao; Liu, Lin; Niu, Tongjun; Sun, Xiaosong

    2017-01-01

    Highlights: • Visible-light-driven Pr 6 O 11 /Ag 3 PO 4 /Pt photocatalysts were prepared. • Pr 6 O 11 /Ag 3 PO 4 /Pt showed highly efficient and stable photocatalystic activity. • The photocatalytic mechanism of Pr 6 O 11 /Ag 3 PO 4 /Pt composite was given. - Abstract: Ag 3 PO 4 is an excellent photocatalyst with high efficiency and quantum yield, but suffers from the fast recombination of photogenerated electron-hole pairs and photo-corrosion. Hereby, the highly efficient and stable visible-light-driven Pr 6 O 11 /Ag 3 PO 4 /Pt photocatalyst were prepared via a three-step wet chemical approach. The as-prepared Pr 6 O 11 /Ag 3 PO 4 /Pt composite was characterized by X-ray diffraction, US-vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectra and transient photocurrent as well. Comparing with single Pr 6 O 11 or Ag 3 PO 4 , the prepared Pr 6 O 11 /Ag 3 PO 4 /Pt composite exhibited much higher photocatalytic activity and stability for the degradation of Rhodamine B under visible light irradiation (>420 nm). The enhanced photocatalytic performance of Pr 6 O 11 /Ag 3 PO 4 /Pt composite has been attributed to the efficient separation of photo-generated electron-hole pairs through a scheme system composed of Pr 6 O 11, Ag 3 PO 4 and Pt.

  8. Highly stable new organic-inorganic perovskite (CH₃NH₃)₂PdBr₄: synthesis, structure and physical properties.

    Science.gov (United States)

    Liu, Xixia; Huang, Tang Jiao; Zhang, Liuyang; Tang, Baoshan; Zhang, Nengduo; Shi, Diwen; Gong, Hao

    2018-01-11

    Lead halide perovskite has attracted striking attention recently due to their appealing properties. However, toxicity and stability are two main factors restricting its application. In this work, we experimentally synthesized less toxic and highly stable Pd-based hybrid perovskite after exploring different experimental conditions. This new hybrid organic-inorganic perovskite (CH₃NH₃)₂PdBr₄ was found to be an orthorhombic crystal (Cmce, Z=4) with lattice parameters a=8.00 Å, b=7.99 Å, c= 18.89 Å. The Cmce symmetry and lattices parameters were confirmed using Pawley refinement. The atoms positions were testified based on DFT calculation. This perovskite compound was determined to be a p-type semiconductor, with a resistivity of 102.9 kΩ*cm, a carrier concentration of 3.4 ×1012 /cm³ and a mobility of 23.4 cm² /(V*S). Interestingly, XRD and UV-vis measurements indicated that the phase of this new perovskite was maintained with an optical gap of 1.91 eV after leaving in air with a high humidity of 60% for 4 days, and unchanged for months in N₂ ambiance, much more stable than most existing organic-inorganic perovskites. The synthesis and various characterizations of this work further the understanding of this (CH₃NH₃)₂PdBr₄ organic-inorganic hybrid perovskite material. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1994-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets, with a few more additions - with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers - exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the foree of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc. (orig.)

  10. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  11. Buckling control of morphing composite airfoil structure using multi-stable laminate by piezoelectric sensors/actuators

    Science.gov (United States)

    Zareie, Shahin; Zabihollah, Abolghassem; Azizi, Aydin

    2011-04-01

    In the present work, an unsymmetric laminated plate with surface bonded piezoelectric sensors, and actuators has been considered. Piezoelectric sensor were used to monitor the load and deformation bifurcation occurs. Monitoring the shape and load of a morphing structure is essential to ascertain that the structure is properly deployed and it is not loaded excessively ,thus, preventing structural to failure. A piezoceramic actuator is used to provide activation load and to force the structure to change its stability state from one to another. A non-linear finite element model based on the layerwise displacement theory considering the electro-mechanical coupling effects of piezoelectric elements has been developed for simulation purposes. A control mechanism is also employed to actively control the shape of the structure. It is observed that, utilizing multistable composite to design a morphing structure may significantly reduce the energy required for changing the shape. Further controlling the buckling phenomena using piezoelectric sensor and actuator along with an ON/OFF controller can effectively and efficiency enhance the performance of the morphing structure during manoeuver.

  12. Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin

    Science.gov (United States)

    Bartos, Timothy T.; Hallberg, Laura L.; Eddy-Miller, Cheryl

    2015-07-14

    In cooperation with the Bureau of Land Management, groundwater levels in wells located in the northern Green River Basin in Wyoming, an area of ongoing energy development, were measured by the U.S. Geological Survey from 2010 to 2014. The wells were completed in the uppermost aquifers of the Green River Basin lower Tertiary aquifer system, which is a complex regional aquifer system that provides water to most wells in the area. Except for near perennial streams, groundwater-level altitudes in most aquifers generally decreased with increasing depth, indicating a general downward potential for groundwater movement in the study area. Drilled depth of the wells was observed as a useful indicator of depth to groundwater such that deeper wells typically had a greater depth to groundwater. Comparison of a subset of wells included in this study that had historical groundwater levels that were measured during the 1960s and 1970s and again between 2012 and 2014 indicated that, overall, most of the wells showed a net decline in groundwater levels.

  13. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  14. Thermally Stable and Electrically Conductive, Vertically Aligned Carbon Nanotube/Silicon Infiltrated Composite Structures for High-Temperature Electrodes.

    Science.gov (United States)

    Zou, Qi Ming; Deng, Lei Min; Li, Da Wei; Zhou, Yun Shen; Golgir, Hossein Rabiee; Keramatnejad, Kamran; Fan, Li Sha; Jiang, Lan; Silvain, Jean-Francois; Lu, Yong Feng

    2017-10-25

    Traditional ceramic-based, high-temperature electrode materials (e.g., lanthanum chromate) are severely limited due to their conditional electrical conductivity and poor stability under harsh circumstances. Advanced composite structures based on vertically aligned carbon nanotubes (VACNTs) and high-temperature ceramics are expected to address this grand challenge, in which ceramic serves as a shielding layer protecting the VACNTs from the oxidation and erosive environment, while the VACNTs work as a conductor. However, it is still a great challenge to fabricate VACNT/ceramic composite structures due to the limited diffusion of ceramics inside the VACNT arrays. In this work, we report on the controllable fabrication of infiltrated (and noninfiltrated) VACNT/silicon composite structures via thermal chemical vapor deposition (CVD) [and laser-assisted CVD]. In laser-assisted CVD, low-crystalline silicon (Si) was quickly deposited at the VACNT subsurfaces/surfaces followed by the formation of high-crystalline Si layers, thus resulting in noninfiltrated composite structures. Unlike laser-assisted CVD, thermal CVD activated the precursors inside and outside the VACNTs simultaneously, which realized uniform infiltrated VACNT/Si composite structures. The growth mechanisms for infiltrated and noninfiltrated VACNT/ceramic composites, which we attributed to the different temperature distributions and gas diffusion mechanism in VACNTs, were investigated. More importantly, the as-farbicated composite structures exhibited excellent multifunctional properties, such as excellent antioxidative ability (up to 1100 °C), high thermal stability (up to 1400 °C), good high velocity hot gas erosion resistance, and good electrical conductivity (∼8.95 Sm -1 at 823 K). The work presented here brings a simple, new approach to the fabrication of advanced composite structures for hot electrode applications.

  15. 2,6,10-Tris(dialkylamino)trioxatriangulenium ions. Synthesis, structure, and properties of exceptionally stable carbenium ions

    DEFF Research Database (Denmark)

    Laursen, B.W.; Krebs, Frederik C; Nielsen, M.F.

    1998-01-01

    A general synthetic route to a novel type of triamino-substituted planar carbenium ions (5) is reported. The synthetic method is based on a facile and selective nucleophilic aromatic substitution on the 4,6-trimethoxyphenyl)carbenium ion (1) with amines and gives access to a wide variety of more...... complex amino-substituted carbenium ions. X-ray crystallography shows that the cis(N-pyrrolidinyl)-4,8,12-trioxatriangulenium ion (5b) is planar and forms segregated stacks of cations and PF6 anions in the solid phase. The stability of the 2,6, 0-tris(diethylamino)- 4,8,12-trioxatriangulenium ion 5a...... is expressed as the pK(R+) value, which is determined in strongly basic nonaqueous solution on-the basis of a new acidity function C-. The pK(R+) value of 5a is measured to be 19.7, which is 10 orders of magnitude higher than the values found for the most stable carbenium ions previously reported...

  16. More Stable Ties or Better Structure? An Examination of the Impact of Co-author Network on Team Knowledge Creation

    Directory of Open Access Journals (Sweden)

    Mingze Li

    2017-09-01

    Full Text Available This study aims to explore the influence of co-author network on team knowledge creation. Integrating the two traditional perspectives of network relationship and network structure, we examine the direct and interactive effects of tie stability and structural holes on team knowledge creation. Tracking scientific articles published by 111 scholars in the research field of human resource management from the top 8 American universities, we analyze scholars’ scientific co-author networks. The result indicates that tie stability changes the teams’ information processing modes and, when graphed, results in an inverted U-shape relationship between tie stability and team knowledge creation. Moreover, structural holes in co-author network are proved to be harmful to team knowledge sharing and diffusion, thereby impeding team knowledge creation. Also, tie stability and structural hole interactively influence team knowledge creation. When the number of structural hole is low in the co-author network, the graphical representation of the relationship between tie stability and team knowledge creation tends to be a more distinct U-shape.

  17. Stable loop in the crystal structure of the intercalated four-stranded cytosine-rich metazoan telomere

    Science.gov (United States)

    Kang, C.; Berger, I.; Lockshin, C.; Ratliff, R.; Moyzis, R.; Rich, A.

    1995-01-01

    In most metazoans, the telomeric cytosine-rich strand repeating sequence is d(TAACCC). The crystal structure of this sequence was solved to 1.9-A resolution. Four strands associate via the cytosine-containing parts to form a four-stranded intercalated structure held together by C.C+ hydrogen bonds. The base-paired strands are parallel to each other, and the two duplexes are intercalated into each other in opposite orientations. One TAA end forms a highly stabilized loop with the 5' thymine Hoogsteen-base-paired to the third adenine. The 5' end of this loop is in close proximity to the 3' end of one of the other intercalated cytosine strands. Instead of being entirely in a DNA duplex, this structure suggests the possibility of an alternative conformation for the cytosine-rich telomere strands.

  18. Facile synthesis of stable structured MoS{sub 2}-Mo-CNFs heteroarchitecture with enhanced hydrogen evolution

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Qionghua [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Faculty of Material and Energy, South West University, Chongqing 400700 (China); Yao, Yucen [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Liu, Bitao, E-mail: liubitao007@163.com [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Peng, Lingling; Yan, Hengqing; Hou, Zhupei; Wang, Jun [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Lin, Yue, E-mail: linyue@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026 (China)

    2017-06-01

    3D structured MoS{sub 2} are grown in-situ on Mo particles embedded carbon nanofibers (CNFs) via a hydrothermal method. Due to this special structure, the bonding and effective electron delivery between CNFs and MoS{sub 2} are both enhanced, and which will exhibits a better hydrogen evolution activity. The onset potential of this MoS{sub 2}-Mo-CNFs catalyst will decreased to 60 mV compared to the 90 mV for the MoS{sub 2}-CNFs. And its current density nearly no change with 5000 cycles which is better than the 32.3% decrease of MoS{sub 2}-CNFs at η = 300 mV (V vs RHE). - Highlights: • Newly structured MoS{sub 2}-Mo-CNFs with effectively connection between MoS{sub 2} and CNFs successfully synthesized. • This structure can enhance the charge transfer and significantly increase electrocatalytic efficiency. • Nearly no HER activity loss after 5000 CV cycles.

  19. Microbial food web mapping: linking carbon cycling and community structure in soils through pyrosequencing enabled stable isotope probing

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Daniel H. [Cornell Univ., Ithaca, NY (United States)

    2015-03-15

    Soil represents a massive reservoir of active carbon and climate models vary dramatically in predicting how this carbon will respond to climate change over the coming century. A major cause of uncertainty is that we still have a very limited understand the microorganisms that dominate the soil carbon cycle. The vast majority of soil microbes cannot be cultivated in the laboratory and the diversity of organisms and enzymes that participate in the carbon cycle is staggeringly complex. We have developed a new toolbox for exploring the carbon cycle and the metabolic and ecological characteristics of uncultivated microorganisms. The high-resolution nucleic acid stable isotope probing approach that we have developed makes it possible to characterize microbial carbon cycling dynamics in soil. The approach allows us to track multiple 13C-labeled substrates into thousands of microbial taxa over time. Using this approach we have discovered several major lineages of uncultivated microorganisms that participate in cellulose metabolism and are found widely in soils (including Verrucomicrobia and Chloroflexi, which have not previously been implicated as major players in the soil carbon cycle). Furthermore, isotopic labelling of nucleic acids enables community genomics and permits genome fragment binning for a majority of these cellulolytic microorganisms allowing us to explore the metabolic underpinnings of cellulose degradation. This approach has allowed us to describe unexpected dynamics of carbon metabolism with different microbial taxa exhibiting characteristic patterns of carbon substrate incorporation, indicative of distinct ecological strategies. The data we describe allows us to characterize the activity of novel microorganisms as they occur in the environment and these data provide a basis for understanding how the physiological traits of discrete microorganisms sum to govern the complex responses of the soil carbon cycle.

  20. Modeling food web structure and selenium biomagnification in Lake Macquarie, New South Wales, Australia, using stable carbon and nitrogen isotopes.

    Science.gov (United States)

    Schneider, Larissa; Maher, William A; Potts, Jaimie; Taylor, Anne M; Batley, Graeme E; Krikowa, Frank; Chariton, Anthony A; Gruber, Bernd

    2015-03-01

    As a consequence of coal-fired power station operations, elevated selenium concentrations have been reported in the sediments and biota of Lake Macquarie (New South Wales, Australia). In the present study, an ecosystem-scale model has been applied to determine how selenium in a seagrass food web is processed from sediments and water through diet to predators, using stable isotopes (δ(13) C and δ(15) N) to establish the trophic position of organisms. Trophic position, habitat, and feeding zone were examined as possible factors influencing selenium bioaccumulation. Selenium concentrations ranged from 0.2 μg/g dry weight in macroalgae species to 12.9 μg/g in the carnivorous fish Gerres subfasciatus. A mean magnification factor of 1.39 per trophic level showed that selenium is biomagnifying in the seagrass food web. Habitat and feeding zone influenced selenium concentrations in invertebrates, whereas feeding zone was the only significant factor influencing selenium concentrations in fish. The sediment-water partitioning coefficient (Kd ) of 4180 showed that partitioning of selenium entering the lake to particulate organic material (POM) is occurring, and consequently availability to food webs from POM is high. Trophic transfer factors (invertebrate = 1.9; fish = 1.2) were similar to those reported for other water bodies, showing that input source is not the main determinant of the magnitude of selenium bioaccumulation in a food web, but rather the initial partitioning of selenium into bioavailable POM. Environ Toxicol Chem 2015;34:608-617. © 2014 SETAC. © 2014 SETAC.

  1. Dynamic reorganization of chromatin structure and selective DNA demethylation prior to stable enhancer complex formation during differentiation of primary hematopoietic cells in vitro.

    Science.gov (United States)

    Tagoh, Hiromi; Melnik, Svitlana; Lefevre, Pascal; Chong, Suyinn; Riggs, Arthur D; Bonifer, Constanze

    2004-04-15

    In order to gain insights in the true molecular mechanisms involved in cell fate decisions, it is important to study the molecular details of gene activation where such decisions occur, which is at the level of the chromatin structure of individual genes. In the study presented here we addressed this issue and examined the dynamic development of an active chromatin structure at the chicken lysozyme locus during the differentiation of primary myeloid cells from transgenic mouse bone marrow. Using in vivo footprinting we found that stable enhancer complex assembly and high-level gene expression are late events in cell differentiation. However, even before the onset of gene expression and stable transcription factor binding, specific chromatin alterations are observed. This includes changes in DNA topology and the selective demethylation of CpG dinucleotides located in the cores of critical transcription factor binding sites, but not in flanking DNA. These results firmly support the idea that epigenetic programs guiding blood cell differentiation are engraved into the chromatin of lineage-specific genes and that such chromatin changes are implemented before cell lineage specification.

  2. Fundamental understanding of oxygen reduction and reaction behavior and developing high performance and stable hetero-structured cathodes

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xingbo [West Virginia Univ., Morgantown, WV (United States)

    2016-11-14

    New unique hetero-structured cathode has been developed in this project. La2NiO4+δ (LNO) as a surface catalyst with interstitial oxygen defects was introduced onto the state-of-the-art (La0.6Sr0.4)0.95Co0.2Fe0.8O3-δ (LSCF) cathode to enhance the surface-limited ORR kinetics on SOFC cathode. Furthermore, the hetero-structured cathode surface maintains high activity under electrode polarization with much less negative effects from surface cation segregation of Sr, which is known to cause degradation issues for conventional LSCF and LSC cathodes, thus improving the cathode long-term stability. The interface chemistry distribution and oxygen transport properties have been studied to prove the enhancement of power out and stability of LNO-infiltrated LSCF cathode. The further investigation demonstrates that CeO2 & La2-xNiO4+δ (x=0-0.2) co-infiltration is a simple and cost-effective method to improve both performance and stability of LSCF cathode by limiting nano-particles growth/delamination and further improve the surface stability. For the first time, a physical model is proposed to illustrate how unique interstitial species on hetero-structured cathode surface work to regulate the exchange rate of the incorporation reaction. Meanwhile, fundamental investigation of the surface oxygen exchange and bulk oxygen transport properties under over-potential conditions across cathode materials have been carried out in this project, which were discussed and compared to the Nernst equation that is generally applied to treat any oxide electrodes under equilibrium.

  3. Atomic structure of a stable high-index Ge surface: G2(103)-(4x1)

    DEFF Research Database (Denmark)

    Seehofer, L.; Bunk, O.; Falkenberg, G.

    1997-01-01

    Based on scanning tunneling microscopy and surface X-ray diffraction, we propose a complex structural model for the Ge(103)-(4 x 1) reconstruction. Each unit cell contains two (103) double steps, which gives rise to the formation of stripes of Ge atoms oriented in the [] direction....... The stripes and the spaces between them are covered with threefold-coordinated Ge adatoms. Charge is transferred from the bulk-like edge atoms of the double steps to the adatoms. The formation of the reconstruction can be explained in terms of stress relief, charge transfer, and minimization of the dangling...

  4. Stable structures and potential energy surface of the metallic clusters: Ni, Cu, Ag, Au, Pd, and Pt

    Science.gov (United States)

    Wu, Xia; Sun, Yan

    2017-06-01

    Metallic clusters have been widely studied due to their special electrical, optical, and catalytic properties. The many-body Gupta potential is applied to describe the interatomic interaction of Ni, Cu, Ag, Au, Pd, and Pt clusters, and their global minimal structures within 100 atoms are optimized using dynamic lattice searching (DLS) method. The configurational distribution of global minima is analyzed, and the geometrical difference among these clusters is demonstrated. Results show that the dominant motif of Ni and Cu clusters is the icosahedron, and in Ag and Au clusters the number of decahedra is slightly larger than that of the icosahedra. However, more face-centered cubic (fcc), stacking fault fcc, and amorphous structures are formed in Au clusters than in Ag clusters. Furthermore, the main motif of Pd and Pt clusters is the decahedron. In particular, Ni98 adopts a Leary tetrahedral motif, and Pt54 is a central vacant icosahedron. The difference related to the potential parameters of these metallic clusters is further investigated by energy analysis. Moreover, the potential energy surfaces (PES) of 38-atom metallic clusters is characterized in terms of conformational analysis. It was found that the sequence of the number of local minima on the PES from large to low is Ni, Cu, Ag, Pt, Pd, and Au.

  5. Structural and photoluminescence behavior of thermally stable Eu3+activated CaWO4 nanophosphors via Li+ incorporation

    Science.gov (United States)

    Ramakrishna, P. V.; Lakshmana Rao, T.; Singh, Arvind; Benarji, B.; Dash, S.

    2017-12-01

    We have studied the structural and photo physical analogue of Eu3+ activated CaWO4 nanophosphors via Lithium (Li+ = 2, 5 7 and 10 at.%) ion incorporation. As-prepared (APS) samples were annealed at 900 °C to eliminate unwanted organic moieties present in the sample and to improve crystallinity. The samples are characterized employing X-ray diffraction (XRD), Fourier transform IR spectroscopy (FTIR), UV-VIS spectroscopy, photoluminescence studies and lifetime decay studies. FTIR features an absorption band at ∼832 cm-1, which correspond to its antisymmetric vibrations into Osbnd Wsbnd O band in the WO42- tetrahedron. CaWO4 having the scheelite type structure with C4h point group and I41/a space group. The surface morphology of the samples are studied with Scanning Electron Microscopy (SEM). Lithium Co-doped CaWO4:Eu3+ nanoparticles show red luminescence because of strong host contribution and different energy transfer rates from host to Eu3+ ions under 266 nm excitations. Lithium ion enhances the crystallinity and radiative transition rate thus results in higher emissive property. Calculated CIE co-ordinates of these Li+ doped 900 °C annealed samples under 266 nm excitation is x = 0.65 & y = 0.34, which are closer to the standard of NTSC (x = 0.67 & y = 0.33). This material may be potential candidates for white light emitting diodes.

  6. The high Andes, gene flow and a stable hybrid zone shape the genetic structure of a wide-ranging South American parrot

    Directory of Open Access Journals (Sweden)

    Schaefer H Martin

    2011-06-01

    Full Text Available Abstract Background While the gene flow in some organisms is strongly affected by physical barriers and geographical distance, other highly mobile species are able to overcome such constraints. In southern South America, the Andes (here up to 6,900 m may constitute a formidable barrier to dispersal. In addition, this region was affected by cycles of intercalating arid/moist periods during the Upper/Late Pleistocene and Holocene. These factors may have been crucial in driving the phylogeographic structure of the vertebrate fauna of the region. Here we test these hypotheses in the burrowing parrot Cyanoliseus patagonus (Aves, Psittaciformes across its wide distributional range in Chile and Argentina. Results Our data show a Chilean origin for this species, with a single migration event across the Andes during the Upper/Late Pleistocene, which gave rise to all extant Argentinean mitochondrial lineages. Analyses suggest a complex population structure for burrowing parrots in Argentina, which includes a hybrid zone that has remained stable for several thousand years. Within this zone, introgression by expanding haplotypes has resulted in the evolution of an intermediate phenotype. Multivariate regressions show that present day climatic variables have a strong influence on the distribution of genetic heterogeneity, accounting for almost half of the variation in the data. Conclusions Here we show how huge barriers like the Andes and the regional environmental conditions imposed constraints on the ability of a parrot species to colonise new habitats, affecting the way in which populations diverged and thus, genetic structure. When contact between divergent populations was re-established, a stable hybrid zone was formed, functioning as a channel for genetic exchange between populations.

  7. PP3 forms stable tetrameric structures through hydrophobic interactions via the C-terminal amphipathic helix and undergoes reversible thermal dissociation and denaturation.

    Science.gov (United States)

    Pedersen, Lise R L; Nielsen, Søren B; Hansted, Jon G; Petersen, Torben E; Otzen, Daniel E; Sørensen, Esben S

    2012-01-01

    The milk protein proteose peptone component 3 (PP3), also called lactophorin, is a small phosphoglycoprotein that is expressed exclusively in lactating mammary tissue. The C-terminal part of the protein contains an amphipathic helix, which, upon proteolytic liberation, shows antibacterial activity. Previous studies indicate that PP3 forms multimeric structures and inhibits lipolysis in milk. PP3 is the principal component of the proteose peptone fraction of milk. This fraction is obtained by heating and acidifying skimmed milk, and in the dairy industry milk products are also typically exposed to treatments such as pasteurization, which potentially could result in irreversible denaturation and inactivation of bioactive components. We show here, by the use of CD, that PP3 undergoes reversible thermal denaturation and that the α-helical structure of PP3 remains stable even at gastric pH levels. This suggests that the secondary structure survives treatment during the purification and possibly some of the industrial processing of milk. Finally, asymmetric flow field-flow fractionation and multi-angle light scattering reveal that PP3 forms a rather stable tetrameric complex, which dissociates and unfolds in guanidinium chloride. The cooperative unfolding of PP3 was completely removed by the surfactant n-dodecyl-β-d-maltoside and by oleic acid. We interpret this to mean that the PP3 monomers associate through hydrophobic interactions via the hydrophobic surface of the amphipathic helix. These observations suggest that PP3 tetramers act as reservoirs of PP3 molecules, which in the monomeric state may stabilize the milk fat globule. © 2011 The Authors Journal compilation © 2011 FEBS.

  8. Stable channel of reclaimed tidal lowland

    Science.gov (United States)

    Syarifudin, Achmad; Imanuddin, Momon S.; Moerwanto, Arie S.; Suryadi, F. X.

    2017-11-01

    This study aimed to develop models of the Operation and Maintenance in the reclaimed tidal marsh area to get a stable channel. The research location is reclaimed tidal delta area Telang I Primary 8 representing land typology A/B and a survey conducted in 13 South Secondary Schemes following existing tertiary Telang I. MIKE - 11 computer models used used to analyze the movement of sediment in the channel in both the Primary channel 8, SPD, SDU and tertiary channels in block 13 South. Calibration model with multiple channels in the field of physical parameters has been performed to obtain results close to the results of measurement modeling sediment movement in the channel. The integration models of MIKE - 11 models with various scenarios are used to model the operation and maintenance of the channel in the tidal marsh area to get a stable channel. According to the scheme P8 - 13S, OM models obtained 75 percent, in which the secondary channel (SPD/SDU) and built flap gate in tertiary channel, get a well prototype model of the stable channel (equilibriums), where the average erosion on P8 at a distance of 3,200 m in the amount of 4,472,049 m3 and the mean sedimentation in the SPD of 963,836 m3 and mean of sedimentation in the tertiary channel of 3,508,213 m3. Similarly, on average erosion P8 by 4,135,649 m3 and the mean sedimentation in the SDU of 681,304 m3 and the mean sedimentation in the tertiary channel of 3,454,345 m3.

  9. Ultra-stable Molecule-Surface Architectures at Metal Oxides: Structure, Bonding, and Electron-transfer Processes

    Energy Technology Data Exchange (ETDEWEB)

    Hamers, Robert John

    2013-12-07

    Research funded by this project focused on the development of improved strategies for functionalization of metal oxides to enhance charge-transfer processes relevant to solar energy conversion. Initial studies included Fe2O3, WO3, TiO2, SnO2, and ZnO as model oxide systems; these systems were chosen due to differences in metal oxidation state and chemical bonding types in these oxides. Later studies focused largely on SnO2 and ZnO, as these materials show particularly promising surface chemistry, have high electron mobility, and can be readily grown in both spherical nanoparticles and as elongated nanorods. New molecules were synthesized that allowed the direct chemical assembly of novel nanoparticle ?dyadic? structures in which two different oxide materials are chemically joined, leading to an interface that enhances the separation of of charge upon illumination. We demonstrated that such junctions enhance photocatalytic efficiency using model organic compounds. A separate effort focused on novel approaches to linking dye molecules to SnO2 and ZnO as a way to enhance solar conversion efficiency. A novel type of surface binding through

  10. Stratigraphy, structure, and some petrographic features of Tertiary volcanic rocks in the USW G-2 drill hole, Yucca Mountain, Nye County, Nevada

    Science.gov (United States)

    Maldonado, Florian; Koether, S.L.

    1983-01-01

    A continuously cored drill hole designated as USW G-2, located at Yucca Mountain in southwestern Nevada, penetrated 1830.6 m of Tertiary volcanic strata composed of abundant silicic ash-flow tuffs, minor lava and flow breccias, and subordinate volcaniclastic rocks. The volcanic strata penetrated are comprised of the following in descending order: Paintbrush Tuff (Tiva Canyon Member, Yucca Mountain Member, bedded tuff, Pah Canyon Member, and Topopah Spring Member), tuffaceous beds of Calico Hills, Crater Flat Tuff (Prow Pass Member, Bullfrog Member, and Tram unit), lava and flow breccia (rhyodacitic), tuff of Lithic Ridge, bedded and ash-flow tuff, lava and flow breccia (rhyolitic, quartz latitic, and dacitic), bedded tuff, conglomerate and ash-flow tuff, and older tuffs of USW G-2. Comparison of unit thicknesses at USW G-2 to unit thicknesses at previously drilled holes at Yucca Mountain indicate the following: (1) thickening of the Paintbrush Tuff members and tuffaceous beds of Calico Hills toward the northern part of Yucca Mountain; (2) thickening of the Prow Pass Member but thinning of the Bullfrog Member and Tram unit; (3) thinning of the tuff of Lithic Ridge; (4) presence of approximately 280 m of lava and flow breccia not previously penetrated by any drill hole; and (5) presence of an ash-flow tuff unit at the bottom of the drill hole not previously intersected, apparently the oldest unit penetrated at Yucca Mountain to date. Petrographic features of some of the units include: (1) decrease in quartz and K-feldspar and increases in biotite and plagioclase with depth in the tuffaceous beds of Calico Hills; (2) an increase in quartz phenocrysts from the top to the bottom members of the Crater Flat Tuff; (3) a low quartz content in the tuff of Lithic Ridge, suggesting tapping of the magma chamber at quartz-poor levels; (4) a change in zeolitic alteration from heulandite to clinoptilolite to mordenite with increasing depth; (5) lavas characterized by a rhyolitic

  11. Functional Aspects of the Solution Structure and Dynamics of PAF, a Highly Stable Antifungal Protein from Penicillium chrysogenum

    Science.gov (United States)

    Batta, Gyula; Barna, Teréz; Gáspári, Zoltán; Sándor, Szabolcs; Kövér, Katalin E.; Binder, Ulrike; Sarg, Bettina; Kaiserer, Lydia; Chhillar, Anil Kumar; Eigentler, Andrea; Leiter, Éva; Hegedüs, Nikoletta; Pócsi, István; Lindner, Herbert; Marx, Florentine

    2015-01-01

    Summary PAF is a promising antimycotic without toxic effects on mammalian cells and therefore may be a drug candidate against the often lethal Aspergillus infections in human. The pathogenesis of PAF on sensitive fungi involves G-protein coupled signaling followed by apoptosis. Here, the solution structure of this small, cationic, antifungal protein from Penicillium chrysogenum is determined by solution NMR. We proved that PAF belongs to the SCOP fold class of its closest homologue AFP from Aspergillus giganteus. PAF comprises five β—strands forming two orthogonally packed β—sheets sharing a common interface. The ambiguity in the assignment of two disulfide bonds of three was investigated by NMR dynamics combined with restrained molecular dynamics calculations. The clue could not be resolved: two ensembles with different disulfide patterns and the one with no S-S bond exhibit essentially the same fold. 15N relaxation dispersion and interference experiments did not reveal disulfide bond rearrangements via slow exchange. The measured order parameters and the 3.0 ns correlation time is appropriate for a compact monomeric protein of this size. We demonstrated by site-directed mutagenesis that the highly conserved and positively charged lysine-rich domain region on the surface enhances the toxicity of PAF. However, the efficacy of the OB fold is reduced in PAF compared to AFP, due to less solvent exposed aromatic regions explaining the absence of chitobiose binding. The present work lends further support to the understanding of the documented substantial differences between the mode of action of two highly homologous antifungal proteins. PMID:19459942

  12. Crystal structure of mouse thymidylate synthase in tertiary complex with dUMP and raltitrexed reveals N-terminus architecture and two different active site conformations.

    Science.gov (United States)

    Dowierciał, Anna; Wilk, Piotr; Rypniewski, Wojciech; Rode, Wojciech; Jarmuła, Adam

    2014-01-01

    The crystal structure of mouse thymidylate synthase (mTS) in complex with substrate dUMP and antifolate inhibitor Raltitrexed is reported. The structure reveals, for the first time in the group of mammalian TS structures, a well-ordered segment of 13 N-terminal amino acids, whose ordered conformation is stabilized due to specific crystal packing. The structure consists of two homodimers, differing in conformation, one being more closed (dimer AB) and thus supporting tighter binding of ligands, and the other being more open (dimer CD) and thus allowing weaker binding of ligands. This difference indicates an asymmetrical effect of the binding of Raltitrexed to two independent mTS molecules. Conformational changes leading to a ligand-induced closing of the active site cleft are observed by comparing the crystal structures of mTS in three different states along the catalytic pathway: ligand-free, dUMP-bound, and dUMP- and Raltitrexed-bound. Possible interaction routes between hydrophobic residues of the mTS protein N-terminal segment and the active site are also discussed.

