An Exploration of Students' Conceptions of Accounting Work

ERIC Educational Resources Information Center

Sin, Samantha; Reid, Anna; Jones, Alan

2012-01-01

This study, undertaken at an Australian university, investigates undergraduate accounting students' conceptions of accounting work and discusses the relevance of such conceptions for the work readiness of graduates. Findings based on a phenomenographic investigation show variations in students' awareness of the functional and human aspects of…

hCG Triggering in ART: An Evolutionary Concept.

PubMed

Hershko Klement, Anat; Shulman, Adrian

2017-05-17

Human chorionic gonadotropin (hCG) is no longer a single, omnipotent ovulation triggering option. Gonadotropin releasing hormone (GnRH) agonist, initially presented as a substitute for hCG, has led to a new era of administering GnRH agonist followed by hCG triggering. According to this new concept, GnRH agonist enables successful ovum maturation, while hCG supports the luteal phase and pregnancy until placental shift.

Knowledge-Based Manufacturing and Structural Design for a High Speed Civil Transport

NASA Technical Reports Server (NTRS)

Marx, William J.; Mavris, Dimitri N.; Schrage, Daniel P.

1994-01-01

The aerospace industry is currently addressing the problem of integrating manufacturing and design. To address the difficulties associated with using many conventional procedural techniques and algorithms, one feasible way to integrate the two concepts is with the development of an appropriate Knowledge-Based System (KBS). The authors present their reasons for selecting a KBS to integrate design and manufacturing. A methodology for an aircraft producibility assessment is proposed, utilizing a KBS for manufacturing process selection, that addresses both procedural and heuristic aspects of designing and manufacturing of a High Speed Civil Transport (HSCT) wing. A cost model is discussed that would allow system level trades utilizing information describing the material characteristics as well as the manufacturing process selections. Statements of future work conclude the paper.

Comparison of three commercial knowledge bases for detection of drug-drug interactions in clinical decision support.

PubMed

Fung, Kin Wah; Kapusnik-Uner, Joan; Cunningham, Jean; Higby-Baker, Stefanie; Bodenreider, Olivier

2017-07-01

To compare 3 commercial knowledge bases (KBs) used for detection and avoidance of potential drug-drug interactions (DDIs) in clinical practice. Drugs in the DDI tables from First DataBank (FDB), Micromedex, and Multum were mapped to RxNorm. The KBs were compared at the clinical drug, ingredient, and DDI rule levels. The KBs were evaluated against a reference list of highly significant DDIs from the Office of the National Coordinator for Health Information Technology (ONC). The KBs and the ONC list were applied to a prescription data set to simulate their use in clinical decision support. The KBs contained 1.6 million (FDB), 4.5 million (Micromedex), and 4.8 million (Multum) clinical drug pairs. Altogether, there were 8.6 million unique pairs, of which 79% were found only in 1 KB and 5% in all 3 KBs. However, there was generally more agreement than disagreement in the severity rankings, especially in the contraindicated category. The KBs covered 99.8-99.9% of the alerts of the ONC list and would have generated 25 (FDB), 145 (Micromedex), and 84 (Multum) alerts per 1000 prescriptions. The commercial KBs differ considerably in size and quantity of alerts generated. There is less variability in severity ranking of DDIs than suggested by previous studies. All KBs provide very good coverage of the ONC list. More work is needed to standardize the editorial policies and evidence for inclusion of DDIs to reduce variation among knowledge sources and improve relevance. Some DDIs considered contraindicated in all 3 KBs might be possible candidates to add to the ONC list. Published by Oxford University Press on behalf of the American Medical Informatics Association 2017. This work is written by US Government employees and is in the public domain in the United States.

Experiences in improving the state of the practice in verification and validation of knowledge-based systems

NASA Technical Reports Server (NTRS)

Culbert, Chris; French, Scott W.; Hamilton, David

1994-01-01

Knowledge-based systems (KBS's) are in general use in a wide variety of domains, both commercial and government. As reliance on these types of systems grows, the need to assess their quality and validity reaches critical importance. As with any software, the reliability of a KBS can be directly attributed to the application of disciplined programming and testing practices throughout the development life-cycle. However, there are some essential differences between conventional software and KBSs, both in construction and use. The identification of these differences affect the verification and validation (V&V) process and the development of techniques to handle them. The recognition of these differences is the basis of considerable on-going research in this field. For the past three years IBM (Federal Systems Company - Houston) and the Software Technology Branch (STB) of NASA/Johnson Space Center have been working to improve the 'state of the practice' in V&V of Knowledge-based systems. This work was motivated by the need to maintain NASA's ability to produce high quality software while taking advantage of new KBS technology. To date, the primary accomplishment has been the development and teaching of a four-day workshop on KBS V&V. With the hope of improving the impact of these workshops, we also worked directly with NASA KBS projects to employ concepts taught in the workshop. This paper describes two projects that were part of this effort. In addition to describing each project, this paper describes problems encountered and solutions proposed in each case, with particular emphasis on implications for transferring KBS V&V technology beyond the NASA domain.

Work engagement in nursing: a concept analysis.

PubMed

Bargagliotti, L Antoinette

2012-06-01

  This article is a report of an analysis of the concept of work engagement. Background.  Work engagement is the central issue for 21st century professionals and specifically for registered nurses. Conceptual clarity about work engagement gives empirical direction for future research and a theoretical underpinning for the myriad studies about nurses and their work environment.   Walker and Avant's method of concept analysis was used. Nursing, business, psychology and health sciences databases were searched using Science Direct, CINAHL, OVID, Academic One File, ABI INFORM and PsycINFO for publications that were: written in English, published between 1990 and 2010, and described or studied work engagement in any setting with any population.   Work engagement is a positive, fulfilling state of mind about work that is characterized by vigour, dedication and absorption. Trust (organizationally, managerially and collegially) and autonomy are the antecedents of work engagement. The outcomes of nurses' work engagement are higher levels of personal initiative that are contagious, decreased hospital mortality rates and significantly higher financial profitability of organizations.   When work engagement is conceptually removed from a transactional job demands-resources model, the relational antecedents of trust and autonomy have greater explanatory power for work engagement in nurses. Untangling the antecedents, attributes and outcomes of work engagement is important to future research efforts. © 2011 Blackwell Publishing Ltd.

Communication: Reactivity borrowing in the mode selective chemistry of H + CHD3 → H2 + CD3

NASA Astrophysics Data System (ADS)

Ellerbrock, Roman; Manthe, Uwe

2017-12-01

Quantum state-resolved reaction probabilities for the H + CHD3 → H2 + CD3 reaction are calculated by accurate full-dimensional quantum dynamics calculations using the multi-layer multi-configurational time-dependent Hartree approach and the quantum transition state concept. Reaction probabilities of various ro-vibrational states of the CHD3 reactant are investigated for vanishing total angular momentum. While the reactivity of the different vibrational states of CHD3 mostly follows intuitive patterns, an unusually large reaction probability is found for CHD3 molecules triply excited in the CD3 umbrella-bending vibration. This surprising reactivity can be explained by a Fermi resonance-type mixing of the single CH-stretch excited and the triple CD3 umbrella-bend excited vibrational states of CHD3. These findings show that resonant energy transfer can significantly affect the mode-selective chemistry of CHD3 and result in counter-intuitive reactivity patterns.

The Concept of Energy Without Heat or Work.

ERIC Educational Resources Information Center

Kemp, H. R.

1984-01-01

Develops the concept of energy without using the terms heat and work. Topic areas considered include mechanical energy, internal energy, total energy, energy conservation, applications of energy conservation, kinds of internal energy, and restrictions on energy changes. Implications for teaching the energy concept are also considered. (JN)

DESM: portal for microbial knowledge exploration systems.

PubMed

Salhi, Adil; Essack, Magbubah; Radovanovic, Aleksandar; Marchand, Benoit; Bougouffa, Salim; Antunes, Andre; Simoes, Marta Filipa; Lafi, Feras F; Motwalli, Olaa A; Bokhari, Ameerah; Malas, Tariq; Amoudi, Soha Al; Othum, Ghofran; Allam, Intikhab; Mineta, Katsuhiko; Gao, Xin; Hoehndorf, Robert; C Archer, John A; Gojobori, Takashi; Bajic, Vladimir B

2016-01-04

Microorganisms produce an enormous variety of chemical compounds. It is of general interest for microbiology and biotechnology researchers to have means to explore information about molecular and genetic basis of functioning of different microorganisms and their ability for bioproduction. To enable such exploration, we compiled 45 topic-specific knowledgebases (KBs) accessible through DESM portal (www.cbrc.kaust.edu.sa/desm). The KBs contain information derived through text-mining of PubMed information and complemented by information data-mined from various other resources (e.g. ChEBI, Entrez Gene, GO, KOBAS, KEGG, UniPathways, BioGrid). All PubMed records were indexed using 4,538,278 concepts from 29 dictionaries, with 1 638 986 records utilized in KBs. Concepts used are normalized whenever possible. Most of the KBs focus on a particular type of microbial activity, such as production of biocatalysts or nutraceuticals. Others are focused on specific categories of microorganisms, e.g. streptomyces or cyanobacteria. KBs are all structured in a uniform manner and have a standardized user interface. Information exploration is enabled through various searches. Users can explore statistically most significant concepts or pairs of concepts, generate hypotheses, create interactive networks of associated concepts and export results. We believe DESM will be a useful complement to the existing resources to benefit microbiology and biotechnology research. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Conceptions of Work in Italian Adults with Intellectual Disability

ERIC Educational Resources Information Center

Ferrari, Lea; Nota, Laura; Soresi, Salvatore

2008-01-01

People's ideas about work can greatly affect the ways in which they characterize their own work experience and their lives. The first aim of the present study was to analyze the concept of work in individuals with mild or moderate intellectual disability working in competitive or sheltered work settings and, second, to compare the notions of work…

Students' Multimodal Construction of the Work-Energy Concept

NASA Astrophysics Data System (ADS)

Tang, Kok-Sing; Chee Tan, Seng; Yeo, Jennifer

2011-09-01

This article examines the role of multimodalities in representing the concept of work-energy by studying the collaborative discourse of a group of ninth-grade physics students engaging in an inquiry-based instruction. Theorising a scientific concept as a network of meaning relationships across semiotic modalities situated in human activity, this article analyses the students' interactions through their use of natural language, mathematical symbolism, depiction, and gestures, and examines the intertextual meanings made through the integration of these modalities. Results indicate that the thematic integration of multimodalities is both difficult and necessary for students in order to construct a scientific understanding that is congruent with the physics curriculum. More significantly, the difficulties in multimodal integration stem from the subtle differences in the categorical, quantitative, and spatial meanings of the work-energy concept whose contrasts are often not made explicit to the students. The implications of these analyses and findings for science teaching and educational research are discussed.

Design consideration in constructing high performance embedded Knowledge-Based Systems (KBS)

NASA Technical Reports Server (NTRS)

Dalton, Shelly D.; Daley, Philip C.

1988-01-01

As the hardware trends for artificial intelligence (AI) involve more and more complexity, the process of optimizing the computer system design for a particular problem will also increase in complexity. Space applications of knowledge based systems (KBS) will often require an ability to perform both numerically intensive vector computations and real time symbolic computations. Although parallel machines can theoretically achieve the speeds necessary for most of these problems, if the application itself is not highly parallel, the machine's power cannot be utilized. A scheme is presented which will provide the computer systems engineer with a tool for analyzing machines with various configurations of array, symbolic, scaler, and multiprocessors. High speed networks and interconnections make customized, distributed, intelligent systems feasible for the application of AI in space. The method presented can be used to optimize such AI system configurations and to make comparisons between existing computer systems. It is an open question whether or not, for a given mission requirement, a suitable computer system design can be constructed for any amount of money.

Working with "H2S": facts and apparent artifacts.