  13. Tertiary classes–after Chern-Simons theory

    Indian Academy of Sciences (India)

    J.N. Iyer Institute of Mathematical Sciences Chennai, India

    2013-11-08

    Nov 8, 2013 ... Euler characteristic class. In early twentieth century, the notion of local product structure, i.e. fiber spaces and their generalizations appeared, in the study of topological spaces (with additional structures). J.N. Iyer. IMSc, Chennai. Tertiary classes–after Chern-Simons theory ...

  14. Self-contacts in Asx and Glx residues of high-resolution protein structures: role of local environment and tertiary interactions.

    Science.gov (United States)

    Pal, Tuhin Kumar; Sankararamakrishnan, Ramasubbu

    2008-08-01

    In protein structures, side-chains of asparagine and aspartic acid (Asx) and glutamine and glutamic acid (Glx) can approach their own backbone nitrogen or carbonyl group. We have systematically analyzed intra-residue contacts in Asx and Glx residues and their secondary structure preferences in two different datasets consisting of 500 and 1506 high-resolution structures. Intra-residue contact in an Asx/Glx residue between the heavy atoms of side-chain and main-chain functional groups of the same residue was investigated irrespective of whether such contacts are due to hydrogen bonding or not. Our search yielded 563 and 1462 cases of self-contacting Asx and Glx residues from the two datasets. Two important observations have been made in this analysis. First, self-contacts involving side-chain oxygen and backbone nitrogen atoms in majority of Asx residues are not due to hydrogen bonds. In the second instance, surprisingly, side-chain and backbone carbonyl oxygens of a significant number of Asx and Glx residues approach each other. For a wide-range of accessible surface areas, self-contacting residues are surrounded by less number of polar groups compared to all other Asx/Glx residues. In buried and partially buried regions, side-chain and main-chain functional groups of these residues together participate in simultaneous interactions with the available polar groups or water molecules. Asx/Glx residues with self-contacts are rarely observed in the middle of an alpha-helix or a beta-strand. Asx/Glx side-chain having contact with its own backbone nitrogen shows different capping preferences compared to those having contact with its backbone oxygen. Examples of proteins with multiple self-contacting Asx/Glx residues are found. We speculate that mutation of a self-contacting residue in the buried or partially buried region of a protein will destabilize the structure. The results of this analysis will help in engineering protein structures and site-directed mutagenesis

  15. Application of nitrogen and carbon stable isotopes (δ(15N and δ(13C to quantify food chain length and trophic structure.

    Directory of Open Access Journals (Sweden)

    Matthew J Perkins

    Full Text Available Increasingly, stable isotope ratios of nitrogen (δ(15N and carbon (δ(13C are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR using δ(15N, and carbon range (CR using δ(13C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in δ(15N or δ(13C from source to consumer between trophic levels and among food chains. δ(15N discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰, and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. δ(13C discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of δ(13C as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority

  16. Application of Nitrogen and Carbon Stable Isotopes (δ15N and δ13C) to Quantify Food Chain Length and Trophic Structure

    Science.gov (United States)

    Perkins, Matthew J.; McDonald, Robbie A.; van Veen, F. J. Frank; Kelly, Simon D.; Rees, Gareth; Bearhop, Stuart

    2014-01-01

    Increasingly, stable isotope ratios of nitrogen (δ15N) and carbon (δ13C) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using δ15N, and carbon range (CR) using δ13C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in δ15N or δ13C from source to consumer) between trophic levels and among food chains. δ15N discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰), and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. δ13C discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of δ13C as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority of ecological systems

  17. Application of nitrogen and carbon stable isotopes (δ(15)N and δ(13)C) to quantify food chain length and trophic structure.

    Science.gov (United States)

    Perkins, Matthew J; McDonald, Robbie A; van Veen, F J Frank; Kelly, Simon D; Rees, Gareth; Bearhop, Stuart

    2014-01-01

    Increasingly, stable isotope ratios of nitrogen (δ(15)N) and carbon (δ(13)C) are used to quantify trophic structure, though relatively few studies have tested accuracy of isotopic structural measures. For laboratory-raised and wild-collected plant-invertebrate food chains spanning four trophic levels we estimated nitrogen range (NR) using δ(15)N, and carbon range (CR) using δ(13)C, which are used to quantify food chain length and breadth of trophic resources respectively. Across a range of known food chain lengths we examined how NR and CR changed within and between food chains. Our isotopic estimates of structure are robust because they were calculated using resampling procedures that propagate variance in sample means through to quantified uncertainty in final estimates. To identify origins of uncertainty in estimates of NR and CR, we additionally examined variation in discrimination (which is change in δ(15)N or δ(13)C from source to consumer) between trophic levels and among food chains. δ(15)N discrimination showed significant enrichment, while variation in enrichment was species and system specific, ranged broadly (1.4‰ to 3.3‰), and importantly, propagated variation to subsequent estimates of NR. However, NR proved robust to such variation and distinguished food chain length well, though some overlap between longer food chains infers a need for awareness of such limitations. δ(13)C discrimination was inconsistent; generally no change or small significant enrichment was observed. Consequently, estimates of CR changed little with increasing food chain length, showing the potential utility of δ(13)C as a tracer of energy pathways. This study serves as a robust test of isotopic quantification of food chain structure, and given global estimates of aquatic food chains approximate four trophic levels while many food chains include invertebrates, our use of four trophic level plant-invertebrate food chains makes our findings relevant for a majority of

  18. Towards tricking a pathogen's protease into fighting infection: the 3D structure of a stable circularly permuted onconase variant cleavedby HIV-1 protease.

    Directory of Open Access Journals (Sweden)

    Mariona Callís

    Full Text Available Onconase® is a highly cytotoxic amphibian homolog of Ribonuclease A. Here, we describe the construction of circularly permuted Onconase® variants by connecting the N- and C-termini of this enzyme with amino acid residues that are recognized and cleaved by the human immunodeficiency virus protease. Uncleaved circularly permuted Onconase® variants are unusually stable, non-cytotoxic and can internalize in human T-lymphocyte Jurkat cells. The structure, stability and dynamics of an intact and a cleaved circularly permuted Onconase® variant were determined by Nuclear Magnetic Resonance spectroscopy and provide valuable insight into the changes in catalytic efficiency caused by the cleavage. The understanding of the structural environment and the dynamics of the activation process represents a first step toward the development of more effective drugs for the treatment of diseases related to pathogens expressing a specific protease. By taking advantage of the protease's activity to initiate a cytotoxic cascade, this approach is thought to be less susceptible to known resistance mechanisms.

  19. Differential effects of CSF-1R D802V and KIT D816V homologous mutations on receptor tertiary structure and allosteric communication.

    Directory of Open Access Journals (Sweden)

    Priscila Da Silva Figueiredo Celestino Gomes

    Full Text Available The colony stimulating factor-1 receptor (CSF-1R and the stem cell factor receptor KIT, type III receptor tyrosine kinases (RTKs, are important mediators of signal transduction. The normal functions of these receptors can be compromised by gain-of-function mutations associated with different physiopatological impacts. Whereas KIT D816V/H mutation is a well-characterized oncogenic event and principal cause of systemic mastocytosis, the homologous CSF-1R D802V has not been identified in human cancers. The KIT D816V oncogenic mutation triggers resistance to the RTK inhibitor Imatinib used as first line treatment against chronic myeloid leukemia and gastrointestinal tumors. CSF-1R is also sensitive to Imatinib and this sensitivity is altered by mutation D802V. Previous in silico characterization of the D816V mutation in KIT evidenced that the mutation caused a structure reorganization of the juxtamembrane region (JMR and facilitated its departure from the kinase domain (KD. In this study, we showed that the equivalent CSF-1R D802V mutation does not promote such structural effects on the JMR despite of a reduction on some key H-bonds interactions controlling the JMR binding to the KD. In addition, this mutation disrupts the allosteric communication between two essential regulatory fragments of the receptors, the JMR and the A-loop. Nevertheless, the mutation-induced shift towards an active conformation observed in KIT D816V is not observed in CSF-1R D802V. The distinct impact of equivalent mutation in two homologous RTKs could be associated with the sequence difference between both receptors in the native form, particularly in the JMR region. A local mutation-induced perturbation on the A-loop structure observed in both receptors indicates the stabilization of an inactive non-inhibited form, which Imatinib cannot bind.

  20. Constraining the Late Mesozoic and Early Tertiary Tectonic Evolution of Southern Mexico: Structure and Deformation History of the Tierra Caliente Region.

    Science.gov (United States)

    Cabral-Cano; Draper; Lang; Harrison

    2000-07-01

    We analyze the structure and assess the deformation history of the Tierra Caliente Metamorphic Complex (TCMC) of southern Mexico, where Laramide accretion of exotic terranes is in debate. The TCMC consists of a south-plunging antiform fault that is bounded on both its eastern and western flanks. Tierra Caliente Metamorphic Complex rocks show at least two phases of compressional deformation. The first and most prominent records a mean tectonic transport direction of 068 degrees. This phase is responsible for east-verging asymmetrical folding and thrusting of both metamorphic and superjacent sedimentary rocks. The second phase has an average transport direction of 232 degrees and is restricted to the western portion of the TCMC. A third phase is responsible for normal faulting. Lack of discernible deformation before Late Cretaceous time indicates that the main deformation phase is coincident with Laramide orogenesis elsewhere in the North American Cordillera. The stratigraphy, structure, and deformational history of the TCMC do not require accretion of exotic terranes. We explain the Mesozoic tectonostratigraphic evolution of the TCMC in terms of deposition and deformation of Mesozoic volcanic and sedimentary strata over the attenuated continental crust of the North American plate.

  1. Tertiary climatic fluctuations and methods of analysis of tertiary floras

    Science.gov (United States)

    Wolfe, J.A.

    1971-01-01

    On theoretical grounds, an analysis of the physiognomy of a Tertiary leaf assemblage is more direct and reliable than a circuitous floristic analysis in assigning thermal regimes to fossil assemblages. Using primarily foliar physiognomy and secondarily floristic composition, it can be shown that: (1) some middle latitude Tertiary assemblages probably lived under meteoroligically tropical climates; (2) a major and rapid climatic deterioration occurred in the Oligocene; and (3) a major climatic fluctuation probably occurred in the Late Eocene. These analyses thus substantiate the conclusions of several other paleobotanists regarding climatic fluctuations. Recent criticisms of these analyses are shown to be invalid and to be based largely on misinterpretations. ?? 1971.

  2. Inducible tertiary lymphoid structures, autoimmunity and exocrine dysfunction in a novel model of salivary gland inflammation in C57BL/6 mice§

    Science.gov (United States)

    Bombardieri, Michele; Barone, Francesca; Lucchesi, Davide; Nayar, Saba; van den Berg, Wim B; Proctor, Gordon; Buckley, Christopher D; Pitzalis, Costantino

    2012-01-01

    Salivary glands in patients with Sjögren’s syndrome (SS) develop ectopic lymphoid structures (ELS) characterized by B/T cell compartmentalization, the formation of high endothelial venules (HEV), follicular dendritic cell networks (FDCs), functional B cell activation with expression of activation-induced cytidine deaminase (AID) as well as local differentiation of autoreactive plasma cells. The mechanisms triggering ELS formation, autoimmunity and exocrine dysfunction in SS are largely unknown. Here we present a novel model of inducible ectopic lymphoid tissue formation, breach of humoral self-tolerance and salivary hypofunction following delivery of a replication-deficient adenovirus-5 (AdV5) in submandibular glands of C57BL/6 mice through retrograde excretory duct cannulation. In this model, inflammation rapidly and consistently evolves from diffuse infiltration towards the development of SS-like periductal lymphoid aggregates within 2 weeks from AdV delivery. These infiltrates progressively acquire ELS features and support functional GL7+/AID+ germinal centers. Formation of ELS is preceded by ectopic expression of lymphoid chemokines CXCL13, CCL19 and lymphotoxin-β and is associated with development of anti-nuclear antibodies in up to 75% of mice. Finally, reduction in salivary flow was observed over 3 weeks post AdV infection consistent with exocrine gland dysfunction as a consequence of the inflammatory response. This novel model has the potential to unravel the cellular and molecular mechanisms regulating ELS formation and their role in exocrine dysfunction and autoimmunity in SS. PMID:22942425

  3. Inducible tertiary lymphoid structures, autoimmunity, and exocrine dysfunction in a novel model of salivary gland inflammation in C57BL/6 mice.

    Science.gov (United States)

    Bombardieri, Michele; Barone, Francesca; Lucchesi, Davide; Nayar, Saba; van den Berg, Wim B; Proctor, Gordon; Buckley, Christopher D; Pitzalis, Costantino

    2012-10-01

    Salivary glands in patients with Sjögren's syndrome (SS) develop ectopic lymphoid structures (ELS) characterized by B/T cell compartmentalization, the formation of high endothelial venules, follicular dendritic cell networks, functional B cell activation with expression of activation-induced cytidine deaminase, as well as local differentiation of autoreactive plasma cells. The mechanisms that trigger ELS formation, autoimmunity, and exocrine dysfunction in SS are largely unknown. In this article, we present a novel model of inducible ectopic lymphoid tissue formation, breach of humoral self-tolerance, and salivary hypofunction after delivery of a replication-deficient adenovirus-5 in submandibular glands of C57BL/6 mice through retrograde excretory duct cannulation. In this model, inflammation rapidly and consistently evolves from diffuse infiltration toward the development of SS-like periductal lymphoid aggregates within 2 wk from AdV delivery. These infiltrates progressively acquire ELS features and support functional GL7(+)/activation-induced cytidine deaminase(+) germinal centers. Formation of ELS is preceded by ectopic expression of lymphoid chemokines CXCL13, CCL19, and lymphotoxin-β, and is associated with development of anti-nuclear Abs in up to 75% of mice. Finally, reduction in salivary flow was observed over 3 wk post-AdV infection, consistent with exocrine gland dysfunction as a consequence of the inflammatory response. This novel model has the potential to unravel the cellular and molecular mechanisms that regulate ELS formation and their role in exocrine dysfunction and autoimmunity in SS.

  4. Efficient and stable, structurally inverted poly(3-hexylthiopen): [6,6]-phenyl-C61-butyric acid methyl ester heterojunction solar cells with fibrous like poly(3-hexylthiopen)

    International Nuclear Information System (INIS)

    Bandara, Jayasundera; Shankar, Karthik; Grimes, Craig A.; Thelakkat, Mukundan

    2011-01-01

    We investigated an inverted organic photovoltaic device structure in which a densely packed ∼ 100 nm thin TiO 2 layer on fluorine doped conducting glass serves as anode and poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)/Au layer on top of the active layer serves as cathode. The active layer is comprised of a blend of poly(3-hexylthiopene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The rectification behavior of such a device is improved significantly and injection losses are minimized compared to devices without any compact TiO 2 layer. Moreover, nanostructured P3HT active layer was achieved in-situ by spin coating concentrated pure P3HT and P3HT:PCBM blend and solar cell performances on thickness of the active layer were also investigated. For the inverted solar cells constructed with different concentrations of P3HT and PCBM keeping the P3HT:PCBM ratio 1:0.8 (wt.%), the highest short circuit current and efficiency was observed when the P3HT and PCBM concentration was equal to 1.5 (wt.%) and 1.2 (wt.%) respectively. This leads to highly stable and reproducible power conversion efficiency above 3.7% at 100 mW/cm 2 light intensity under AM 1.5 conditions.

  5. Synthesis and X-ray Crystal Structure of a Stable cis-1,2-bis(diphenylphosphinoethene Monodentate Thiolate Platinum Complex and TGA Studies of its Precursors

    Directory of Open Access Journals (Sweden)

    Vaz Rodrigo H.

    2002-01-01

    Full Text Available The stable Pt(II complex [Pt(SPh2(dppen (4, (dppen, Ph2PCH=CHPPh2 was obtained from [PtCl(SPh2(SnPh3cod] (1 (cod = 1,5-cyclooctadiene by reductive elimination reaction of SnClPh3 and substitution of the cod ligand by the diphosphine, albeit in low yields. Yields of 80% were obtained when [Pt(SPh2cod] (3 was used as the starting material instead. The viability of these reactions was suggested by a TG study, performed on the starting materials. Complex 4 was characterized by multinuclear NMR (195Pt, 31P, ¹H and 13C and IR spectroscopies and elemental analysis. The molecular structure, solved by an X-ray diffraction study, exhibted a slightly distorted square-planar geometry and short C=C and Pt-P bond distances which were interpreted in terms of a p interaction between the double bond and the metal-ligand bond, as observed for other diphosphine compounds described previously.

  6. Synergetic effects of solution-processable fluorinated graphene and PEDOT as a hole-transporting layer for highly efficient and stable normal-structure perovskite solar cells.

    Science.gov (United States)

    Yu, Jae-Hun; Lee, Cheol-Ho; Joh, Han-Ik; Yeo, Jun-Seok; Na, Seok-In

    2017-11-16

    We demonstrate that a bi-interlayer consisting of water-free poly(3,4-ethylenedioxythiophene) (PEDOT) and fluorinated reduced graphene oxide (FrGO) noticeably enhances the efficiency and the stability of the normal-structure perovskite solar cells (PeSCs). With simple and low temperature solution-processing, the PeSC employing the PEDOT + FrGO interlayer exhibits a significantly improved power conversion efficiency (PCE) of 14.9%. Comprehensive investigations indicate that the enhanced PCE is mostly attributed to the retarded recombination in the devices. The minimized recombination phenomena are related to the interfacial dipoles at the PEDOT/FrGO interface, which facilitates the electron-blocking and the higher built-in potential in the devices. Furthermore, the PEDOT + FrGO device shows a better stability by maintaining 70% of the initial PCE over the 30 days exposure to ambient conditions. This is because the more hydrophobic graphitic sheets of the FrGO on the PEDOT further protect the perovskite films from oxygen/water penetration. Consequently, the introduction of composite interfacial layers including graphene derivatives can be an effective and versatile strategy for high-performing, stable, and cost-effective PeSCs.

  7. Evidence of stable genetic structure across a remote island archipelago through self-recruitment in a widely dispersed coral reef fish

    KAUST Repository

    Priest, Mark

    2012-11-19

    We used microsatellite markers to assess the population genetic structure of the scribbled rabbitfish Siganus spinus in the western Pacific. This species is a culturally important food fish in the Mariana Archipelago and subject to high fishing pressure. Our primary hypothesis was to test whether the individuals resident in the southern Mariana Island chain were genetically distinct and hence should be managed as discrete stocks. In addition to spatial sampling of adults, newly-settled individuals were sampled on Guam over four recruitment events to assess the temporal stability of the observed spatial patterns, and evidence of self-recruitment. We found significant genetic structure in S. spinus across the western Pacific, with Bayesian analyses revealing three genetically distinct clusters: the southernMariana Islands, east Micronesia, and the west Pacific; with the southern Mariana Islands beingmore strongly differentiated fromthe rest of the region. Analyses of temporal samples from Guam indicated the southern Mariana cluster was stable over time, with no genetic differentiation between adults versus recruits, or between samples collected across four separate recruitment events spanning 11 months. Subsequent assignment tests indicated seven recruits had self-recruited from within the Southern Mariana Islands population. Our results confirm the relative isolation of the southern Mariana Islands population and highlight how local processes can act to isolate populations that, by virtue of their broad-scale distribution, have been subject to traditionally high gene flows. Our results add to a growing consensus that self-recruitment is a highly significant influence on the population dynamics of tropical reef fish. 2012 The Authors. Ecology and Evolution published by Blackwell Publishing Ltd.

  8. Why Do Tertiary Education Graduates Regret Their Study Program? A Comparison between Spain and the Netherlands

    Science.gov (United States)

    Kucel, Aleksander; Vilalta-Bufi, Montserrat

    2013-01-01

    In this paper we investigate the determinants of regret of study program for tertiary education graduates in Spain and the Netherlands. These two countries differ in their educational system in terms of the tracking structure in their secondary education and the strength of their education-labor market linkages in tertiary education. Therefore, by…

  9. Tertiary architecture of the Oceanobacillus iheyensis group II intron

    Energy Technology Data Exchange (ETDEWEB)

    Toor, Navtej; Keating, Kevin S.; Fedorova, Olga; Rajashankar, Kanagalaghatta; Wang, Jimin; Pyle, Anna Marie (Yale); (Cornell)

    2010-05-03

    Group II introns are large ribozymes that act as self-splicing and retrotransposable RNA molecules. They are of great interest because of their potential evolutionary relationship to the eukaryotic spliceosome, their continued influence on the organization of many genomes in bacteria and eukaryotes, and their potential utility as tools for gene therapy and biotechnology. One of the most interesting features of group II introns is their relative lack of nucleobase conservation and covariation, which has long suggested that group II intron structures are stabilized by numerous unusual tertiary interactions and backbone-mediated contacts. Here, we provide a detailed description of the tertiary interaction networks within the Oceanobacillus iheyensis group IIC intron, for which a crystal structure was recently solved to 3.1 {angstrom} resolution. The structure can be described as a set of several intricately constructed tertiary interaction nodes, each of which contains a core of extended stacking networks and elaborate motifs. Many of these nodes are surrounded by a web of ribose zippers, which appear to further stabilize local structure. As predicted from biochemical and genetic studies, the group II intron provides a wealth of new information on strategies for RNA folding and tertiary structural organization.

  10. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  11. Discovery of Tertiary Sulfonamides as Potent Liver X Receptor Antagonists

    Energy Technology Data Exchange (ETDEWEB)

    Zuercher, William J.; Buckholz†, Richard G.; Campobasso, Nino; Collins, Jon L.; Galardi, Cristin M.; Gampe, Robert T.; Hyatt, Stephen M.; Merrihew, Susan L.; Moore, John T.; Oplinger, Jeffrey A.; Reid, Paul R.; Spearing, Paul K.; Stanley, Thomas B.; Stewart, Eugene L.; Willson, Timothy M. (GSKNC)

    2010-08-12

    Tertiary sulfonamides were identified in a HTS as dual liver X receptor (LXR, NR1H2, and NR1H3) ligands, and the binding affinity of the series was increased through iterative analogue synthesis. A ligand-bound cocrystal structure was determined which elucidated key interactions for high binding affinity. Further characterization of the tertiary sulfonamide series led to the identification of high affinity LXR antagonists. GSK2033 (17) is the first potent cell-active LXR antagonist described to date. 17 may be a useful chemical probe to explore the cell biology of this orphan nuclear receptor.

  12. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  13. Parathyroid carcinoma in tertiary hyperparathyroidism.

    Science.gov (United States)

    Kim, Byung Seup; Ryu, Han Suk; Kang, Kyung Ho; Park, Sung Jun

    2016-10-01

    Parathyroid carcinoma is a rare disease of unknown etiology. This study presents a case of parathyroid carcinoma in a patient with tertiary hyperparathyroidism. Despite a successful kidney transplantation, the intact parathyroid hormone (iPTH) level of the patient was elevated consistently and could not be controlled by medical therapy. Due to the development of tertiary hyperparathyroidism with bone pain and osteoporosis, subtotal parathyroidectomy was performed 4 months after the kidney transplantation. Histological evaluation revealed that one of four parathyroid lesions was a parathyroid carcinoma, while the others were diffuse hyperplasia. Postoperative laboratory studies indicated a decreased level of iPTH. A positron emission tomography-computed tomography performed 6 months after the operation revealed no evidence of local recurrence or distant metastasis. Copyright © 2013. Published by Elsevier Taiwan.

  14. 87 Sr/86 Sr anomalies in Late Cretaceous–Early Tertiary strata of ...

    Indian Academy of Sciences (India)

    The Ariyalur–Pondicherry sub-basin of the Cauvery basin comprises a near complete stratigraphic record of Upper Cretaceous–Lower Tertiary periods. Earlier studies have documented variations of clay mineral assemblages, change in microtexture of siliciclasts and many geochemical and stable isotopic anomalies far ...

  15. Herbivory of Omnivorous Fish Shapes the Food Web Structure of a Chinese Tropical Eutrophic Lake: Evidence from Stable Isotope and Fish Gut Content Analyses

    Directory of Open Access Journals (Sweden)

    Jian Gao

    2017-01-01

    Full Text Available Studies suggest that, unlike the situation in temperate lakes, high biomasses of omnivorous fish are maintained in subtropical and tropical lakes when they shift from a turbid phytoplankton-dominated state to a clear water macrophyte-dominated state, and the predation pressure on large-bodied zooplankton therefore remains high. Whether this reflects a higher degree of herbivory in warm lakes than in temperate lakes is debatable. We combined food web studies using stable isotopes with gut content analyses of the most dominant fish species to elucidate similarities and differences in food web structure between a clear water macrophyte-dominated basin (MDB and a turbid phytoplankton-dominated basin (PDB of Huizhou West Lake, a shallow tropical Chinese lake. The δ13C–δ15N biplot of fish and invertebrates revealed community-wide differences in isotope-based metrics of the food webs between MDB and PDB. The range of consumer δ15N (NR was lower in MDB than in PDB, indicating shorter food web length in MDB. The mean nearest neighbor distance (MNND and standard deviation around MNND (SDNND were higher in MDB than in PDB, showing a markedly low fish trophic overlap and a more uneven packing of species in niches in MDB than in PDB. The range of fish δ13C (CR of consumers was more extensive in MDB than in PDB, indicating a wider feeding range for fish in MDB. Mixing model results showed that macrophytes and associated periphyton constituted a large fraction of basal production sources for the fish in MDB, while particulate organic matter (POM contributed a large fraction in PDB. In MDB, the diet of the dominant fish species, crucian carp (Carassius carassius, consisted mainly of vegetal matter (macrophytes and periphyton and zooplankton, while detritus was the most important food item in PDB. Our results suggest that carbon from macrophytes with associated periphyton may constitute an important food resource for omnivorous fish, and this may strongly

  16. Stable isotopes and amphibole chemistry on hydrothermally altered granitoids in the North Chilean Precordillera: a limited role for meteoric water?

    NARCIS (Netherlands)

    Agemar, T.; Wörner, G.; Heumann, A.

    1999-01-01

    Whole rock and mineral stable isotope and microprobe analyses are presented from granitoids of the North Chilean Precordillera. The Cretaceous to Tertiary plutonic rocks contain important ore deposits and frequently display compositional and textural evidence of hydrothermal alteration even in

  17. Paleomagnetism of early Tertiary Alaska Peninsula rocks and implications for docking of peninsular terrane

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, J.W.; Levinson, R.A.; Van Alstine, D.R.

    1985-04-01

    In order to refine the tectonic history of the peninsular terrane, Alaska, 22 sites (averaging 10 samples/site) in Paleogene Tertiary volcanic and sedimentary formations were sampled in the vicinity of Chignik, on the Pacific side of the Alaska Peninsula. Ten of the sites were drilled in the early Oligocene Meshik volcanics, ranging from andesite to basalt, and the other twelve sites were drilled in the late Eocene Tolstoi Formation sediments. Nine of the volcanic sites yielded stable R and/or N characteristic magnetization. Virtually no fine-grained, interbedded sediments occur with the Meshik volcanics at the sample sites, thus making reliable paleohorizontal determinations difficult. Although flow attitudes were tentatively used, it became rapidly apparent that problems of initial dip were insurmountable. As a result, all volcanic sites were considered unreliable for determining a meaningful paleomagnetic inclination. Upon thermal demagnetization, five of the sedimentary sites were judged stable. The mode of the paleomagnetic direction was calculated, D/I = 349.8/75.3(..beta..95 = 8.5), indicating no significant rotation. Uncertainties in structural corrections, however, may render only the inclination meaningful, which, from McFadden statistics yields, I = 75.9, ..cap alpha..95 = 7.9, corresponding to a paleolatitude of 63.3/sup 0/. This paleolatitude agrees with the expected value for the North American craton at 40 m.y. B.P., implying that the peninsular terrane had docked at at least that time.

  18. Tuning the Structure and Ionic Interactions in a Thermochemically Stable Hybrid Layered Titanate-Based Nanocomposite for High Temperature Solid Lubrication

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.; Lubbers, Roy; Veldhuis, Sjoerd; Narygina, Olga; Lette, Walter; Schipper, Dirk J.; ten Elshof, Johan E.

    2017-01-01

    Solid inorganic lubricants are thermally stable but they are often limited by their lack of deformability, while organic lubricants have limitations in terms of thermal stability. In this study, a novel solid organic–inorganic nanocomposite lubricant that synergistically combines the

  19. Eutectic Gallium-Indium (EGaIn) : A Liquid Metal Alloy for the Formation of Stable Structures in Microchannels at Room Temperature

    NARCIS (Netherlands)

    Dickey, Michael D.; Chiechi, Ryan C.; Larsen, Ryan J.; Weiss, Emily A.; Weitz, David A.; Whitesides, George M.

    2008-01-01

    This paper describes the rheological behavior of the liquid metal eutectic gallium-indium (EGaIn) as it is injected into microfluidic channels to form stable microstructures of liquid metal. EGaIn is well-suited for this application because of its rheological properties at room temperature: it

  20. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  1. [Decomposition model of energy-related carbon emissions in tertiary industry for China].

    Science.gov (United States)

    Lu, Yuan-Qing; Shi, Jun

    2012-07-01

    Tertiary industry has been developed in recent years. And it is very important to find the factors influenced the energy-related carbon emissions in tertiary industry. A decomposition model of energy-related carbon emissions for China is set up by adopting logarithmic mean weight Divisia method based on the identity of carbon emissions. The model is adopted to analyze the influence of energy structure, energy efficiency, tertiary industry structure and economic output to energy-related carbon emissions in China from 2000 to 2009. Results show that the contribution rate of economic output and energy structure to energy-related carbon emissions increases year by year. Either is the contribution rate of energy efficiency or the tertiary industry restraining to energy-related carbon emissions. However, the restrain effect is weakening.

  2. Duplex structural differences and not 2′-hydroxyls explain the more stable binding of HIV-reverse transcriptase to RNA-DNA versus DNA-DNA

    OpenAIRE

    Olimpo, Jeffrey T.; DeStefano, Jeffrey J.

    2010-01-01

    Human immunodeficiency virus reverse transcriptase (HIV-RT) binds more stably in binary complexes with RNA–DNA versus DNA–DNA. Current results indicate that only the -2 and -4 RNA nucleotides (-1 hybridized to the 3′ recessed DNA base) are required for stable binding to RNA–DNA, and even a single RNA nucleotide conferred significantly greater stability than DNA–DNA. Replacing 2′- hydroxyls on pivotal RNA bases with 2′-O-methyls did not affect stability, indicating that interactions between hy...

  3. Assessing Strategies for Reducing HIV/AIDS Scourge among Fitness and Recreation Student Clientele of EDO State Tertiary Institutions

    Science.gov (United States)

    Okunbor, A. O.; Agwubike, E. O.

    2007-01-01

    The study assessed strategies for reducing the HIV/AIDS scourge among fitness and recreation student clientele in Edo State tertiary institutions. A total of 192 males and 88 females participated in the study. The participants were drawn from five tertiary institutions and a self-structured questionnaire was used in collecting data for the study.…

  4. Thermodynamic properties of donor-acceptor complexes of tertiary amine with aryl ketones in hexane medium

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, R. [Department of Physics, The New College, Chennai 600 014 (India); Jayakumar, S. [Department of Physics, R.K.M. Vivekananda College, Chennai 600 004 (India); Kannappan, V., E-mail: vkannappan@hotmail.com [Department of Chemistry, Presidency College, Chennai 600 005 (India)

    2012-05-20

    Highlights: Black-Right-Pointing-Pointer Ultrasonic scan is carried out on ternary systems of aromatic tertiary amine and three aryl ketones. Black-Right-Pointing-Pointer Formation of CT complexes is found between tertiary amine with aryl ketones. Black-Right-Pointing-Pointer Stability constant values are computed by ultrasonic and spectral methods are compared. Black-Right-Pointing-Pointer The trend in the 'K' suggests that substituents in ketones influence the stabilities of these complexes. Black-Right-Pointing-Pointer The thermodynamic parameters suggest CT interaction is exothermic and the complexes are thermodynamically stable. - The thermodynamic stability of complexes formed between N,N-dimethylaniline (DMANI) and three ketones, namely, acetophenone (ACP), 4-chloroactophenone (ClACP) and 4-methylacetophenone (MACP) in n-hexane is extensively investigated by spectral and ultrasonic methods. The ultrasound scan was carried out in the temperature range 208.15-313.15 K and at atmospheric pressure on solutions containing equimolar concentrations of components ranging from 0.025 to 0.2 M. The existence of solute-solute interactions has also been confirmed through electronic absorption spectra analyzed with Benesi-Hildebrand theory at 303.15 K. The stability constants of the donor-acceptor complexes determined both by spectroscopic and ultrasonic methods are comparable and follow similar trends. The trend in the formation constants is discussed with structures of the components. The thermodynamic behavior of the systems was explained through the computed values of the free energy ({Delta}G), enthalpy ({Delta}H) and entropy ({Delta}S) changes for complex formation are computed and discussed.

  5. Thermodynamic properties of donor–acceptor complexes of tertiary amine with aryl ketones in hexane medium

    International Nuclear Information System (INIS)

    Kumar, R.; Jayakumar, S.; Kannappan, V.

    2012-01-01

    Highlights: ► Ultrasonic scan is carried out on ternary systems of aromatic tertiary amine and three aryl ketones. ► Formation of CT complexes is found between tertiary amine with aryl ketones. ► Stability constant values are computed by ultrasonic and spectral methods are compared. ► The trend in the ‘K’ suggests that substituents in ketones influence the stabilities of these complexes. ► The thermodynamic parameters suggest CT interaction is exothermic and the complexes are thermodynamically stable. - The thermodynamic stability of complexes formed between N,N-dimethylaniline (DMANI) and three ketones, namely, acetophenone (ACP), 4-chloroactophenone (ClACP) and 4-methylacetophenone (MACP) in n-hexane is extensively investigated by spectral and ultrasonic methods. The ultrasound scan was carried out in the temperature range 208.15–313.15 K and at atmospheric pressure on solutions containing equimolar concentrations of components ranging from 0.025 to 0.2 M. The existence of solute–solute interactions has also been confirmed through electronic absorption spectra analyzed with Benesi-Hildebrand theory at 303.15 K. The stability constants of the donor–acceptor complexes determined both by spectroscopic and ultrasonic methods are comparable and follow similar trends. The trend in the formation constants is discussed with structures of the components. The thermodynamic behavior of the systems was explained through the computed values of the free energy (ΔG), enthalpy (ΔH) and entropy (ΔS) changes for complex formation are computed and discussed.

  6. Learning Enhancement in Tertiary Institutions Using Mobile ...

    African Journals Online (AJOL)

    2012-12-01

    Dec 1, 2012 ... Abstract. The educational standard in tertiary institutions has witnessed a down turn in the area of teaching and learning. This paper links this down fall to traditional face-to-face educational model that is still by far the dominant mode of education and learning in tertiary institutions. In addition to identifying ...

  7. Tertiary Education Fees Public Opinion Poll, Australia.

    Science.gov (United States)

    McNair Anderson Associates Pty., Ltd., (Australia).

    The public reaction to the proposal that the Australian government should reintroduce fees for tertiary education was surveyed in 1985. The influence of the proposal on the way people would vote in a federal election was also investigated. The fee would be between $900 and $1,500 per year for full-time tertiary education. As part of a McNair…

  8. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  9. Stable Boundary Layer Issues

    NARCIS (Netherlands)

    Steeneveld, G.J.

    2012-01-01

    Understanding and prediction of the stable atmospheric boundary layer is a challenging task. Many physical processes are relevant in the stable boundary layer, i.e. turbulence, radiation, land surface coupling, orographic turbulent and gravity wave drag, and land surface heterogeneity. The

  10. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    IAS Admin

    After Maynard-Smith and Price [1] mathematically derived why a given behaviour or strategy was adopted by a certain proportion of the population at a given time, it was shown that a strategy which is currently stable in a population need not be stable in evolutionary time (across generations). Additionally it was sug-.

  11. Synthesis and characterization of highly efficient and stable Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt ternary hybrid structure

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jiatao; Liu, Lin; Niu, Tongjun; Sun, Xiaosong, E-mail: sunxs@scu.edu.cn

    2017-05-01

    Highlights: • Visible-light-driven Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt photocatalysts were prepared. • Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt showed highly efficient and stable photocatalystic activity. • The photocatalytic mechanism of Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite was given. - Abstract: Ag{sub 3}PO{sub 4} is an excellent photocatalyst with high efficiency and quantum yield, but suffers from the fast recombination of photogenerated electron-hole pairs and photo-corrosion. Hereby, the highly efficient and stable visible-light-driven Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt photocatalyst were prepared via a three-step wet chemical approach. The as-prepared Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite was characterized by X-ray diffraction, US-vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, photoluminescence spectra and transient photocurrent as well. Comparing with single Pr{sub 6}O{sub 11} or Ag{sub 3}PO{sub 4}, the prepared Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite exhibited much higher photocatalytic activity and stability for the degradation of Rhodamine B under visible light irradiation (>420 nm). The enhanced photocatalytic performance of Pr{sub 6}O{sub 11}/Ag{sub 3}PO{sub 4}/Pt composite has been attributed to the efficient separation of photo-generated electron-hole pairs through a scheme system composed of Pr{sub 6}O{sub 11,} Ag{sub 3}PO{sub 4} and Pt.

  12. Two stable steady states in the Hodgkin-Huxley axons

    OpenAIRE

    Aihara, K.; Matsumoto, G.

    1983-01-01

    Two stable steady states were found in the numerical solution of the Hodgkin-Huxley equations for the intact squid axon bathed in potassium-rich sea water with an externally applied inward current. Under the conditions the two stable steady-states exist, the Hodgkin-Huxley equations have a complex bifurcation structure including, in addition to the two stable steady-states, a stable limit cycle, two unstable equilibrium points, and one asymptotically stable equilibrium point. It was also conc...

  13. Tertiary evolution of the northeastern Venezuela offshore

    Science.gov (United States)

    Ysaccis B., Raul

    1998-12-01

    On the northeastern offshore Venezuela, the pre-Tertiary basement consists of a deeply subducted accretionary complex of a Cretaceous island arc system that formed far to the west of its present location. The internal structure of this basement consists of metamorphic nappes that involve passive margin sequences, as well as oceanic (ophiolitic) elements. The Tertiary evolution of the northeastern Venezuela offshore is dominated by Paleogene (Middle Eocene-Oligocene) extension and Neogene transtension, interrupted by Oligocene to Middle Miocene inversions. The Paleogene extension is mainly an arc-normal extension associated with a retreating subduction boundary. It is limited to the La Tortuga and the La Blanquilla Basins and the southeastern Margarita and Caracolito subbasins. All of these basins are farther north of and not directly tied to the El Pilar fault system. On a reconstruction, these Paleogene extensional systems were located to the north of the present day Maracaibo Basin. By early Miocene the leading edge of the now overall transpressional system had migrated to a position to the north of the Ensenada de Barcelona. This relative to South America eastward migration is responsible for the Margarita strike-slip fault and the major inversions that began during the Oligocene and lasted into the Middle Miocene. The Bocono-El Pilar-Casanay-Warm Springs and the La Tortuga-Coche-North Coast fault systems are exclusively Neogene with major transtension occurring during the Late Miocene to Recent and act independently from the earlier Paleogene extensional system. They are responsible for the large Neogene transtensional basins of the area: the Cariaco trough, the Northern Tuy-Cariaco and the Paria sub-basins, and the Gulf of Paria Basin. This latest phase is characterized by strain-partitioning into strike slip faults, a transtensional northern domain and a transpressional southern domain that is responsible for the decollement tectonics and/or inversions of the

  14. New insight in the structural features of haloadaptation in α-amylases from halophilic Archaea following homology modeling strategy: folded and stable conformation maintained through low hydrophobicity and highly negative charged surface

    Science.gov (United States)

    Zorgani, Mohamed Amine; Patron, Kevin; Desvaux, Mickaël

    2014-07-01

    Proteins from halophilic archaea, which live in extreme saline conditions, have evolved to remain folded, active and stable at very high ionic strengths. Understanding the mechanism of haloadaptation is the first step toward engineering of halostable biomolecules. Amylases are one of the main enzymes used in industry. Yet, no three-dimensional structure has been experimentally resolved for α-amylases from halophilic archaea. In this study, homology structure modeling of α-amylases from the halophilic archaea Haloarcula marismortui, Haloarcula hispanica, and Halalkalicoccus jeotgali were performed. The resulting models were subjected to energy minimization, evaluation, and structural analysis. Calculations of the amino acid composition, salt bridges and hydrophobic interactions were also performed and compared to a set of non-halophilic counterparts. It clearly appeared that haloarchaeal α-amylases exhibited lower propensities for helix formation and higher propensities for coil-forming regions. Furthermore, they could maintain a folded and stable conformation in high salt concentration through highly negative charged surface with over representation of acidic residues, especially Asp, and low hydrophobicity with increase of salt bridges and decrease in hydrophobic interactions on the protein surface. This study sheds some light on the stability of α-amylases from halophilic archaea and provides strong basis not only to understand haloadaptation mechanisms of proteins in microorganisms from hypersalines environments but also for biotechnological applications.

  15. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    This paper discusses two classes of distributions, and stochastic processes derived from them: modified stable (MS) laws and normal modified stable (NMS) laws. This extends corresponding results for the generalised inverse Gaussian (GIG) and generalised hyperbolic (GH) or normal generalised inverse...... Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...

  16. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  17. Trophic structure in a pilot system for the integrated multi-trophic aquaculture off the east coast of Korean peninsula as determined by stable isotopes

    International Nuclear Information System (INIS)

    Park, Hyun Je; Han, Eunah; Lee, Won Chan; Kwak, Jung Hyun; Kim, Hyung Chul; Park, Mi Seon; Kang, Chang-Keun

    2015-01-01

    Highlights: • A pilot system for the integrated multi-trophic aquaculture was installed. • The black rockfish, sea cucumber, oyster, and macroalgae were co-cultured. • Co-cultured sea cucumber at the IMTA site assimilated aquaculture wastes. • Fish cage-waste contribution to food web in/around the IMTA system was minor. • The sea cucumber was identified as an extractive species of fish cage wastes. - Abstract: To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, δ 13 C and δ 15 N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment

  18. Trophic structure in a pilot system for the integrated multi-trophic aquaculture off the east coast of Korean peninsula as determined by stable isotopes.

    Science.gov (United States)

    Park, Hyun Je; Han, Eunah; Lee, Won Chan; Kwak, Jung Hyun; Kim, Hyung Chul; Park, Mi Seon; Kang, Chang-Keun

    2015-06-15

    To assess the potential for nutritional exploitation of caged-fish-derived waste through the use of extractive co-cultured species in a pilot system for an integrated multi-trophic aquaculture (IMTA), we compared their C and N stable isotope ratios with those of uncultured macroinvertebrates in and around the system. Black rockfish were co-cultured with sea cucumber, oyster, and two macroalgae as extractive species. Isotope signatures of the co-cultured sea cucumber at the IMTA site differed from those at the control site, indicating their assimilation of aquaculture wastes. In contrast, δ(13)C and δ(15)N of individual taxa of the cultured oyster and uncultured invertebrates were consistent between sites, suggesting a minor contribution of the aquaculture waste to benthic and pelagic food chains in and around the IMTA system. These results provide evidence of the suitability of using sea cucumber as an extractive species to reduce the impact of a monoculture system on the ambient environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Hierarchical MoS2 tubular structures internally wired by carbon nanotubes as a highly stable anode material for lithium-ion batteries.

    Science.gov (United States)

    Chen, Yu Ming; Yu, Xin Yao; Li, Zhen; Paik, Ungyu; Lou, Xiong Wen David

    2016-07-01

    Molybdenum disulfide (MoS2), a typical two-dimensional material, is a promising anode material for lithium-ion batteries because it has three times the theoretical capacity of graphite. The main challenges associated with MoS2 anodes are the structural degradation and the low rate capability caused by the low intrinsic electric conductivity and large strain upon cycling. Here, we design hierarchical MoS2 tubular structures internally wired by carbon nanotubes (CNTs) to tackle these problems. These porous MoS2 tubular structures are constructed from building blocks of ultrathin nanosheets, which are believed to benefit the electrochemical reactions. Benefiting from the unique structural and compositional characteristics, these CNT-wired MoS2 tubular structures deliver a very high specific capacity of ~1320 mAh g(-1) at a current density of 0.1 A g(-1), exceptional rate capability, and an ultralong cycle life of up to 1000 cycles. This work may inspire new ideas for constructing high-performance electrodes for electrochemical energy storage.

  20. Analysing Stable Time Series

    National Research Council Canada - National Science Library

    Adler, Robert

    1997-01-01

    We describe how to take a stable, ARMA, time series through the various stages of model identification, parameter estimation, and diagnostic checking, and accompany the discussion with a goodly number...

  1. Variability in the combustion-derived fraction of urban humidity in Salt Lake City winter estimated from stable water vapor isotopes and its relationship to atmospheric stability and inversion structure

    Science.gov (United States)

    Fiorella, R.; Bares, R.; Lin, J. C.; Strong, C.; Bowen, G. J.

    2017-12-01

    Water released from the combustion of fossil fuels, while a negligible part of the global hydrological cycle, may be a significant contributor to urban humidity as fossil fuel emissions are strongly concentrated in space and time. The fraction of urban humidity comprised of combustion-derived vapor (CDV) cannot be observed through humidity measurements alone. However, the distinct stable isotopic composition of CDV, which arises from the reaction of 18O-enriched atmospheric O2 with 2H-depleted organic molecules, represents a promising method to apportion observed humidity between CDV and advected vapor. We apply stable water vapor isotopes to investigate variability in CDV amount and its relationship to atmospheric conditions in Salt Lake City, Utah. The Salt Lake Valley experiences several periods of atmospheric stratification during winter known as cold air pools, during which concentrations of CDV and pollutants can be markedly elevated due to reduced atmospheric mixing. Therefore, the SLV during winter is an ideal place to investigate variability in CDV fraction across a spectrum of boundary layer conditions, ranging from well-mixed to very stable. We present water vapor isotope data from four winters (2013-2017) from the top of a 30 m building on the University of Utah (U of U) Campus. Additionally, we present water vapor isotope data from the summit of Hidden Peak from the 2016-2017 winter, 25 km SE and 2000 m above the U of U site. The Hidden Peak site is consistently above the cold air pool emplaced in the SLV during stable events. We find the expression of the CDV signal in the valley is related to the atmospheric structure of the cold air pools in the SLV, and that the fraction of CDV inferred in the valley is likely related to the mixing height within the cold air pool. Furthermore, we find that patterns between the Hidden Peak and U of U sites during inversion events may record the large-scale atmospheric dynamics promoting emplacement of the cold air

  2. Oleaceous laurophyllous leaf fossils and pollen from the European Tertiary.

    Science.gov (United States)

    Sachse, M

    2001-06-01

    By using cuticular analysis for the first time laurophyllous leaf remains from the European Tertiary have been reliably identified as belonging to the Oleaceae. Despite ecologically determined variation in cuticular structures, Late Miocene leaf material from northern Italy is assigned to a single species, Oleinites liguricus Sachse n. sp. The associated oleaceous pollen grains support that this species has been a prominent component, at least locally, of a laurophyllous forest community. From extensive comparisons with leaf cuticles and pollen of extant Oleaceae it may be concluded, that the fossil leaves and probably corresponding pollen represent the tribe Oleeae and may originate from a plant closely comparable to extant Chionanthus and Fraxinus. A reinvestigation of some Oligocene laurophyllous leaf remains has uncovered two more oleaceous species in the European Tertiary: Oleinites maii (Buzek et al.) Sachse comb. nov., and Oleinites hallbaueri (Mai) Sachse comb. nov. Considering the high diversity of laurophyllous Oleaceae in modern evergreen and mixed mesophytic forests and the common presence of oleaceous pollen in the fossil record it may be expected that cuticular analysis of laurophyllous leaf fossils will lead to the recognition of an increased number of oleaceous taxa in Tertiary leaf assemblages.

  3. The influence of nitrogen inputs on biomass and trophic structure of ocean plankton: a study using biomass and stable isotope size-spectra

    KAUST Repository

    Mompeán, Carmen

    2016-08-18

    Large scale patterns in planktonic food web structure were studied by applying continuous size-scaled models of biomass and δ15N to plankton samples, collected at 145 stations during the Malaspina-2010 Expedition across three ocean basins and including major biomes. Carbon biomass and δ15N were determined in size-fractionated samples (40 to 5000 μm) collected by vertical hauls (0–200 m). Biomass-normalized size-spectra were constructed to summarize food web structure and spatial patterns in spectral parameters were analyzed using geographically-weighted regression analysis. Except in the northwestern Atlantic, size-spectra showed low variability, reflecting a homogeneity in nitrogen sources and food web structure for the central oceans. Estimated predator-to-prey mass ratios <104 and mean trophic transfer efficiency values between 16% (coastal biome) and >20% (Trades and Westerlies biomes) suggested that oceanic plankton food webs may support a larger number of trophic levels than current estimates based on high efficiency values. The largest changes in spectral parameters and nitrogen sources were related to inputs of atmospheric nitrogen, either from diazotrophic organisms or dust deposition. These results suggest geographic homogeneity in the net transfer of nitrogen up the food web.

  4. Stable hydrogen and oxygen isotopes of tap water reveal structure of the San Francisco Bay Area's water system and adjustments during a major drought.

    Science.gov (United States)

    Tipple, Brett J; Jameel, Yusuf; Chau, Thuan H; Mancuso, Christy J; Bowen, Gabriel J; Dufour, Alexis; Chesson, Lesley A; Ehleringer, James R

    2017-08-01

    Water availability and sustainability in the Western United States is a major flashpoint among expanding communities, growing industries, and productive agricultural lands. This issue came to a head in 2015 in the State of California, when the State mandated a 25% reduction in urban water use following a multi-year drought that significantly depleted water resources. Water demands and challenges in supplying water are only expected to intensify as climate perturbations, such as the 2012-2015 California Drought, become more common. As a consequence, there is an increased need to understand linkages between urban centers, water transport and usage, and the impacts of climate change on water resources. To assess if stable hydrogen and oxygen isotope ratios could increase the understanding of these relationships within a megalopolis in the Western United States, we collected and analyzed 723 tap waters across the San Francisco Bay Area during seven collection campaigns spanning 21 months during 2013-2015. The San Francisco Bay Area was selected as it has well-characterized water management strategies and the 2012-2105 California Drought dramatically affected its water resources. Consistent with known water management strategies and previously collected isotope data, we found large spatiotemporal variations in the δ 2 H and δ 18 O values of tap waters within the Bay Area. This is indicative of complex water transport systems and varying municipality-scale management decisions. We observed δ 2 H and δ 18 O values of tap water consistent with waters originating from snowmelt from the Sierra Nevada Mountains, local precipitation, ground water, and partially evaporated reservoir sources. A cluster analysis of the isotope data collected in this study grouped waters from 43 static sampling sites that were associated with specific water utility providers within the San Francisco Bay Area and known management practices. Various management responses to the drought, such as

  5. Structure-property relationship of bifunctional MnO2 nanostructures: highly efficient, ultra-stable electrochemical water oxidation and oxygen reduction reaction catalysts identified in alkaline media.

    Science.gov (United States)

    Meng, Yongtao; Song, Wenqiao; Huang, Hui; Ren, Zheng; Chen, Sheng-Yu; Suib, Steven L

    2014-08-13

    Manganese oxides of various structures (α-, β-, and δ-MnO2 and amorphous) were synthesized by facile methods. The electrocatalytic properties of these materials were systematically investigated for catalyzing both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in alkaline media. Extensive characterization was correlated with the activity study by investigating the crystal structures (XRD, HRTEM), morphologies (SEM), porosities (BET), surfaces (XPS, O2-TPD/MS), and electrochemical properties (Tafel analysis, Koutechy-Levich plots, and constant-current electrolysis). These combined results show that the electrocatalytic activities are strongly dependent on the crystallographic structures, and follow an order of α-MnO2 > AMO > β-MnO2 > δ-MnO2. Both OER studies and ORR studies reveal similar structure-determined activity trends in alkaline media. In the OER studies, α-MnO2 displays an overpotential of 490 mV compared to 380 mV shown by an Ir/C catalyst in reaching 10 mA cm(-2). Meanwhile, α-MnO2 also exhibits stability for 3 h when supplying a constant current density of 5 mA cm(-2). This was further improved by adding Ni(2+) dopants (ca. 8 h). The superior OER activity was attributed to several factors, including abundant di-μ-oxo bridges existing in α-MnO2 as the protonation sites, analogous to the OEC in PS-II of the natural water oxidation system; the mixed valencies (AOS = 3.7); and the lowest charge transfer resistances (91.8 Ω, η = 430 mV) as revealed from in situ electrochemical impedance spectroscopy (EIS). In the ORR studies, when reaching 3 mA cm(-2), α-MnO2 shows 760 mV close to 860 mV for the best ORR catalyst (20% Pt/C). The outstanding ORR activity was due to the strongest O2 adsorption capability of α-MnO2 suggested by temperature-programmed desorption. As a result, this discovery of the structure-related electrocatalytic activities could provide guidance in the further development of easily prepared, scalable, and low

  6. Syntheses, structures and photoelectrochemical properties of three water-stable, visible light absorbing mental-organic frameworks based on tetrakis(4-carboxyphenyl)silane and 1,4-bis(pyridyl)benzene mixed ligands

    Science.gov (United States)

    Guo, Tiantian; Yang, Xiaowei; Li, Ruyan; Liu, Xiaoyu; Gao, Yanling; Dai, Zhihui; Fang, Min; Liu, Hong-Ke; Wu, Yong

    2017-09-01

    Photovoltaics (PV), which directly convert solar energy into electricity generally using semiconductors, offer a practical and sustainable solution to the current energy shortage and environmental pollution crisis. Photovoltaic applications of metal-organic frameworks (MOFs) belong to a relatively new area of research. Given that UV light accounts for only 4% while visible light contributes 43% of solar energy, it is rather imperative to develop semiconductors with narrow band gaps so that they could absorb visible light. In this work, three water-stable, narrow band semiconducting MOFs of [Cu(H2TCS)(H2O)] (1), [Co(H2TCS)(BPB)] (2) and [Ni(H2TCS)(BPB)] (3) were synthesized using tetrakis(4-carboxyphenyl)silane (H4TCS) and 1,4-bis (pyridyl)benzene (BPB) in water, and structurally characterized by single-crystal X-ray diffractions. MOF 1 has a 2D structure. MOF 2 and 3 are isostructrual and have 3D frameworks formed by interwoven 2D layers. All three MOFs are stable in acidic water solutions and can be stable in water for 7 days. MOFs 1-3 absorb UV and visible light and have band gaps of 0.50, 1.77 and 1.49 eV, respectively. Rapid and stable photocurrent responses of MOFs 1-3 under UV and visible light illuminations are observed. This work demonstrates that using electron rich Cu2+, Co2+, or Ni2+ as metal nodes can effectively decrease the band gaps of MOFs to make them absorbing visible light. To increase the conjugation in the linker is generally considered to be the method to decrease the band gap of MOFs. The conjugation in H4TCS is not significant and this ligand basically only absorbs UV light. However, by using electron rich Cu2+ ions as metal nodes, the prepared [Cu(H2TCS)(H2O)]·H2O (1) absorbs broadly in the visible light region. Thus, this work suggests that by using electron rich Cu2+, many narrow-band semiconductor MOFs can be prepared even by using ligands which only absorbs UV light.

  7. Radioguided parathyroidectomy for tertiary hyperparathyroidism.

    Science.gov (United States)

    Somnay, Yash R; Weinlander, Eric; Alfhefdi, Amal; Schneider, David; Sippel, Rebecca S; Chen, Herbert

    2015-05-15

    Tertiary hyperparathyroidism (3HPT) is defined as the persistent hyperproduction of parathyroid hormone and resulting hypercalcemia after renal transplantation. Here, we examine the utility of radioguided parathyroidectomy (RGP) in patients with 3HPT. We reviewed a prospective surgery database containing 80 3HPT patients who underwent RGP from January 2001-July 2014 at our institution. We evaluated patient demographics, operative management, radioguided neoprobe utilization, and operative outcomes. Data are reported as mean ± standard error of the mean. The mean age of the patients was 52 ± 1 y, and 46% were male. A total of 69 patients had hyperplasia and received subtotal parathyroidectomy, whereas 5 patients had double adenomas and 6 patients had single adenomas. The average calcium level among 3HPT patients was 10.8 ± 0.1 mg/dL preoperatively and 8.7 ± 0.1 mg/dL postoperatively. In vivo radioguided counts normalized to background counts averaged 145 ± 4%, whereas ex vivo counts normalized to background counts averaged 69 ± 5%. All but one ex vivo count was >20%. Ectopically located glands were successfully localized in 38 patients using the gamma probe. Ex vivo percentage did not correlate with parathyroid gland weight, preoperative parathyroid hormone, or preoperative calcium. Our radioguided approach achieved normocalcemia in 96% of 3HPT patients undergoing RGP; two patients developed recurrent disease. In this series, all enlarged parathyroid glands were localized and resected using the gamma probe. Thus, RGP reliably localizes adenomatous, hyperplastic, and ectopically located glands in patients with 3HPT, resulting in high cure rate after resection. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Energy Management Systems and tertiary regulation in hierarchical control architectures for islanded micro-grids

    DEFF Research Database (Denmark)

    Sanseverino, Eleonora Riva; Di Silvestre, Maria Luisa; Quang, Ninh Nguyen

    2015-01-01

    In this paper, the structure of the highest level of a hierarchical control architecture for micro-grids is proposed. Such structure includes two sub-levels: the Energy Management System, EMS, and the tertiary regulation. The first devoted to energy resources allocation in each time slot based...

  9. Tertiary Logistics in the Focus of All Logistics

    OpenAIRE

    Ratko Zelenika; Mirjana Grèiæ; Helga Pavliæ Skender

    2008-01-01

    Trade logistics, traffic logistics, transport logistics and warehouse logistics are just some of the tertiary logistics which enables production processes of all economic sector products and services. Tertiary logistics representing the tertiary economic sector is the most sofisticated and the most important logistics due to the characteristics of the tertiary sector as a service sector that promotes business conditions in all economic sectors. Accordingly, tertiary logistics has a crucial ro...

  10. Synthesis and X-Ray Crystal Structure of the First Pure and Air-Stable Salt of Peroxymonosulphuric Acid: (Ph4PHSO5

    Directory of Open Access Journals (Sweden)

    Marco Crisma

    2000-06-01

    Full Text Available In this paper we describe the synthesis of tetraphenylphosphonium peroxymonosulphate, its crystal structure and packing mode. The asymmetric unit accomodates two independent molecules of the monopersulphate anion, which are held together by hydrogen bonds. In the packing mode, rows of such dimers are surrounded by four rows of tetraphenyl cations. The consequence is that the highly water sensitive HSO5¯ anions are segregated inside hydrophobic channels composed by the lipophilic cations. This circumstance presumably accounts for the exceptional stability of the title compound.

  11. Comparative trophic structures of macrobenthic food web in two macrotidal wetlands with and without a dike on the temperate coast of Korea as revealed by stable isotopes.

    Science.gov (United States)

    Park, Hyun Je; Kang, Hee Yoon; Park, Tae Hee; Kang, Chang-Keun

    2017-10-01

    This study characterized trophic structures of the macrobenthic food webs in two contrasting estuarine wetlands, with and without a dike, on the southern coast of Korea, based on the δ 13 C and δ 15 N values of dominant macrobenthic consumers. The pelagic algal biomasses were similar in the upper Phragmites australis-covered and lower bare intertidal habitats partitioned by the dike, but the microphytobenthos (MPB) biomasses were extremely low in the Phragmites bed. The consumer δ 13 C values were more negative and their isotopic niche width was much narrower in the upper than in the lower habitat at the diked site. These dissimilar spatial patterns between sites suggest a simplified food-web structure, which reflects the reduced availability of MPB in the upper habitat in the dike-impacted site. Overall, our findings suggest that restriction of the tides by dike construction induces local changes in basal resource availability and faunal composition, leading to macrobenthic community trophic reorganization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Structure of long human telomeric RNA (TERRA): G-quadruplexes formed by four and eight UUAGGG repeats are stable building blocks.

    Science.gov (United States)

    Martadinata, Herry; Heddi, Brahim; Lim, Kah Wai; Phan, Anh Tuân

    2011-07-26

    The discovery of long RNA transcripts of telomeric repeats (TERRA) and their potential to form G-quadruplexes stimulated studies on the possible arrangements of G-quadruplexes along TERRA. Here we performed ribonuclease protection assay to investigate the structures formed by long human TERRA. We found that G-quadruplexes comprising four and eight UUAGGG repeats were most resistant to RNase T1 digestion, presumably with the former adopting an all-parallel-stranded propeller-type conformation and the latter forming a structure with two tandemly stacked G-quadruplex subunits each containing three G-tetrad layers. Molecular dynamics simulations of eight-repeat human TERRA sequences consisting of different stacking interfaces between the two G-quadruplex subunits, i.e., 5'-5', 3'-3', 3'-5', and 5'-3', demonstrated stacking feasibility for all but the 5'-3' arrangement. A continuous stacking of the loop bases from one G-quadruplex subunit to the next was observed for the 5'-5' stacking conformation. We also put forward other possible stacking arrangements that involve more than one linker connecting the two G-quadruplex subunits. On the basis of these results, we propose a "beads-on-a-string"-like arrangement along human TERRA, whereby each bead is made up of either four or eight UUAGGG repeats in a one- or two-block G-quadruplex arrangement, respectively. © 2011 American Chemical Society

  13. Thermally induced solid-state transformation of cimetidine. A multi-spectroscopic/chemometrics determination of the kinetics of the process and structural elucidation of one of the products as a stable N{sub 3}-enamino tautomer

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Natalia L.; Simonetti, Sebastian O.; Maggio, Rubén M.; Kaufman, Teodoro S., E-mail: kaufman@iquir-conicet.gov.ar

    2015-05-22

    Highlights: • Thermally stressed cimetidine above its melting point affords a stable N{sub 3} tautomer. • Multi-spectroscopic/chemometric approach developed to monitor tautomerization. • First combined use of NMR, UV and IR spectroscopies with chemometrics. • Solid cimetidine suffers first order degradation upon submission to dry heat. • Theoretical chemistry analysis confirmed the relative stability of cimetidine tautomer. - Abstract: Exposure of cimetidine (CIM) to dry heat (160–180 °C) afforded, upon cooling, a glassy solid containing new and hitherto unknown products. The kinetics of this process was studied by a second order chemometrics-assisted multi-spectroscopic approach. Proton and carbon-13 nuclear magnetic resonance (NMR), as well as ultraviolet and infrared spectroscopic data were jointly used, whereas multivariate curve resolution with alternating least squares (MCR-ALS) was employed as the chemometrics method to extract process information. It was established that drug degradation follows a first order kinetics. One of the products was structurally characterized by mono- and bi-dimensional NMR experiments. It was found to be the N{sub 3}-enamino tautomer (TAU) of CIM, resulting from the thermal isomerization of the double bond of the cyanoguanidine moiety of the drug, from the imine form to its N{sub 3}-enamine state. The thus generated tautomer demonstrated to be stable for months in the glassy solid and in methanolic solutions. A theoretical study of CIM and TAU revealed that the latter is less stable; however, the energy barrier for tautomer interconversion is high enough, precluding the process to proceed rapidly at room temperature.

  14. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  15. Profile of voice professionals seen in a tertiary health center.

    Science.gov (United States)

    Fortes, Felipe Sartor Guimarães; Imamura, Rui; Tsuji, Domingos Hiroshi; Sennes, Luiz Ubirajara

    2007-01-01

    Work-related laryngopathy may have negative consequences for voice professionals. To analyze the profile of voice professionals seen in a tertiary level hospital. a longitudinal historical cohort. A retrospective analysis of patient files. Diagnosis was reached using videostroboscopy. 163 patients (119 females and 44 males) were seen. The mean age was 36.5 years. Professionals included spoken voice users (salesman, teachers, telemarketers, receptionists, health professionals) and singers. The most frequent diagnoses were: minor structural changes (33%), nodules (22%), Reinkes edema (10%), and polyps (6%). A correlation was observed between smoking, age and gender; there was an association between smoking and Reinkes edema, leucoplasia and tabagism, females and Reinkes edema, nodules and minor structural changes, and also between patients aged over 40 years and Reinkes edema, and patients under 40 with nodules, laryngitis, and minor structural changes. Symptoms lasted more than 6 months in 74% of patients. The profile of voice professionals seen in a tertiary hospital included spoken voice patients and singers. In our study minor structural changes predominated, followed by nodules, Reinke edema and polyps.

  16. Purification, biochemical characterization and structural modelling of alkali-stable β-1,4-xylan xylanohydrolase from Aspergillus fumigatus R1 isolated from soil.

    Science.gov (United States)

    Deshmukh, Rehan Ahmed; Jagtap, Sharmili; Mandal, Madan Kumar; Mandal, Suraj Kumar

    2016-02-04

    Aspergillus fumigatus R1 produced xylanase under submerged fermentation which degrades the complex hemicelluloses contained in agricultural substrates. Xylanases have gained considerable attention because of their tremendous applications in industries. The purpose of our study was to purify xylanase and study its biochemical properties. We have predicted the secondary structure of purified xylanase and evaluated its active site residues and substrate binding sites based on the global and local structural similarity. Various microorganisms were isolated from Puducherry soil and screened by Congo-red test. The best isolate was identified to be Aspergillus fumigatus R1. The production kinetics showed the highest xylanase production (208 IU/ml) by this organism in 96 h using 1 % rice bran as the only carbon source. The purification of extracellular xylanase was carried out by fractional ammonium sulphate precipitation (30-55 %), followed by extensive dialysis and Bio-Gel P-60 Gel-filtration chromatography. The enzyme was purified 58.10 folds with a specific activity of 38196.22 IU/mg. The biochemical characterization of the pure enzyme was carried out for its optimum pH and temperature (5.0 and 50(0)C), pH and temperature stability, molecular mass (Mr) (24.5 kDa) and pI (6.29). The complete sequence of protein was obtained by mass spectrometry analysis. Apparent Km and Vmax values of the xylanase for birchwood xylan were 11.66 mg/ml and 87.6 μmol min(-1) mg(-1) respectively. Purified xylanase was analyzed by mass-spectrometry which revealed 2 unique peptides. Xylanase under current study showed significant production using agricultural residues and a broad range of pH stability in the alkaline region. Xylanase produced by Aspergillus fumigatus R1 could serve as the enzyme of choice in industries.