PubMed

Wedmann, Rudolf; Bertlein, Sarah; Macinkovic, Igor; Böltz, Sebastian; Miljkovic, Jan Lj; Muñoz, Luis E; Herrmann, Martin; Filipovic, Milos R

2014-09-15

Hydrogen sulfide (H2S) is an important signaling molecule with physiological endpoints similar to those of nitric oxide (NO). Growing interest in its physiological roles and pharmacological potential has led to large sets of contradictory data. The principle cause of these discrepancies can be the common neglect of some of the basic H2S chemistry. This study investigates how the experimental outcome when working with H2S depends on its source and dose and the methodology employed. We show that commercially available NaHS should be avoided and that traces of metal ions should be removed because these can reduce intramolecular disulfides and change protein structure. Furthermore, high H2S concentrations may lead to a complete inhibition of cell respiration, mitochondrial membrane potential depolarization and superoxide generation, which should be considered when discussing the biological effects observed upon treatment with high concentrations of H2S. In addition, we provide chemical evidence that H2S can directly react with superoxide. H2S is also capable of reducing cytochrome c(3+) with the concomitant formation of superoxide. H2S does not directly react with nitrite but with NO electrodes that detect H2S. In addition, H2S interferes with the Griess reaction and should therefore be removed from the solution by Cd(2+) or Zn(2+) precipitation prior to nitrite quantification. 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) is reduced by H2S, and its use should be avoided in combination with H2S. All these constraints must be taken into account when working with H2S to ensure valid data. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparative Analyses of H3K4 and H3K27 Trimethylations Between the Mouse Cerebrum and Testis

PubMed Central

Cui, Peng; Liu, Wanfei; Zhao, Yuhui; Lin, Qiang; Zhang, Daoyong; Ding, Feng; Xin, Chengqi; Zhang, Zhang; Song, Shuhui; Sun, Fanglin; Yu, Jun; Hu, Songnian

2012-01-01

The global features of H3K4 and H3K27 trimethylations (H3K4me3 and H3K27me3) have been well studied in recent years, but most of these studies were performed in mammalian cell lines. In this work, we generated the genome-wide maps of H3K4me3 and H3K27me3 of mouse cerebrum and testis using ChIP-seq and their high-coverage transcriptomes using ribominus RNA-seq with SOLiD technology. We examined the global patterns of H3K4me3 and H3K27me3 in both tissues and found that modifications are closely-associated with tissue-specific expression, function and development. Moreover, we revealed that H3K4me3 and H3K27me3 rarely occur in silent genes, which contradicts the findings in previous studies. Finally, we observed that bivalent domains, with both H3K4me3 and H3K27me3, existed ubiquitously in both tissues and demonstrated an invariable preference for the regulation of developmentally-related genes. However, the bivalent domains tend towards a “winner-takes-all” approach to regulate the expression of associated genes. We also verified the above results in mouse ES cells. As expected, the results in ES cells are consistent with those in cerebrum and testis. In conclusion, we present two very important findings. One is that H3K4me3 and H3K27me3 rarely occur in silent genes. The other is that bivalent domains may adopt a “winner-takes-all” principle to regulate gene expression. PMID:22768982

Intramolecular H-transfer reactions in Si 2H n (for n=3-5)

NASA Astrophysics Data System (ADS)

Ernst, M. C.; Sax, A. F.; Kalcher, J.

1993-12-01

Intramolecular rearrangement reactions for doublet Si 2H 5 and Si 2H 3, quartet Si 2H 3, and singlet Si 2H 4 have been studied. aim of the study was to characterize a series of intramolecular H-transfer reactions in silicon hydrides with vrying degrees of saturation. The transition states belonging to the reactions presented in this work possess a monobridged Si 2H moiety. Structural features of the transition states and relative barrier heights have been examined; the geometry optimizations were performed with the use of CAS-SCF wavefunctions and the barrier height estimates were obtained with single-point CI calculations.

Frequency Comb Assisted IR Measurements of H_3^+, H_2D^+ and D_2H^+ Transitions

NASA Astrophysics Data System (ADS)

Jusko, Pavol; Asvany, Oskar; Schlemmer, Stephan

2016-06-01

We present recent measurements of the fundamental transitions of H_3^+, H_2D^+ and D_2H^+ in a 4 K 22-pole trap by action spectroscopic techniques. Either Laser Induced Inhibition of Cluster Growth (He attachment at T≈4 K), endothermic reaction of H_3^+ with O_2, or deuterium exchange has been used as measurement scheme. We used a 3 μm optical parametric oscillator coupled to a frequency comb in order to achieve accuracy generally below 1 MHz. Five transitions of H_3^+, eleven of H_2D^+ and ten of D_2H^+ were recorder in our spectral range. We compare our H_3^+ results with two previous frequency comb assisted works. Moreover, accurate determination of the frequency allows us to predict pure rotational transitions for H_2D^+ and D_2H^+ in the THz range. P. Jusko, C. Konietzko, S. Schlemmer, O. Asvany, J. Mol. Spec. 319 (2016) 55 O. Asvany, S. Brünken, L. Kluge, S. Schlemmer, Appl. Phys. B 114 (2014) 203 O. Asvany, J. Krieg, S. Schlemmer, Rev. Sci. Instr. 83 (2012) 093110 J.N. Hodges, A.J. Perry, P.A. Jenkins, B.M. Siller, B.J. McCall, J. Chem. Phys. 139 (2013) 164201 H.-C. Chen, C.-Y. Hsiao, J.-L. Peng, T. Amano, J.-T. Shy, Phys. Rev. Lett. 109 (2012) 263002

A Co3O4-CDots-C3N4 three component electrocatalyst design concept for efficient and tunable CO2 reduction to syngas.

PubMed

Guo, Sijie; Zhao, Siqi; Wu, Xiuqin; Li, Hao; Zhou, Yunjie; Zhu, Cheng; Yang, Nianjun; Jiang, Xin; Gao, Jin; Bai, Liang; Liu, Yang; Lifshitz, Yeshayahu; Lee, Shuit-Tong; Kang, Zhenhui

2017-11-28

Syngas, a CO and H 2 mixture mostly generated from non-renewable fossil fuels, is an essential feedstock for production of liquid fuels. Electrochemical reduction of CO 2 and H + /H 2 O is an alternative renewable route to produce syngas. Here we introduce the concept of coupling a hydrogen evolution reaction (HER) catalyst with a CDots/C 3 N 4 composite (a CO 2 reduction catalyst) to achieve a cheap, stable, selective and efficient route for tunable syngas production. Co 3 O 4 , MoS 2 , Au and Pt serve as the HER component. The Co 3 O 4 -CDots-C 3 N 4 electrocatalyst is found to be the most efficient among the combinations studied. The H 2 /CO ratio of the produced syngas is tunable from 0.07:1 to 4:1 by controlling the potential. This catalyst is highly stable for syngas generation (over 100 h) with no other products besides CO and H 2 . Insight into the mechanisms balancing between CO 2 reduction and H 2 evolution when applying the HER-CDots-C 3 N 4 catalyst concept is provided.

Structural classification of CDR-H3 revisited: a lesson in antibody modeling.

PubMed

Kuroda, Daisuke; Shirai, Hiroki; Kobori, Masato; Nakamura, Haruki

2008-11-15

Among the six complementarity-determining regions (CDRs) in the variable domains of an antibody, the third CDR of the heavy chain (CDR-H3), which lies in the center of the antigen-binding site, plays a particularly important role in antigen recognition. CDR-H3 shows significant variability in its length, sequence, and structure. Although difficult, model building of this segment is the most critical step in antibody modeling. Since our first proposal of the "H3-rules," which classify CDR-H3 structure based on amino acid sequence, the number of experimentally determined antibody structures has increased. Here, we revise these H3-rules and propose an improved classification scheme for CDR-H3 structure modeling. In addition, we determine the common features of CDR-H3 in antibody drugs as well as discuss the concept of "antibody druggability," which can be applied as an indicator of antibody evaluation during drug discovery.

Using computer software to improve group decision-making.

PubMed

Mockler, R J; Dologite, D G

1991-08-01

This article provides a review of some of the work done in the area of knowledge-based systems for strategic planning. Since 1985, with the founding of the Center for Knowledge-based Systems for Business Management, the project has focused on developing knowledge-based systems (KBS) based on these models. In addition, the project also involves developing a variety of computer and non-computer methods and techniques for assisting both technical and non-technical managers and individuals to do decision modelling and KBS development. This paper presents a summary of one segment of the project: a description of integrative groupware useful in strategic planning. The work described here is part of an ongoing research project. As part of this project, for example, over 200 non-technical and technical business managers, most of them working full-time during the project, developed over 160 KBS prototype systems in conjunction with MBA course in strategic planning and management decision making. Based on replies to a survey of this test group, 28 per cent of the survey respondents reported their KBS were used at work, 21 per cent reportedly received promotions, pay rises or new jobs based on their KBS development work, and 12 per cent reported their work led to participation in other KBS development projects at work. All but two of the survey respondents reported that their work on the KBS development project led to a substantial increase in their job knowledge or performance.

Photoabsorption and photoionization cross sections of NH3, PH3, H2S, C2H2, and C2H4 in the VUV region

NASA Technical Reports Server (NTRS)

Xia, T. J.; Chien, T. S.; Wu, C. Y. Robert; Judge, D. L.

1991-01-01

Using synchrotron radiation as a continuum light source, the photoabsorption and photoionization cross sections of NH3, PH3, H2S, C2H2, and C2H4 have been measured from their respective ionization thresholds to 1060 A. The vibrational constants associated with the nu(2) totally symmetric, out-of-plane bending vibration of the ground electronic state of PH3(+) have been obtained. The cross sections and quantum yields for producing neutral products through photoexcitation of these molecules in the given spectral regions have also been determined. In the present work, autoionization processes were found to be less important than dissociation and predissociation processes in NH3, PH3, and C2H4. Several experimental techniques have been employed in order to examine the various possible systematic errors critically.

Investigating the high school students' cognitive structures about the work concept

NASA Astrophysics Data System (ADS)

Tavukçuoǧlu, Erdem; Özcan, Özgür

2018-02-01

The purpose of this study is to determine the high school students' cognitive structures related to the concepts of work. The participants of the study were composed of the students enrolled in 11. and 12. class of an Anatolian high school in Turkey. The data were collected via word association test related to the key concept to determine the students' cognitive structures. The collected data were analyzed according to the content analysis method. In the data analysis process, we determined firstly the number of words, the number of answers and the semantic relations between the words written by students. The words having semantic connections were grouped under the same category. Thus, at the end of the study, high school students' cognitive structures and some alternative conceptions were determined related to concepts of work.

Students' Mathematical Work on Absolute Value: Focusing on Conceptions, Errors and Obstacles

ERIC Educational Resources Information Center

Elia, Iliada; Özel, Serkan; Gagatsis, Athanasios; Panaoura, Areti; Özel, Zeynep Ebrar Yetkiner

2016-01-01

This study investigates students' conceptions of absolute value (AV), their performance in various items on AV, their errors in these items and the relationships between students' conceptions and their performance and errors. The Mathematical Working Space (MWS) is used as a framework for studying students' mathematical work on AV and the…

Synthesis of polycyclic molecules by double C(sp2)-H/C(sp3)-H arylations with a single palladium catalyst.

PubMed

Pierre, Cathleen; Baudoin, Olivier

2011-04-01

Polycyclic molecules were obtained in good yields by double C(sp(2))-H/C(sp(3))-H arylations mediated by a single palladium/phosphine catalyst. Both double intermolecular/intramolecular and intramolecular/intramolecular C-C couplings were performed successfully, which indicates that this concept has a broad applicability for the rapid construction of molecular complexity.