  17. Stable Hemiaminals: 2-Aminopyrimidine Derivatives

    Directory of Open Access Journals (Sweden)

    Anna Kwiecień

    2015-08-01

    Full Text Available Stable hemiaminals can be obtained in the one-pot reaction between 2-aminopyrimidine and nitrobenzaldehyde derivatives. Ten new hemiaminals have been obtained, six of them in crystal state. The molecular stability of these intermediates results from the presence of both electron-withdrawing nitro groups as substituents on the phenyl ring and pyrimidine ring, so no further stabilisation by intramolecular interaction is required. Hemiaminal molecules possess a tetrahedral carbon atom constituting a stereogenic centre. As the result of crystallisation in centrosymmetric space groups both enantiomers are present in the crystal structure.

  18. Facile construction of novel CoMoO4 microplates@CoMoO4 microprisms structures for well-stable supercapacitors

    Directory of Open Access Journals (Sweden)

    Xuewen Geng

    2016-06-01

    Full Text Available A simple and controllable strategy has been developed to fabricate CoMoO4 microplates/CoMoO4 microprisms (CMCMs structures on Ni foam via a facile, cost-effective, two-step hydrothermal route. The as-grown 3D architecture exhibited excellent areal capacitance of 4.33 F cm−2 at a galvanostatic charge-discharge current density of 50 mA cm−2 (6 A g−1 and outstanding cycle performance with only 2.8% degradation over 6500 cycles in the 3 M KOH solution. The asymmetric all-solid-state supercapacitors based on activated carbon (AC and CMCMs exhibited much better electrochemical performance than the symmetric counterpart, showing an areal capacitance of 95.22 mF cm−2 at the current density of 12 mA cm−2 and excellent cycling stability with 92.27% of the initial capacitance after 5000 cycles. These results may provide useful guidelines for materials selection and configuration designs for the novel energy storage devices based on CoMoO4 components and substrates.

  19. Evolutionary Stable Strategy

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General ... Using some examples of classical games, we show how evolutionary game theory can help understand behavioural decisions of animals.

  20. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  1. Manifolds admitting stable forms

    Czech Academy of Sciences Publication Activity Database

    Le, Hong-Van; Panák, Martin; Vanžura, Jiří

    2008-01-01

    Roč. 49, č. 1 (2008), s. 101-11 ISSN 0010-2628 R&D Projects: GA ČR(CZ) GP201/05/P088 Institutional research plan: CEZ:AV0Z10190503 Keywords : stable forms * automorphism groups Subject RIV: BA - General Mathematics

  2. Interactive Stable Ray Tracing

    DEFF Research Database (Denmark)

    Dal Corso, Alessandro; Salvi, Marco; Kolb, Craig

    2017-01-01

    Interactive ray tracing applications running on commodity hardware can suffer from objectionable temporal artifacts due to a low sample count. We introduce stable ray tracing, a technique that improves temporal stability without the over-blurring and ghosting artifacts typical of temporal post-pr...

  3. The stable subgroup graph

    Directory of Open Access Journals (Sweden)

    Behnaz Tolue

    2018-07-01

    Full Text Available In this paper we introduce stable subgroup graph associated to the group $G$. It is a graph with vertex set all subgroups of $G$ and two distinct subgroups $H_1$ and $H_2$ are adjacent if $St_{G}(H_1\\cap H_2\

  4. Core-shell structural nanodiamond@TiN supported Pt nanoparticles as a highly efficient and stable electrocatalyst for direct methanol fuel cells

    International Nuclear Information System (INIS)

    Zhao, Yuling; Wang, Yanhui; Dong, Liang; Zhang, Yan; Huang, Junjie; Zang, Jianbing; Lu, Jing; Xu, Xipeng

    2014-01-01

    Highlights: • Core-shell structural nanodiamond@TiN was used as a novel support for Pt catalysts. • The ND@TiN support possessed a high electrochemical stability than carbon black. • The Pt/ND@TiN showed a higher catalytic activity for MOR and ORR than the Pt/C. • The Pt/ND@TiN demonstrated a much better durability compared with the Pt/C. - Abstract: A novel core-shell support material was designed with nanodiamond (ND) as core possessed excellent stability and TiN as shell improved the conductivity of support. The nano-TiN shell was decorated on the surface of ND by annealing TiO 2 in nitrogen atmosphere, and the obtained ND@TiN was employed to support Pt nanoparticles (NPs). The ND@TiN support and Pt/ND@TiN electrocatalyst were characterized by X-ray diffraction and transmission electron microscopy. ND particles were coated uniformly by the TiN layer and Pt NPs with a mean size of 4.2 nm were highly dispersed on the surface of ND@TiN. The electrochemical results confirmed that the ND@TiN support possessed a much more stability than the carbon black and exhibited a bigger background current density than the ND. The Pt/ND@TiN catalyst showed higher catalytic activity and better stability in methanol oxidation and oxygen reduction reactions compared with the Pt/C and Pt/ND

  5. Seasonal and inter-annual dynamics of growth, non-structural carbohydrates and C stable isotopes in a Mediterranean beech forest.

    Science.gov (United States)

    Scartazza, Andrea; Moscatello, Stefano; Matteucci, Giorgio; Battistelli, Alberto; Brugnoli, Enrico

    2013-07-01

    Seasonal and inter-annual dynamics of growth, non-structural carbohydrates (NSC) and carbon isotope composition (δ(13)C) of NSC were studied in a beech forest of Central Italy over a 2-year period characterized by different environmental conditions. The net C assimilated by forest trees was mainly used to sustain growth early in the season and to accumulate storage carbohydrates in trunk and root wood in the later part of the season, before leaf shedding. Growth and NSC concentration dynamics were only slightly affected by the reduced soil water content (SWC) during the drier year. Conversely, the carbon isotope analysis on NSC revealed seasonal and inter-annual variations of photosynthetic and post-carboxylation fractionation processes, with a significant increase in δ(13)C of wood and leaf soluble sugars in the drier summer year than in the wetter one. The highly significant correlation between δ(13)C of leaf soluble sugars and SWC suggests a decrease of the canopy C isotope discrimination and, hence, an increased water-use efficiency with decreasing soil water availability. This may be a relevant trait for maintaining an acceptable plant water status and a relatively high C sink capacity during dry seasonal periods. Our results suggest a short- to medium-term homeostatic response of the Collelongo beech stand to variations in water availability and solar radiation, indicating that this Mediterranean forest was able to adjust carbon-water balance in order to prevent C depletion and to sustain plant growth and reserve accumulation during relatively dry seasons.

  6. Stable isotope switching (SIS): a new stable isotope probing (SIP) approach to determine carbon flow in the soil food web and dynamics in organic matter pools.

    Science.gov (United States)

    Maxfield, P J; Dildar, N; Hornibrook, E R C; Stott, A W; Evershed, R P

    2012-04-30

    Recent advances in stable isotope probing (SIP) have allowed direct linkage of microbial population structure and function. This paper details a new development of SIP, Stable Isotope Switching (SIS), which allows the simultaneous assessment of carbon (C) uptake, turnover and decay, and the elucidation of soil food webs within complex soils or sedimentary matrices. SIS utilises a stable isotope labelling approach whereby the (13)C-labelled substrate is switched part way through the incubation to a natural abundance substrate. A (13)CH(4) SIS study of landfill cover soils from Odcombe (Somerset, UK) was conducted. Carbon assimilation and dissimilation processes were monitored through bulk elemental analysis isotope ratio mass spectrometry and compound-specific gas chromatography/combustion/isotope ratio mass spectrometry, targeting a wide range of biomolecular components including: lipids, proteins and carbohydrates. Carbon assimilation by primary consumers (methanotrophs) and sequential assimilation into secondary (Gram-negative and -positive bacteria) and tertiary consumers (Eukaryotes) was observed. Up to 45% of the bacterial membrane lipid C was determined to be directly derived from CH(4) and at the conclusion of the experiment ca. 50% of the bulk soil C derived directly from CH(4) was retained within the soil. This is the first estimate of soil organic carbon derived from CH(4) and it is comparable with levels observed in lakes that have high levels of benthic methanogenesis. SIS opens the way for a new generation of SIP studies aimed at elucidating total C dynamics (incorporation, turnover and decay) at the molecular level in a wide range of complex environmental and biological matrices. Copyright © 2012 John Wiley & Sons, Ltd.

  7. The carbonaceous phyllite rock-hosted Pedra Verde copper mine, Borborema Province, Brazil: Stable isotope constraints, structural controls and metallogenic evolution

    Science.gov (United States)

    da Silva Nogueira de Matos, José Henrique; Saraiva dos Santos, Ticiano José; Virgínia Soares Monteiro, Lena

    2017-12-01

    The Pedra Verde Copper Mine is located in the Viçosa do Ceará municipality, State of Ceará, NE Brazil. The copper mineralization is hosted by the Pedra Verde Phyllite, which is a carbonaceous chlorite-calcite phyllite with subordinate biotite. It belongs to the Neoproterozoic Martinópole Group of the Médio Coreaú Domain, Borborema Province. The Pedra Verde deposit is stratabound and its ore zoning is conspicuous, according to the following sequence, from bottom to top: marcasite/pyrite, native silver, chalcopyrite, bornite, chalcocite, native copper and hematite. Barite and carbonaceous material are reported in ore zones. Zoning reflects the ore formation within a redox boundary developed due to the interaction between oxidized copper- and sulfate-bearing fluids and the reduced phyllite. Structural control on mineralization is evidenced by the association of the ore minerals with veins, hinge folds, shadow pressures, and mylonitic foliation. It was mainly exercised by a dextral transcurrent shear zone developed during the third deformational stage identified in the Médio Coreaú Domain between 590 Ma and 570 Ma. This points to the importance of epigenetic, post-metamorphic deformational events for ore formation. Oxygen isotopic composition (δ18OH2O = 8.94 to 11.28‰, at 250 to 300 °C) estimated for the hydrothermal fluids in equilibrium with calcite indicates metamorphic or evolved meteoric isotopic signatures. The δ13CPDB values (-2.60 to -9.25‰) obtained for hydrothermal calcite indicate mixing of carbon sources derived from marine carbonate rocks and carbonaceous material. The δ34SCDT values (14.88 to 36.91‰) of sulfides suggest evaporites as sulfate sources or a closed system in relation to SO42- availability to form H2S. Carbonaceous matter had a key role in thermochemical sulfate processes and sulfide precipitation. The Pedra Verde Copper Mine is considered the first stratabound meta-sedimentary rock-hosted copper deposit described in Brazil

  8. Tertiary phosphine complexes of the f-block metals. Preparation of pentamethylcyclopentadienyl-tertiary phosphine complexes of ytterbium(II), ytterbium(III), and europium(II). Crystal structure of Yb(Me5C5)2Cl(Me2PCH2PMe2)

    International Nuclear Information System (INIS)

    Tilley, T.D.; Andersen, R.A.; Zalkin, A.

    1983-01-01

    The diphosphine, Me 2 PCH 2 CH 2 PMe 2 , reacts with M(Me 5 C 5 ) 2 (OEt 2 ) to give insoluble M(Me 5 C 5 ) 2 (Me 2 PCH 2 CH 2 PMe 2 ), where M is Eu or Yb. In contrast, Me 2 PCH 2 PMe 2 gives the hydrocarbon-soluble complexes M(Me 5 C 5 ) 2 (Me 2 PCH 2 PMe 2 ), where M is Eu or Yb. The ytterbium complex reacts with YbCl 3 in toluene to give Yb(Me 5 C 5 ) 2 Cl(Me 2 PCH 2 PMe 2 ), and the crystal structure shows that the phosphine is acting as a monodentate ligand. Yb(Me 5 C 5 ) 2 Cl(Me 2 PCH 2 PMe 2 ) crystallizes in the monoclinic space group P2 1 /c with a = 16.358 (6) A, b = 8.595 (4) A, c - 20.712 (7) A, β = 104.75 (4) 0 , V = 2816 A 3 , and d(calcd) = 1.45 g cm -3 for Z = 4 and mol wt = 615.15. Diffraction data were collected with a CAD-4 automated diffractometer, and the structure was refined to R = 0.054 for 3309 reflections with 4 0 0 (Mo Kα radiation). The Yb is coordinated to the two Me 5 C 5 groups, to the chlorine atom, and to one phosphorus atom of the bis(dimethylphosphino)methane ligand. The Yb-P and Yb-Cl distances are 2.94 and 2.53 A, respectively. The centroids of the C 5 Me 5 ligands and the Cl and P atoms are in an approximate tetrahedral arrangement about the Yb atom

  9. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  10. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  11. Management Information in Tertiary Institutions.

    Science.gov (United States)

    Findlay, A. W.

    1981-01-01

    A college or university's management information system corresponds roughly to the institution's structure, with these elements in descending order in the hierarchy: policy and planning, a planning system, control and coordination, and typical operating systems (payroll, exams, scheduling, library, facilities assignments, and accounting…

  12. Reflections on entrepreneurship education in African tertiary institutions

    Directory of Open Access Journals (Sweden)

    K. Bawuah

    2006-12-01

    Full Text Available It is a well-established fact that several developed economies grew on the back of small businesses and entrepreneurial development. It stands to reason then that the development of Sub-Saharan Africa (SSA can also be catalysed by a rise in the number of entrepreneurs and entrepreneurial activity. In that general regard, this paper sought to investigate the state of entrepreneurship education in Sub-Saharan Africa (SSA. The method adopted in investigating this phenomenon was to critique the existing tertiary education entrepreneurship structures (where these existed at all and to proffer recommendations where anomalies were discovered. It came to light that despite the critical importance of entrepreneurs in the economic development of a nation, Sub-Saharan African (SSA countries have not fully developed strategies to tap this resource. What the countries have, are haphazard policies designed to promote the lesser or uneducated individuals in the informal sector into entrepreneurship. SSA educational leaders must find ways to structure their curricula so that all or most of their students can take courses in entrepreneurship. This is essential for SSA countries in order to move them from their present disadvantaged economic status, to greater economic and social development. A tentative syllabus for African tertiary education is proffered at the end of the article but its robustness needs to be tested.

  13. Solvent effects on the magnetic shielding of tertiary butyl alcohol

    African Journals Online (AJOL)

    )4 and tetramethyl ammonium cation N(CH3)4(+) have also been presented. KEY WORDS: Solvent effects, Magnetic shielding, Tertiary butyl alcohol, Tertiary butyl amine, Continuum solvation calculations, Chemical shift estimation methods

  14. Sexual promiscuity among female undergraduates in tertiary ...

    African Journals Online (AJOL)

    The study focused on sexual promiscuity among female undergraduates and the attendant health implications. It was carried out in the tertiary institutions in Imo State using 415 final year degree students drawn from four institutions in the State. Three research questions were formulated to guide the study. The design was a ...

  15. Indigenous Students in the Tertiary Education Sector

    Science.gov (United States)

    Bandias, Susan; Fuller, Don; Larkin, Steven

    2014-01-01

    Important recent objectives of indigenous education policy in Australia have been aimed at redressing indigenous economic and social disadvantage through increasing student retention, progression and completion rates in both compulsory and post-compulsory education. The two sectors of the tertiary education system, vocational education and…

  16. American Tertiary mollusks of the genus Clementia

    Science.gov (United States)

    Woodring, W.P.

    1927-01-01

    Aside from its value as an aid in determining the age of Tertiary beds, the chief interest of the genus Clementia lies in the anomalous features of its present and former distribution. An attempt is made in this paper to trace its geologic history, to point out its paleobiologic significance, and to describe all the known American Tertiary species. The fossils from Colombia used in preparing this report were collected during explorations made under the direction of Dr. 0. B. Hopkins, chief geologist of the Imperial Oil Co. (Ltd.), who kindly donated them to the United States National Museum. Dr. T. Wayland Vaughan, of the Scripps Institution of Oceanography, furnished information relating to specimens collected by him in Mexico. Dr. Bruce L. Clark, of the University of California; Dr. G. Dallas Hanna, of the California Academy of Sciences; Dr. H. A. Pilsbry, of the Philadelphia Academy of Natural Sciences; and Dr. W. D. Matthew, of the American Museum of Natural History, generously loaned type specimens and other material. Doctor Clark and Doctor Hanna also gave information concerning the Tertiary species from California. Mr. Ralph B. Stewart, of the University of California, read the manuscript, and I have taken advantage of his suggestions. I am also indebted to Mr. L. R. Cox, of the British Museum, for information relating to the fossil species from Persia, Zanzibar, and Burma, and to Dr. Axel A. Olsson, of the International Petroleum Co., for data concerning undescribed Tertiary species from Peru.

  17. Misconception of emergency contraception among tertiary school ...

    African Journals Online (AJOL)

    Objective: To assess the degree of awareness and use of emergency contraception among tertiary school students in Akwa Ibom State, Nigeria. Design: A self-administered questionnaire survey. Setting: The Akwa Ibom State Polytechnic, Ikot Osurua, located on the outskirts of Ikot Ekpene local government area between ...

  18. RELIGIOUS EXTREMISM AS A CHALLENGE TO TERTIARY ...

    African Journals Online (AJOL)

    IK

    2016-07-01

    Jul 1, 2016 ... tertiary institutions in Nigeria, through General Studies, should educate the youth to be self- reliant so that they are not lured by religious extremists to achieve their political and economic agenda. Publication of well researched papers and books that contribute to the study of religions and cultures should be ...

  19. Recruitment Of International Students Into Cameroon Tertiary ...

    African Journals Online (AJOL)

    This paper highlights the importance of Cameroon\\'s tertiary institutions\\' cooperation links with other African Universities given the rebirth of Organisation of African Unity as African Union, and the New Partnership for Africa Development (NEPAD). The present system of recruiting international students is haphazardly been ...

  20. Dimensionally Stable Structural Space Cable, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Jet Propulsion Laboratory (JPL) is involved in an ongoing effort to design and demonstrate a full-scale (30-32m diameter) Starshade engineering demonstrator that...

  1. Dimensionally Stable Structural Space Cable, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In response to the need for an affordable exoplanet-analysis science mission, NASA has recently embarked on the ROSES Technology Development for Exoplanet Missions...

  2. Multi-Stable Morphing Cellular Structures

    Science.gov (United States)

    2015-05-14

    varying thickness and height were waterjet cut from a 0.02-m-thick sheet of DuPont Delrin II 150SA NC010 (see Figure 9). The waterjet cut through the...from strips cut from a NiTiNOL sheet on the waterjet machine. Based on the availability, the superelastic, 56.1% nickel NDC SE 508 alloy was chosen...conforming to American Society for Testing Materials (ASTM) standard D638-10 was cut from the same sheet. The superelastic NiTiNOL arches originated

  3. Economics of Tertiary Education - Challenges and dynamics of the public tertiary education in Albania

    Directory of Open Access Journals (Sweden)

    Gledian Llatja

    2016-07-01

    Full Text Available The tertiary education is a critic mechanism for the socio-economic progress, for individuals who aspire a brighter future and it is also considered an important catalyzer of the economic mobility (Department of Treasury and Department of Education, 2012, 2. Based on the positive role and impact that the tertiary education has on the sustainable development, President Obama once stated that it is of damage to treat education as a luxurious public service. In line with the general considerations about the tertiary education in the U.S. the parallel comparison with Albania comes as a direct interpretation of utopia in the education policy-making. As policies are usually drafted based on data and findings, in the case of Albania there is a lack of data on expenses on tertiary education as share of GDP. This stands also for the main limitation of the paper.

  4. Teaching manufacturing engineering at tertiary institutions in conjunction with engineering design and engineering materials

    OpenAIRE

    V. Kosse; Iyer, Mahalinga-Iyer; P. Yarlagadda

    2008-01-01

    Purpose: In this paper we discuss the innovative curriculum structure, teaching and learning approaches ofcoherent delivery of manufacturing in conjunction with engineering design and materials from year one to yearfour, including specializations, real life projects and final year projects.Design/methodology/approach: Tertiary institutions now face serious challenges. Modern industry requiresengineering graduates with strong knowledge of modern technologies, highly practical focus, management...

  5. Oro-Dental and Maxillofacial Trauma in Epilepsy at a Tertiary ...

    African Journals Online (AJOL)

    Background: Seizure-related injuries are common and are a major cause of morbidity in subjects with epilepsy. Objective: To determine the frequency and types of oro-facial injuries in epileptic patients attending a tertiary hospital. Methods: A structured questionnaire was used to obtain information about injuries to the oral ...

  6. Tertiary Education in the Czech Republic: The Pathway to Change

    Science.gov (United States)

    Pesik, Richard; Gounko, Tatiana

    2011-01-01

    This article analyzes recent policy proposals to reform Czech tertiary education. A brief overview of the evolution of Czech tertiary education presents the background against which emerging policy trends in education are examined. We relate the changes in tertiary education to the policy framework and recommendations of the OECD, underpinned by…

  7. Defining fish community structure in Lake Winnipeg using stable isotopes (δ{sup 13}C, δ{sup 15}N, δ{sup 34}S): Implications for monitoring ecological responses and trophodynamics of mercury and other trace elements

    Energy Technology Data Exchange (ETDEWEB)

    Ofukany, Amy F.A. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3 (Canada); Wassenaar, Leonard I. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Bond, Alexander L., E-mail: alex.bond@rspb.org.uk [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada); Hobson, Keith A. [Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan S7N 3H5 (Canada)

    2014-11-01

    The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km{sup 2} watershed and the arrival of non-native zooplankters and fishes. We measured δ{sup 13}C, δ{sup 15}N, and δ{sup 34}S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ{sup 13}C and δ{sup 34}S, and lower δ{sup 15}N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. - Highlights: • Anthropogenic eutrophication and non-native species affect Lake Winnipeg’s ecosystem. • We measured stable isotopes and trace elements in 15 native fish species. • There was more evidence for growth dilution than biomagnification for most elements. • The trophic structures of the north and south basins were different. • These results will help determine the effects of recent arrival of zebra mussels.

  8. Defining fish community structure in Lake Winnipeg using stable isotopes (δ13C, δ15N, δ34S): Implications for monitoring ecological responses and trophodynamics of mercury and other trace elements

    International Nuclear Information System (INIS)

    Ofukany, Amy F.A.; Wassenaar, Leonard I.; Bond, Alexander L.; Hobson, Keith A.

    2014-01-01

    The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km 2 watershed and the arrival of non-native zooplankters and fishes. We measured δ 13 C, δ 15 N, and δ 34 S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ 13 C and δ 34 S, and lower δ 15 N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. - Highlights: • Anthropogenic eutrophication and non-native species affect Lake Winnipeg’s ecosystem. • We measured stable isotopes and trace elements in 15 native fish species. • There was more evidence for growth dilution than biomagnification for most elements. • The trophic structures of the north and south basins were different. • These results will help determine the effects of recent arrival of zebra mussels

  9. Periodicity of the stable isotopes

    CERN Document Server

    Boeyens, J C A

    2003-01-01

    It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)

  10. Stable States of Biological Organisms

    Science.gov (United States)

    Yukalov, V. I.; Sornette, D.; Yukalova, E. P.; Henry, J.-Y.; Cobb, J. P.

    2009-04-01

    A novel model of biological organisms is advanced, treating an organism as a self-consistent system subject to a pathogen flux. The principal novelty of the model is that it describes not some parts, but a biological organism as a whole. The organism is modeled by a five-dimensional dynamical system. The organism homeostasis is described by the evolution equations for five interacting components: healthy cells, ill cells, innate immune cells, specific immune cells, and pathogens. The stability analysis demonstrates that, in a wide domain of the parameter space, the system exhibits robust structural stability. There always exist four stable stationary solutions characterizing four qualitatively differing states of the organism: alive state, boundary state, critical state, and dead state.

  11. Cooperative activity and its potential for learning in tertiary education

    Directory of Open Access Journals (Sweden)

    Cirila Peklaj

    2007-01-01

    Full Text Available A learning situation can be structured in different ways, as an individual, competitive, or cooperative activity. Each of these structures can be used for different purposes and can lead to different learning outcomes. This paper focuses on cooperative activity and its potential for learning in tertiary education. After defining cooperative activity (or, in a broader sense, learning in interaction and introducing the CAMS theoretical framework to analyse cooperative activity, the main discussion focuses on the theoretical reasons for the usefulness of group learning and on the research of effects of cooperative learning on cognitive (metacognitive, affective-motivational and social processes in university students. The key elements that should be established for successful cooperation are also discussed. At the end, a new direction in using cooperative activity in learning—computer supported collaborative learning (CSCL, which emerged with rapid technology development in the last two decades—is presented and discussed.

  12. Stable magnetic remanence in antiferromagnetic goethite.

    Science.gov (United States)

    Strangway, D W; McMahon, B E; Honea, R M

    1967-11-10

    Goethite, known to be antiferromagnetic, acquires thermoremanent magnetization at its Neel temperature of 120 degrees C. This remanence, extremely stable, is due to the presence of unbalanced spins in the antiferromagnetic structure; the spins may result from grain size, imperfections, or impurities.

  13. Marginally Stable Nuclear Burning

    Science.gov (United States)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  14. EXPLORING THE TERTIARY EFL STUDENTS' ACADEMIC WRITING COMPETENCIES

    Directory of Open Access Journals (Sweden)

    Aunurrahman Aunurrahman

    2017-05-01

    Full Text Available For tertiary English as a Foreign Language (EFL students, academic writing is not an easy task. It requires knowledge of the academic writing genres with their particular linguistic features. Moreover, academic writing demands good critical thinking. This research aims to explore the students' academic writing competencies that also focus on critical thinking. The research involved thirty-six first-year tertiary EFL students from a regular class of a private university in Pontianak, West Kalimantan, Indonesia. The source for data collection was the students’ texts. Three texts were selected and the students were categorized into low, medium, and high levels of writing achievement. The text analysis utilized functional grammar rooted in systemic functional linguistics (Emilia, 2014. The analysis shows that the students, regardless of their levels of writing achievement, have little control over the schematic structure and linguistic features of an argumentative writing. The text analysis also shows that the students’ texts have some limitations as regards their critical thinking capacity. Still, a few examples of academic language were detected in the texts. The findings suggest that the lecturer should incorporate explicit teaching and cooperative learning activities to alleviate the students' difficulties and develop their academic writing and critical thinking capacity.

  15. Dual Core-Shell Structured Si@SiOx@C Nanocomposite Synthesized via a One-Step Pyrolysis Method as a Highly Stable Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Jiang, Bolun; Zeng, Shi; Wang, Hui; Liu, Daotan; Qian, Jiangfeng; Cao, Yuliang; Yang, Hanxi; Ai, Xinping

    2016-11-23

    Silicon (Si) has been regarded as a promising high-capacity anode material for developing advanced lithium-ion batteries (LIBs), but the practical application of Si anodes is still unsuccessful mainly due to the insufficient cyclability. To deal with this issue, we propose a new route to construct a dual core-shell structured Si@SiO x @C nanocomposite by direct pyrolysis of poly(methyl methacrylate) (PMMA) polymer on the surface of Si nanoparticles. Since the PMMA polymers can be chemically bonded on the nano-Si surface through the interaction between ester group and Si surface group, and thermally decomposed in the subsequent pyrolysis process with their alkyl chains converted to carbon and the residue oxygen recombining with Si to form SiO x , the dual core-shell structure can be conveniently formed in a one-step procedure. Benefiting from the strong buffering effect of the SiO x interlayer and the efficient blocking action of dense outer carbon layer in preventing electrolyte permeation, the obtained nanocomposite demonstrates a high capacity of 1972 mA h g -1 , a stable cycling performance with a capacity retention of >1030 mA h g -1 over 500 cycles, and particularly a superiorly high Coulombic efficiency of >99.5% upon extended cycling, exhibiting a great promise for practical uses. More importantly, the synthetic method proposed in this work is facile and low cost, making it more suitable for large-scale production of high capacity anode for advanced LIBs.

  16. Missed injury and the tertiary trauma survey.

    Science.gov (United States)

    Thomson, Charles B; Greaves, Ian

    2008-01-01

    Missed injury in the context of major trauma remains a persistent problem, both from a clinical and medico-legal point-of-view. Estimates of the incidence vary widely, dependent on the precise parameters of the studied population, the definition of missed injury and the extent of follow-up, but may be as high as 38%. The tertiary survey, in which formal repeated examination of the patient is undertaken after initial resuscitation and treatment have taken place, has been suggested as a way of identifying injuries not found at presentation. This paper appraises the concept of the tertiary survey, and also reviews the literature on missed injury in order to identify the risk factors, the types of injury and the reasons for error.

  17. Alcohol consumption in tertiary education students

    Directory of Open Access Journals (Sweden)

    Reavley Nicola J

    2011-07-01

    Full Text Available Abstract Background Heavy alcohol consumption among adolescents and young adults is an issue of significant public concern. With approximately 50% of young people aged 18-24 attending tertiary education, there is an opportunity within these settings to implement programs that target risky drinking. The aim of the current study was to survey students and staff within a tertiary education institution to investigate patterns of alcohol use, alcohol-related problems, knowledge of current National Health and Medical Research Council (NHMRC guidelines for alcohol consumption and intentions to seek help for alcohol problems. Methods Students of an Australian metropolitan university (with staff as a comparison group participated in a telephone interview. Questions related to knowledge of NHMRC guidelines, drinking behaviour, alcohol-related problems and help-seeking intentions for alcohol problems. Level of psychological distress was also assessed. Results Of the completed interviews, 774 (65% were students and 422 (35% were staff. While staff were more likely to drink regularly, students were more likely to drink heavily. Alcohol consumption was significantly higher in students, in males and in those with a history of earlier onset drinking. In most cases, alcohol-related problems were more likely to occur in students. The majority of students and staff had accurate knowledge of the current NHMRC guidelines, but this was not associated with lower levels of risky drinking. Psychological distress was associated with patterns of risky drinking in students. Conclusions Our findings are consistent with previous studies of tertiary student populations, and highlight the disconnect between knowledge of relevant guidelines and actual behaviour. There is a clear need for interventions within tertiary education institutions that promote more effective means of coping with psychological distress and improve help-seeking for alcohol problems, particularly among

  18. Tertiary lymphoid organs in Takayasu Arteritis

    OpenAIRE

    Marc eClement; Marc eClement; Adrien eGaly; Patrick eBruneval; Marion eMorvan; Fabien eHyafil; Fabien eHyafil; Khadija eBenali; Nicoletta ePasi; Lydia eDeschamps; Quentin ePellenc; Quentin ePellenc; Thomas ePapo; Antonino eNicoletti; Antonino eNicoletti

    2016-01-01

    Objective: The role of B cells in the pathogenesis of Takayasu arteritis (TA) is controversial. We aimed to study the presence of tertiary lymphoid organs (TLOs) in the aortic wall of TA patients.Methods: Hematoxylin and eosin–stained sections from aorta specimens from patients with TA were screened for TLOs. The presence of B cell aggregates (CD20), follicular dendritic cells (FDCs, CD21), and high endothelial venules (HEVs, PNAd) was investigated by immunohistochemistry. Immune cells from t...

  19. Tertiary Lymphoid Organs in Takayasu Arteritis

    OpenAIRE

    Clement, Marc; Galy, Adrien; Bruneval, Patrick; Morvan, Marion; Hyafil, Fabien; Benali, Khadija; Pasi, Nicoletta; Deschamps, Lydia; Pellenc, Quentin; Papo, Thomas; Nicoletti, Antonino; Sacre, Karim

    2016-01-01

    Objective The role of B cells in the pathogenesis of Takayasu arteritis (TA) is controversial. We aimed to study the presence of tertiary lymphoid organs (TLOs) in the aortic wall of TA patients. Methods Hematoxylin and eosin-stained sections from aorta specimens from patients with TA were screened for TLOs. The presence of B cell aggregates (CD20), follicular dendritic cells (FDCs, CD21), and high endothelial venules (HEVs, PNAd) was investigated by immunohistochemistry. Immune ce...

  20. Optimising Tertiary Student Accommodation within University Neighbourhoods

    OpenAIRE

    Ike, Nnenna; Baldwin, Claudia; Lathouras, Athena

    2017-01-01

    Tertiary students’ activities within neighbourhoods adjacent to universities engender positive and negative impacts that have consequences for neighbourhood sustainability. This might lead to studentification, a process that triggers physical, economic and socio-cultural transformation of university towns. Where non-student residents perceive negative impacts, it can lead to conflict and resentment towards the student population, mistrust between student and local resident groups and a decrea...

  1. Observation of long-range tertiary interactions during ligand binding by the TPP riboswitch aptamer.

    Science.gov (United States)

    Duesterberg, Van K; Fischer-Hwang, Irena T; Perez, Christian F; Hogan, Daniel W; Block, Steven M

    2015-12-28

    The thiamine pyrophosphate (TPP) riboswitch is a cis-regulatory element in mRNA that modifies gene expression in response to TPP concentration. Its specificity is dependent upon conformational changes that take place within its aptamer domain. Here, the role of tertiary interactions in ligand binding was studied at the single-molecule level by combined force spectroscopy and Förster resonance energy transfer (smFRET), using an optical trap equipped for simultaneous smFRET. The 'Force-FRET' approach directly probes secondary and tertiary structural changes during folding, including events associated with binding. Concurrent transitions observed in smFRET signals and RNA extension revealed differences in helix-arm orientation between two previously-identified ligand-binding states that had been undetectable by spectroscopy alone. Our results show that the weaker binding state is able to bind to TPP, but is unable to form a tertiary docking interaction that completes the binding process. Long-range tertiary interactions stabilize global riboswitch structure and confer increased ligand specificity.

  2. Influence Factor of Tertiary Students’ Employability Awareness Adjust Industry 4.0

    Directory of Open Access Journals (Sweden)

    Chun-Mei Chou

    2017-09-01

    Full Text Available This study aims to analyze the correlation (N=621 among tertiary students’ career planning, erecruiting adoption acceptance, and employability awareness in Taiwan. Tertiary students’ perceived career planning includes four factors, namely, self-appraisal, job expectancy, goal selection, and problem solving. E-recruiting adoption acceptance includes four factors, namely, playfulness, ease of use, effectiveness, and usefulness. Employability awareness includes four factors, namely, personal adaptability, employability ambition, career identity, and labour market. Participants responded to a 5-point Likert-type scale for each factor. Analysis was conducted using the structural equation modeling (SEM, and a good model fit was found for both the measurement and structural models. Research findings demonstrate that tertiary students’ career planning significantly and directly influences employability awareness. Career planning significantly and indirectly influences employability awareness by e-recruiting adoption acceptance. Tertiary students’ career planning and e-recruiting adoption acceptance fit the influence model and empirical data of employability awareness. Implications of this study, including the value of student self-assessment of their skills and utility of the e-recruiting to underpin personal career development planning and inform graduate recruitment processes, are discussed and recommendations made.

  3. Tukey max-stable processes for spatial extremes

    KAUST Repository

    Xu, Ganggang

    2016-09-21

    We propose a new type of max-stable process that we call the Tukey max-stable process for spatial extremes. It brings additional flexibility to modeling dependence structures among spatial extremes. The statistical properties of the Tukey max-stable process are demonstrated theoretically and numerically. Simulation studies and an application to Swiss rainfall data indicate the effectiveness of the proposed process. © 2016 Elsevier B.V.

  4. Cooperative formation of native-like tertiary contacts in the ensemble of unfolded states of a four-helix protein

    DEFF Research Database (Denmark)

    Bruun, Susanne W; Iesmantavicius, Vytautas; Danielsson, Jens

    2010-01-01

    In studies of the ensembles of unfolded structures of a four-helix bundle protein, we have detected the presence of potential precursors of native tertiary structures. These observations were based on the perturbation of NMR chemical shifts of the protein backbone atoms by single site mutations. ...

  5. Effects of osmolytes and macromolecular crowders on stable GAAA tetraloops and their preference for a CG closing base pair

    Directory of Open Access Journals (Sweden)

    Kaethe N. Leonard

    2018-02-01

    Full Text Available Osmolytes and macromolecular crowders have the potential to influence the stability of secondary structure motifs and alter preferences for conserved nucleic acid sequences in vivo. To further understand the cellular function of RNA we observed the effects of a model osmolyte, polyethylene glycol (PEG 200, and a model macromolecular crowding agent, PEG 8000, on the GAAA tetraloop motif. GAAA tetraloops are conserved, stable tetraloops, and are critical participants in RNA tertiary structure. They also have a thermodynamic preference for a CG closing base pair. The thermal denaturation of model hairpins containing GAAA loops was monitored using UV-Vis spectroscopy in the presence and absence of PEG 200 or PEG 8000. Both of the cosolutes tested influenced the thermodynamic preference for a CG base pair by destabilizing the loop with a CG closing base pair relative to the loop with a GC closing base pair. This result also extended to a related DNA triloop, which provides further evidence that the interactions between the loop and closing base pair are identical for the d(GCA triloop and the GAAA tetraloop. Our results suggest that in the presence of model PEG molecules, loops with a GC closing base pair may retain some preferential interactions with the cosolutes that are lost in the presence of the CG closing base pair. These results reveal that relatively small structural changes could influence how neutral cosolutes tune the stability and function of secondary structure motifs in vivo.

  6. Dynamical attraction to stable processes

    OpenAIRE

    Fisher, Albert M.; Talet, Marina

    2012-01-01

    We apply dynamical ideas within probability theory, proving an almost-sure invariance principle in log density for stable processes. The familiar scaling property (self-similarity) of the stable process has a stronger expression, that the scaling flow on Skorokhod path space is a Bernoulli flow. We prove that typical paths of a random walk with i.i.d. increments in the domain of attraction of a stable law can be paired with paths of a stable process so that, after applying a non-random regula...

  7. Highly Water-Stable Novel Lanthanide Wheel Cluster Organic Frameworks Featuring Coexistence of Hydrophilic Cagelike Chambers and Hydrophobic Nanosized Channels.

    Science.gov (United States)

    Zhou, Yuan-Yuan; Shi, Yang; Geng, Bing; Bo, Qi-Bing

    2017-02-15

    In attempts to investigate the potential luminescent sensing materials for sensitive detection of environmental pollutants, a new family of lanthanide wheel cluster organic frameworks (Ln-WCOFs) UJN-Ln4 has been constructed by employing one of the cycloalkane dicarboxylic acid derivatives. Adopting different conformations, the ligand links Ln 4 second building units (SBUs) and Ln 24 tertiary building units (TBUs) to form a unique wheel cluster layer-pillared 3D framework featuring the coexistence of hydrophobic nanosized channels and trigonal antiprism arrays with hydrophilic cagelike chambers. Apart from charming structures, isostructural UJN-Ln4 displays interesting porous, water-stable features. Systematic luminescence studies demonstrate that solvent water molecules can enhance the emission intensity of solid-state UJN-Eu4. Acting as a recyclable luminescent probe, water-stable luminescent UJN-Eu4 exhibits superior "turn-off" detection for Fe 3+ and Cu 2+ ions in aqueous solutions. Due to the nanosized hydrophobic channels, UJN-Eu4 also shows highly sensitive sensing of sodium dodecyl benzenesulfonate (SDBS) via luminescence "turn-on" respondence, representing the first example of quantitatively detecting SDBS in aqueous solutions by employing luminescent lanthanide frameworks as fluorescent sensors. The results also open up the exploration of novel luminescent Ln-WCOFs exhibiting unique applications in sensitive detecting of harmful pollutants in aquatic environments.

  8. Stable propagation of interacting crack systems and modeling of damage

    International Nuclear Information System (INIS)

    Bazant, Z.P.; Tabbara, M.R.

    1989-01-01

    This paper presents general thermodynamic criteria for the stable states and stable path of structures with an interacting system of cracks. In combination with numerical finite element results for various cracked structure geometries, these criteria indicate that the crack response path of structures may exhibit bifurcations, after which the symmetry of the crack system is broken and some cracks grow preferentially. The problem is of interest for the prediction of ultimate loads, ductility and energy absorption capability of nuclear concrete structures as well as structures made of composites and ceramics

  9. Pushing the frontiers of atomic models for protein tertiary structure ...

    Indian Academy of Sciences (India)

    of proteins in an explicit solvent environment at a much faster rate and 100 times longer time scales.28 Taking the protein folding in a new direction, researchers at the University of Washington developed a protein fold- ing video game Foldit that uses human visual prob- lem solving and strategy development capabilities ...

  10. Small catalytic RNA: Structure, function and application

    Energy Technology Data Exchange (ETDEWEB)

    Monforte, Joseph Albert [Univ. of California, Berkeley, CA (United States)

    1991-04-01

    We have utilized a combination of photochemical cross-linking techniques and site-directed mutagenesis to obtain secondary and tertiary structure information for the self-cleaving, self-ligating subsequence of RNA from the negative strand of Satellite Tobacco Ringspot Virus. We have found that the helical regions fold about a hinge to promoting four different possible tertiary interactions, creating a molecular of similar shape to a paperclip. A model suggesting that the ``paperclip`` and ``hammerhead`` RNAs share a similar three dimensional structure is proposed. We have used a self-cleaving RNA molecule related to a subsequence of plant viroids, a ``hammerhead,`` to study the length-dependent folding of RNA produced during transcription by RNA polymerase. We have used this method to determine the length of RNA sequestered within elongating E. coli and T7 RNA polymerase complexes. The data show that for E. coli RNA polymerase 121±s are sequestered within the ternary complex, which is consistent with the presence of an RNA-DNA hybrid within the transcription bubble, as proposed by others. The result for T7 RNA polymerase differs from E. coli RNA polymerase, with only 10{plus_minus}1 nucleotides sequestered within the ternary complex, setting a new upper limit for the minimum RNA-DNA required for a stable elongating complex. Comparisons between E. coli and T7 RNA polymerase are made. The relevance of the results to models or transcription termination, abortive initiation, and initiation to elongation mode transitions are discussed.

  11. Stable isotopes in Lithuanian bioarcheological material

    Science.gov (United States)

    Skipityte, Raminta; Jankauskas, Rimantas; Remeikis, Vidmantas

    2015-04-01

    Investigation of bioarcheological material of ancient human populations allows us to understand the subsistence behavior associated with various adaptations to the environment. Feeding habits are essential to the survival and growth of ancient populations. Stable isotope analysis is accepted tool in paleodiet (Schutkowski et al, 1999) and paleoenvironmental (Zernitskaya et al, 2014) studies. However, stable isotopes can be useful not only in investigating human feeding habits but also in describing social and cultural structure of the past populations (Le Huray and Schutkowski, 2005). Only few stable isotope investigations have been performed before in Lithuanian region suggesting a quite uniform diet between males and females and protein intake from freshwater fish and animal protein. Previously, stable isotope analysis has only been used to study a Stone Age population however, more recently studies have been conducted on Iron Age and Late medieval samples (Jacobs et al, 2009). Anyway, there was a need for more precise examination. Stable isotope analysis were performed on human bone collagen and apatite samples in this study. Data represented various ages (from 5-7th cent. to 18th cent.). Stable carbon and nitrogen isotope analysis on medieval populations indicated that individuals in studied sites in Lithuania were almost exclusively consuming C3 plants, C3 fed terrestrial animals, and some freshwater resources. Current investigation demonstrated social differences between elites and country people and is promising in paleodietary and daily life reconstruction. Acknowledgement I thank prof. dr. G. Grupe, Director of the Anthropological and Palaeoanatomical State Collection in Munich for providing the opportunity to work in her laboratory. The part of this work was funded by DAAD. Antanaitis-Jacobs, Indre, et al. "Diet in early Lithuanian prehistory and the new stable isotope evidence." Archaeologia Baltica 12 (2009): 12-30. Le Huray, Jonathan D., and Holger

  12. Prevalence and mitigation strategies of HIV/AIDS infection risks in Namibian tertiary education institutional hostels

    OpenAIRE

    Zimba, Roderick F.; Likando, Gilbert N.

    2014-01-01

    Abstract The purpose of this study was to investigate risk factors that could promote HIV infection amongst adolescents and young adults living in tertiary educational institutional hostels in Namibia. Employing structured questionnaires and focus group discussions, we sought to answer questions pertaining to factors, beliefs systems, values, traditions and sexual relations that could promote HIV infection in the student hostels. The data on these issues were gathered from 306 male and 314 fe...

  13. Adolescent smoking and tertiary education: opposing pathways linking socio-economic background to alcohol consumption.

    Science.gov (United States)

    Green, Michael J; Leyland, Alastair H; Sweeting, Helen; Benzeval, Michaela

    2016-08-01

    If socio-economic disadvantage is associated with more adolescent smoking, but less participation in tertiary education, and smoking and tertiary education are both associated with heavier drinking, these may represent opposing pathways to heavy drinking. This paper examines contextual variation in the magnitude and direction of these associations. Comparing cohort studies. United Kingdom. Participants were from the 1958 National Child Development Study (NCDS58; n = 15 672), the British birth cohort study (BCS70; n = 12 735) and the West of Scotland Twenty-07 1970s cohort (T07; n = 1515). Participants self-reported daily smoking and weekly drinking in adolescence (age 16 years) and heavy drinking (> 14/21 units in past week) in early adulthood (ages 22-26 years). Parental occupational class (manual versus non-manual) indicated socio-economic background. Education beyond age 18 was coded as tertiary. Models were adjusted for parental smoking and drinking, family structure and adolescent psychiatric distress. Respondents from a manual class were more likely to smoke and less likely to enter tertiary education (e.g. in NCDS58, probit coefficients were 0.201 and -0.765, respectively; P education were more likely to drink heavily in early adulthood (0.110 for males, 0.182 for females; P education. With some variation in magnitude, these associations were consistent across all three cohorts. In Britain, young adults are more likely to drink heavily both if they smoke and participate in tertiary education (college and university) despite socio-economic background being associated in opposite directions with these risk factors. © 2016 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

  14. Crime and Crime Management in Nigeria Tertiary Institutions

    Science.gov (United States)

    Adebanjo, Margaret Adewunmi

    2014-01-01

    This paper examines crime and its management in Nigerian tertiary institutions. Tertiary institutions today have become arenas for crime activities such as rape, cultism, murder, theft, internet fraud, drug abuse, and examination malpractices. This paper delves into what crime is, and its causes; and the positions of the law on crime management.…

  15. Determinants of propensity of tertiary agricultural students in Ghana ...

    African Journals Online (AJOL)

    The study aimed to identify factors that affect the decision of tertiary agricultural students in Ghana to enter agribusiness as a self-employment venture after graduation. The results showed that tertiary agricultural students in Ghana were predominantly males with little or no farming background. They had a rather moderate ...

  16. Capacity of non-tertiary Kenyan health facilities selected for ...

    African Journals Online (AJOL)

    Capacity of non-tertiary Kenyan health facilities selected for decentralised dental training. ... Design: A descriptive cross-sectional study. Setting: The Dental departments of six non-tertiary Kenyan health facilities. Main outcome measures: Capacity of the hospitals to be used as sites for decentralised dental education.

  17. Education and training in recreation management at tertiary ...

    African Journals Online (AJOL)

    Tertiary institutions should realise the gaps and opportunities that could be filled in recreation management training. The current article reviews literature focussing on the ... This information is used to stress the need to train professionals in recreation management at tertiary institutions. Recommendations are made as to the ...

  18. Massification and Quality Assurance in Tertiary Education: The ...

    African Journals Online (AJOL)

    The study sets out to examine massification and its impact on quality assurance in tertiary education and the extent to which lecturer–student ratio, adequacy of infrastructure and pedagogical resources affect quality in tertiary institutions. Two research questions and one hypothesis were posed to guide the investigation.

  19. Ensuring Effective Mentoring in Tertiary Institutions in Anambra State ...

    African Journals Online (AJOL)

    This paper concerns itself only with ascertaining the strategies that could ensure effective mentoring in tertiary institutions. The survey method was employed. The study population comprised 78 teacher educators in tertiary institutions in Anambra State. One research question guided the study while one null hypothesis was ...

  20. Academic mentoring and the future of tertiary education in Nigeria ...

    African Journals Online (AJOL)

    Tertiary education is a major outlet for the provision of high manpower for national development. This paper therefore highlighted the challenges of tertiary education in Nigeria, early perspectives of mentoring undergraduates, the rationale for academic mentoring, the role of a mentor, and the role of library as catalyst in the ...

  1. Opinions of Nigerian students in tertiary institutions on family size ...

    African Journals Online (AJOL)

    The study examined the opinions of Nigerian students in tertiary institutions on their ideal family size. It was conducted among students in four tertiary institutions in Edo State of Nigeria. A sample size of 454 final year students was randomly drawn from the halls of residence in the institutions using the stratified sampling ...

  2. The Impediments Facing Community Engagement in Omani Educational Tertiary Institutions

    Science.gov (United States)

    Issa, Jinan Hatem

    2016-01-01

    Prior to the vital role that social capital plays in accomplishing prosperity for any educational tertiary institution, it was emphasised in several countries' agendas, including the Sultanate of Oman. This study endeavours to explore the impediments facing the enhancement of the social capital in Omani educational tertiary institutions through…

  3. Literacy Skills Development for Tertiary Institutions: A Case Study of ...

    African Journals Online (AJOL)

    Literacy Skills Development for Tertiary Institutions: A Case Study of the University of Calabar. ... These were drawn from five faculties, namely Education, Social Sciences, Law, Arts and Agriculture. The study observed that there is a ... more literacy skills. Key Words: Literacy skills, university, Nigeria, tertiary institution ...

  4. Maternal mortality ratio in a Tertiary Hospital offering free maternity ...

    African Journals Online (AJOL)

    AbstRACt. Aim: To determine annual trends of maternal mortality ratio in a tertiary hospital offering free maternity services. settings and Design: This retrospective descriptive study was conducted at the Mother and Child Hospital Akure, Ondo. State, a busy purpose‑built tertiary care facility premised on evidence‑based ...

  5. The Returns of Investment in Tertiary Technological Education in Greece.

    Science.gov (United States)

    Tsamadias, Constantinos

    2002-01-01

    Return on investment was estimated from earnings data on Greek graduates of tertiary technological education and secondary education, using elaborate and Mincerian estimation models. Return rates were similar in both methods. Differences were greater for females. Both societal and individual investment in tertiary technological education was…

  6. Terminology development at tertiary institutions: A South African ...

    African Journals Online (AJOL)

    Terminology development at tertiary institutions: A South African perspective. M Alberts. Abstract. There is a dire need in South Africa for multilingual polythematic terminology. Currently no tertiary institution presents terminology theory and practice as a fully-fledged subject and there is also no sufficient mechanism for the ...

  7. Stable Continental Region Earthquakes in South China

    Science.gov (United States)

    Liu, L.

    This paper reviews some remarkable characteristics of earthquakes in a Stable Continental Region (SCR) of the South China Block (SCB). The kernel of the SCB is the Yangtze platform solidified in late Proterozoic time, with continental growth to the southeast by a series of fold belts in Paleozoic time. The facts that the deviatoric stress is low, the orientations of the major tectonic features in the SCB are substantially normal to the maximum horizontal principal stress, and a relatively uniform crust, seem to be the major reasons for lack of significant seismicity in most regions of the SCB. Earthquakes in this region are mainly associated with three seismic zones: (1) the Southeast China Coast seismic zone related to Guangdong-Fujian coastal folding belt (associated with Eurasia-Philippine Sea plate collision); (2) the Southern Yellow Sea seismic zone associated with continental shelf rifts and basins; and (3) the Downstream Yangtze River seismic zone spatially coinciding with Tertiary rifts and basin development. All three seismic zones are close to one or two major economic and population centers in the SCB so that they pose significant seismic hazards. Earthquake focal mechanisms in the SCB are consistent with strike-slip to normal faulting stress regimes. Because of the global and national economic significance of the SCB and its dense population, the seismic hazard of the region is of outstanding importance. Comparing the SCB with another less developed region, a pending earthquake with the same size and tectonic setting would cause substantially more severe social and economic losses in the SCB. This paper also compiles an inventory of historic moderate to great earthquakes in the SCB; most of the data are not widely available in English literature.

  8. Shelf-Stable Food Safety

    Science.gov (United States)

    ... is an MRE? Is an MRE shelf stable? What foods are packaged in retort packages? What is aseptic ... type of package is used for aseptic processing? What foods are packaged in aseptic packages? Can I microwave ...

  9. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  10. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  11. MetalionRNA: computational predictor of metal-binding sites in RNA structures.

    Science.gov (United States)

    Philips, Anna; Milanowska, Kaja; Lach, Grzegorz; Boniecki, Michal; Rother, Kristian; Bujnicki, Janusz M

    2012-01-15

    Metal ions are essential for the folding of RNA molecules into stable tertiary structures and are often involved in the catalytic activity of ribozymes. However, the positions of metal ions in RNA 3D structures are difficult to determine experimentally. This motivated us to develop a computational predictor of metal ion sites for RNA structures. We developed a statistical potential for predicting positions of metal ions (magnesium, sodium and potassium), based on the analysis of binding sites in experimentally solved RNA structures. The MetalionRNA program is available as a web server that predicts metal ions for RNA structures submitted by the user. The MetalionRNA web server is accessible at http://metalionrna.genesilico.pl/.

  12. Coalfields obscured by Mesozoic - Tertiary cover in Asturias. Cuencas carboniferas ocultas por la cobertera mesozoica - terciaria en Asturias

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Fernandez, L.

    1988-01-01

    The fundamental objective is to discover whether there are productive carboniferous deposits concealed by the Mesozoic-Tertiary cover and thus to assess the likelihood of the existence of coal deposits in potentially interesting areas where, at present, there are insufficient geological data. It should be pointed out that the structures hidden below the Mesozoic-Tertiary cover which form the subject of this study, contain highly productive carboniferous strata in the areas situated immediately to the south and which produce 4.9 mt of saleable coal per year.

  13. Stable Boundary Layer Education (STABLE) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Turner, David D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The properties of, and the processes that occur in, the nocturnal stable boundary layer are not well understood, making it difficult to represent adequately in numerical models. The nocturnal boundary layer often is characterized by a temperature inversion and, in the Southern Great Plains region, a low-level jet. To advance our understanding of the nocturnal stable boundary layer, high temporal and vertical resolution data on the temperature and wind properties are needed, along with both large-eddy simulation and cloud-resolving modeling.

  14. Tertiary ice sheet dynamics: The Snow Gun Hypothesis

    Science.gov (United States)

    Prentice, M. L.; Matthews, R. K.

    1991-04-01

    We observe strong negative correlation between Tertiary low- to mid-latitude planktonic foraminiferal δ18O and the difference between these data and coeval benthic foraminiferal δ18O. Late Quaternary data do not show this correlation. Coupling statistical model/δ18O comparisons and evidence for Antarctic ice and ocean temperature variation, we infer that Tertiary ice volume, recorded by tropical planktonic δ18O, increased as the deep ocean warmed. Because the isotopic signatures of deepwater temperature variation and ice volume change were of opposite sign, the sum of these signals in Tertiary benthic δ18O became lost in the noise. This renders low correlation between Tertiary planktonic and benthic δ18O time series compared to late Quaternary data. We contend that Tertiary ice sheet growth was commonly driven by warming of deep water from low- to mid-latitude marginal seas (snow gun hypothesis). In contrast, late Quaternary ice sheets grew as deep water, formed at high latitude, cooled. Because tectonic forcing and orbital forcing at low-latitude primarily controlled production and temperature variations of this Warm Saline Deep Water, these influences largely dictated Tertiary ice volume fluctuations. Through the Tertiary, we infer ice volume fluctuations to be an important component of sea level history on timescales between 103 and 107 years.

  15. Factors influencing phase-disengagement rates in solvent-extraction systems employing tertiary amine extractants

    International Nuclear Information System (INIS)

    Moyer, B.A.; McDowell, W.J.

    1981-01-01

    The primary purpose of the present investigation was to examine the effects of amine size and structure on phase disengagement. Nine commercial tertiary amines were tested together with four laboratory-quality amines for uranium extraction and both organic-continuous (OC) and aqueous-continuous (AC) phase disengagement under Amex-type conditions. Synthetic acid sulfate solutions with and without added colloidal silica and actual ore leach solutions were used as the aqueous phases. Phase disengagement results were correlated with amine size and branching and solution wetting behavior on a silicate (glass) surface. The results suggest that the performance of some Amex systems may be improved by using branched chain tertiary amine extractants of higher molecular weight than are now normally used

  16. Detonation of Meta-stable Clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, Allen; Kuhl, Allen L.; Fried, Laurence E.; Howard, W. Michael; Seizew, Michael R.; Bell, John B.; Beckner, Vincent; Grcar, Joseph F.

    2008-05-31

    We consider the energy accumulation in meta-stable clusters. This energy can be much larger than the typical chemical bond energy (~;;1 ev/atom). For example, polymeric nitrogen can accumulate 4 ev/atom in the N8 (fcc) structure, while helium can accumulate 9 ev/atom in the excited triplet state He2* . They release their energy by cluster fission: N8 -> 4N2 and He2* -> 2He. We study the locus of states in thermodynamic state space for the detonation of such meta-stable clusters. In particular, the equilibrium isentrope, starting at the Chapman-Jouguet state, and expanding down to 1 atmosphere was calculated with the Cheetah code. Large detonation pressures (3 and 16 Mbar), temperatures (12 and 34 kilo-K) and velocities (20 and 43 km/s) are a consequence of the large heats of detonation (6.6 and 50 kilo-cal/g) for nitrogen and helium clusters respectively. If such meta-stable clusters could be synthesized, they offer the potential for large increases in the energy density of materials.

  17. A Study on the Condensation Reaction of 4-Amino-3,5-dimethyl-1,2,4-triazole with Benzaldehydes: Structure and Spectroscopic Properties of Some New Stable Hemiaminals

    Directory of Open Access Journals (Sweden)

    Katarzyna Wajda-Hermanowicz

    2015-09-01

    Full Text Available Studies on the stable hemiaminals and Schiff bases formation in the reaction of substituted benzaldehydes with primary 3,5-dimethyl-1,2,4-triazole 4-amine were carried out under neutral conditions. These products were investigated by IR, Raman, MS, 1H- and 13C-NMR spectra as well as by X-ray crystallography. The effect of reaction conditions: temperature, polarity of the solvents utilized, substrate concentration and the ortho and para benzaldehyde substituents on the yield of products was also examined.

  18. Forensic analysis of tertiary-butyl alcohol (TBA) detections in a hydrocarbon-rich groundwater basin.

    Science.gov (United States)

    Quast, Konrad W; Levine, Audrey D; Kester, Janet E; Fordham, Carolyn L

    2016-04-01

    Tertiary-butyl alcohol (TBA), a high-production volume (HPV) chemical, was sporadically detected in groundwater and coalbed methane (CBM) wells in southeastern Colorado's hydrocarbon-rich Raton Basin. TBA concentrations in shallow water wells averaged 75.1 μg/L, while detections in deeper CBM wells averaged 14.4 μg/L. The detection of TBA prompted a forensic investigation to try to identify potential sources. Historic and recent data were reviewed to determine if there was a discernable pattern of TBA occurrence. Supplemental samples from domestic water wells, monitor wells, CBM wells, surface waters, and hydraulic fracturing (HF) fluids were analyzed for TBA in conjunction with methyl tertiary-butyl ether (MTBE) and ethyl tertiary-butyl ether (ETBE), proxies for evidence of contamination from reformulated gasoline or associated oxygenates. Exploratory microbiological sampling was conducted to determine if methanotrophic organisms co-occurred with TBA in individual wells. Meaningful comparisons of historic TBA data were limited due to widely varying reporting limits. Mapping of TBA occurrence did not reveal any spatial patterns or physical associations with CBM operations or contamination plumes. Additionally, TBA was not detected in HF fluids or surface water samples. Given the widespread use of TBA in industrial and consumer products, including water well completion materials, it is likely that multiple diffuse sources exist. Exploratory data on stable isotopes, dissolved gases, and microbial profiling provide preliminary evidence that methanotrophic activity may be producing TBA from naturally occurring isobutane. Reported TBA concentrations were significantly below a conservative risk-based drinking water screening level of 8000 μg/L derived from animal toxicity data.

  19. Job satisfaction among anesthesiologists at a tertiary hospital in Nigeria.

    Science.gov (United States)

    Rukewe, Ambrose; Fatiregun, Akinola; Oladunjoye, Adeolu O; Oladunjoye, Olubunmi O

    2012-01-01

    We assessed job satisfaction among anesthesiologists at a tertiary hospital in Nigeria and identified elements of job stress and dissatisfaction. A cross-sectional study design was employed; a structured self-administered questionnaire was distributed, which focused on sociodemographic data, rating of job satisfaction, identification of stressors, and work relationships. Out of 55 questionnaires distributed, 46 (83.6%) completed questionnaires were returned. Overall, 27 (58.7%) of the anesthesiologists were satisfied with their job. While 8.7% were very satisfied (grade 5), 6.5% were very dissatisfied (grade 1) with their job. The stressors identified by the respondents were time pressures, long working hours with complaints of insufficient sleep, and employment status. Among the respondents, the medical officers were the most discontented (9 out of 12, 75%), followed by senior registrars (5 out of 9, 56%). A high percentage of participants (54.1%) declared that the one change if implemented that would enhance their job satisfaction was having a definite closing time. Our results showed that despite the demanding nature of anesthesiology as a specialty, many anesthesiologists were contented with their job.

  20. Job satisfaction among anesthesiologists at a tertiary hospital in Nigeria

    Directory of Open Access Journals (Sweden)

    Ambrose Rukewe

    2012-01-01

    Full Text Available Background : We assessed job satisfaction among anesthesiologists at a tertiary hospital in Nigeria and identified elements of job stress and dissatisfaction. Methods : A cross-sectional study design was employed; a structured self-administered questionnaire was distributed, which focused on sociodemographic data, rating of job satisfaction, identification of stressors, and work relationships. Results : Out of 55 questionnaires distributed, 46 (83.6% completed questionnaires were returned. Overall, 27 (58.7% of the anesthesiologists were satisfied with their job. While 8.7% were very satisfied (grade 5, 6.5% were very dissatisfied (grade 1 with their job. The stressors identified by the respondents were time pressures, long working hours with complaints of insufficient sleep, and employment status. Among the respondents, the medical officers were the most discontented (9 out of 12, 75%, followed by senior registrars (5 out of 9, 56%. A high percentage of participants (54.1% declared that the one change if implemented that would enhance their job satisfaction was having a definite closing time. Conclusion : Our results showed that despite the demanding nature of anesthesiology as a specialty, many anesthesiologists were contented with their job.

  1. Aquatic Life Criteria - Methyl Tertiary-Butyl Ether (MTBE)

    Science.gov (United States)

    Information pertaining to the 1999 Acute and Chronic Ambient Aquatic Life Water Quality Criteria for Methyl Tertiary-Butyl Ether (MTBE) for freshwater and salt water. Information includes the safe levels of MTBE that should protect the majority of species.

  2. Social Activities and Manifest Anxiety among Freshmen in Tertiary ...

    African Journals Online (AJOL)

    ) in tertiary institutions in Lagos state of Nigeria were analysed to determine the relationship between social activities and manifest anxiety. Social activities in the study were measured in terms of freshmen adjustment to religious activities and ...

  3. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    Rekers, J.W.

    1986-01-01

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  4. Monitoring of stable glaucoma patients

    NARCIS (Netherlands)

    K.M. Holtzer-Goor (Kim); N.S. Klazinga (Niek); M.A. Koopmanschap (Marc); H.G. Lemij (Hans); T. Plochg; E. van Sprundel (Esther)

    2010-01-01

    textabstractA high workload for ophthalmologists and long waiting lists for patients challenge the organization of ophthalmic care. Tasks that require less specialized skills, like the monitoring of stable (well controlled) glaucoma patients could be substituted from ophthalmologists to other

  5. Assessment Quality in Tertiary Education: An Integrative Literature Review

    OpenAIRE

    Gerritsen-van Leeuwenkamp, Karin; Joosten-ten Brinke, Desirée; Kester, Liesbeth

    2018-01-01

    In tertiary education, inferior assessment quality is a problem that has serious consequences for students, teachers, government, and society. A lack of a clear and overarching conceptualization of assessment quality can cause difficulties in guaranteeing assessment quality in practice. Thus, the aim of this study is to conceptualize assessment quality in tertiary education by providing an overview of the assessment quality criteria, their influences, the evaluation of the assessment quality ...

  6. Challenges with Tertiary-Level Mechatronic Fluid Power

    DEFF Research Database (Denmark)

    Dransfield, Peter; Conrad, Finn

    1996-01-01

    As authors we take the view that mechatronics, as it relates to fluid power, has three levels which we designate as primary, secondary and tertiary. A brief review of the current status of fluid power, hydraulic and pneumatic, and of electronic control of it is presented and discussed. The focus...... is then on tertiary-level mechatronic fluid power and the challenges to it being applied successfully....

  7. EXPLORING THE TERTIARY EFL STUDENTS' ACADEMIC WRITING COMPETENCIES

    OpenAIRE

    Aunurrahman Aunurrahman; Fuad Abdul Hamied Hamied; Emi Emilia

    2017-01-01

    For tertiary English as a Foreign Language (EFL) students, academic writing is not an easy task. It requires knowledge of the academic writing genres with their particular linguistic features. Moreover, academic writing demands good critical thinking. This research aims to explore the students' academic writing competencies that also focus on critical thinking. The research involved thirty-six first-year tertiary EFL students from a regular class of a private university in Pontianak, West Kal...