Histone H3 Variants in Trichomonas vaginalis

PubMed Central

Zubáčová, Zuzana; Hostomská, Jitka

2012-01-01

The parabasalid protist Trichomonas vaginalis is a widespread parasite that affects humans, frequently causing vaginitis in infected women. Trichomonad mitosis is marked by the persistence of the nuclear membrane and the presence of an asymmetric extranuclear spindle with no obvious direct connection to the chromosomes. No centromeric markers have been described in T. vaginalis, which has prevented a detailed analysis of mitotic events in this organism. In other eukaryotes, nucleosomes of centromeric chromatin contain the histone H3 variant CenH3. The principal aim of this work was to identify a CenH3 homolog in T. vaginalis. We performed a screen of the T. vaginalis genome to retrieve sequences of canonical and variant H3 histones. Three variant histone H3 proteins were identified, and the subcellular localization of their epitope-tagged variants was determined. The localization of the variant TVAG_185390 could not be distinguished from that of the canonical H3 histone. The sequence of the variant TVAG_087830 closely resembled that of histone H3. The tagged protein colocalized with sites of active transcription, indicating that the variant TVAG_087830 represented H3.3 in T. vaginalis. The third H3 variant (TVAG_224460) was localized to 6 or 12 distinct spots at the periphery of the nucleus, corresponding to the number of chromosomes in G1 phase and G2 phase, respectively. We propose that this variant represents the centromeric marker CenH3 and thus can be employed as a tool to study mitosis in T. vaginalis. Furthermore, we suggest that the peripheral distribution of CenH3 within the nucleus results from the association of centromeres with the nuclear envelope throughout the cell cycle. PMID:22408228

The histone H3 variant H3.3 regulates gene body DNA methylation in Arabidopsis thaliana.

PubMed

Wollmann, Heike; Stroud, Hume; Yelagandula, Ramesh; Tarutani, Yoshiaki; Jiang, Danhua; Jing, Li; Jamge, Bhagyshree; Takeuchi, Hidenori; Holec, Sarah; Nie, Xin; Kakutani, Tetsuji; Jacobsen, Steven E; Berger, Frédéric

2017-05-18

Gene bodies of vertebrates and flowering plants are occupied by the histone variant H3.3 and DNA methylation. The origin and significance of these profiles remain largely unknown. DNA methylation and H3.3 enrichment profiles over gene bodies are correlated and both have a similar dependence on gene transcription levels. This suggests a mechanistic link between H3.3 and gene body methylation. We engineered an H3.3 knockdown in Arabidopsis thaliana and observed transcription reduction that predominantly affects genes responsive to environmental cues. When H3.3 levels are reduced, gene bodies show a loss of DNA methylation correlated with transcription levels. To study the origin of changes in DNA methylation profiles when H3.3 levels are reduced, we examined genome-wide distributions of several histone H3 marks, H2A.Z, and linker histone H1. We report that in the absence of H3.3, H1 distribution increases in gene bodies in a transcription-dependent manner. We propose that H3.3 prevents recruitment of H1, inhibiting H1's promotion of chromatin folding that restricts access to DNA methyltransferases responsible for gene body methylation. Thus, gene body methylation is likely shaped by H3.3 dynamics in conjunction with transcriptional activity.

Average rainwater pH, concepts of atmospheric acidity, and buffering in open systems

NASA Astrophysics Data System (ADS)

Liljestrand, Howard M.

The system of water equilibrated with a constant partial pressure of CO 2, as a reference point for pH acidity-alkalinity relationships, has nonvolatile acidity and alkalinity components as conservative quantities, but not [H +]. Simple algorithms are presented for the determination of the average pH for combinations of samples both above and below pH 5.6. Averaging the nonconservative quantity [H +] yields erroneously low mean pH values. To extend the open CO 2 system to include other volatile atmospheric acids and bases distributed among the gas, liquid and particulate matter phases, a theoretical framework for atmospheric acidity is presented. Within certain oxidation-reduction limitations, the total atmospheric acidity (but not free acidity) is a conservative quantity. The concept of atmospheric acidity is applied to air-water systems approximating aerosols, fogwater, cloudwater and rainwater. The buffer intensity in hydrometeors is described as a function of net strong acidity, partial pressures of acid and base gases and the water to air ratio. For high liquid to air volume ratios, the equilibrium partial pressures of trace acid and base gases are set by the pH or net acidity controlled by the nonvolatile acid and base concentrations. For low water to air volume ratios as well as stationary state systems such as precipitation scavenging with continuous emissions, the partial pressures of trace gases (NH 3, HCl, HNO 3, SO 2 and CH 3COOH) appear to be of greater or equal importance as carbonate species as buffers in the aqueous phase.

The interstellar chemistry of C3H and C3H2 isomers

PubMed Central

Loison, Jean-Christophe; Agúndez, Marcelino; Wakelam, Valentine; Roueff, Evelyne; Gratier, Pierre; Marcelino, Núria; Nuñez Reyes, Dianailys; Cernicharo, José; Gerin, Maryvonne

2017-01-01

We report the detection of linear and cyclic isomers of C3H and C3H2 towards various starless cores and review the corresponding chemical pathways involving neutral (C3Hx with x=1,2) and ionic (C3Hx+ with x = 1,2,3) isomers. We highlight the role of the branching ratio of electronic Dissociative Recombination (DR) reactions of C3H2+ and C3H3+ isomers showing that the statistical treatment of the relaxation of C3H* and C3H2* produced in these DR reactions may explain the relative c,l-C3H and c,l-C3H2 abundances. We have also introduced in the model the third isomer of C3H2 (HCCCH). The observed cyclic-to-linear C3H2 ratio vary from 110 ± 30 for molecular clouds with a total density around 1×104 molecules.cm-3 to 30 ± 10 for molecular clouds with a total density around 4×105 molecules.cm-3, a trend well reproduced with our updated model. The higher ratio for low molecular cloud densities is mainly determined by the importance of the H + l-C3H2 → H + c-C3H2 and H + t-C3H2 → H + c-C3H2 isomerization reactions. PMID:29142332

The interstellar chemistry of C3H and C3H2 isomers

NASA Astrophysics Data System (ADS)

Loison, Jean-Christophe; Agúndez, Marcelino; Wakelam, Valentine; Roueff, Evelyne; Gratier, Pierre; Marcelino, Núria; Reyes, Dianailys Nuñez; Cernicharo, José; Gerin, Maryvonne

2017-10-01

We report the detection of linear and cyclic isomers of C3H and C3H2 towards various starless cores and review the corresponding chemical pathways involving neutral (C3Hx with x = 1,2) and ionic (C3Hx+ with x = 1,2,3) isomers. We highlight the role of the branching ratio of electronic dissociative recombination (DR) reactions of C3H2+ and C3H3+ isomers, showing that the statistical treatment of the relaxation of C3H* and C3H2* produced in these DR reactions may explain the relative c,l-C3H and c,l-C3H2 abundances. We have also introduced in the model the third isomer of C3H2 (HCCCH). The observed cyclic-to-linear C3H2 ratio varies from 110 ± 30 for molecular clouds with a total density of about 1 × 104 molecules cm-3 to 30 ± 10 for molecular clouds with a total density of about 4 × 105 molecules cm-3, a trend well reproduced with our updated model. The higher ratio for molecular clouds with low densities is determined mainly by the importance of the H + l-C3H2 → H + c-C3H2 and H + t-C3H2 → H + c-C3H2 isomerization reactions.

A Ring Polymer Molecular Dynamics Approach to Study the Transition between Statistical and Direct Mechanisms in the H2 + H3+ → H3+ + H2 Reaction.

PubMed

Suleimanov, Yury V; Aguado, Alfredo; Gómez-Carrasco, Susana; Roncero, Octavio

2018-05-03

Because of its fundamental importance in astrochemistry, the H 2 + H 3 + → H 3 + + H 2 reaction has been studied experimentally in a wide temperature range. Theoretical studies of the title reaction significantly lag primarily because of the challenges associated with the proper treatment of the zero-point energy (ZPE). As a result, all previous theoretical estimates for the ratio between a direct proton-hop and indirect exchange (via the H 5 + complex) channels deviate from the experiment, in particular, at lower temperatures where the quantum effects dominate. In this work, the ring polymer molecular dynamics (RPMD) method is applied to study this reaction, providing very good agreement with the experiment. RPMD is immune to the shortcomings associated with the ZPE leakage and is able to describe the transition from direct to indirect mechanisms below room temperature. We argue that RPMD represents a useful tool for further studies of numerous ZPE-sensitive chemical reactions that are of high interest in astrochemistry.

Intraoperative computed tomography guided neuronavigation: concepts, efficiency, and work flow.

PubMed

Matula, C; Rössler, K; Reddy, M; Schindler, E; Koos, W T

1998-01-01

Image-guided surgery is currently considered to be of undisputed value in microsurgical and endoscopical neurosurgery, but one of its major drawbacks is the degradation of accuracy during frameless stereotactic neuronavigation due to brain and/or lesion shift. A computed tomography (CT) scanner system (Philips Tomoscan M) developed for the operating room was connected to a pointer device navigation system for image-guided surgery (Philips EasyGuide system) in order to provide an integrated solution to this problem, and the advantages of this combination were evaluated in 20 cases (15 microsurgical and 5 endoscopic). The integration of the scanner into the operating room setup was successful in all procedures. The patients were positioned on a specially developed scanner table, which permitted movement to a scanning position then back to the operating position at any time during surgery. Contrast-enhanced preoperative CCTs performed following positioning and draping were of high quality in all cases, because a radiolucent head fixation technique was used. The accuracy achieved with this combination was significantly better (1.6:1.22.2). The overall concept is one of working in a closed system where everything is done in the same room, and the efficiency of this is clearly proven in different ways. The most important fact is the time saved in the overall treatment process (about 55 h for one operating room over a 6-month period). The combination of an intraoperative CCT scanner with the pointer device neuronavigation system permits not only the intraoperative control of resection of brain tumors, but also (in about 20% of cases) the identification of otherwise invisible residual tumor tissue by intraoperative update of the neuronavigation data set. Additionally, an image update solves the problem of intraoperative brain and/or tumor shifts during image-guided resection. Having the option of making an intraoperative quality check at any time leads to significantly

Dual-resolution modeling demonstrates greater conformational heterogeneity of CENP-A/H4 dimer than that of H3/H4

NASA Astrophysics Data System (ADS)

Zhao, Haiqing

Centromere protein A (CENP-A) is a centromere-specific H3 histone variant and shares only about 50% amino acid sequence identity with the canonical H3 protein. CENP-A is required for packaging the centromere and for the proper separation of chromosomes during mitosis. Despite their discrete functions, previously reported crystal structures of the CENP-A/H4 and H3/H4 dimers reveal surprising similarity. In this work, we characterize the structure and dynamics of CENP-A/H4 and H3/H4 dimers with a dual-resolution approach, using both all-atom and coarse-grained (CG) molecular dynamics (MD) simulations. Interestingly, the histone dimer containing CENP-A is more structurally variable than the canonical H3 dimer. Furthermore, our calculations revealed significant conformational distinctions between the interface profiles of CENP-A/H4 and H3/H4. In addition, the presence of the CENP-A-specific chaperone HJURP dramatically reduced the conformational heterogeneity of CENP-A/H4. Overall, these results are in general agreement with the available experimental data and provide new dynamic insights into the mechanisms underpinning the chaperone-mediated assembly of CENP-A nucleosomes in vivo.

Integrating Design and Manufacturing for a High Speed Civil Transport Wing

NASA Technical Reports Server (NTRS)

Marx, William J.; Mavris, Dimitri N.; Schrage, Daniel P.

1994-01-01

The aerospace industry is currently addressing the problem of integrating design and manufacturing. Because of the difficulties associated with using conventional, procedural techniques and algorithms, it is the authors' belief that the only feasible way to integrate the two concepts is with the development of an appropriate Knowledge-Based System (KBS). The authors propose a methodology for an aircraft producibility assessment, including a KBS, that addresses both procedural and heuristic aspects of integrating design and manufacturing of a High Speed Civil Transport (HSCT) wing. The HSCT was chosen as the focus of this investigation since it is a current NASA/aerospace industry initiative full of technological challenges involving many disciplines. The paper gives a brief background of selected previous supersonic transport studies followed by descriptions of key relevant design and manufacturing methodologies. Georgia Tech's Concurrent Engineering/Integrated Product and Process Development methodology is discussed with reference to this proposed conceptual producibility assessment. Evaluation criteria are presented that relate pertinent product and process parameters to overall product producibility. In addition, the authors' integration methodology and reasons for selecting a KBS to integrate design and manufacturing are presented in this paper. Finally, a proposed KBS is given, as well as statements of future work and overall investigation objectives.

Comparison of 2- and 3-Phase Bearingless Slice Motor Concepts

NASA Astrophysics Data System (ADS)

Zürcher, Franz; Nussbaumer, Thomas; Gruber, Wolfgang; Kolar, Johann W.

Several processes in chemical, pharmaceutical, biotechnology and semiconductor industry require contactless levitation and rotation through a hermetically closed process chamber. A highly interesting topology for these applications is the “bearingless slice motor” concept, where already some research has been done in the past, especially focusing on topology and implementation issues. However, only little work has been done to evaluate the ideal number of motor phases. In this paper, a performance evaluation between 2-phase and 3-phase bearingless slice motor concepts is undertaken. It is shown, that 3-phase systems can supply almost the same power as state-of-the-art 2-phase systems and achieve nearly the same acceleration behavior, although they have significantly less power electronics effort.

Histone H3.3 sub-variant H3mm7 is required for normal skeletal muscle regeneration.

PubMed

Harada, Akihito; Maehara, Kazumitsu; Ono, Yusuke; Taguchi, Hiroyuki; Yoshioka, Kiyoshi; Kitajima, Yasuo; Xie, Yan; Sato, Yuko; Iwasaki, Takeshi; Nogami, Jumpei; Okada, Seiji; Komatsu, Tetsuro; Semba, Yuichiro; Takemoto, Tatsuya; Kimura, Hiroshi; Kurumizaka, Hitoshi; Ohkawa, Yasuyuki

2018-04-11

Regulation of gene expression requires selective incorporation of histone H3 variant H3.3 into chromatin. Histone H3.3 has several subsidiary variants but their functions are unclear. Here we characterize the function of histone H3.3 sub-variant, H3mm7, which is expressed in skeletal muscle satellite cells. H3mm7 knockout mice demonstrate an essential role of H3mm7 in skeletal muscle regeneration. Chromatin analysis reveals that H3mm7 facilitates transcription by forming an open chromatin structure around promoter regions including those of myogenic genes. The crystal structure of the nucleosome containing H3mm7 reveals that, unlike the S57 residue of other H3 proteins, the H3mm7-specific A57 residue cannot form a hydrogen bond with the R40 residue of the cognate H4 molecule. Consequently, the H3mm7 nucleosome is unstable in vitro and exhibited higher mobility in vivo compared with the H3.3 nucleosome. We conclude that the unstable H3mm7 nucleosome may be required for proper skeletal muscle differentiation.

[ORGANIZATIONAL COMMITMENT AND WORK ENGAGEMENT - THEORETICAL CONCEPTIONS AND TERMINOLOGICAL PROBLEMS].

PubMed

Łaguna, Mariola; Mielniczuk, Emilia; Żaliński, Adam; Wałachowska, Karolina

2015-01-01

Engagement in professional activities and positive attitudes towards an organization are of significant importance to functioning and health of employees. Studies analysing the phenomena of employees' engagement and their relations with an organization undergo a dynamic development in both international and Polish research. Two theoretical conceptions: organizational commitment (by Meyer and Allen) and work engagement (by Schaufeli and Bakker) have become prominent in the field. They capture 2 similar, albeit distinct constructs. In English-language journals academics concentrate on theoretical and empirical analyses of similarities and differences between the 2 concepts, while in Polish publications scholars also have to deal with the issue of the original term translation. The problem lies mostly in Polish nomenclature of the dimensions proposed in both of these conceptions. Lack of common translations for different studies may cause confusion in this area of research. In the paper authors present a review of Polish translations of terms used in the discussed conceptions and a linguistic analysis of terms, both in English and in Polish. Authors provide solutions which could help to clarify terminology in Polish-language publications concerning organizational commitment and work engagement. This allows for further development of research in this field.

Knowledge-based system V and V in the Space Station Freedom program

NASA Technical Reports Server (NTRS)

Kelley, Keith; Hamilton, David; Culbert, Chris

1992-01-01

Knowledge Based Systems (KBS's) are expected to be heavily used in the Space Station Freedom Program (SSFP). Although SSFP Verification and Validation (V&V) requirements are based on the latest state-of-the-practice in software engineering technology, they may be insufficient for Knowledge Based Systems (KBS's); it is widely stated that there are differences in both approach and execution between KBS V&V and conventional software V&V. In order to better understand this issue, we have surveyed and/or interviewed developers from sixty expert system projects in order to understand the differences and difficulties in KBS V&V. We have used this survey results to analyze the SSFP V&V requirements for conventional software in order to determine which specific requirements are inappropriate for KBS V&V and why they are inappropriate. Further work will result in a set of recommendations that can be used either as guidelines for applying conventional software V&V requirements to KBS's or as modifications to extend the existing SSFP conventional software V&V requirements to include KBS requirements. The results of this work are significant to many projects, in addition to SSFP, which will involve KBS's.

Rate contants for CF{sub 3} + H{sub 2} {yields} CF{sub 3}H + H and CF{sub 3}H + H {yields} CF{sub 3} + H{sub 2} reactions in the temperature range 1100-1600 K.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hranisavljevic, J.; Michael, V.; Chemistry

1998-09-24

The shock tube technique coupled with H-atom atomic resonance absorption spectrometry has been used to study the reactions (1) CF{sub 3} + H{sub 2} {yields} CF{sub 3}H + H and (2) CF{sub 3}H + H{yields} CF{sub 3} + H{sub 2} over the temperature ranges 1168-1673 K and 1111-1550 K, respectively. The results can be represented by the Arrhenius expressions k1 = 2.56 x 10{sup -11} exp(-8549K/T) and k2 = 6.13 x 10{sup -11} exp(-7364K/T), both in cm3 molecule-1 s-1. Equilibrium constants were calculated from the two Arrhenius expressions in the overlapping temperature range, and good agreement was obtained with themore » literature values. The rate constants for reaction 2 were converted into rate constants for reaction 1 using literature equilibrium constants. These data are indistinguishable from direct k1 measurements, and an Arrhenius fit for the joint set is k{sub 1} = 1.88 x 10{sup -11} exp(-8185K/T) cm3 molecule-1 s-1. The CF{sub 3} + H{sub 2} {yields} CF{sub 3}H + H reaction was further modeled using conventional transition-state theory, which included ab initio electronic structure determinations of reactants, transition state, and products.« less

The concept of `work ability' from the view point of employers.

PubMed

Jansson, Inger; Björklund, Anita; Perseius, Kent-Inge; Gunnarsson, A Birgitta

2015-01-01

Since work ability is manifested in working life and ``bought'' by employers, employers perceptions of the concept are important to understand. Studies have shown that people with health problems want to take part in the labour market, but experience difficulties in gaining access. Additionally, studies have demonstrated the doubt felt by employers when they consider hiring a person with a disability. The aim was to identify and characterise employers' conceptions of work ability. The study design was qualitative with a phenomenographic approach. Six male and six female employers from various workplaces and geographical areas in Sweden were interviewed. Three domains were identified: employees' contributions to work ability, employers' contributions to work ability and circumstances with limited work ability. Work ability was regarded as a tool in production and its output, production, was the main issue. The employees' commitment and interest could bridge other shortcomings. The employers highlighted their own contributions in shaping work ability in order to fit with work circumstances. Health problems were not the only limiting issues; other circumstances, such as individual characteristics and contextual factors, could limit work ability too. Knowing the importance of commitment and interest is valuable in work rehabilitation.

Ternary recombination of H3+, H2D+, HD2+, and D3+ with electrons in He/Ar/H2/D2 gas mixtures

NASA Astrophysics Data System (ADS)

Kalosi, Abel; Dohnal, Petr; Plasil, Radek; Johnsen, Rainer; Glosik, Juraj

2016-09-01

The temperature dependence of the ternary recombination rate coefficients of H2D+ and HD2+ ions has been studied in the temperature range of 80-150 K at pressures from 500 to 1700 Pa in a stationary afterglow apparatus equipped with a cavity ring-down spectrometer. Neutral gas mixtures consisting of He/Ar/H2/D2 (with typical number densities 1017 /1014 /1014 /1014 cm-3) were employed to produce the desired ionic species and their fractional abundances were monitored as a function of helium pressure and the [D2]/[H2] ratio of the neutral gas. In addition, the translational and the rotational temperature and the ortho to para ratio were monitored for both H2D+ and HD2+ ions. A fairly strong pressure dependence of the effective recombination rate coefficient was observed for both ion species, leading to ternary recombination rate coefficients close to those previously found for (helium assisted) ternary recombination of H3+ and D3+. Work supported by: Czech Science Foundation projects GACR 14-14649P, GACR 15-15077S, GACR P209/12/0233, and by Charles University in Prague Project Nr. GAUK 692214.

40 CFR 721.5540 - 1H,3H,5H-oxazolo [3,4-c] oxazole, dihydro-7a-methyl-.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1H,3H,5H-oxazolo [3,4-c] oxazole... Specific Chemical Substances § 721.5540 1H,3H,5H-oxazolo [3,4-c] oxazole, dihydro-7a-methyl-. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as 1H,3H,5H...

Rate constants for CF{sub 3} + H{sub 2} {r_arrow} CF{sub 3}H + H and CF{sub 3}H + H {r_arrow} CF{sub 3} + H{sub 2} reactions in the temperature range 1100--1600 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hranisavljevic, J.; Michael, J.V.

1998-09-24

The shock tube technique coupled with H-atom atomic resonance absorption spectrometry has been used to study the reactions (1) CF{sub 3} + H{sub 2} {r_arrow} CF{sub 3}H + H and (2) CF{sub 3}H + H {r_arrow} CF{sub 3} + H{sub 2} over the temperature ranges 1168--1673 K and 1111--1550 K, respectively. The results can be represented by the Arrhenius expressions k{sub 1} = 2.56 {times} 10{sup {minus}11} exp({minus}8549K/T) and k{sub 2} = 6.13 {times} 10{sup {minus}11} exp({minus}7364K/T), both in cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. Equilibrium constants were calculated from the two Arrhenius expressions in the overlapping temperature range, andmore » good agreement was obtained with the literature values. The rate constants for reaction 2 were converted into rate constants for reaction 1 using literature equilibrium constants. These data are indistinguishable from direct k{sub 1} measurements, and an Arrhenius fit for the joint set is k{sub 1} = 1.88 {times} 10{sup {minus}11} exp({minus}8185K/T) cm{sup 3} molecule{sup {minus}1} s{sup {minus}1}. The CF{sub 3} + H{sub 2} {r_arrow} CF{sub 3}H + H reaction was further modeled using conventional transition-state theory, which included ab initio electronic structure determinations of reactants, transition state, and products.« less

The Development of the Concept of Work: A Case where History Can Inform Pedagogy

NASA Astrophysics Data System (ADS)

de Berg, Kevin C.

An historical analysis of the work concept with particular emphasis given to the contributions of John Smeaton and Daniel Bernouilli is provided with a view to enlightening or resolving current difficulties experienced in the teaching and learning of the concept of work and its relationship to kinetic and potential energies. An approach which emphasises the work done by both applied and resisting forces and which gives some technological significance to the (force x distance) definition of work is recommended.

Swine influenza virus vaccine serologic cross-reactivity to contemporary US swine H3N2 and efficacy in pigs infected with an H3N2 similar to 2011-2012 H3N2v.