  8. Emergency peripartum hysterectomy: The experience of a tertiary referral hospital

    OpenAIRE

    Y. Mesbah; A. Ragab; E. Fialla; R. Barakat; A. Badawy; Ahmed Ragab

    2013-01-01

    Objective(s): The aim of this study was to review the frequency, indication, associated risk factors, rates of maternal morbidity and mortality as well as neonatal outcome after emergency peripartum hysterectomy at a tertiary care referral hospital. Study design: A retrospective observational study carried out from November 2008 to 2011. Patients and methods: The study comprised of 29 patients at Mansoura University Hospitals a tertiary referral hospital Egypt. Frequency, indications, a...

  9. Evidence of carpinus (betulaceae) in the late tertiary (pliocene) of alabama.

    Science.gov (United States)

    Stults, Debra Z; Axsmith, Brian J; Haywick, Douglas

    2002-09-01

    Carpinus is a common and widespread element of the modern North American forest vegetation, but its scant fossil record on the continent is perplexing, especially considering the abundant and relatively continuous record of the genus in the Tertiary of Europe and Asia. Despite earlier claims of Tertiary Carpinus remains, recent reviews have indicated that a definitive post-Eocene Tertiary record of the genus in North America is lacking. Therefore, it remains uncertain if Carpinus was present but left no clear fossil record or if the genus became extinct in North America and migrated back to the continent more recently. A reinvestigation of the Citronelle Formation paleoflora has yielded conclusive evidence for the presence of Carpinus in the Gulf Coastal Plain of Alabama during the Pliocene based upon the discovery of a nutlet bract. Carpinus bracts are distinctive and consist of a central bract fused basally with two lateral bractlets. This specimen provides proof of the existence of Carpinus on this continent by the Pliocene Epoch, and any future research on the biogeography of the genus must consider this as the earliest, post-Eocene record of the genus in North America based on unequivocal reproductive structures.

  10. Medical neglect at a tertiary paediatric hospital.

    Science.gov (United States)

    Parmeter, Julia; Tzioumi, Dimitra; Woolfenden, Susan

    2018-03-01

    Medical neglect is under-researched and the extent of the problem in Australia is unknown. We conducted a review of the referrals for medical neglect to the Child Protection Unit (CPU) at a tertiary children's hospital in Sydney over a 5 years period, from 2011 to 2016, to determine what medical conditions are being referred, the reason for the medical neglect concern and whether cases are managed in line with American Academy of Pediatrics (AAP) guideline on medical neglect. 61 cases of medical neglect were identified, constituting 4.1% of all referrals to the Child Protection Unit for physical abuse and neglect. There was a wide variety of medical conditions. Most were chronic medical conditions (87%). The top two medical conditions were chronic and complex multi-system disorders (37.7%) and endocrine disorders (18%). The majority of medical neglect were related to concerns that the caregivers were unwilling to follow medical advice (45.9%) or unable to provide necessary medical care (26.2%). In line with the AAP guideline on medical neglect, all cases were managed by addressing communication difficulties (100%) and resource issues were addressed in 80% of cases. A report to statutory child protection agencies was made in 50% of cases. Directly observed therapy and medical contracts were used in 30% and 26% of cases. We conclude that children with chronic medical conditions may be at risk of medical neglect. Communication difficulties were a factor in all cases. Statutory agency intervention is often required. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. CLINICAL SPECTRUM OF HYPONATRAEMIA IN TERTIARY CENTRE

    Directory of Open Access Journals (Sweden)

    Suresh Chincholi

    2017-02-01

    Full Text Available BACKGROUND Hyponatraemia is defined as a serum sodium level less than 135 mEq/L. High mortality among the patients of hyponatraemia is secondary to the underlying medical condition. Frequency is high in elderly patients. MATERIALS AND METHODS The study was conducted at a tertiary care centre (Basaveshwar Teaching and General Hospital, Gulbarga, from the period September 2014 to August 2016. These patients were evaluated for the underlying cause of hyponatraemia, which included detailed history and physical examination followed by appropriate laboratory investigations. Patients were followed up till the hyponatraemia was treated or patients were discharged from the hospital. RESULTS 100 patients of hyponatraemia were included in the study. 46% of the patients were asymptomatic. 33% patients had lethargy, 28% patients had postural dizziness and 19% had abnormal behaviour. Overall incidence of hyponatraemia was 4.58% in the hospitalised population, whereas its incidence in ICU patients was 22.4%. Twelve patients of symptomatic severe hyponatraemia were treated with hypertonic saline infusion, 25% patients were given loop diuretics with oral supplementation of sodium chloride for free water excretion in SIADH cases and in patients with hypervolaemia, hyponatraemia, fluid restriction was advised to 44 patients, oral supplementation of sodium chloride was given in 36 patients and 64 patients received normal saline. 9 patients included in the study died, 5 of which had advanced cirrhosis of liver as underlying cause. One patient developed Osmotic Demyelination Syndrome (ODS. CONCLUSION The possible cause of hyponatraemia should always be sought as outcome in severe hyponatraemia is governed by aetiology, and not by the serum sodium level. Treatment of severe symptomatic hyponatraemia with hypertonic saline is safe if recommendation for the rate of correction of hyponatraemia is strictly followed.

  12. Tertiary lymphoid organs in Takayasu Arteritis

    Directory of Open Access Journals (Sweden)

    Marc eClement

    2016-04-01

    Full Text Available Objective: The role of B cells in the pathogenesis of Takayasu arteritis (TA is controversial. We aimed to study the presence of tertiary lymphoid organs (TLOs in the aortic wall of TA patients.Methods: Hematoxylin and eosin–stained sections from aorta specimens from patients with TA were screened for TLOs. The presence of B cell aggregates (CD20, follicular dendritic cells (FDCs, CD21, and high endothelial venules (HEVs, PNAd was investigated by immunohistochemistry. Immune cells from the adventitial layer of one patient were characterized by flow cytometry. Demographic, medical history, laboratory, imaging, treatment and follow up data were extracted from medical records.Results: Aorta specimens from Bentall procedures were available from 7 patients (five female, aged 22 to 57 years with TA. Surgical treatment was performed at TA diagnosis (n=4 or at a median of 108 months [84-156] after TA diagnosis. Disease was active at surgery in four patients according to NIH score. B cell aggregates-TLOs containing HEVs were observed in the adventitia of all but one patient.. Of note, ectopic follicles containing CD21+ FDCs were found in all patients (4/4 with increased aortic FDG uptake before surgery but were absent in all but one patients (2/3 with no FDG uptake. In addition, flow cytometry analysis confirmed the accumulation of memory/germinal center–like B cells in the adventitial layer and showed the presence of antigen-experienced T follicular helper cells.Conclusion: Ectopic lymphoid neogenesis displaying functional features can be found in the aortic wall of a subset of patients with active TA. The function of these local B cell clusters on the pathogenesis of TA remains to be elucidated.

  13. Tertiary Lymphoid Organs in Takayasu Arteritis.

    Science.gov (United States)

    Clement, Marc; Galy, Adrien; Bruneval, Patrick; Morvan, Marion; Hyafil, Fabien; Benali, Khadija; Pasi, Nicoletta; Deschamps, Lydia; Pellenc, Quentin; Papo, Thomas; Nicoletti, Antonino; Sacre, Karim

    2016-01-01

    The role of B cells in the pathogenesis of Takayasu arteritis (TA) is controversial. We aimed to study the presence of tertiary lymphoid organs (TLOs) in the aortic wall of TA patients. Hematoxylin and eosin-stained sections from aorta specimens from patients with TA were screened for TLOs. The presence of B cell aggregates (CD20), follicular dendritic cells (FDCs, CD21), and high endothelial venules (HEVs, PNAd) was investigated by immunohistochemistry. Immune cells from the adventitial layer of one patient were characterized by flow cytometry. Demographic, medical history, laboratory, imaging, treatment, and follow-up data were extracted from medical records. Aorta specimens from Bentall procedures were available from seven patients (5 females, aged 22-57 years) with TA. Surgical treatment was performed at TA diagnosis (n = 4) or at a median of 108 months (84-156) after TA diagnosis. Disease was active at surgery in four patients according to NIH score. B cell aggregates-TLOs containing HEVs were observed in the adventitia of all but one patient. Of note, ectopic follicles containing CD21(+) FDCs were found in all patients (4/4) with increased aortic (18)F-fluoro-deoxyglucose (FDG) uptake before surgery but were absent in all but one patients (2/3) with no FDG uptake. In addition, flow cytometry analysis confirmed the accumulation of memory/germinal center-like B cells in the adventitial layer and showed the presence of antigen-experienced T follicular helper cells. Ectopic lymphoid neogenesis displaying functional features can be found in the aortic wall of a subset of patients with active TA. The function of these local B cell clusters on the pathogenesis of TA remains to be elucidated.

  14. Binocular diplopia in a tertiary hospital: Aetiology, diagnosis and treatment.

    Science.gov (United States)

    Merino, P; Fuentes, D; Gómez de Liaño, P; Ordóñez, M A

    2017-12-01

    To study the causes, diagnosis and treatment in a case series of binocular diplopia. A retrospective chart review was performed on patients seen in the Diplopia Unit of a tertiary centre during a one-year period. Diplopia was classified as: acute≤1 month since onset; subacute (1-6 months); and chronic (>6 months). Resolution of diplopia was classified as: spontaneous if it disappeared without treatment, partial if the course was intermittent, and non-spontaneous if treatment was required. It was considered a good outcome when diplopia disappeared completely (with or without treatment), or when diplopia was intermittent without significantly affecting the quality of life. A total of 60 cases were included. The mean age was 58.65 years (60% female). An acute or subacute presentation was observed in 60% of the patients. The mean onset of diplopia was 82.97 weeks. The most frequent aetiology was ischaemic (45%). The most frequent diagnosis was sixth nerve palsy (38.3%), followed by decompensated strabismus (30%). Neuroimaging showed structural lesions in 17.7% of the patients. There was a spontaneous resolution in 28.3% of the cases, and there was a good outcome with disappearance of the diplopia in 53.3% at the end of the study. The most frequent causes of binocular diplopia were cranial nerve palsies, especially the sixth cranial nerve, followed by decompensated strabismus. Structural lesions in imaging tests were more than expected. Only one third of patients had a spontaneous resolution, and half of them did not have a good outcome despite of treatment. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  15. Toward Practical Secure Stable Matching

    Directory of Open Access Journals (Sweden)

    Riazi M. Sadegh

    2017-01-01

    Full Text Available The Stable Matching (SM algorithm has been deployed in many real-world scenarios including the National Residency Matching Program (NRMP and financial applications such as matching of suppliers and consumers in capital markets. Since these applications typically involve highly sensitive information such as the underlying preference lists, their current implementations rely on trusted third parties. This paper introduces the first provably secure and scalable implementation of SM based on Yao’s garbled circuit protocol and Oblivious RAM (ORAM. Our scheme can securely compute a stable match for 8k pairs four orders of magnitude faster than the previously best known method. We achieve this by introducing a compact and efficient sub-linear size circuit. We even further decrease the computation cost by three orders of magnitude by proposing a novel technique to avoid unnecessary iterations in the SM algorithm. We evaluate our implementation for several problem sizes and plan to publish it as open-source.

  16. Complex tectonic and tectonostratigraphic evolution of an Alpine foreland basin: The western Duero Basin and the related Tertiary depressions of the NW Iberian Peninsula

    Science.gov (United States)

    Martín-González, F.; Heredia, N.

    2011-04-01

    The tectonic and tectonostratigaphic evolution of foreland basins and related Tertiary depressions are the key to investigate deformation history and the uplifting of the continental lithosphere of the Alpine-Pyrenean Orogeny. The northern part of the Duero basin is the foreland basin of the Cantabrian Mountains, which are, in turn, the western part of the Pyrenean Orogen. We have studied the western sharp end of the Duero foreland basin, and its relation to the Tertiary deposits of the NW Iberian Peninsula and the topography evolution. In order to propose a coherent tectonic and tectonosedimentary model that could explain all Tertiary deposits, we have analysed the depositional environment, stratigraphic sequences, paleocurrents and established a correlation of the main outcrops. Besides, a detailed structural mapping of the Alpine structures that limit and affect the main Tertiary outcrops has been carried out. The Tertiary deposits of the NW Iberian Peninsula depressions are affected and fragmented by Alpine structures that limit their extensions and locations. The stratigraphic succession is similar in the NW Tertiary outcrops; they are mainly terrigenous and carbonated continental deposits formed by assemblage of alluvial fans developed at the mountains front, in arid or semiarid conditions. Three formations can be identified in the main depressions: Toral Fm, Santalla Fm and Médulas Fm. The NW Tertiary outcrops were the western deposits of the Duero foreland basin that surrounded the lateral termination of the Pyrenean Orogen. These deposits were fragmented and eroded by the subsequent uplift of the Galaico-Leoneses Mountains and the NE-SW strike-slip faults activity (broken foreland basin). Only the latest stages of some of these outcrops can be considered as intramontane basins as traditionally have been interpreted. The sedimentation started in the northeast (Oviedo-Infiesto) during the Eocene and migrated to the west (As Pontes) during the Late Oligocene

  17. Towards stable acceleration in LINACS

    CERN Document Server

    Dubrovskiy, A D

    2014-01-01

    Ultra-stable and -reproducible high-energy particle beams with short bunches are needed in novel linear accelerators and, in particular, in the Compact Linear Collider CLIC. A passive beam phase stabilization system based on a bunch compression with a negative transfer matrix element R56 and acceleration at a positive off-crest phase is proposed. The motivation and expected advantages of the proposed scheme are outlined.

  18. Medieval horse stable; the results of multi proxy interdisciplinary research.

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle.

  19. Medieval Horse Stable; The Results of Multi Proxy Interdisciplinary Research

    Science.gov (United States)

    Dejmal, Miroslav; Lisá, Lenka; Fišáková Nývltová, Miriam; Bajer, Aleš; Petr, Libor; Kočár, Petr; Kočárová, Romana; Nejman, Ladislav; Rybníček, Michal; Sůvová, Zdenka; Culp, Randy; Vavrčík, Hanuš

    2014-01-01

    A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle. PMID:24670874

  20. Medieval horse stable; the results of multi proxy interdisciplinary research.

    Directory of Open Access Journals (Sweden)

    Miroslav Dejmal

    Full Text Available A multi proxy approach was applied in the reconstruction of the architecture of Medieval horse stable architecture, the maintenance practices associated with that structure as well as horse alimentation at the beginning of 13th century in Central Europe. Finally, an interpretation of the local vegetation structure along Morava River, Czech Republic is presented. The investigated stable experienced two construction phases. The infill was well preserved and its composition reflects maintenance practices. The uppermost part of the infill was composed of fresh stabling, which accumulated within a few months at the end of summer. Horses from different backgrounds were kept in the stable and this is reflected in the results of isotope analyses. Horses were fed meadow grasses as well as woody vegetation, millet, oat, and less commonly hemp, wheat and rye. Three possible explanations of stable usage are suggested. The stable was probably used on a temporary basis for horses of workers employed at the castle, courier horses and horses used in battle.

  1. LHC Report: First stable beams at 6.5 TeV

    CERN Multimedia

    Mike Lamont, Jorg Wenninger, Jan Uythoven, Stefano Redaelli, Wolfgang Hofle and Massimo Giovannozzi for the LHC team

    2015-01-01

    Give or take some important loose ends, the morning of Wednesday, 3 June saw the nominal end of an intense eight weeks of beam commissioning and the delivery of the first stable beams at 6.5 TeV. Under the gaze of the media, 3 nominal bunches per beam were taken through the full cycle into collisions. This was followed by the declaration of stable beams, marking the start of Run 2 physics data-taking.   The scenes in the CCC as stable beams at an energy of 6.5 TeV marked the start of run 2 physics at the LHC. The final stages of preparation involved the set-up of the tertiary collimators. These are situated on the incoming beam about 120 to 140 m from the interaction point where the beams are still in separate beam pipes. As the local orbit changes in this region during the squeeze and after the collapse of the separation bumps, the tertiary collimators set-up with respect to the beam is required both at the end of the squeeze and with colliding beams. The orbit and optics at the main collima...

  2. Crystal structure of ATVORF273, a new fold for a thermo- and acido-stable protein from the Acidianus two-tailed virus

    DEFF Research Database (Denmark)

    Felisberto-Rodrigues, Catarina; Blangy, Stéphanie; Goulet, Adeline

    2012-01-01

    in the viral world. To understand this intriguing phenomenon, we have undertaken structural studies of ATV virion proteins and here we present the crystal structure of one of these proteins, ATV[Formula: see text]. ATV[Formula: see text] forms tetramers in solution and a molecular envelope is provided...... for the tetramer, computed from small-angle X-ray scattering (SAXS) data. The crystal structure has properties typical of hyperthermostable proteins, including a relatively high number of salt bridges. However, the protein also exhibits flexible loops and surface pockets. Remarkably, ATV[Formula: see text......] displays a new [Formula: see text] protein fold, consistent with the absence of homologues of this protein in public sequence databases....

  3. Primary and tertiary health professionals' views on the health-care of patients with co-morbid diabetes and chronic kidney disease - a qualitative study.

    Science.gov (United States)

    Lo, Clement; Ilic, Dragan; Teede, Helena; Fulcher, Greg; Gallagher, Martin; Kerr, Peter G; Murphy, Kerry; Polkinghorne, Kevan; Russell, Grant; Usherwood, Timothy; Walker, Rowan; Zoungas, Sophia

    2016-05-18

    Health-care for co-morbid diabetes and chronic kidney disease (CKD) is often sub-optimal. To improve health-care, we explored the perspectives of general practitioners (GPs) and tertiary health-care professionals concerning key factors influencing health-care of diabetes and CKD. A total of 65 health professionals were purposively sampled from Australia's 2 largest cities to participate in focus groups and semi-structured interviews. Four focus groups were conducted with GPs who referred to 4 tertiary health services in Australia's 2 largest cities, with 6 focus groups conducted with tertiary health-care professionals from the 4 tertiary health services. An additional 8 semi-structured interviews were performed with specialist physicians who were heads of diabetes and renal units. All discussions were facilitated by the same researcher, with discussions digitally recorded and transcribed verbatim. All qualitative data was thematically analysed independently by 2 researchers. Both GPs and tertiary health-care professionals emphasised the importance of primary care and that optimal health-care was an inter-play between patient self-management and primary health-care, with specialist tertiary health-care support. Patient self-management, access to specialty care, coordination of care and a preventive approach were identified as key factors that influence healthcare and require improvement. Both groups suggested that an integrated specialist diabetes-kidney service could improve care. Unit heads emphasised the importance of quality improvement activities. GPs and tertiary health-care professionals emphasised the importance of patient self-management and primary care involvement in the health-care of diabetes and CKD. Supporting GPs with an accessible, multidisciplinary diabetes-renal health service underpinned by strong communication pathways, a preventive approach and quality improvement activities, may improve health-care and patient outcomes in co-morbid diabetes

  4. Application of stable isotope to breath test

    International Nuclear Information System (INIS)

    Sasaki, Yasuto

    1988-01-01

    Needles to say, radioisotopes have good characteristics as a tracer for examining biological functions. In fact, scyntigraphy is widely used over Japan. It is true, however, that there are some difficulties in applying radioisotopes to humans. Thus, greater attention began to be attracted to stable isotopes in the late 1960s, because these substances can be used for infants and pregnant women. They can be stored for a long period of time since they do not suffer damping as in the case of radioisotopes. In addition to serving as a tracer, stable isotopes can provide structural-chemical information including the position of isotope labels, and the mass and atomic composition of fragment ions. Such techniques as NMR spectroscopy is employed for this purpose. The method is currently used to perform examinations of congenital metabolic disorders. The carbon isotopes of 13 C and 14 C are used for breath test. Compounds labeled with these isotopes are administered and their ratio to the total CO 2 in breath is measured to diagnose diseases. In the early 1970s, 13 C has come into use for breath test. Similar breath test is applied to diagnosis of the bacterial overgrowth syndrome and ileal dysfunction syndrome. (Nogami, K.)

  5. Stable states in a strong IR field

    Science.gov (United States)

    Zhong, Changchun; Robicheaux, Francis

    2015-05-01

    It is found that 10% of atoms stay in the quasi-stable states after being exposed to intense laser or microwave (MW) pulses, even though the pulses' intensity is much stronger than that needed for static fields ionization. The reason why atoms survive those strong pulses has attracted growing attentions. A. Arakelyan et al. have observed the optical spectra of the surviving Lithium atoms after interaction with intense 38-GHz MW fields for more than 1000 cycles, and the spectra exhibit a periodic train of peaks 38 GHz apart. It suggests that those weakly bound Rydberg electrons seldom go back to the ionic core, where the cycle average energy exchange happens. In this study, we are interested in the electron behavior in the presence of intense infrared fields with a much shorter wavelength (1000 nm). By solving the full 3D time dependent Schrodinger equation, we calculate the spectra of the surviving atoms under intense IR fields. Our numerical calculations show atoms survive the intense field in quasi-stable states for a long time, and the optical spectra are obviously modulated by the IR frequency. Through tuning the ponderomotive energy, we see how field parameters affect the behavior of electrons. Different atoms, such as Hydrogen, Helium, Lithium, and Sodium, are tested to see how atom's energy structures influence the results.

  6. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  7. Stable agents for imaging investigations

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    This invention concerns highly stable compounds useful in preparing technetium 99m based scintiscanning exploration agents. The compounds of this invention include a pertechnetate reducing agent or a solution of oxidized pertechnetate and an efficient proportion, sufficient to stabilize the compounds in the presence of oxygen and of radiolysis products, of ascorbic acid or a pharmaceutically acceptable salt or ester of this acid. The invention also concerns a perfected process for preparing a technetium based exploration agent, consisting in codissolving the ascorbic acid or a pharmaceutically acceptable salt or ester of such an acid and a pertechnetate reducing agent in a solution of oxidized pertechnetate [fr

  8. VfoldCPX Server: Predicting RNA-RNA Complex Structure and Stability.

    Science.gov (United States)

    Xu, Xiaojun; Chen, Shi-Jie

    RNA-RNA interactions are essential for genomic RNA dimerization, mRNA splicing, and many RNA-related gene expression and regulation processes. The prediction of the structure and folding stability of RNA-RNA complexes is a problem of significant biological importance and receives substantial interest in the biological community. The VfoldCPX server provides a new web interface to predict the two-dimensional (2D) structures of RNA-RNA complexes from the nucleotide sequences. The VfoldCPX server has several novel advantages including the ability to treat RNAs with tertiary contacts (crossing base pairs) such as loop-loop kissing interactions and the use of physical loop entropy parameters. Based on a partition function-based algorithm, the server enables prediction for structure with and without tertiary contacts. Furthermore, the server outputs a set of energetically stable structures, ranked by their stabilities. The results allow users to gain extensive physical insights into RNA-RNA interactions and their roles in RNA function. The web server is freely accessible at "http://rna.physics.missouri.edu/vfoldCPX".

  9. Sexual harassment experiences of female graduates of Nigerian tertiary institutions.

    Science.gov (United States)

    Owoaje, Eme T; Olusola-Taiwo, Omolara

    The sexual harassment experiences of female graduates from tertiary institutions in Nigeria, were explored using self-administered questionnaires. Information was obtained on the respondents' socio-demographic characteristics and experiences of sexual harassment while in their various tertiary institutions. The majority (69.8%) of the respondents had been sexually harassed, with the main perpetrators being male classmates and lecturers. About two-thirds experienced the non-physical type of sexual harassment; 48.2% experienced the physical type. Non-physical harassment included sexual comments (57.8%) and requests to do something sexual in exchange for academic favors (32.2%). Physical forms of sexual harassment included unwanted sexual touching (29.4%) and being intentionally brushed against in a sexual way (28.9%). The effects experienced by victims were depression and perceived insecurity on campus. Sexual harassment is a common occurrence in Nigerian tertiary institutions. Appropriate institutional interventions should be developed to reduce these occurrences.

  10. Mechanisms for tertiary creep of single crystal superalloy

    Science.gov (United States)

    Staroselsky, Alexander; Cassenti, Brice

    2008-12-01

    During the thermal-mechanical loading of high temperature single crystal turbine components, all three creep—stages: primary, secondary and tertiary, manifest themselves and, hence, none of them can be neglected. The development of a creep law that includes all three stages is especially important in the case of non-homogeneous thermal loading of the component where significant stress redistribution and relaxation will result. Thus, local creep analysis is crucial for proper design of damage tolerant airfoils. We have developed a crystallographic-based constitutive model and fully coupled it with damage kinetics. The model extends existing approaches for cyclic and thermal-cyclic loading of anisotropic elasto-viscoplastic deformation behavior and damage kinetics of single-crystal materials, allowing prediction of tertiary creep and failure initiation of high temperature components. Our damage model bridges the gap between dislocation dynamics and the continuum mechanics scales and can be used to represent tertiary as well as primary and secondary creep.

  11. Stable cosmology in chameleon bigravity

    Science.gov (United States)

    De Felice, Antonio; Mukohyama, Shinji; Oliosi, Michele; Watanabe, Yota

    2018-02-01

    The recently proposed chameleonic extension of bigravity theory, by including a scalar field dependence in the graviton potential, avoids several fine-tunings found to be necessary in usual massive bigravity. In particular it ensures that the Higuchi bound is satisfied at all scales, that no Vainshtein mechanism is needed to satisfy Solar System experiments, and that the strong coupling scale is always above the scale of cosmological interest all the way up to the early Universe. This paper extends the previous work by presenting a stable example of cosmology in the chameleon bigravity model. We find a set of initial conditions and parameters such that the derived stability conditions on general flat Friedmann background are satisfied at all times. The evolution goes through radiation-dominated, matter-dominated, and de Sitter eras. We argue that the parameter space allowing for such a stable evolution may be large enough to encompass an observationally viable evolution. We also argue that our model satisfies all known constraints due to gravitational wave observations so far and thus can be considered as a unique testing ground of gravitational wave phenomenologies in bimetric theories of gravity.

  12. Characteristics of patients presenting to the vascular emergency department of a tertiary care hospital: a 2-year study

    Directory of Open Access Journals (Sweden)

    Kotsikoris Ioannis

    2011-11-01

    Full Text Available Abstract Background The structure of health care in Greece is receiving increased attention to improve its cost-effectiveness. We sought to examine the epidemiological characteristics of patients presenting to the vascular emergency department of a Greek tertiary care hospital during a 2-year period. We studied all patients presenting to the emergency department of vascular surgery at Red Cross Hospital, Athens, Greece between 1st January 2009 and 31st December 2010. Results Overall, 2452 (49.4% out of 4961 patients suffered from pathologies that should have been treated in primary health care. Only 2509 (50.6% needed vascular surgical intervention. Conclusions The emergency department of vascular surgery in a Greek tertiary care hospital has to treat a remarkably high percentage of patients suitable for the primary health care level. These results suggest that an improvement in the structure of health care is needed in Greece.

  13. Spatio-temporal observations of the tertiary ozone maximum

    Directory of Open Access Journals (Sweden)

    V. F. Sofieva

    2009-07-01

    Full Text Available We present spatio-temporal distributions of the tertiary ozone maximum (TOM, based on GOMOS (Global Ozone Monitoring by Occultation of Stars ozone measurements in 2002–2006. The tertiary ozone maximum is typically observed in the high-latitude winter mesosphere at an altitude of ~72 km. Although the explanation for this phenomenon has been found recently – low concentrations of odd-hydrogen cause the subsequent decrease in odd-oxygen losses – models have had significant deviations from existing observations until recently. Good coverage of polar night regions by GOMOS data has allowed for the first time to obtain spatial and temporal observational distributions of night-time ozone mixing ratio in the mesosphere.

    The distributions obtained from GOMOS data have specific features, which are variable from year to year. In particular, due to a long lifetime of ozone in polar night conditions, the downward transport of polar air by the meridional circulation is clearly observed in the tertiary ozone maximum time series. Although the maximum tertiary ozone mixing ratio is achieved close to the polar night terminator (as predicted by the theory, TOM can be observed also at very high latitudes, not only in the beginning and at the end, but also in the middle of winter. We have compared the observational spatio-temporal distributions of the tertiary ozone maximum with that obtained using WACCM (Whole Atmosphere Community Climate Model and found that the specific features are reproduced satisfactorily by the model.

    Since ozone in the mesosphere is very sensitive to HOx concentrations, energetic particle precipitation can significantly modify the shape of the ozone profiles. In particular, GOMOS observations have shown that the tertiary ozone maximum was temporarily destroyed during the January 2005 and December 2006 solar proton events as a result of the HOx enhancement from the increased ionization.

  14. Sexual harassment in tertiary institutions: A comparative perspective

    Directory of Open Access Journals (Sweden)

    Joseph Janice

    2015-01-01

    Full Text Available Sexual harassment is not a new phenomenon in tertiary institutions. It has been receiving considerable attention in research and the media and public awareness has increased dramatically. However, the term sexual harassment is not used uniformly across the globe because countries have defined it differently. Consequently, prevalence of sexual harassment in education varies across cultures. This paper examines sexual harassment from a comparative perspective. It specifically focuses on the definition of sexual harassment, incidence of sexual harassment of students in tertiary institutions, effects of sexual harassment on victims; and victims’ responses to sexual harassment. It also offers suggestions for curtailing sexual harassment in these institutions.

  15. Usability of cerebrospinal fluid biomarkers in a tertiary memory clinic

    DEFF Research Database (Denmark)

    Brandt, C.; Bahl, J.C.; Heegaard, N.H.

    2008-01-01

    AIM: Assays for cerebrospinal fluid (CSF) levels of total tau, phospho-tau protein and beta-amyloid 1-42 have been available for some years. The aim of the study was to assess the usability of these biomarkers in a mixed population of tertiary dementia referral patients in a university-based memory......, the sensitivity of a single abnormal value was between 33 and 66%. The specificity was high except when discriminating AD from amnestic mild cognitive impairment. Two or more abnormal markers further increased the specificity and decreased the sensitivity. CONCLUSION: In a tertiary setting, abnormal CSF biomarker...

  16. Kinetic and thermodynamic framework for P4-P6 RNA reveals tertiary motif modularity and modulation of the folding preferred pathway

    Science.gov (United States)

    Bisaria, Namita; Greenfeld, Max; Limouse, Charles; Pavlichin, Dmitri S.; Mabuchi, Hideo; Herschlag, Daniel

    2016-01-01

    The past decade has seen a wealth of 3D structural information about complex structured RNAs and identification of functional intermediates. Nevertheless, developing a complete and predictive understanding of the folding and function of these RNAs in biology will require connection of individual rate and equilibrium constants to structural changes that occur in individual folding steps and further relating these steps to the properties and behavior of isolated, simplified systems. To accomplish these goals we used the considerable structural knowledge of the folded, unfolded, and intermediate states of P4-P6 RNA. We enumerated structural states and possible folding transitions and determined rate and equilibrium constants for the transitions between these states using single-molecule FRET with a series of mutant P4-P6 variants. Comparisons with simplified constructs containing an isolated tertiary contact suggest that a given tertiary interaction has a stereotyped rate for breaking that may help identify structural transitions within complex RNAs and simplify the prediction of folding kinetics and thermodynamics for structured RNAs from their parts. The preferred folding pathway involves initial formation of the proximal tertiary contact. However, this preference was only ∼10 fold and could be reversed by a single point mutation, indicating that a model akin to a protein-folding contact order model will not suffice to describe RNA folding. Instead, our results suggest a strong analogy with a modified RNA diffusion-collision model in which tertiary elements within preformed secondary structures collide, with the success of these collisions dependent on whether the tertiary elements are in their rare binding-competent conformations. PMID:27493222

  17. The secondary structure of the 5′ end of the FIV genome reveals a long-range interaction between R/U5 and gag sequences, and a large, stable stem–loop

    Science.gov (United States)

    Kenyon, Julia C.; Ghazawi, Akela; Cheung, Winsome K.S.; Phillip, Pretty S.; Rizvi, Tahir A.; Lever, Andrew M.L.