PubMed

Kitikoon, Pravina; Gauger, Phillip C; Anderson, Tavis K; Culhane, Marie R; Swenson, Sabrina; Loving, Crystal L; Perez, Daniel R; Vincent, Amy L

2013-12-01

Swine influenza A virus (IAV) reassortment with 2009 H1N1 pandemic (H1N1pdm09) virus has been documented, and new genotypes and subclusters of H3N2 have since expanded in the US swine population. An H3N2 variant (H3N2v) virus with the H1N1pdm09 matrix gene and the remaining genes of swine triple reassortant H3N2 caused outbreaks at agricultural fairs in 2011-2012. To assess commercial swine IAV vaccines' efficacy against H3N2 viruses, including those similar to H3N2v, antisera to three vaccines were tested by hemagglutinin inhibition (HI) assay against contemporary H3N2. Vaccine 1, with high HI cross-reactivity, was further investigated for efficacy against H3N2 virus infection in pigs with or without maternally derived antibodies (MDA). In addition, efficacy of a vaccine derived from whole inactivated virus (WIV) was compared with live attenuated influenza virus (LAIV) against H3N2. Hemagglutinin inhibition cross-reactivity demonstrated that contemporary swine H3N2 viruses have drifted from viruses in current swine IAV vaccines. The vaccine with the highest level of HI cross-reactivity significantly protected pigs without MDA. However, the presence of MDA at vaccination blocked vaccine efficacy. The performance of WIV and LAIV was comparable in the absence of MDA. Swine IAV in the United States is complex and dynamic. Vaccination to minimize virus shedding can help limit transmission of virus among pigs and people. However, vaccines must be updated. A critical review of the use of WIV in sows is required in the context of the current IAV ecology and vaccine application in pigs with MDA. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Trimethylation of histone H3 lysine 4 impairs methylation of histone H3 lysine 9

PubMed Central

LeRoy, Gary; Bua, Dennis J; Garcia, Benjamin A; Gozani, Or; Richard, Stéphane

2010-01-01

Chromatin is broadly compartmentalized in two defined states: euchromatin and heterochromatin. Generally, euchromatin is trimethylated on histone H3 lysine 4 (H3K4me3) while heterochromatin contains the H3K9me3 mark. The H3K9me3 modification is added by lysine methyltransferases (KMTs) such as SETDB1. Herein, we show that SETDB1 interacts with its substrate H3, but only in the absence of the euchromatic mark H3K4me3. In addition, we show that SETDB1 fails to methylate substrates containing the H3K4me3 mark. Likewise, the functionally related H3K9 KMTs G9A, GLP and SUV39H1 also fail to bind and to methylate H3K4me3 substrates. Accordingly, we provide in vivo evidence that H3K9me2-enriched histones are devoid of H3K4me2/3 and that histones depleted of H3K4me2/3 have elevated H3K9me2/3. The correlation between the loss of interaction of these KMTs with H3K4me3 and concomitant methylation impairment leads to the postulate that at least these four KMTs require stable interaction with their respective substrates for optimal activity. Thus, novel substrates could be discovered via the identification of KMT interacting proteins. Indeed, we find that SETDB1 binds to and methylates a novel substrate, the inhibitor of growth protein ING2, while SUV39H1 binds to and methylates the heterochromatin protein HP1α. Thus, our observations suggest a mechanism of post-translational regulation of lysine methylation and propose a potential mechanism for the segregation of the biologically opposing marks, H3K4me3 and H3K9me3. Furthermore, the correlation between H3-KMTs interaction and substrate methylation highlights that the identification of novel KMT substrates may be facilitated by the identification of interaction partners. PMID:21124070

Job characteristics and work safety climate among North Carolina farmworkers with H-2A visas.

PubMed

Arcury, Thomas A; Summers, Phillip; Talton, Jennifer W; Nguyen, Ha T; Chen, Haiying; Quandt, Sara A

2015-01-01

ABSTRACT Migrant farmworkers are a vulnerable population. Migrant farmworkers with H-2A visas are the only agricultural workers with temporary work permits. Little research has directly focused on the job characteristics and work safety of workers with H-2A visas. This analysis (1) describes their personal and job characteristics, job hazards, and stressors; (2) describes their perceived work safety climate; and (3) examines associations of perceived work safety climate with job characteristics, job hazards, and stressors. Data are from a cross-sectional component of a larger study of farmworker pesticide exposure; in 2012 interviews were conducted with 163 migrant farmworkers with H-2A visas in North Carolina. The sample was limited to men aged 30 to 70 years. Migrant farmworkers with H-2A visas experience the same hazards as do other farmworkers. Their mean score on the Perceived Work Safety Climate Scale 25.5 (SD = 3.7) is similar to that of other farmworkers and other immigrant workers. Perceived work safety climate is associated with hours worked per week (P = .02), precarious employment (P < .001), planting and cultivating (P = .002), topping tobacco (P = .0012), and stress (P = .02). Perceived work safety climate is particularly important for migrant farmworkers with H-2A visas because their labor contracts limit their options to change employers. Additional research on the status of work safety climate among agricultural workers is needed, as well as on the factors that affect work safety climate and on the safety characteristics that are affected by work safety climate. Policy changes that lead to improved work safety climate should be considered.

Job Characteristics and Work Safety Climate among North Carolina Farmworkers with H-2A Visas

PubMed Central

Arcury, Thomas A.; Summers, Phillip; Talton, Jennifer W.; Nguyen, Ha T.; Chen, Haiying; Quandt, Sara A.

2016-01-01

Migrant farmworkers are a vulnerable population. Migrant farmworkers with H-2A visas are the only agricultural workers with temporary work permits. Little research has directly focused on the job characteristics and work safety of workers with H-2A visas. This analysis (1) describes their personal and job characteristics, job hazards, and stressors; (2) describes their perceived work safety climate; and (3) examines associations of perceived work safety climate with job characteristics, job hazards, and stressors. Data are from a cross-sectional component of a larger study of farmworker pesticide exposure; in 2012 interviews were conducted with 163 migrant farmworkers with H-2A visas in North Carolina. The sample was limited to men aged 30 to 70 years. Migrant farmworkers with H-2A visas experience the same hazards as do other farmworkers. Their mean score on the perceived work safety climate scale 25.5 (SD=3.7) is similar to that of other farmworkers and other immigrant workers. Perceived work safety climate is associated with hours worked per week (p=0.02), precarious employment (p<0.001), planting and cultivating (p=0.002); topping tobacco (p=0.0012), and stress (p=0.02). Perceived work safety climate is particularly important for migrant farmworkers with H-2A visas because their labor contracts limit their options to change employers. Additional research on the status of work safety climate among agricultural workers is needed, as well as on the factors that affect work safety climate and on the safety characteristics that are affected by work safety climate. Policy changes that lead to improved work safety climate should be considered. PMID:25635744

Structural basis for recognition of H3K56-acetylated histone H3-H4 by the chaperone Rtt106

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Dan; Hu, Qi; Li, Qing

2013-04-08

Dynamic variations in the structure of chromatin influence virtually all DNA-related processes in eukaryotes and are controlled in part by post-translational modifications of histones. One such modification, the acetylation of lysine 56 (H3K56ac) in the amino-terminal α-helix (αN) of histone H3, has been implicated in the regulation of nucleosome assembly during DNA replication and repair, and nucleosome disassembly during gene transcription. In Saccharomyces cerevisiae, the histone chaperone Rtt106 contributes to the deposition of newly synthesized H3K56ac-carrying H3-H4 complex on replicating DNA, but it is unclear how Rtt106 binds H3-H4 and specifically recognizes H3K56ac as there is no apparent acetylated lysinemore » reader domain in Rtt106. Here, we show that two domains of Rtt106 are involved in a combinatorial recognition of H3-H4. An N-terminal domain homodimerizes and interacts with H3-H4 independently of acetylation while a double pleckstrin-homology (PH) domain binds the K56-containing region of H3. Affinity is markedly enhanced upon acetylation of K56, an effect that is probably due to increased conformational entropy of the αN helix of H3. Our data support a mode of interaction where the N-terminal homodimeric domain of Rtt106 intercalates between the two H3-H4 components of the (H3-H4) 2 tetramer while two double PH domains in the Rtt106 dimer interact with each of the two H3K56ac sites in (H3-H4) 2. We show that the Rtt106-(H3-H4) 2 interaction is important for gene silencing and the DNA damage response.« less

H3+ Measurements in the Jovian Atmosphere with JIRAM/Juno

NASA Astrophysics Data System (ADS)

Mura, A.; Migliorini, A.; Dinelli, B. M.; Moriconi, M. L.; Altieri, F.; Adriani, A.; Fabiano, F.; Piccioni, G.; Tosi, F.; Filacchione, G.; Sindoni, G.; Grassi, D.; Noschese, R.; Cicchetti, A.; Sordini, R.; Bolton, S. J.; Connerney, J. E. P.; Atreya, S. K.; Levin, S.; Lunine, J. I.; Gerard, J. C. M. C.; Turrini, D.; Stefani, S.; Olivieri, A.; Plainaki, C.

2017-12-01

The NASA Juno mission has been investigating Jupiter's atmosphere since August 2016, providing unprecedented insights into the giant planet. The Jupiter Infrared Auroral Mapper (JIRAM) experiment, on board Juno, performed spectroscopic observations of the H3+ emissions both in the auroral regions (Dinelli et al., 2017; Adriani et al., 2017; Mura et al., 2017) and at mid latitudes. In the present work, we analyse the observations acquired by the JIRAM spectrometer during the first perijove passage on 26-27 August 2016, when the spacecraft was at about 500,000-1,200,000 km (7-17 RJ) from the planet. During a portion of the observations, the slit of the spectrometer sampled Jupiter's limb in the latitude range from 30° to 60° in both hemispheres. The limb spectra show the typical features of the H3+ emission in the 3-4 μm spectral range, which are generally used to retrieve the H3+ concentration and temperature in the auroral region. In this work we employ above spectral region to provide new insight into the H3+ vertical distribution. The spatial resolution of the limb observations of Jupiter, ranging between 50 and 130 km, is favorable for investigating the vertical distribution of H3+. The vertical profiles of the H3+ limb intensity will be presented along with the preliminary results of the retrieval on H3+ vertical volume mixing ratio (VMR) height profiles, and comparison with predictions from the available atmospheric models of the planet. Possible variability of the altitude of the peak emission with respect to latitude and longitude will also be discussed.

Applying the Concept of Working Memory to Foreign Language Listening Comprehension.

ERIC Educational Resources Information Center

Service, Elisabet

Memory research has recently moved from looking at performance in highly artificial laboratory tasks to examination of tasks in everyday life. One consequence is the development of the concept of "working memory." For the learner, foreign language comprehension makes great demands on working memory capacity. Comprehension of a message requires…

Interstellar H3+

PubMed Central

Oka, Takeshi

2006-01-01

Protonated molecular hydrogen, H3+, is the simplest polyatomic molecule. It is the most abundantly produced interstellar molecule, next only to H2, although its steady state concentration is low because of its extremely high chemical reactivity. H3+ is a strong acid (proton donor) and initiates chains of ion-molecule reactions in interstellar space thus leading to formation of complex molecules. Here, I summarize the understandings on this fundamental species in interstellar space obtained from our infrared observations since its discovery in 1996 and discuss the recent observations and analyses of H3+ in the Central Molecular Zone near the Galatic center that led to a revelation of a vast amount of warm and diffuse gas existing in the region. PMID:16894171

ANTHROPOLOGY AT WAR: ROBERT H. LOWIE AND THE TRANSFORMATION OF THE CULTURE CONCEPT, 1904 to 1954.

PubMed

Bargheer, Stefan

2017-03-01

The concept of culture used in American anthropology has fundamentally transformed throughout the first half of the twentieth century. The changing resonance of the work of Robert H. Lowie offers revealing insights into this development. Lowie was part of the first generation of students of Franz Boas that highlighted the importance of individual variation for the study of both primitive and civilized societies. Yet, its initial resonance notwithstanding, the culture concept that prevailed in the discipline went into a different direction as the result of anthropologists' involvement in the war effort. It was advanced by the second generation of Boas' students such as Ruth Benedict and Margaret Mead, who stressed the homogeneity of cultures. The contrast highlights the diversity of approaches available within anthropology in the first half of the century and the crucial impact of World War II in determining which of these possibilities became institutionalized in the decades after the war. © 2017 Wiley Periodicals, Inc.