    2008-01-01

    Feline immunodeficiency virus (FIV) is a lentivirus that infects cats and is related to human immunodeficiency virus (HIV). Although it is a common worldwide infection, and has potential uses as a human gene therapy vector and as a nonprimate model for HIV infection, little detail is known of the viral life cycle. Previous experiments have shown that its packaging signal includes two or more regions within the first 511 nucleotides of the genomic RNA. We have undertaken a secondary structural analysis of this RNA by minimal free-energy structural prediction, biochemical mapping, and phylogenetic analysis, and show that it contains five conserved stem–loops and a conserved long-range interaction between heptanucleotide sequences 5′-CCCUGUC-3′ in R/U5 and 5′-GACAGGG-3′ in gag. This long-range interaction is similar to that seen in primate lentiviruses where it is thought to be functionally important. Along with strains that infect domestic cats, this heptanucleotide interaction can also occur in species-specific FIV strains that infect pumas, lions, and Pallas' cats where the heptanucleotide sequences involved vary. We have analyzed spliced and genomic FIV RNAs and see little structural change or sequence conservation within single-stranded regions of the 5′ UTR that are important for viral packaging, suggesting that FIV may employ a cotranslational packaging mechanism. PMID:18974279

  18. Efficient and facile synthesis of novel stable monodeuterium labeled ractopamine.

    Science.gov (United States)

    Su, Feifei; Wu, Fulong; Tang, He; Wang, Zhonghua; Wu, Fanhong

    2015-01-01

    A novel synthetic route to stable deuterium labeled ractopamine was disclosed with 6.49% total yield and 97.7% isotopic abundance. Its structure and the isotope-abundance were confirmed according to (1)H-NMR and high-resolution mass spectrometry. Copyright © 2015 John Wiley & Sons, Ltd.

  19. Help-seeking behavior of patients with mental health problems visiting a tertiary care center in north India

    OpenAIRE

    Mishra, Nitin; Nagpal, Sajanjiv Singh; Chadda, Rakesh K.; Sood, Mamta

    2011-01-01

    Background: Patients with mental health problems in the nonwestern world seek help from a variety of sources, such as the family physicians, psychiatrists, psychologists, traditional faith-healers, or alternative medicine practitioners. Understanding the help-seeking behavior is important from the public health perspective. Materials and Methods: Two hundred new patients visiting a psychiatric outpatient service at a tertiary care hospital were interviewed on a semi-structured questionnaire f...

  20. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  1. A Clinical Study of Blunt Ocular Trauma in a Tertiary Care Centre

    Directory of Open Access Journals (Sweden)

    Shobha G Pai

    2013-08-01

    Full Text Available Purpose: To analyze blunt eye injuries with respect to mode of injury, sites involved and outcome. Method: This was a retrospective study of 32 patients with blunt ocular trauma from 2010 to 2012 in a tertiary care centre. Patient data, mode and extent of injury, management and outcome was noted and analyzed. Result: The commonest age of presentation was 10-20 years (28.125% and the commonest mode of injury was road traffic accident (28.125%. The most commonly involved structure was conjunctiva (84.375%, followed by lid and adnexa (62.5%. Anterior segment involvement included corneal epithelial defect (7 cases, hyphaema (4 cases, iritis (3 cases and anterior dislocation of lens (1 case. Posterior segment involvement included vitreous haemorrhage (1 case and commotio retinae (2 cases. Conclusion: This study reinforces that blunt trauma can cause any extent of damage to ocular structures and the final visual outcome is dependent on the structures injured.

  2. Stable rotating dipole solitons in nonlocal media

    DEFF Research Database (Denmark)

    Lopez-Aguayo, Servando; Skupin, Stefan; Desyatnikov, Anton S.

    2006-01-01

    We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons.......We present the first example of stable rotating two-soliton bound states in nonlinear optical media with nonlocal response. We show that, in contrast to media with local response, nonlocality opens possibilities to generate stable azimuthons....

  3. Stable double helical iodine chains inside single-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Zhen [College of Science, Liaoning University of Technology, Jinzhou, Liaoning, 121001 (China); Liu, Chun-Jian [College of Mathematics and Physics, Bohai University, Jinzhou, Liaoning, 121000 (China); Lv, Hang [Institute of New Energy, Bohai University, Jinzhou, Liaoning, 121000 (China); Liu, Bing-Bing, E-mail: liubb@jlu.edu.cn [State Key Laboratory of Superhard Materials, Jilin University, Changchun, 130012 (China)

    2016-08-12

    The helicity of stable double helical iodine chains inside single-walled carbon nanotubes (SWCNTs) is studied by calculating the systematic interaction energy. Our results present clear images of stable double helical structures inside SWCNTs. The optimum helical radius and helical angle increase and decrease with increasing diameter, respectively. The tube's diameter plays a leading role in the helicity of encapsulated structures, while the tube's chirality may induce different metastable structures. This study indicates that the observed double helical iodine chains in experiments are not necessarily the optimum structures, but may also be metastable structures. - Highlights: • The stable double helical iodine chain inside single-walled carbon nanotubes is proposed. • The influence of tube's diameter and chirality on the stability of encapsulated iodine chains is studied. • The metastable double helical structures may be co-existence with the stable structure but not in the same tubes.

  4. Phosphorus K4 Crystal: A New Stable Allotrope

    OpenAIRE

    Jie Liu; Shunhong Zhang; Yaguang Guo; Qian Wang

    2016-01-01

    The intriguing properties of phosphorene motivate scientists to further explore the structures and properties of phosphorus materials. Here, we report a new allotrope named K 4 phosphorus composed of three-coordinated phosphorus atoms in non-layered structure which is not only dynamically and mechanically stable, but also possesses thermal stability comparable to that of the orthorhombic black phosphorus (A17). Due to its unique configuration, K 4 phosphorus exhibits exceptional properties: i...

  5. Uses of stable isotopes in fish ecology

    Science.gov (United States)

    Analyses of fish tissues (other than otoliths) for stable isotope ratios can provide substantial information on fish ecology, including physiological ecology. Stable isotopes of nitrogen and carbon frequently are used to determine the mix of diet sources for consumers. Stable i...

  6. Preventing structural degradation from Na3V2(PO4)3 to V2(PO4)3: F-doped Na3V2(PO4)3/C cathode composite with stable lifetime for sodium ion batteries

    Science.gov (United States)

    Chen, Yanjun; Xu, Youlong; Sun, Xiaofei; Zhang, Baofeng; He, Shengnan; Li, Long; Wang, Chao

    2018-02-01

    A prospective NASICON-type F-doped Na3V2(PO4)2.93F0.07/C (F-0.07-NVP/C) composite is synthesized by a solid-state reaction method. F-doping can restrain the structural degradation from Na3V2(PO4)3 to V2(PO4)3 and enhance the structural stability. Meanwhile, it can decrease the particle size to diminish the pathway of Na+ diffusion, which can increase ionic conductivity efficiently. The kinetic behavior is significantly improved and it is beneficial to reinforcing the electrochemical performance of F-doping composites. Compared with Undoped-NVP/C sample, F-0.07-NVP/C composite delivers a 113 mAh g-1 discharge capacity at 10 mA g-1, which is very close to the theoretical capacity (117 mAh g-1). As for cycle performance, a reversible capacity of 97.8 mAh g-1 can be obtained and it retains 86% capacity after 1000 cycles at 200 mA g-1. F-0.07-NVP/C composite presents the highest DNa+ (2.62 × 10-15 cm2s-1), two orders of magnitude higher than the undoped sample (4.8 × 10-17 cm2s-1). This outstanding electrochemical performance is ascribed to the synergetic effect from improved kinetic behavior and enhanced structural stability due to F-doping. Hence, the F-doped composite would be a promising cathode material in SIB for energy storage and conversion.

  7. Theory of stable allocations II

    Directory of Open Access Journals (Sweden)

    Pantelić Svetlana

    2015-01-01

    Full Text Available The Swedish Royal Academy awarded the 2012 Nobel Prize in Economics to Lloyd Shapley and Alvin Roth, for the theory of stable allocations and the practice of market design. These two American researchers worked independently from each other, combining basic theory and empirical investigations. Through their experiments and practical design they generated a flourishing field of research and improved the performance of many markets. Shapley provided the fundamental theoretical contribution to this field of research, whereas Roth, a professor at the Harvard University in Boston, developed and upgraded these theoretical investigations by applying them to the American market of medical doctors. Namely, their research helps explain the market processes at work, for instance, when doctors are assigned to hospitals, students to schools and human organs for transplant to recipients.

  8. Stable massive particles at colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, M.; /Stockholm U.; Kraan, A.C.; /Pennsylvania U.; Milstead, D.A.; /Stockholm U.; Sjostrand, T.; /Lund U.; Skands, P.; /Fermilab; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  9. Polymer Solar Cells – Non Toxic Processing and Stable Polymer Photovoltaic Materials

    DEFF Research Database (Denmark)

    Søndergaard, Roar

    The field of polymer solar cell has experienced enormous progress in the previous years, with efficiencies of small scale devices (~1 mm2) now exceeding 8%. However, if the polymer solar cell is to achieve success as a renewable energy resource, mass production of sufficiently stable and efficient...... and development of more stable materials. The field of polymer solar cells has evolved around the use of toxic and carcinogenic solvents like chloroform, benzene, toluene, chlorobenzene, dichlorobenzene and xylene. As large scale production of organic solar cells is envisaged to production volumes corresponding...... synthesis of polymers carrying water coordinating side chains which allow for processing from semi-aqueous solution. A series of different side chains were synthesized and incorporated into the final polymers as thermocleavable tertiary esters. Using a cleavable side chain induces stability to solar cells...

  10. Defining fish community structure in Lake Winnipeg using stable isotopes (δ(13)C, δ(15)N, δ(34)S): implications for monitoring ecological responses and trophodynamics of mercury & other trace elements.

    Science.gov (United States)

    Ofukany, Amy F A; Wassenaar, Leonard I; Bond, Alexander L; Hobson, Keith A

    2014-11-01

    The ecological integrity of freshwater lakes is influenced by atmospheric and riverine deposition of contaminants, shoreline development, eutrophication, and the introduction of non-native species. Changes to the trophic structure of Lake Winnipeg, Canada, and consequently, the concentrations of contaminants and trace elements measured in tissues of native fishes, are likely attributed to agricultural runoff from the 977,800 km(2) watershed and the arrival of non-native zooplankters and fishes. We measured δ(13)C, δ(15)N, and δ(34)S along with concentrations of 15 trace elements in 17 native fishes from the north and south basins of Lake Winnipeg in 2009 and 2010. After adjusting for differences in isotopic baseline values between the two basins, fishes in the south basin had consistently higher δ(13)C and δ(34)S, and lower δ(15)N. We found little evidence of biomagnification of trace elements at the community level, but walleye (Sander vitreus) and freshwater drum (Aplodinotus grunniens) had higher mercury and selenium concentrations with increased trophic position, coincident with increased piscivory. There was evidence of growth dilution of cobalt, copper, manganese, molybdenum, thallium, and vanadium, and bioaccumulation of mercury, which could be explained by increases in algal (and consequently, lake and fish) productivity. We conclude that the north and south basins of Lake Winnipeg represent very different communities with different trophic structures and trace element concentrations. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Small catalytic RNA: Structure, function and application

    Energy Technology Data Exchange (ETDEWEB)

    Monforte, J.A.

    1991-04-01

    We have utilized a combination of photochemical cross-linking techniques and site-directed mutagenesis to obtain secondary and tertiary structure information for the self-cleaving, self-ligating subsequence of RNA from the negative strand of Satellite Tobacco Ringspot Virus. We have found that the helical regions fold about a hinge to promoting four different possible tertiary interactions, creating a molecular of similar shape to a paperclip. A model suggesting that the paperclip'' and hammerhead'' RNAs share a similar three dimensional structure is proposed. We have used a self-cleaving RNA molecule related to a subsequence of plant viroids, a hammerhead,'' to study the length-dependent folding of RNA produced during transcription by RNA polymerase. We have used this method to determine the length of RNA sequestered within elongating E. coli and T7 RNA polymerase complexes. The data show that for E. coli RNA polymerase 12{plus minus}1 nucleotides are sequestered within the ternary complex, which is consistent with the presence of an RNA-DNA hybrid within the transcription bubble, as proposed by others. The result for T7 RNA polymerase differs from E. coli RNA polymerase, with only 10{plus minus}1 nucleotides sequestered within the ternary complex, setting a new upper limit for the minimum RNA-DNA required for a stable elongating complex. Comparisons between E. coli and T7 RNA polymerase are made. The relevance of the results to models or transcription termination, abortive initiation, and initiation to elongation mode transitions are discussed.

  12. Sexism and Sexual Harassment in Tertiary Institutions | Akpotor ...

    African Journals Online (AJOL)

    Sexual harassment is a recurring decimal in tertiary institutions. The paper therefore investigates the effects of sexual harassment on the academic performance of female students, using Delta State University, Abraka, as case study. The participants were randomly selected 200level – 500level students from various ...

  13. Sexual Harassment in Tertiary Science: Implications for Gender Equity

    African Journals Online (AJOL)

    The paper focuses on the incidence of sexual harassment in tertiary science education and its attendant effects on students and academics. Data from a survey of six higher institutions comprising two universities, two colleges of education and two polytechnics was used. Results indicate high rate of sexual harassment of ...

  14. A sequence of events across the Cretaceous-Tertiary boundary

    NARCIS (Netherlands)

    Smit, J.; Romein, A.J.T.

    1985-01-01

    The lithological and biological sequence of events across the Cretaceous-Tertiary (K/T), as developed in thick and complete landbased sections and termed the standard K/T event sequence, is also found in many DSDP cores from all over the globe. Microtektite-like spherules have been found in

  15. Effect of health education on knowledge and attitude of tertiary ...

    African Journals Online (AJOL)

    Background: In order to make good decisions about their sexual and reproductive health, young people need reliable information. This study assessed the effect of health education on the knowledge and attitude of tertiary school students towards sexually transmitted infections. Methods: The study employed a ...

  16. Learning to teach mathematical modelling in secondary and tertiary education

    Science.gov (United States)

    Ferri, Rita Borromeo

    2017-07-01

    Since 2003 mathematical modelling in Germany is not only a topic for scientific disciplines in university mathematics courses, but also in school starting with primary school. This paper shows what mathematical modelling means in school and how it can be taught as a basis for complex modeling problems in tertiary education.

  17. tertiary education trust fund (tetfund) and the management of ...

    African Journals Online (AJOL)

    PROF EKWUEME

    The paper examines the role of the Tertiary Education Trust Fund (TETFund) in the management of. University education in Nigeria. A brief history of University education in Nigeria as well as the creation of TETFund was examined. Also the paper was guided with the use the Management by Objectives theory developed by ...

  18. Integrated Identity and Access Management System for Tertiary ...

    African Journals Online (AJOL)

    Integrated Identity and Access Management System for Tertiary Institutions in Developing Countries. BU Stephen, GA Chukwudebe, CP Ezenkwu. Abstract. Issuance of disparate identifiers to students, manual method of student identity management and access control and the unavailability of actionable information on ...

  19. Obesity and associated factors in young adults attending tertiary ...

    African Journals Online (AJOL)

    Obesity and associated factors in young adults attending tertiary institutions in south-eastern Nigeria. ... A validated questionnaire on sociodemographic, dietary and lifestyle factors was used. Variables studied included body mass index ... Keywords: association, obesity, overweight, socio-demographic factors, young adults ...

  20. Geological and geochemical variations in Mid-Tertiary Ethiopian ...

    African Journals Online (AJOL)

    The paper presents the results of a comprehensive major element, trace element, and Sr-Nd-Pb-Hf isotopic study of Mid-Tertiary volcanic sequences from the northwestern flood basalt province in Ethiopia. The volcanic rocks studied range in composition from basanites, alkaline basalts, and ankaramites, which form the 1st ...

  1. Tertiary syphilis in the lumbar spine: a case report.

    Science.gov (United States)

    Bai, Yang; Niu, Feng; Liu, Lidi; Sha, Hui; Wang, Yimei; Zhao, Song

    2017-07-24

    The incidence of tertiary syphilis involvement in the spinal column with destructive bone lesions is very rare. It is difficult to establish the correct diagnosis from radiographs and histological examination alone. Limited data are available on surgical treatment to tertiary syphilitic spinal lesions. In this article, we report a case of tertiary syphilis in the lumbar spine with osteolytic lesions causing cauda equina compression. A 44-year-old man who suffered with low back pain for 6 months and progressive radiating pain at lower extremity for 1 week. Radiologic findings showed osteolytic lesion and new bone formation in the parts of the bodies of L4 and L5. Serum treponema pallidum hemagglutination (TPHA) test was positive. A surgery of posterior debridement, interbody and posterolateral allograft bone fusion with instrumentation from L3 to S1 was performed. The low back pain and numbness abated after operation. But the follow-up radiographs showed absorption of the bone grafts and failure of instrumentation. A Charcot's arthropathy was formed between L4 and L5. It is challenging to diagnose the tertiary syphilis in the spine. Surgery is a reasonable auxiliary method to antibiotic therapy for patients who suffered with neuropathy. Charcot's arthropathy should be considered as an operative complication.

  2. Perception of patients attending a tertiary hospital in Nigeria about ...

    African Journals Online (AJOL)

    Background: Criteria for a good dental practice as expressed by patients have influence on their behavior in terms of compliance with clinical advice, less pain and anxiety and more utilization of dental care. Objective: To assess the opinion of patients attending the dental clinic of a tertiary hospital Southwestern, Nigeria ...

  3. Caesarean delivery: An experience from a tertiary institution in North ...

    African Journals Online (AJOL)

    Objective: To assess the overall caesarean section (CS) rate, indications and outcomes in a tertiary hospital in Northwestern Nigeria. Materials and Methods: A cross-sectional study carried out over a period of two years. All patients who had caesarean section at any time within the day were noted and followed up till ...

  4. Motivation in vocational education: a reform issue in tertiary ...

    African Journals Online (AJOL)

    Working in a non-motivating environment is a nagging issue in various tertiary institutions in Cross River State .This dampens staff morale a great deal. However, the provision of motivation in work places will be a great boost to staff morale especially in Vocational Education. This paper discusses the meaning of motivation, ...

  5. Self care activities among patients with diabetes attending a tertiary ...

    African Journals Online (AJOL)

    Self care activities among patients with diabetes attending a tertiary care hospital in Mangalore Karnataka, India. ... Conclusions: Self‑care practices were found to be unsatisfactory in almost all aspects except for blood sugar monitoring and treatment adherence. As these practices are essential for prevention of ...

  6. Auditing surgical service provision at a South African tertiary institution

    African Journals Online (AJOL)

    Auditing surgical service provision at a South African tertiary institution: Implications for the development of district services. ... A total of 1272 (30.5%) operative procedures performed were assessed as district-level operations. The time intervals of 07:00–07:59 and 17:00–17:59 were identified as the time periods during ...

  7. Septic Abortion Managed in a Tertiary Hospital in West Bengal ...

    African Journals Online (AJOL)

    Background: Septic abortion is still a challenging problem and a major cause of maternal mortality and morbidity in developing countries. Aim: The present study was conducted to estimate incidence, causes, risk factors, associated microorganisms, and treatment modalities of cases of septic abortion managed in a tertiary ...

  8. Design and development of a tertiary institutions decision support ...

    African Journals Online (AJOL)

    MySQL database server was used to manage all the data in the application. The Joint Admissions and Matriculation Board (JAMB) Brochure was used extensively in order to give current information about the courses and universities available in Nigeria. Keyword: Tertiary institutions, Decision Support System, Unified ...

  9. Automated Stock Control System for Bookshops in Tertiary Institutions

    African Journals Online (AJOL)

    PROF. O. E. OSUAGWU

    2013-09-01

    Sep 1, 2013 ... Abstract. The recent need for automated stock control system for bookshops in tertiary institutions was generated by unequal availability of books and stiff scarcity of books in some areas while in other areas books are being wasted or unsold. This research has made use of distributed database systems in ...

  10. Drug Production in Tertiary Health Institutions – Needs, Constraints ...

    African Journals Online (AJOL)

    The use of questionnaires was employed in the study covering all pharmacists in the pharmaceutical services department, pharmacy technicians and quality control technologist in the drug production unit of the hospital. It was unanimously agreed by the respondents that local drug production was necessary in tertiary ...

  11. managing tertiary institutions for the promotion of lifelong learning in ...

    African Journals Online (AJOL)

    Global Journal

    The study investigated ways of managing tertiary institutions for the promotion of lifelong learning in. Cross River State, Nigeria. One research question was raised and one hypothesis formulated to guide the study. Multistage sampling procedure was adopted for the study. Stratified random sampling technique and simple ...

  12. Management of necrotizing enterocolitis: experience at a tertiary ...

    African Journals Online (AJOL)

    Management of necrotizing enterocolitis: experience at a tertiary care hospital in Oman. Kirtikumar J. Rathod a. , Asfaq A. Khan b. , Mathew Kripail b. , Muhammad Fazallulah b. ,. Zainab Al Balushi a and Mohamed Abdellatif b. Introduction Necrotizing enterocolitis (NEC) is the most common surgical emergency in the ...

  13. Building Social Justice among Academic Staffs of Tertiary ...

    African Journals Online (AJOL)

    The study investigated the influence of acculturation, networking and school management support on social justice building among university academic staffs of tertiary institutions. A descriptive survey research design was adopted for the study. The sample for the study was three hundred (300) randomly selected academic ...

  14. Sexual harassment in tertiary institutions: A comparative perspective

    OpenAIRE

    Joseph Janice

    2015-01-01

    Sexual harassment is not a new phenomenon in tertiary institutions. It has been receiving considerable attention in research and the media and public awareness has increased dramatically. However, the term sexual harassment is not used uniformly across the globe because countries have defined it differently. Consequently, prevalence of sexual harassment in education varies across cultures. This paper examines sexual harassment from a comparative perspective...

  15. Impact assessment of electronic mass communication in a tertiary ...

    African Journals Online (AJOL)

    The proliferation of computer networks and Internet access opened new communication channels such as blogs, websites, e-mail, social media and mobile apps. In view of the current economic recession in Nigeria, tertiary institutions are turning to information technology for educational and communications solutions to ...

  16. Outcome of Teenage Pregnancy at a Tertiary Hospital in Abakaliki ...

    African Journals Online (AJOL)

    education, women enlightenment and empowerment will be essential in reducing the problems of teenage pregnancy. KEY W ORDS: Abakaliki, outcome, teenage pregnancy, tertiary hospital. INTRODUCTION. Teenage pregnancy dates back to the early centuries and a famous teenage pregnancy in history was Mary,.

  17. Epidemiology of death in the emergency department of a tertiary ...

    African Journals Online (AJOL)

    A recorded death rate of 8.6% is high, suspected contributory factors include systemic deficiencies such as the lack of a trauma system, prehospital care; late presentation, the role of chemist operators, traditional healers, and delayed referral systems. Key words: Epidemiology of death, emergency department, tertiary health ...

  18. Genesis of some tertiary Indian coals from the chemical composition ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 123; Issue 7. Genesis of some tertiary Indian coals from the chemical composition of ash – a statistical approach: Part 1. Arpita Sharma Ananya Saikia Puja Khare B P Baruah. Volume 123 Issue 7 October 2014 pp 1705-1715 ...

  19. Analysis of Cutaneous Adverse Drug Reactions at a Tertiary Care ...

    African Journals Online (AJOL)

    Erah

    Tertiary Care Hospital – a Prospective Study. SP Shah*, MK Desai and ... drug reactions manifest as skin rashes and/or eruptions. The incidence ..... Safety Monitoring on. Medicinal Products. Geneva (Switzerland):. Office of Publications, World Health. Organization; 2002. 6. Hartwig SC, Siegel J, Schneider PJ. Preventability.

  20. Tertiary Institutions, Entrepreneurship Education and Youth Empowerment in Nigeria

    Science.gov (United States)

    Olasunkanmi, Abari Ayodeji; Olufunke, Oyetola Idowu; Adetayo, Okunuga Adedapo

    2013-01-01

    Entrepreneurship Education has recently become a global phenomenon in the development of world youths for self employment and self-reliance. The Nigerian nation cannot afford to be left out and left behind in this new trend in education both at the secondary and tertiary levels. However, while the Universal Basic Education (UBE) curriculum has…

  1. Counselling for Sustainable Peace in Tertiary Institutions in Nigeria

    Science.gov (United States)

    Nduka-Ozo, Stella Ngozi

    2016-01-01

    This study reviewed the nature of peace in Tertiary Institutions in Nigeria using Ebonyi State University as a case study. The purpose of the study was to review the various factors responsible for lack of peace. The sample was drawn from the three hundred level students of the Faculty of Education. Thirty students were selected from each of the…

  2. Automated Stock Control System for Bookshops in Tertiary Institutions

    African Journals Online (AJOL)

    The recent need for automated stock control system for bookshops in tertiary institutions was generated by unequal availability of books and stiff scarcity of books in some areas while in ... This approach provides for faster response times for users because the database is local to each business unit within the organization.

  3. Montane pollen from the Tertiary of NW. Borneo

    NARCIS (Netherlands)

    Muller, J.

    1966-01-01

    In NW. Borneo thick series of Tertiary sediments occur which are rich in fossil pollen and spores. The majority of these plant microfossils were derived from the various types of tropical lowland vegetation such as mangrove (Muller, 1964), mixed peat swamp forest and mixed Dipterocarp forest. Some

  4. Omalizumab use during pregnancy for CIU: a tertiary care experience.

    Science.gov (United States)

    Cuervo-Pardo, L; Barcena-Blanch, M; Radojicic, C

    2016-07-01

    The treatment of antihistamine and steroid resistant Chronic Idiopathic Urticaria (CIU) during pregnancy poses a challenge due to teratogenicity of immunosuppressants. Omalizumab is a recently FDA approved therapy for CIU and is classified as pregnancy category B. We present an initial series of subjects treated at a tertiary care center for antihistamine and steroid resistant CIU with omalizumab who became pregnant during therapy.

  5. An audit of colorectal cancer histopathology reports in a Tertiary ...

    African Journals Online (AJOL)

    Objective: To audit the completeness of histopathologic reports of Colorectal Cancer for prognostic information in a tertiary care hospital in the light of the minimum reporting standards for colorectal cancer resections recently proposed for use in Nigeria. Material and Methods: Twenty–five histopathology reports of colorectal ...

  6. Surgical inpatient mortality in a Nigerian Tertiary Hospital

    African Journals Online (AJOL)

    2015-09-10

    Sep 10, 2015 ... Background: There is paucity of literatures on audit of mortality in the surgical units of tertiary hospitals in the country. This has made the spectrum of mortality not to been known in some of the centers and therefore, there is a great disparity and dearth in apportioning health care services appropriately.

  7. Hand Washing Practices amongst Doctors in A Tertiary Hospital in ...

    African Journals Online (AJOL)

    Hand Washing Practices amongst Doctors in A Tertiary Hospital in Port Harcourt, Nigeria. BA Alex-Hart, PI Opara. Abstract. Washing hand with soap and water is said to be the single most important intervention against hospital acquired infections. This study aimed to explore perceptions, attitudes and hand washing ...

  8. The Impact of Cooperative Learning on Tertiary EFL Learners' Motivation

    Science.gov (United States)

    Ning, Huiping; Hornby, Garry

    2014-01-01

    This study was aimed at investigating the impact of cooperative learning on the motivation of tertiary English learners. Participants were from two randomly assigned classes at a university in the north of China. A pre-test-post-test control group design was employed to compare the impact of the cooperative learning approach with that of…

  9. Obstetric intensive care admissions at a tertiary hospital in Limpopo ...

    African Journals Online (AJOL)

    Objective. To determine the characteristics of obstetric patients admitted to the intensive care unit (ICU) at a tertiary hospital in the Limpopo Province, South Africa. Methods. Hospital files of all obstetric patients admitted to the Pietersburg provincial referral hospital ICU from 1 January 2008 to 31 December 2012 were ...

  10. Infection control in anaesthesia in regional, tertiary and central ...

    African Journals Online (AJOL)

    Background: Anaesthetic equipment is a potential vector for the transmission of disease. This study was undertaken to observe current infection control practices among anaesthetic nurses regarding the decontamination of anaesthetic equipment in regional, tertiary and central hospitals in KwaZulu-Natal. Method: All ...

  11. Keratoconus - a Review from a Tertiary Eye-Care Center

    Directory of Open Access Journals (Sweden)

    Rajeswari Mahadevan

    2009-01-01

    Conclusion: This study brings out the clinical profile of keratoconus patients in a tertiary eye-care center in south India. The findings in this study stresses out the importance of defining the treatment options in keratoconus with the appropriate contact lenses.

  12. Nurses' communication and patient satisfaction in a tertiary hospital ...

    African Journals Online (AJOL)

    Nurses' communication of nursing care provision in tertiary health facilities and patient satisfaction are closely related. This has remained a yardstick for measuring success of the services provided in many health facilities. This study investigated the influence of nurses' communication of nursing care on patient satisfaction ...

  13. Measuring Student Satisfaction in Higher and Tertiary Education: A ...

    African Journals Online (AJOL)

    The research set out to establish the views of students about service provision in higher and tertiary education institutions. A case study approach was used. Important parameters such as tangibles, reliability, responsiveness, assurance and empathy were used to obtain students' views about quality of service provision in ...

  14. Determinants of the Employability of Tertiary Institution Graduates in ...

    African Journals Online (AJOL)

    We found that (i) proportionately different labour market performance engagements existed among tertiary institution graduates; (ii) more graduates were engaged in government than private sector and self sector employments and (iii) retrogressively common entrepreneurial practices, introvert personality trait, cognitive ...

  15. Geological and geochemical variations in Mid-Tertiary Ethiopian ...

    African Journals Online (AJOL)

    Mekelle University. Geological and geochemical variations in Mid-Tertiary Ethiopian Flood Basalt. Province, Maychew, Tigray Region, Ethiopia. Kurkura Kabeto*. Department of Earth Science, College of Natural and Computational Sciences, P.O. Box 231,. Mekelle University, Ethiopia (*kurkura57@yahoo.com). ABSTRACT.

  16. English Textbooks in Parallel-Language Tertiary Education

    Science.gov (United States)

    Pecorari, Diane; Shaw, Philip; Malmstrom, Hans; Irvine, Aileen

    2011-01-01

    Tertiary education in many countries is increasingly bilingual, with English used in parallel with the national language, particularly as a reading language. This article describes the results of a survey of student attitudes toward, and reading practices regarding, English language textbooks. Over 1,000 students at three Swedish universities…

  17. Gender attitude and commitment to teaching in tertiary educational ...

    African Journals Online (AJOL)

    This study examined the attitudes and level of commitment of lecturers towards teaching in tertiary educational institutions in south Eastern Nigeria. Five hypotheses guided the study. The sample consisted of 1991 lecturers and 828 students drawn through proportionate stratified random sampling techniques. Three sets of ...

  18. Septic Abortion Managed in a Tertiary Hospital in West Bengal

    African Journals Online (AJOL)

    Background: Septic abortion is still a challenging problem and a major cause of maternal mortality and morbidity in developing countries. Aim: The present study was conducted to estimate incidence, causes, risk factors, associated microorganisms, and treatment modalities of cases of septic abortion managed in a tertiary ...

  19. Perception of patients attending a tertiary hospital in Nigeria about ...

    African Journals Online (AJOL)

    2013-01-02

    Jan 2, 2013 ... Background: Criteria for a good dental practice as expressed by patients have influence on their behavior in terms of .... attention in Nigeria.[10] Therefore, this study assessed the opinion of patients attending the dental clinic of a tertiary hospital Southwestern, Nigeria about their perception of a good dental ...

  20. Managing tertiary institutions for the promotion of lifelong learning in ...

    African Journals Online (AJOL)

    The study investigated ways of managing tertiary institutions for the promotion of lifelong learning in Cross River State, Nigeria. One research question was raised and one hypothesis formulated to guide the study. Multistage sampling procedure was adopted for the study. Stratified random sampling technique and simple ...

  1. Obstetric intensive care admissions at a tertiary hospital in Limpopo ...

    African Journals Online (AJOL)

    continuous data were reported as mean (standard deviation (SD)). Statistical software (STATA 9.0, StataCorp, USA) was ... causes of admission into ICUs, accounting for 8 - 30%;[1,12,21,22,23] however, in our .... Critically ill obstetric patients in Australia: A retrospective audit of 8 years experience in a tertiary intensive care ...

  2. Factors affecting utilization of University health services in a tertiary ...

    African Journals Online (AJOL)

    2013-01-16

    Jan 16, 2013 ... Results: High cost of drugs (72.0%), non availability of essential drugs (54.8%), time spent waiting for treatment (67.2%), inadequate referral ... Key words: Health services, health workers, South West Nigeria, tertiary institution, utilization. Date of .... proper attitude by the health workers towards their patients.

  3. Strength and Deformation Properties of Tertiary Clay at Moesgaard Museum

    DEFF Research Database (Denmark)

    Kaufmann, Kristine Lee; Nielsen, Benjaminn Nordahl; Augustesen, Anders Hust

    The tertiary clay at Moesgaard Museum near Aarhus in the eastern part of Jutland in Denmark is a highly plastic, glacially disturbed nappe of Viborg Clay. The clay is characterised as a swelling soil, which could lead to damaging of the building due to additional heave of the soil. To take...

  4. Outcome of Breech Deliveries at a Tertiary Health Institution in ...

    African Journals Online (AJOL)

    Outcome of Breech Deliveries at a Tertiary Health Institution in Southwestern Nigeria. AS Adeyemi, DA Adekanle, AF Afolabi, FF Fadero. Abstract. The aetiology of breech presentation is not clear, however, several factors had been found to be associated with increased risk of breech presentation. The mode of delivery of ...