Development of rotorcraft interior noise control concepts. Phase 3: Development of noise control concepts

NASA Technical Reports Server (NTRS)

Yoerkie, Charles A.; Gintoli, P. J.; Ingraham, S. T.; Moore, J. A.

1986-01-01

The goal of this research is the understanding of helicopter internal noise mechanisms and the development, design, and testing of noise control concepts which will produce significant reductions in the acoustic environment to which passengers are exposed. The Phase 3 effort involved the identification and evaluation of current and advanced treatment concepts, including isolation of structure-borne paths. In addition, a plan was devised for the full-scale evaluation of an isolation concept. Specific objectives were as follows: (1) identification and characterization of various noise control concepts; (2) implementation of noise control concepts within the S-76 SEA (statistical energy analysis) model; (3) definition and evaluation of a preliminary acoustic isolation design to reduce structure-borne transmission of acoustic frequency main gearbox gear clash vibrations into the airframe; (4) formulation of a plan for the full-scale validation of the isolation concept; and (5) prediction of the cabin noise environment with various noise control concepts installed.

Executive Summary of Ares V: Lunar Capabilities Concept Review Through Phase A-Cycle 3

NASA Technical Reports Server (NTRS)

Holladay, J. B.; Baggett, K. E.; Feldman, S. M.

2011-01-01

This Technical Memorandum (TM) was generated as an overall Ares V summary from the Lunar Capabilities Concept Review (LCCR) through Phase A-Cycle 3 (PA-C3) with the intent that it may be coupled with separately published appendices for a more detailed, integrated narrative. The Ares V has evolved from the initial point of departure (POD) 51.00.48 LCCR configuration to the current candidate POD, PA-C3D, and the family of vehicles concept that contains vehicles PA-C3A through H. The logical progression from concept to POD vehicles is summarized in this TM and captures the trade space and performance of each. The family-of-vehicles concept was assessed during PA-C3 and offered flexibility in the path forward with the ability to add options deemed appropriate. A description of each trade space is given in addition to a summary of each Ares V element. The Ares V contributions to a Mars campaign are also highlighted with the goal of introducing Ares V capabilities within the trade space. The assessment of the Ares V vehicle as it pertains to Mars missions remained locked to the architecture presented in Mars Design Reference Authorization 5.0 using the PA-C3D vehicle configuration to assess Mars transfer vehicle options, in-space EDS capabilities, docking adaptor and propellant transfer assessments, and lunar and Mars synergistic potential.

βig-h3 Represses T-Cell Activation in Type 1 Diabetes.

PubMed

Patry, Maeva; Teinturier, Romain; Goehrig, Delphine; Zetu, Cornelia; Ripoche, Doriane; Kim, In-San; Bertolino, Philippe; Hennino, Ana

2015-12-01

βig-h3/TGF-βi is a secreted protein capable of binding to both extracellular matrix and cells. Human genetic studies recently revealed that in the tgfbi gene encoding for βig-h3, three single nucleotide polymorphisms were significantly associated with type 1 diabetes (T1D) risk. Pancreatic islets express βig-h3 in physiological conditions, but this expression is reduced in β-cell insult in T1D. Since the integrity of islets is destroyed by autoimmune T lymphocytes, we thought to investigate the impact of βig-h3 on T-cell activation. We show here that βig-h3 inhibits T-cell activation markers as well as cytotoxic molecule production as granzyme B and IFN-γ. Furthermore, βig-h3 inhibits early T-cell receptor signaling by repressing the activation of the early kinase protein Lck. Moreover, βig-h3-treated T cells are unable to induce T1D upon transfer in Rag2 knockout mice. Our study demonstrates for the first time that T-cell activation is modulated by βig-h3, an islet extracellular protein, in order to efficiently avoid autoimmune response. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

Modeling 3H-3He Gas-Liquid Phase Transport for Interpretation of Groundwater Age

NASA Astrophysics Data System (ADS)

Carle, S. F.; Esser, B.; Moran, J. E.

2009-12-01

California’s Groundwater Ambient Monitoring and Assessment (GAMA) Program has measured many hundreds of tritium (3H) and helium-3 (3He) concentrations in well water samples to derive estimates of groundwater age at production and monitoring wells in California basins. However, a 3H-3He age differs from an ideal groundwater age tracer in several respects: (1) the radioactive decay of 3H results in the accumulation of 3He being first-order with respect to 3H activity (versus a zero-order age-mass accumulation process for an ideal tracer), (2) surface concentrations of 3H as measured in precipitation over the last several decades have not been uniform, and (3) the 3H-3He “clock” begins at the water table and not at the ground surface where 3H source measurements are made. To better understand how these non-idealities affect interpretation of 3H-3He apparent groundwater age, we are modeling coupled gas-liquid phase flow and 3H-3He transport including processes of radiogenic decay, phase equilibrium, and molecular diffusion for water, air, 3H, and 3He components continuously through the vadose zone and saturated zone. Assessment of coupled liquid-gas phase processes enables consideration of 3H-3He residence time and dispersion within the vadose zone, including partitioning of tritiogenic 3He to the gas phase and subsequent diffusion into the atmosphere. The coupled gas-liquid phase modeling framework provides direct means to compare apparent 3H-3He age to ideal mean or advective groundwater ages for the same groundwater flow conditions. Examples are given for common groundwater flow systems involving areal recharge, discharge to streams or long-screened wells, and aquifer system heterogeneity. The Groundwater Ambient Monitoring and Assessment program is sponsored by the California State Water Resources Control Board and carried out in cooperation with the U.S. Geological Survey. This work was performed under the auspices of the U.S. Department of Energy by

Precision saturated absorption spectroscopy of H3+

NASA Astrophysics Data System (ADS)

Guan, Yu-Chan; Chang, Yung-Hsiang; Liao, Yi-Chieh; Peng, Jin-Long; Wang, Li-Bang; Shy, Jow-Tsong

2018-03-01

In our previous work on the Lamb-dips of the ν2 fundamental band transitions of H3+, the saturated absorption spectrum was obtained by third-derivative spectroscopy using frequency modulation with an optical parametric oscillator (OPO). However, frequency modulation also caused errors in the absolute frequency determination. To solve this problem, we built a tunable offset locking system to lock the pump frequency of the OPO to an iodine-stabilized Nd:YAG laser. With this improvement, we were able to scan the OPO idler frequency precisely and obtain the saturated absorption profile using intensity modulation. Furthermore, ion concentration modulation was employed to subtract the background noise and increase the signal-to-noise ratio. To determine the absolute frequency of the idler wave, the OPO signal frequency was locked to an optical frequency comb. The absolute frequency accuracy of our spectrometer was better than 7 kHz, demonstrated by measuring the wavelength standard transition of methane at 3.39 μm. Finally, we measured 16 transitions of H3+ and our results agree very well with other precision measurements. This work successfully resolved the discrepancies between our previous measurements and other precision measurements.

Differential binding of /sup 3/H-imipramine and /sup 3/H-mianserin in rat cerebral cortex

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dumbrille-Ross, A.; Tang, S.W.; Coscina, D.V.

1981-11-16

Drug competition profiles, effect of raphe lesion, and sodium dependency of the binding of two antidepressant drugs /sup 3/H-imipramine and /sup 3/H-mianserin to rat cerebral cortex homogenate were compared to examine whether the drugs bound to a common ''antidepressant receptor.'' Of the neurotransmitters tested, only serotonin displaced binding of both /sup 3/H-imipramine and /sup 3/H-mianserin. /sup 3/H-Mianserin binding was potently displaced by serotonin S/sub 2/ antagonists and exhibited a profile similar to that of /sup 3/H-spiperone binding. In the presence of the serotonin S/sub 2/ antagonist spiperone, antihistamines (H/sub 1/) potently displaced /sup 3/H-mianserin binding. /sup 3/H-Imipramine binding was displacedmore » potently by serotonin uptake inhibitors. The order of potency of serotonergic drugs in displacing /sup 3/H-imipramine binding was not similar to their order in displacing /sup 3/H-spiperone or -3H-serotonin binding. Prior midbrain raphe lesions greatly decreased the binding of /sup 3/H-imipramine but did not alter binding of /sup 3/H-mianserin. Binding of /sup 3/H-imipramine but not /sup 3/H-mianserin was sodium dependent. These results show that /sup 3/H-imipramine and /sup 3/H-mianserin bind to different receptors. /sup 3/H-Imipramine binds to a presynaptic serotonin receptor which is probably related to a serotonin uptake recognition site, the binding of which is sodium dependent. /sup 3/H-Mianserin binds to postsynaptic receptors, possibly both serotonin S/sub 2/ and histamine H/sub 1/ receptors, the binding of which is sodium independent.« less

Work ability: concept and assessment from a physiotherapeutic perspective. An interview study.

PubMed

Stigmar, K; Ekdahl, C; Grahn, B

2012-07-01

The aim of this study was to ascertain experiences and perceptions among physiotherapists (PTs) in Sweden regarding the concept of work ability as well as their perspectives of their professional role in work ability assessments. We conducted an in-depth interview study with four male and twelve female physiotherapists working in the field of occupational health care, orthopaedics, primary health care or rehabilitation. Qualitative content analysis was applied to the data. Work ability was perceived as the ability to perform work tasks as requested. Having the potential to adjust at work and to allocate resources, having an attachment to the workplace and time factors were vital. The physiotherapists were striving for a well-defined role within a multiprofessional team, where work ability assessments were performed in a real work environment. The PTs experienced contradictory roles in relation to the patient but believed they could contribute with valuable material for assessments; this professional help was not always requested. It was noted that there was a need for experience and further education to enable PTs to further engage in work ability assessments. It is important to improve collaboration and to further discuss the work ability concept from the viewpoints of different professionals.

Epithelial–Mesenchymal Interactions as a Working Concept for Oral Mucosa Regeneration

PubMed Central

Liu, Jiarong

2011-01-01

Oral mucosa consists of two tissue layers, the superficial epithelium and the underlying lamina propria. Together, oral mucosa functions as a barrier against exogenous substances and pathogens. In development, interactions of stem/progenitor cells of the epithelium and mesenchyme are crucial to the morphogenesis of oral mucosa. Previous work in oral mucosa regeneration has yielded important clues for several meritorious proof-of-concept approaches. Tissue engineering offers a broad array of novel tools for oral mucosa regeneration with reduced donor site trauma and accelerated clinical translation. However, the developmental concept of epithelial–mesenchymal interactions (EMIs) is rarely considered in oral mucosa regeneration. EMIs in postnatal oral mucosa regeneration likely will not be a simple recapitulation of prenatal oral mucosa development. Biomaterial scaffolds play an indispensible role for oral mucosa regeneration and should provide a conducive environment for pivotal EMIs. Autocrine and paracrine factors, either exogenously delivered or innately produced, have rarely been and should be harnessed to promote oral mucosa regeneration. This review focuses on a working concept of epithelial and mesenchymal interactions in oral mucosa regeneration. PMID:21062224

Energy recovery from mixed H-/H0/H+ beams and collector simulations

NASA Astrophysics Data System (ADS)

Variale, V.; Cavenago, M.; Baltador, C.; Serianni, G.; Veltri, P.; Sartori, E.; Agostinetti, P.

2017-08-01

An axisymmetric system to recover beam energy from partially neutralized H- beams was recently proposed, for a given beam acceleration voltage Vs. In the case of ion source NIO1 Vs may range from 20 to 60 kV. A realistic beam with 3 mrad divergence, and a composition of 25 : 50 : 25 of H-, H0 and H+ has been considered. The collector works by decelerating the H- ions (into a system similar to a Faraday cup provided with an exit hole electrode), so that they are radially deflected by space charge and anode lens effects, and collected to a low kinetic energy Kc (less than 1 keV), while neutral and H+ ions can pass through the exit hole electrode. A following collector can recover H+ energy. Since the space charge calculations are challenging for highly nonlinear problem and for a possible (numerically unstable) virtual cathode phenomena different computation tools were compared for simulations. Stabilization techniques are compared. Limits for local perveance are discussed. Also mesh asymmetry effects and the related transverse oscillations of H+ beam may be observed. Efficiency over 90 % can be reached in typical conditions. The secondary yield (which is low thanks to low impact energy Kc and Faraday cup concept) is estimated.

Knowledge Based Systems: A Critical Survey of Major Concepts, Issues, and Techniques. M.S. Thesis Final Report, 1 Jul. 1985 - 31 Dec. 1987

NASA Technical Reports Server (NTRS)

Dominick, Wayne D. (Editor); Kavi, Srinu

1984-01-01

This Working Paper Series entry presents a detailed survey of knowledge based systems. After being in a relatively dormant state for many years, only recently is Artificial Intelligence (AI) - that branch of computer science that attempts to have machines emulate intelligent behavior - accomplishing practical results. Most of these results can be attributed to the design and use of Knowledge-Based Systems, KBSs (or ecpert systems) - problem solving computer programs that can reach a level of performance comparable to that of a human expert in some specialized problem domain. These systems can act as a consultant for various requirements like medical diagnosis, military threat analysis, project risk assessment, etc. These systems possess knowledge to enable them to make intelligent desisions. They are, however, not meant to replace the human specialists in any particular domain. A critical survey of recent work in interactive KBSs is reported. A case study (MYCIN) of a KBS, a list of existing KBSs, and an introduction to the Japanese Fifth Generation Computer Project are provided as appendices. Finally, an extensive set of KBS-related references is provided at the end of the report.

48 CFR 34.005-3 - Concept exploration contracts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Concept exploration... SPECIAL CATEGORIES OF CONTRACTING MAJOR SYSTEM ACQUISITION General 34.005-3 Concept exploration contracts. Whenever practicable, contracts to be performed during the concept exploration phase shall be for...

Breast Cancer Detection by B7-H3-Targeted Ultrasound Molecular Imaging.

PubMed

Bachawal, Sunitha V; Jensen, Kristin C; Wilson, Katheryne E; Tian, Lu; Lutz, Amelie M; Willmann, Jürgen K

2015-06-15

Ultrasound complements mammography as an imaging modality for breast cancer detection, especially in patients with dense breast tissue, but its utility is limited by low diagnostic accuracy. One emerging molecular tool to address this limitation involves contrast-enhanced ultrasound using microbubbles targeted to molecular signatures on tumor neovasculature. In this study, we illustrate how tumor vascular expression of B7-H3 (CD276), a member of the B7 family of ligands for T-cell coregulatory receptors, can be incorporated into an ultrasound method that can distinguish normal, benign, precursor, and malignant breast pathologies for diagnostic purposes. Through an IHC analysis of 248 human breast specimens, we found that vascular expression of B7-H3 was selectively and significantly higher in breast cancer tissues. B7-H3 immunostaining on blood vessels distinguished benign/precursors from malignant lesions with high diagnostic accuracy in human specimens. In a transgenic mouse model of cancer, the B7-H3-targeted ultrasound imaging signal was increased significantly in breast cancer tissues and highly correlated with ex vivo expression levels of B7-H3 on quantitative immunofluorescence. Our findings offer a preclinical proof of concept for the use of B7-H3-targeted ultrasound molecular imaging as a tool to improve the diagnostic accuracy of breast cancer detection in patients. ©2015 American Association for Cancer Research.

Ross Works on the Assembly Concept for Construction of Erectable Space Structure (ACCESS) During

NASA Technical Reports Server (NTRS)

1985-01-01

The crew assigned to the STS-61B mission included Bryan D. O'Conner, pilot; Brewster H. Shaw, commander; Charles D. Walker, payload specialist; mission specialists Jerry L. Ross, Mary L. Cleave, and Sherwood C. Spring; and Rodolpho Neri Vela, payload specialist. Launched aboard the Space Shuttle Atlantis November 28, 1985 at 7:29:00 pm (EST), the STS-61B mission's primary payload included three communications satellites: MORELOS-B (Mexico); AUSSAT-2 (Australia); and SATCOM KU-2 (RCA Americom). Two experiments were conducted to test assembling erectable structures in space: EASE (Experimental Assembly of Structures in Extravehicular Activity), and ACCESS (Assembly Concept for Construction of Erectable Space Structure). In a joint venture between NASA/Langley Research Center in Hampton, Virginia, and the Marshall Space Flight Center (MSFC), EASE and ACCESS were developed and demonstrated at MSFC's Neutral Buoyancy Simulator (NBS). In this STS-61B onboard photo, astronaut Ross works on ACCESS high above the orbiter. The primary objective of these experiments was to test the structural assembly concepts for suitability as the framework for larger space structures and to identify ways to improve the productivity of space construction.

Raman characterization of H:LiNbO3 waveguides

NASA Astrophysics Data System (ADS)

Savova, I.; Savatinova, I.; Kircheva, P.; Liarokapis, E.

2001-10-01

In this work we present polarized Raman measurements of z-cut multimode H:LiNbO3 waveguides in the κi- and βi-phase states. A spectrum with unexpected form and behaviour, originating from the layer at the very surface, was observed in samples with various degrees of Li-H substitution. Possible reasons for the presence of this strange spectrum are considered.

Working Time and the Volume of Work in Germany: The IAB Concept of Measurement. IAB Labour Market Research Topics.

ERIC Educational Resources Information Center

Bach, Hans-Uwe; Koch, Susanne

The Institut fuer Arbeitsmarkt- und Berufsforschung (IAB) or Institute for Employment Research has developed a detailed working time and volume of work measurement concept in order to more comprehensively assess the demand for labor. The individual components of working time in Germany are obtained from various data sources and combined to form…

Proton relays in anomalous carbocations dictate spectroscopy, stability, and mechanisms: case studies on C2H5+ and C3H3.

PubMed

Sager, LeeAnn M; Iyengar, Srinivasan S

2017-10-18

We present a detailed analysis of the anomalous carbocations: C 2 H 5 + and C 3 H 3 + . This work involves (a) probing electronic structural properties, (b) ab initio dynamics simulations over a range of internal energies, (c) analysis of reduced dimensional potential surfaces directed along selected conformational transition pathways, (d) dynamically averaged vibrational spectra computed from ab initio dynamics trajectories, and (e) two-dimensional time-frequency analysis to probe conformational dynamics. Key findings are as follows: (i) as noted in our previous study on C 2 H 3 + , it appears that these non-classical carbocations are stabilized by delocalized nuclear frameworks and "proton shuttles". We analyze this nuclear delocalization and find critical parallels between conformational changes in C 2 H 3 + , C 2 H 5 + , and C 3 H 3 + . (ii) The vibrational signatures of C 2 H 5 + are dominated by the "bridge-proton" conformation, but also show critical contributions from the "classical" configuration, which is a transition state at almost all levels of theory. This result is further substantiated through two-dimensional time-frequency analysis and is at odds with earlier explanations of the experimental spectra, where frequencies close to the classical region were thought to arise from an impurity. While this is still possible, our results here indicate an additional (perhaps more likely) explanation that involves the "classical" isomer. (iii) Finally, in the case of C 3 H 3 + our explanation of the experimental result includes the presence of multiple, namely, "cyclic", "straight", and propargyl, configurations. Proton shuttles and nuclear delocalization, reminiscent of those seen in the case of C 2 H 3 + , were seen all through and have a critical role in all our observations.

Effects of Aging Stereotype Threat on Working Self-Concepts: An Event-Related Potentials Approach

PubMed Central

Zhang, Baoshan; Lin, Yao; Gao, Qianyun; Zawisza, Magdalena; Kang, Qian; Chen, Xuhai

2017-01-01

Although the influence of stereotype threat (ST) on working self-concepts has been highlighted in recent years, its neural underpinnings are unclear. Notably, the aging ST, which largely influences older adults’ cognitive ability, mental and physical health, did not receive much attention. In order to investigate these issues, electroencephalogram (EEG) data were obtained from older adults during a modified Stroop task using neutral words, positive and negative self-concept words in aging ST vs. neutral control conditions. Results showed longer reaction times (RTs) for identifying colors of words under the aging ST compared to the neutral condition. More importantly, the negative self-concept elicited more positive late P300 amplitudes and enhanced theta band activities compared to the positive self-concept or neutral words under the aging ST condition, whereas no difference was found between these self-concepts and neutral words in the control condition. Furthermore, the aging ST induced smaller theta band synchronization and enhanced alpha band synchronization compared to the control condition. Moreover, we also observed valence differences in self-concepts where the negative self-concept words reduced early P150/N170 complex relative to neutral words. These findings suggest that priming ST could activate negative self-concepts as current working self-concept, and that this influence occurred during a late neural time course. PMID:28747885

Recurrent Loss of APOBEC3H Activity during Primate Evolution.

PubMed

Garcia, Erin I; Emerman, Michael

2018-06-20

Genes in the APOBEC3 family encode cytidine deaminases that provide a barrier against viral infection and retrotransposition. Of all APOBEC3 genes in humans, APOBEC3H ( A3H ) is the most polymorphic: some haplotypes encode stable and active A3H proteins, while others are unstable and poorly antiviral. Such variation in human A3H affects interactions with the lentiviral antagonist Vif, which counteracts A3H via proteasomal degradation. In order to broaden our understanding of A3H-Vif interactions, as well as its evolution in Old World monkeys, we characterized A3H variation within four African green monkey (AGM) subspecies. We found that A3H is highly polymorphic in AGMs and has lost antiviral activity in multiple Old World monkeys. This loss of function was partially related to protein expression levels but was also influenced by amino acid mutations in the N-terminus. Moreover, we demonstrate that the evolution of A3H in the primate lineages leading to AGMs was not driven by Vif. Our work suggests that activity of A3H is evolutionarily dynamic and may have a negative effect on host fitness, resulting in its recurrent loss in primates. IMPORTANCE Adaptation of viruses to their hosts is critical for transmission of viruses between different species. Previous studies had identified changes in a protein from the APOBEC3 family that influenced species-specificity of simian immunodeficiency viruses (SIVs) in African green monkeys. We studied the evolution of a related protein in the same system, APOBEC3H, which has experienced a loss of function in humans. This evolutionary approach revealed that recurrent loss of APOBEC3H activity has taken place during primate evolution suggesting that APOBEC3H places a fitness cost on hosts. The variability of APOBEC3H activity between different primates highlights the differential selective pressures on the APOBEC3 gene family. Copyright © 2018 American Society for Microbiology.

The impact of a single 24 h working day on cognitive and psychomotor performance in staff anaesthesiologists.