  5. Research Productivity of ]unior Academic Staff at a Tertiary Medical ...

    African Journals Online (AJOL)

    Research Productivity of ]unior Academic Staff at a Tertiary Medical College in South West, Nigeria. OA Lesi, OO Orenuga, A Roberts, OO Abudu. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL.

  6. Severity of Stress Induced Factors Among Students in Tertiary ...

    African Journals Online (AJOL)

    The thrust of this study was to assess the serverity of ten main stress induced factors among students in tertiary institutions in llorin metropolis. A total of 600 respondents participated in the study. The findings revealed that financial, family, infrastructure!, academic and social relationship stress induced factors were ranked as ...

  7. managing tertiary institutions for the promotion of lifelong learning

    African Journals Online (AJOL)

    Global Journal

    management of personnel (teaching and non teaching staff),prudent management and utilization of funds for the establishment of a motivating teaching and learning environment and introduction of modern pedagogy. Jackson. (2013) added that promoting lifelong tertiary education is the only sure way to breakthroughs.

  8. Cervical epithelial changes in a tertiary hospital in northern Nigeria ...

    African Journals Online (AJOL)

    Cervical epithelial changes in a tertiary hospital in northern Nigeria. PH Daru, IC Pam, J Musa, MG Daniyan, OI Silas, OA Adesina, IF Adewole. Abstract. Introduction: Cervical cancer is the commonest gynaecological malignancy in Nigeria, accounting for most deaths from cancers in women. Screening remains one of the ...

  9. An Audit of Otorhinolaryngological Practice in a Tertiary Institution in ...

    African Journals Online (AJOL)

    Background: The Niger Delta University Teaching Hospital (NDUTH) is a young tertiary hospital with recently established department in various specialties. In spite of this it caters for the health needs of a lot of the patients in Bayelsa state and its environs. The aim of this study therefore is to audit the otorhinolaryngological ...

  10. Maternal mortality audit in a tertiary health institution in Nigeria ...

    African Journals Online (AJOL)

    Introduction: Nigeria has the second highest number of maternal deaths in the world.The study aimed at determining the causes of and non-obstetric contributors to maternal mortality at a tertiary referral hospital. Materials and Methods: It was a prospective audit of all consecutive maternal deaths in the hospital over a ...

  11. An Innovation Systems Perspectives on Tertiary-Level Agricultural ...

    African Journals Online (AJOL)

    This paper examines how tertiary-level agricultural education in sub-Saharan Africa can contribute to agricultural development beyond its current role as a source of technical training. The paper draws on data and information gathered from semistructured key informant interviews conducted in late 2006 in and around Addis ...

  12. Assessment Quality in Tertiary Education: An Integrative Literature Review

    NARCIS (Netherlands)

    Gerritsen-van Leeuwenkamp, Karin; Joosten-ten Brinke, Desirée; Kester, Liesbeth

    2018-01-01

    In tertiary education, inferior assessment quality is a problem that has serious consequences for students, teachers, government, and society. A lack of a clear and overarching conceptualization of assessment quality can cause difficulties in guaranteeing assessment quality in practice. Thus, the

  13. Experiences with childhood colostomy at a tertiary hospital in ...

    African Journals Online (AJOL)

    Experiences with childhood colostomy at a tertiary hospital in Mwanza, Tanzania. ... Tanzania Journal of Health Research ... This cross-sectional study was carried out to describe experiences with childhood colostomy outlining the common indications, complications and their management and to identify factors associated ...

  14. State of physical facilities in Nigerian tertiary educational institutions ...

    African Journals Online (AJOL)

    This paper examined the state of physical facilities in Nigerian tertiary institutions in comparison with cost of facilities management in the institutions. This was achieved by determining the availability of physical facilities in the institution, assessment of the various facilities managers in the institution, and determining if the ...

  15. Dating Violence in South-Western Nigeria Tertiary Institutions ...

    African Journals Online (AJOL)

    This paper examined peace education as a means of curbing gap in knowledge and dating violence in South-western Nigeria tertiary institutions. Economic, social and psychological problems exert enormous pressures on students making them violent or docile in the face of challenges. These factors combine to make ...

  16. Childhood Conduct Problem and Alcohol Use of Students in Tertiary ...

    African Journals Online (AJOL)

    Early behavioural problems in children may place them at risk of alcohol abuse in later life. The study investigated the association between childhood conduct problem and alcohol abuse of students in tertiary institutions in Nigeria. The data for this cross sectional study was collected from a randomly selected sample of ...

  17. Improving listening skills of tertiary level students for effective ...

    African Journals Online (AJOL)

    Listening is essential to the leaming process. Students in tertiary institutions of learning need to acquire effective listening and note-taking skiils in order to benefit from lectures. This paper focused on factors militating against effective listening during lectures such as poor rate of presentation, poor communication skills, ...

  18. Patterns of Eye Diseases in Children Visiting a Tertiary Teaching ...

    African Journals Online (AJOL)

    Background: About 19 million children worldwide live with visual impairments resulting from different ocular morbidities. This study aimed to identify the different causes of eye diseases in children visiting a tertiary eye centre at Jimma University Hospital. Methods: We conducted a retrospective review of charts of patients of ...

  19. Assessment of user satisfaction with library services in tertiary ...

    African Journals Online (AJOL)

    The main objective of this study was to determine the relationship between library services and user satisfaction in tertiary institution libraries in Akwa Ibom State, Nigeria. Survey research design was considered appropriate and adopted for the study To achieve the purpose of the study, two hypotheses were formulated to ...

  20. Initial Educational Experiences of Tertiary Students. LSAY Briefing Number 14

    Science.gov (United States)

    Hillman, Kylie

    2008-01-01

    This "Briefing" presents information about the initial tertiary education experiences, such as satisfaction with aspects of student life and changes to initial enrolments, of two groups of young people, based on two recent Longitudinal Surveys of Australian Youth (LSAY) research reports. One study focused on the first year experiences of…

  1. Cretaceous–Tertiary Mass Extinction Meteoritic Versus Volcanic ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 3. Cretaceous – Tertiary Mass Extinction Meteoritic Versus Volcanic Causes. P V Sukumaran. General Article Volume 3 Issue 3 March 1998 pp 8-17. Fulltext. Click here to view fulltext PDF. Permanent link:

  2. Patient satisfaction in neurological second opinions and tertiary referrals

    NARCIS (Netherlands)

    Wijers, D.; Wieske, L.; Vergouwen, M. D. I.; Richard, E.; Stam, J.; Smets, E. M. A.

    2010-01-01

    Although the number of neurological second opinions (SOs) and tertiary referrals (TRs) is increasing, only little is known about expectations and patient satisfaction in this group of patients. Therefore, the purpose of this study was to explore expectations of patients who get a neurological SO or

  3. Symptomatic pelvic organ prolapse: Experience at a tertiary ...

    African Journals Online (AJOL)

    To determine the demographic characteristics in patients presenting with symptomatic POP to a tertiary urogynaecology .... regarding their vaginal symptoms, namely: 1. Are you aware of a dragging pain in your lower abdomen? 2. Are you aware of soreness in your vagina? 3. ... for each question on a scale from 1 to 10.

  4. Teaching the Attributes of Venture Teamwork in Tertiary Entrepreneurship Programmes

    Science.gov (United States)

    Kotey, Bernice

    2007-01-01

    Purpose: The paper seeks to demonstrate the characteristics of group work that are required to teach the attributes of real world venture teamwork in tertiary entrepreneurship programmes. Design/methodology/approach: One-tailed Spearman correlation analysis is used to assess the associations between students' grades in four group assessment tasks…

  5. A Conceptual Approach for Blended Leadership for Tertiary Education Institutions

    Science.gov (United States)

    Jones, Sandra; Harvey, Marina; Lefoe, Geraldine

    2014-01-01

    Over the last 20 years, the tertiary education sector has adopted new administrative management approaches, with the aim of improving accountable and strategic focus. Over the same period, the question of how to build leadership capacity to improve learning and teaching and research outcomes has led to discussion on what constitutes academic…

  6. Cultism and violent behaviours in tertiary institutions in Nigeria ...

    African Journals Online (AJOL)

    This paper discusses: (a) the beginning of cultism in tertiary institutions in Nigeria with particular reference to the traditional societies which prepared the way for campus cultism, (b) the reasons for the emergence of fatal cultism on campus, (c) various factors that encouraged students to join cults, (d) names of violent cult ...

  7. Tackling the Menace of Cultism in Africa's Tertiary Educational ...

    African Journals Online (AJOL)

    Cultism is one of the social vices that have continued to defy solutions in Nigeria's tertiary educational institutions. Many students have been maimed, mutilated and even killed as a result of campus cult activities. This paper examines the origin, types and the initiation procedures of campus cults. The reasons for cult ...

  8. Outbreak of carbapenem-resistant Providencia rettgeri in a tertiary ...

    African Journals Online (AJOL)

    Carbapenem resistance in Enterobacteriaceae is often plasmid mediated, necessitating stringent infection control practices. We describe an outbreak of carbapenem-resistant Providencia rettgeri involving 4 patients admitted to intensive care and high-care units at a tertiary hospital. Clinical and demographic characteristics ...

  9. Sexual behaviours of undergraduates of tertiary institutions in Kwara ...

    African Journals Online (AJOL)

    The study also examined whether or not variables of gender and school type had significant influence on the sexual behaviours of undergraduates of tertiary ... the school counsellors and teachers should provide guidance to students on developmental challenges and help youths to abstain from risky sexual behaviours.

  10. Food Insecurity: Is It an Issue among Tertiary Students?

    Science.gov (United States)

    Gallegos, Danielle; Ramsey, Rebecca; Ong, Kai Wen

    2014-01-01

    Insufficient access to food is known to compromise tertiary studies. Students often belong to groups known to have poor food security such as those renting or relying on government payments. The present study administered a cross-sectional survey incorporating the USDA food security survey module (FSSM) to 810 students at a metropolitan university…

  11. Family Planning Practice in a Tertiary Health Institution in Southern ...

    African Journals Online (AJOL)

    Objective: To determine the contraceptive acceptance rate, characteristics of acceptors, service utilization, preferred methods and their source of information on family planning in a tertiary health institution in Southern Nigeria. Methods: The ... The data were analyzed using SPSS version 11.0 computer software. Results: A ...

  12. Utilization of Antihypertensive Drugs: A Comparison of Tertiary and ...

    African Journals Online (AJOL)

    To compare the quality of antihypertensive prescriptions at 2 different health care levels in a hypertensive Nigerian population.We carried out a retrospective comparative analysis of the quality and pattern of antihypertensive and low-dose aspirin prescription in a tertiary and two secondary health care institutions providing ...

  13. Secondary and Tertiary Hyperparathyroidism, State of the Art Surgical Management

    Science.gov (United States)

    Pitt, Susan C.; Sippel, Rebecca S.

    2010-01-01

    Synopsis This article reviews the current surgical management of patients with secondary and tertiary hyperparathyroidism. The focus is on innovative surgical strategies that have improved the care of these patients over the past 10 to 15 years. Modalities such as intraoperative parathyroid hormone monitoring and radioguided probe utilization are discussed. PMID:19836494

  14. Religious extremism as a challenge to tertiary education in Nigeria ...

    African Journals Online (AJOL)

    Extremists use religion as a shield either for political or economic agenda and manipulate their gullible followers in order to impose their ideology on them. The reality of religious extremism in Nigeria is a challenge to tertiary education to search for a lasting solution that will enable Nigerians overcome the problem and focus ...

  15. Profiling Gestational Trophoblastic Disease in a Tertiary Hospital in ...

    African Journals Online (AJOL)

    ... evaluate the clinical presentation, management and treatment outcomes of gestational trophoblastic diseases in a tertiary health institution. Methodology: This was a descriptive study of all cases of gestational trophoblastic diseases managed at Ebonyi State University Teaching Hospital, Abakaliki over a five-year period.

  16. Depression in pregnancy and the puerperium in a tertiary health ...

    African Journals Online (AJOL)

    BACKGROUND: Depression is common in pregnancy in high-income-countries but rarely spoken about in Nigerian Tertiary Obstetric Centres. OBJECTIVES: This study was conducted to ascertain the prevalence and risk factors for major depression in pregnancy and puerperium at the University of Port Harcourt Teaching ...

  17. Pattern of childhood malignant tumours in two tertiary teaching ...

    African Journals Online (AJOL)

    Background: Cancer is a public health problem worldwide affecting all categories of persons. It is the second common cause of death in developed countries and among the three leading causes of death in developing countries. Objective: To compare the patterns of malignant childhood tumours in two tertiary hospitals in ...

  18. Conceptualising English as a lingua franca (ELF) as a tertiary ...

    African Journals Online (AJOL)

    After briefly sketching the recent research undertakings into English as a lingua franca (ELF) as well as the specificities of English-medium tertiary education in mainland Europe, the paper argues for a conceptual framework of ELF as classroom language that combines sociolinguistic, sociocultural and discursive ...

  19. Fuego Volcano eruption (Guatemala, 1974): evidence of a tertiary fragmentation?

    International Nuclear Information System (INIS)

    Brenes-Andre, Jose

    2014-01-01

    Values for mode and dispersion calculated from SFT were analyzed using the SFT (Sequential Fragmentation/Transport) model to Fuego Volcano eruption (Guatemala, 1974). Analysis results have showed that the ideas initially proposed for Irazu, can be applied to Fuego Volcano. Experimental evidence was found corroborating the existence of tertiary fragmentations. (author) [es

  20. An Examination of Tertiary Students' Desire to Found an Enterprise

    Science.gov (United States)

    Birdthistle, Naomi

    2008-01-01

    Purpose: The purpose of this paper is twofold. First, the paper aims to identify and explain the behaviour and intentions of students in their decision to start entrepreneurial activities and establish an enterprise. Second, the paper aims to identify whether students in tertiary level institutions in Ireland display the personality traits of an…

  1. Stroke at a tertiary medical institution in Northern Nigeria: Patients ...

    African Journals Online (AJOL)

    Background: Little is known about the burden of stroke in the northern part of Nigeria as most studies in the country have been in the southern part. The objective of this study was to study the profile of stroke patients and predictors of outcome in a tertiary health centre in Katsina, North-Western Nigeria.. Patients and Method: ...

  2. Colonoscopy in a Tertiary Hospital in Nigeria | Ismaila | Journal of ...

    African Journals Online (AJOL)

    Background: Colonoscopy is an accurate method of diagnosing colonic disease but is technically demanding and operator dependent. Colonoscopy is not a common procedure in Nigeria. After the restructuring of the endoscopic unit of a tertiary hospital in Nigeria, a preliminary survey was carried out with the aim of ...

  3. Postoperative nausea and vomiting at a tertiary care hospital in ...

    African Journals Online (AJOL)

    Background: Postoperative nausea and vomiting is one of the most distressing morbidities associated with surgery. This descriptive prospective study was conducted to determine the incidence, predictors and management of postoperative nausea and vomiting among patients attending a tertiary hospital in north-western ...

  4. Social exclusion of students with visual impairments at a tertiary ...

    African Journals Online (AJOL)

    The experience of social exclusion is multistructural, multidimensional and complex. This article is based on a study that aimed to describe the social exclusion of students with visual impairment at a tertiary institution where the authors are employed. Design: The study was qualitative. It used an exploratory design to provide ...

  5. Stable three-dimensional metallic carbon with interlocking hexagons.

    Science.gov (United States)

    Zhang, Shunhong; Wang, Qian; Chen, Xiaoshuang; Jena, Puru

    2013-11-19

    Design and synthesis of 3D metallic carbon that is stable under ambient conditions has been a long-standing dream. We predict the existence of such phases, T6- and T14-carbon, consisting of interlocking hexagons. Their dynamic, mechanical, and thermal stabilities are confirmed by carrying out a variety of state-of-the-art theoretical calculations. Unlike the previously studied K4 and the simple cubic high pressure metallic phases, the structures predicted in this work are stable under ambient conditions. Equally important, they may be synthesized chemically by using benzene or polyacenes molecules.

  6. Favorability for uranium in tertiary sedimentary rocks, southwestern Montana

    International Nuclear Information System (INIS)

    Wopat, M.A.; Curry, W.E.; Robins, J.W.; Marjaniemi, D.K.

    1977-10-01

    Tertiary sedimentary rocks in the basins of southwestern Montana were studied to determine their favorability for potential uranium resources. Uranium in the Tertiary sedimentary rocks was probably derived from the Boulder batholith and from silicic volcanic material. The batholith contains numerous uranium occurrences and is the most favorable plutonic source for uranium in the study area. Subjective favorability categories of good, moderate, and poor, based on the number and type of favorable criteria present, were used to classify the rock sequences studied. Rocks judged to have good favorability for uranium deposits are (1) Eocene and Oligocene strata and undifferentiated Tertiary rocks in the western Three Forks basin and (2) Oligocene rocks in the Helena basin. Rocks having moderate favorability consist of (1) Eocene and Oligocene strata in the Jefferson River, Beaverhead River, and lower Ruby River basins, (2) Oligocene rocks in the Townsend and Clarkston basins, (3) Miocene and Pliocene rocks in the Upper Ruby River basin, and (4) all Tertiary sedimentary formations in the eastern Three Forks basin, and in the Grasshopper Creek, Horse Prairie, Medicine Lodge Creek, Big Sheep Creek, Deer Lodge, Big Hole River, and Bull Creek basins. The following have poor favorability: (1) the Beaverhead Conglomerate in the Red Rock and Centennial basins, (2) Eocene and Oligocene rocks in the Upper Ruby River basin, (3) Miocene and Pliocene rocks in the Townsend, Clarkston, Smith River, and Divide Creek basins, (4) Miocene through Pleistocene rocks in the Jefferson River, Beaverhead River, and Lower Ruby River basins, and (5) all Tertiary sedimentary rocks in the Boulder River, Sage Creek, Muddy Creek, Madison River, Flint Creek, Gold Creek, and Bitterroot basins

  7. Applications of C and N stable isotopes to ecological and environmental studies in seagrass ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Lepoint, Gilles [Centre MARE, Laboratoire d' Oceanologie, Institut de Chimie, B6, Universite de Liege, B-4000 Liege (Belgium)]. E-mail: g.lepoint@ulg.ac.be; Dauby, Patrick [Centre MARE, Laboratoire d' Oceanologie, Institut de Chimie, B6, Universite de Liege, B-4000 Liege (Belgium); Institut Royal des Sciences Naturelles de Belgique, rue Vautier, B1000 Brussels (Belgium); Gobert, Sylvie [Centre MARE, Laboratoire d' Oceanologie, Institut de Chimie, B6, Universite de Liege, B-4000 Liege (Belgium)

    2004-12-01

    Stable isotopes of carbon and nitrogen are increasingly used in marine ecosystems, for ecological and environmental studies. Here, we examine some applications of stable isotopes as ecological integrators or tracers in seagrass ecosystem studies. We focus on both the use of natural isotope abundance as food web integrators or environmental tracers and on the use of stable isotopes as experimental tools. As ecosystem integrators, stable isotopes have helped to elucidate the general structure of trophic webs in temperate, Mediterranean and tropical seagrass ecosystems. As environmental tracers, stable isotopes have proven their utility in sewage impact measuring and mapping. However, to make such environmental studies more comprehensible, future works on understanding of basic reasons for variations of N and C stable isotopes in seagrasses should be encouraged. At least, as experimental tracers, stable isotopes allow the study of many aspects of N and C cycles at the scale of a plant or at the scale of the seagrass ecosystem.

  8. Severe acute maternal morbidity (SAMM in postpartum period requiring tertiary Hospital care

    Directory of Open Access Journals (Sweden)

    Seema Bibi

    2012-01-01

    Full Text Available Background: Postpartum period is the critically important part of obstetric care but most neglected period for majority of Pakistani women. Only life threatening complications compel them to seek for tertiary hospital care. We describe the nature of these obstetric morbidities in order to help policymakers in improving prevailing situation. Objective: To find out the frequency and causes of severe post-partum maternal morbidity requiring tertiary hospital care and to identify the demographic and obstetrical risk factors and adverse fetal outcome in women suffering from obstetric morbidities. Materials and Methods: This prospective cross-sectional study was carried out in the Department of Gynecology and Obstetrics, Liaquat University Hospital Hyderabad, between April 2008-July 2009. The subjects comprised of all those women who required admission and treatment for various obstetrical reasons during their postpartum period. Women admitted for non-obstetrical reasons were excluded. A structured proforma was used to collect data including demographics, clinical diagnosis, obstetrical history and feto-maternal outcome of index pregnancy, which was then entered and analyzed with SPSS version 11. Results: The frequency of severe postpartum maternal morbidity requiring tertiary hospital care was 4% (125/3292 obstetrical admissions. The majority of them were young, illiterate, multiparous and half of them were referred from rural areas. Nearly two third of the study population had antenatal visits from health care providers and delivered vaginally at hospital facility by skilled birth attendants. The most common conditions responsible for life threatening complications were postpartum hemorrhage (PPH (50%, preeclampsia and eclampsia (30% and puerperal pyrexia 14%. Anemia was associated problem in 100% of cases. Perinatal death rate was 27.2% (34 and maternal mortality rate was 4.8%. Conclusion: PPH, Preeclampsia, sepsis and anemia were important causes

  9. A New Synthesis of Tertiary Alkyl N-Arylcarbamates from Isocyanates.

    Science.gov (United States)

    Bailey, William J.; Griffith, James R.

    1978-01-01

    The method involves the dissolution of a small piece of metallic lithium in a small quantity of tertiary alcohol followed by addition to a mixture of the isocyanate and the tertiary alcohol in ether. This should be useful in organic chemistry laboratory courses for the identification of tertiary alcohols. (Author/BB)

  10. STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

    Directory of Open Access Journals (Sweden)

    Yurij K. Vasil’chuk

    2016-01-01

    Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

  11. Ranking stability and super-stable nodes in complex networks.

    Science.gov (United States)

    Ghoshal, Gourab; Barabási, Albert-László

    2011-07-19

    Pagerank, a network-based diffusion algorithm, has emerged as the leading method to rank web content, ecological species and even scientists. Despite its wide use, it remains unknown how the structure of the network on which it operates affects its performance. Here we show that for random networks the ranking provided by pagerank is sensitive to perturbations in the network topology, making it unreliable for incomplete or noisy systems. In contrast, in scale-free networks we predict analytically the emergence of super-stable nodes whose ranking is exceptionally stable to perturbations. We calculate the dependence of the number of super-stable nodes on network characteristics and demonstrate their presence in real networks, in agreement with the analytical predictions. These results not only deepen our understanding of the interplay between network topology and dynamical processes but also have implications in all areas where ranking has a role, from science to marketing.

  12. Stable Treemaps via Local Moves.

    Science.gov (United States)

    Sondag, Max; Speckmann, Bettina; Verbeek, Kevin

    2018-01-01

    Treemaps are a popular tool to visualize hierarchical data: items are represented by nested rectangles and the area of each rectangle corresponds to the data being visualized for this item. The visual quality of a treemap is commonly measured via the aspect ratio of the rectangles. If the data changes, then a second important quality criterion is the stability of the treemap: how much does the treemap change as the data changes. We present a novel stable treemapping algorithm that has very high visual quality. Whereas existing treemapping algorithms generally recompute the treemap every time the input changes, our algorithm changes the layout of the treemap using only local modifications. This approach not only gives us direct control over stability, but it also allows us to use a larger set of possible layouts, thus provably resulting in treemaps of higher visual quality compared to existing algorithms. We further prove that we can reach all possible treemap layouts using only our local modifications. Furthermore, we introduce a new measure for stability that better captures the relative positions of rectangles. We finally show via experiments on real-world data that our algorithm outperforms existing treemapping algorithms also in practice on either visual quality and/or stability. Our algorithm scores high on stability regardless of whether we use an existing stability measure or our new measure.

  13. A Case Series of the Probability Density and Cumulative Distribution of Laryngeal Disease in a Tertiary Care Voice Center.

    Science.gov (United States)

    de la Fuente, Jaime; Garrett, C Gaelyn; Ossoff, Robert; Vinson, Kim; Francis, David O; Gelbard, Alexander

    2017-11-01

    To examine the distribution of clinic and operative pathology in a tertiary care laryngology practice. Probability density and cumulative distribution analyses (Pareto analysis) was used to rank order laryngeal conditions seen in an outpatient tertiary care laryngology practice and those requiring surgical intervention during a 3-year period. Among 3783 new clinic consultations and 1380 operative procedures, voice disorders were the most common primary diagnostic category seen in clinic (n = 3223), followed by airway (n = 374) and swallowing (n = 186) disorders. Within the voice strata, the most common primary ICD-9 code used was dysphonia (41%), followed by unilateral vocal fold paralysis (UVFP) (9%) and cough (7%). Among new voice patients, 45% were found to have a structural abnormality. The most common surgical indications were laryngotracheal stenosis (37%), followed by recurrent respiratory papillomatosis (18%) and UVFP (17%). Nearly 55% of patients presenting to a tertiary referral laryngology practice did not have an identifiable structural abnormality in the larynx on direct or indirect examination. The distribution of ICD-9 codes requiring surgical intervention was disparate from that seen in clinic. Application of the Pareto principle may improve resource allocation in laryngology, but these initial results require confirmation across multiple institutions.

  14. A crawling robot driven by multi-stable origami

    Science.gov (United States)

    Pagano, Alexander; Yan, Tongxi; Chien, Brian; Wissa, A.; Tawfick, S.

    2017-09-01

    Using origami folding to construct and actuate mechanisms and machines offers attractive opportunities from small, scalable, and cheap robots to deployable adaptive structures. This paper presents the design of a bio-inspired origami crawling robot constructed by folding sheets of paper. The origami building block structure is based on the Kresling crease pattern (CP), a chiral tower with a polygonal base, which expands and contracts through coupled longitudinal and rotational motion similar to a screw. We design the origami to have multi-stable structural equilibria which can be tuned by changing the folding CP. Kinematic analysis of these structures based on rigid-plates and hinges at fold lines precludes the shape transformation associated with the bistability of the physical models. To capture the kinematics of the bi-stable origami, the panels’ deformation behavior is modeled utilizing principles of virtual folds. Virtual folds approximate material bending by hinged, rigid panels, which facilitates the development of a kinematic solution via rigid-plate rotation analysis. As such, the kinetics and stability of folded structures are investigated by assigning suitable torsional spring constants to the fold lines. The results presented demonstrate the effect of fold-pattern geometries on the snapping behavior of the bi-stable origami structure based on the Kresling pattern. The crawling robot is presented as a case study for the use of this origami structure to mimic crawling locomotion. The robot is comprised of two origami towers nested inside a paper bellow, and connected by 3D printed end plates. DC motors are used to actuate the expansion and contraction of the internal origami structures to achieve forward locomotion and steering. Beyond locomotion, this simple design can find applications in manipulators, booms, and active structures.

  15. Structure of a Rabbit Muscle Fructose-1,6-Bisphosphate Aldolase A Dimer Variant

    Energy Technology Data Exchange (ETDEWEB)

    Sherawat,M.; Tolan, D.; Allen, K.

    2008-01-01

    Fructose-1,6-bisphosphate aldolase (aldolase) is an essential enzyme in glycolysis and gluconeogenesis. In addition to this primary function, aldolase is also known to bind to a variety of other proteins, a property that may allow it to perform 'moonlighting' roles in the cell. Although monomeric and dimeric aldolases possess full catalytic activity, the enzyme occurs as an unusually stable tetramer, suggesting a possible link between the oligomeric state and these noncatalytic cellular roles. Here, the first high-resolution X-ray crystal structure of rabbit muscle D128V aldolase, a dimeric form of aldolase mimicking the clinically important D128G mutation in humans associated with hemolytic anemia, is presented. The structure of the dimer was determined to 1.7 Angstroms resolution with the product DHAP bound in the active site. The turnover of substrate to produce the product ligand demonstrates the retention of catalytic activity by the dimeric aldolase. The D128V mutation causes aldolase to lose intermolecular contacts with the neighboring subunit at one of the two interfaces of the tetramer. The tertiary structure of the dimer does not significantly differ from the structure of half of the tetramer. Analytical ultracentrifugation confirms the occurrence of the enzyme as a dimer in solution. The highly stable structure of aldolase with an independent active site is consistent with a model in which aldolase has evolved as a multimeric scaffold to perform other noncatalytic functions.

  16. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  17. Yb(OTf){sub 3}-catalyzed one-pot three component synthesis for tertiary amines

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bum Seok; Kim, Ji Hye; Nam, Tae Kyu; Jang, Doo Ok [Dept. of Chemistry, Yonsei University, Wonju (Korea, Republic of)

    2015-07-15

    Tertiary amine functionality is found in many natural bioactive products such as alkaloids, amino acids, nucleic acids, pharmaceuticals, and agrochemicals. Tertiary amines have also been used as building blocks for nitrogen-containing organic compounds and synthetic polymers. A one-pot method for direct reductive amination of aldehydes has been developed to synthesize tertiary amines using HMDS as a nitrogen source in the presence of Yb(OTf ){sub 3}. With a stoichiometric amount of HMDS, the reaction afforded the desired tertiary amines without competitive reduction of the parent carbonyl compounds. This reaction offers a convenient and efficient protocol for synthesizing aromatic and aliphatic tertiary amines under mild reaction conditions.

  18. Population Games, Stable Games, and Passivity

    Directory of Open Access Journals (Sweden)

    Michael J. Fox

    2013-10-01

    Full Text Available The class of “stable games”, introduced by Hofbauer and Sandholm in 2009, has the attractive property of admitting global convergence to equilibria under many evolutionary dynamics. We show that stable games can be identified as a special case of the feedback-system-theoretic notion of a “passive” dynamical system. Motivated by this observation, we develop a notion of passivity for evolutionary dynamics that complements the definition of the class of stable games. Since interconnections of passive dynamical systems exhibit stable behavior, we can make conclusions about passive evolutionary dynamics coupled with stable games. We show how established evolutionary dynamics qualify as passive dynamical systems. Moreover, we exploit the flexibility of the definition of passive dynamical systems to analyze generalizations of stable games and evolutionary dynamics that include forecasting heuristics as well as certain games with memory.

  19. Pityriasis versicolor: a clinicomycological and epidemiological study from a tertiary care hospital.

    Science.gov (United States)

    Ghosh, Sudip Kumar; Dey, Sunil Kumar; Saha, Indranil; Barbhuiya, Jayasree Nath; Ghosh, Arghyaprasun; Roy, Aloke Kumar

    2008-01-01

    Pityriasis versicolor is a mild, chronic, usually asymptomatic superficial fungal infection of the stratum corneum, caused by Malassezia yeasts. The purpose of the present study is to assess the clinical profile of a group of patients with pityriasis versicolor and to find out the epidemiological characteristics in this part of India as well as any association, if any, with other diseases. For this purpose, 110 consecutive patients of pityriasis versicolor were evaluated clinically and diagnosis was confirmed mycologically at a tertiary care hospital in Kolkata. All data were recorded in a predesigned, pretested semi-structured schedule. The total duration of study period was 12 months. Majority of the patients were young adults. Most of the patients were asymptomatic. There is prominent seasonal variation of the patients with a peak in August and September months. Most of the lesions were hypopigmented scaly macules and were KOH positive. Most commonly involved sites were chest, face and back. Seborrheic dermatitis sometimes coexisted with pityriasis versicolor and a number of patients also had diabetes mellitus and immunosuppressive conditions. Overall, the clinicomycological and epidemiological profile of pityriasis versicolor infection as observed in a tertiary care setting in eastern India does not differ significantly from those observed by previous workers elsewhere.

  20. Pityriasis versicolor: A clinicomycological and epidemiological study from a tertiary care hospital

    Directory of Open Access Journals (Sweden)

    Ghosh Sudip

    2008-01-01

    Full Text Available Background: Pityriasis versicolor is a mild, chronic, usually asymptomatic superficial fungal infection of the stratum corneum, caused by Malassezia yeasts. The purpose of the present study is to assess the clinical profile of a group of patients with pityriasis versicolor and to find out the epidemiological characteristics in this part of India as well as any association, if any, with other diseases. Materials and Methods: For this purpose, 110 consecutive patients of pityriasis versicolor were evaluated clinically and diagnosis was confirmed mycologically at a tertiary care hospital in Kolkata. All data were recorded in a predesigned, pretested semi-structured schedule. The total duration of study period was 12 months. Results: Majority of the patients were young adults. Most of the patients were asymptomatic. There is prominent seasonal variation of the patients with a peak in August and September months. Most of the lesions were hypopigmented scaly macules and were KOH positive. Most commonly involved sites were chest, face and back. Seborrheic dermatitis sometimes coexisted with pityriasis versicolor and a number of patients also had diabetes mellitus and immunosuppressive conditions. Conclusions: Overall, the clinicomycological and epidemiological profile of pityriasis versicolor infection as observed in a tertiary care setting in eastern India does not differ significantly from those observed by previous workers elsewhere.