PubMed

Karanovic, Nenad; Carev, Mladen; Kardum, Goran; Pecotic, Renata; Valic, Maja; Karanovic, Sandra; Ujevic, Ante; Dogas, Zoran

2009-10-01

The profession of anaesthesiologist is demanding and potentially hazardous. Extended work shifts combined with intensive work load may adversely affect physicians' performance. The aim of this study was to explore the impact of a single in-hospital 24 h shift on the cognitive and psychomotor performance of anaesthesiologists in a surgical emergency department. Following ethical and institutional approval, 11 staff anaesthesiologists [six men, five women, age 48 (35-50), years of experience 17 (7-20), median (range)] successfully completed the study protocol. Four computer-generated psychological tests (CRD, Complex Reactionmeter Drenovac, Croatia) consisting of light signal position discrimination (CRD 311), simple visual orientation (CRD 21), simple arithmetic operations (CRD 11), and complex psychomotor coordination (CRD 411) were used to measure objective parameters of cognitive and psychomotor performance at four time points (D1 = 8:00 a.m., D2 = 3:00 p.m., D3 = 11:00 p.m.; and D4 = 7:00-8:00 a.m. next day) during the 24 h working day. The control testing on an ordinary working day was performed at two time points (C1 = 8:00 a.m., C2 = 3:00 p.m.). Three parameters were recorded: total test solving time (TTST), total variability, and total number of errors for all four tests. TTST was significantly impaired during the 24 h shift in all tests, and TTST was prolonged in CRD 21 test at different time points from 1.6 +/- 1.4 to 5.5 +/- 1.6 s compared with the control (F = 6.39, P = 0.001). The reaction times were prolonged from 1.3 +/- 1.8 to 5.4 +/- 1.2 s (F = 3.49, P = 0.009) in CRD 311, from 3.8 +/- 9.0 to 34.3 +/- 5.8 s (F = 5.05, P = 0.002) in CRD 11 TTST, and from 0.8 +/- 3.0 to 16.3 +/- 8.6 s (F = 2.67, P = 0.034) in CRD 411. Total variability was significantly altered during the 24 h shift only in CRD 411 (F = 2.63, P = 0.036). There was no difference in the total number of errors between the 24 h shift and the ordinary working day. Anaesthesiologists' 24 h

H3.Y discriminates between HIRA and DAXX chaperone complexes and reveals unexpected insights into human DAXX-H3.3-H4 binding and deposition requirements

PubMed Central

Zink, Lisa-Maria; Delbarre, Erwan; Eberl, H. Christian; Keilhauer, Eva C.; Bönisch, Clemens; Pünzeler, Sebastian; Bartkuhn, Marek; Collas, Philippe; Mann, Matthias

2017-01-01

Abstract Histone chaperones prevent promiscuous histone interactions before chromatin assembly. They guarantee faithful deposition of canonical histones and functionally specialized histone variants into chromatin in a spatial- and temporally-restricted manner. Here, we identify the binding partners of the primate-specific and H3.3-related histone variant H3.Y using several quantitative mass spectrometry approaches, and biochemical and cell biological assays. We find the HIRA, but not the DAXX/ATRX, complex to recognize H3.Y, explaining its presence in transcriptionally active euchromatic regions. Accordingly, H3.Y nucleosomes are enriched in the transcription-promoting FACT complex and depleted of repressive post-translational histone modifications. H3.Y mutational gain-of-function screens reveal an unexpected combinatorial amino acid sequence requirement for histone H3.3 interaction with DAXX but not HIRA, and for H3.3 recruitment to PML nuclear bodies. We demonstrate the importance and necessity of specific H3.3 core and C-terminal amino acids in discriminating between distinct chaperone complexes. Further, chromatin immunoprecipitation sequencing experiments reveal that in contrast to euchromatic HIRA-dependent deposition sites, human DAXX/ATRX-dependent regions of histone H3 variant incorporation are enriched in heterochromatic H3K9me3 and simple repeat sequences. These data demonstrate that H3.Y's unique amino acids allow a functional distinction between HIRA and DAXX binding and its consequent deposition into open chromatin. PMID:28334823

Centromeres Off the Hook: Massive Changes in Centromere Size and Structure Following Duplication of CenH3 Gene in Fabeae Species

PubMed Central

Neumann, Pavel; Pavlíková, Zuzana; Koblížková, Andrea; Fuková, Iva; Jedličková, Veronika; Novák, Petr; Macas, Jiří

2015-01-01

In most eukaryotes, centromere is determined by the presence of the centromere-specific histone variant CenH3. Two types of chromosome morphology are generally recognized with respect to centromere organization. Monocentric chromosomes possess a single CenH3-containing domain in primary constriction, whereas holocentric chromosomes lack the primary constriction and display dispersed distribution of CenH3. Recently, metapolycentric chromosomes have been reported in Pisum sativum, representing an intermediate type of centromere organization characterized by multiple CenH3-containing domains distributed across large parts of chromosomes that still form a single constriction. In this work, we show that this type of centromere is also found in other Pisum and closely related Lathyrus species, whereas Vicia and Lens genera, which belong to the same legume tribe Fabeae, possess only monocentric chromosomes. We observed extensive variability in the size of primary constriction and the arrangement of CenH3 domains both between and within individual Pisum and Lathyrus species, with no obvious correlation to genome or chromosome size. Search for CenH3 gene sequences revealed two paralogous variants, CenH3-1 and CenH3-2, which originated from a duplication event in the common ancestor of Fabeae species. The CenH3-1 gene was subsequently lost or silenced in the lineage leading to Vicia and Lens, whereas both genes are retained in Pisum and Lathyrus. Both of these genes appear to have evolved under purifying selection and produce functional CenH3 proteins which are fully colocalized. The findings described here provide the first evidence for a highly dynamic centromere structure within a group of closely related species, challenging previous concepts of centromere evolution. PMID:25771197

Centromeres Off the Hook: Massive Changes in Centromere Size and Structure Following Duplication of CenH3 Gene in Fabeae Species.

PubMed

Neumann, Pavel; Pavlíková, Zuzana; Koblížková, Andrea; Fuková, Iva; Jedličková, Veronika; Novák, Petr; Macas, Jiří

2015-07-01

In most eukaryotes, centromere is determined by the presence of the centromere-specific histone variant CenH3. Two types of chromosome morphology are generally recognized with respect to centromere organization. Monocentric chromosomes possess a single CenH3-containing domain in primary constriction, whereas holocentric chromosomes lack the primary constriction and display dispersed distribution of CenH3. Recently, metapolycentric chromosomes have been reported in Pisum sativum, representing an intermediate type of centromere organization characterized by multiple CenH3-containing domains distributed across large parts of chromosomes that still form a single constriction. In this work, we show that this type of centromere is also found in other Pisum and closely related Lathyrus species, whereas Vicia and Lens genera, which belong to the same legume tribe Fabeae, possess only monocentric chromosomes. We observed extensive variability in the size of primary constriction and the arrangement of CenH3 domains both between and within individual Pisum and Lathyrus species, with no obvious correlation to genome or chromosome size. Search for CenH3 gene sequences revealed two paralogous variants, CenH3-1 and CenH3-2, which originated from a duplication event in the common ancestor of Fabeae species. The CenH3-1 gene was subsequently lost or silenced in the lineage leading to Vicia and Lens, whereas both genes are retained in Pisum and Lathyrus. Both of these genes appear to have evolved under purifying selection and produce functional CenH3 proteins which are fully colocalized. The findings described here provide the first evidence for a highly dynamic centromere structure within a group of closely related species, challenging previous concepts of centromere evolution. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Generalizations Related to Concepts Important for Youth Orientation to the World of Work.

ERIC Educational Resources Information Center

Warren, Mary A.; And Others

A basic first step in building a curriculum contributing to the orientation of youth to world of work is identification of concepts important to that orientation. In this study, the generalizations within the concept framework were identified through a developmental process of analysis and synthesis, including a review of current literature, a…

Properties of the pressure-induced superconducting state in trihydrides ScH3 and LaH3

NASA Astrophysics Data System (ADS)

Durajski, A. P.; Szczȩśniak, R.

2014-11-01

The present paper discusses the thermodynamic properties of the superconducting state which gets induced in the following compounds due to the influence of the high pressure: ScH3 ( p = 18 GPa) and LaH3 (p = 11 GPa). Using the Eliashberg formalism, for the Coulomb pseudopotential equal to 0.1, the following quantities have been determined: the maximum critical temperature ({{[{{T}C}]}Sc{{H3}}}=19.3 K and {{[{{T}C}]}La{{H3}}}=22.5 K), the energy gap at the Fermi surface (G), the free energy (F), the thermodynamic critical field (HC), and the specific heat (both for the superconducting (CS) and the normal (CN) state). Then, the dimensionless parameters, namely, {{R}G}\\equiv G≤ft( 0 \\right)/{{k}B}{{T}C}, {{R}H}\\equiv {{T}C}{{C}N}≤ft( {{T}C} \\right)/HC2≤ft( 0 \\right), and {{R}C}\\equiv ≤ft( {{C}S}≤ft( {{T}C} \\right)-{{C}N}≤ft( {{T}C} \\right) \\right)/{{C}N}≤ft( {{T}C} \\right), have been obtained. Those ratios deviate from the predictions of the BCS theory in the case of the studied compounds: {{[{{R}G}]}Sc{{H3}}}=3.85, {{[{{R}G}]}La{{H3}}}=3.92, {{[{{R}H}]}Sc{{H3}}}=0.160, {{[{{R}H}]}La{{H3}}}=0.154, {{[{{R}C}]}Sc{{H3}}}=1.84, and {{[{{R}C}]}La{{H3}}}=2.09. In the last step, it has been proven that the ratio of the electron effective mass (me\\star ) to the electron band mass (me) takes relatively high values, which are weakly dependent on the temperature. For example, it has been shown that {{[me\\star /{{m}e}]}Sc{{H3}}}=1.833 and {{[me\\star /{{m}e}]}La{{H3}}}=1.845 for T={{T}C}.

18 CFR 401.32 - Concept of 3.8.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Concept of 3.8. 401.32 Section 401.32 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE Project Review Under Section 3.8 of the Compact § 401.32 Concept...

18 CFR 401.32 - Concept of 3.8.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Concept of 3.8. 401.32 Section 401.32 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE Project Review Under Section 3.8 of the Compact § 401.32 Concept...

3,4-Methylenedioxyamphetamine (MDA) analogues exhibit differential effects on synaptosomal release of 3H-dopamine and 3H-5-hydroxytryptamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKenna, D.J.; Guan, X.M.; Shulgin, A.T.

1991-03-01

The effect of various analogues of the neurotoxic amphetamine derivative, MDA (3,4-methylenedioxyamphetamine) on carrier-mediated, calcium-independent release of 3H-5-HT and 3H-DA from rat brain synaptosomes was investigated. Both enantiomers of the neurotoxic analogues MDA and MDMA (3,4-methylenedioxymethamphetamine) induce synaptosomal release of 3H-5-HT and 3H-DA in vitro. The release of 3H-5-HT induced by MDMA is partially blocked by 10(-6) M fluoxetine. The (+) enantiomers of both MDA and MDMA are more potent than the (-) enantiomers as releasers of both 3H-5-HT and 3H-DA. Eleven analogues, differing from MDA with respect to the nature and number of ring and/or side chain substituents, alsomore » show some activity in the release experiments, and are more potent as releasers of 3H-5-HT than of 3H-DA. The amphetamine derivatives {plus minus}fenfluramine, {plus minus}norfenfluramine, {plus minus}MDE, {plus minus}PCA, and d-methamphetamine are all potent releasers of 3H-5-HT and show varying degrees of activity as 3H-DA releasers. The hallucinogen DOM does not cause significant release of either 3H-monoamine. Possible long-term serotonergic neurotoxicity was assessed by quantifying the density of 5-HT uptake sites in rats treated with multiple doses of selected analogues using 3H-paroxetine to label 5-HT uptake sites. In the neurotoxicity study of the compounds investigated, only (+)MDA caused a significant loss of 5-HT uptake sites in comparison to saline-treated controls. These results are discussed in terms of the apparent structure-activity properties affecting 3H-monoamine release and their possible relevance to neurotoxicity in this series of MDA congeners.« less

CAF-1-induced oligomerization of histones H3/H4 and mutually exclusive interactions with Asf1 guide H3/H4 transitions among histone chaperones and DNA

PubMed Central

Liu, Wallace H.; Roemer, Sarah C.; Port, Alex M.; Churchill, Mair E. A.

2012-01-01

Anti-silencing function 1 (Asf1) and Chromatin Assembly Factor 1 (CAF-1) chaperone histones H3/H4 during the assembly of nucleosomes on newly replicated DNA. To understand the mechanism of histone H3/H4 transfer among Asf1, CAF-1 and DNA from a thermodynamic perspective, we developed and employed biophysical approaches using full-length proteins in the budding yeast system. We find that the C-terminal tail of Asf1 enhances the interaction of Asf1 with CAF-1. Surprisingly, although H3/H4 also enhances the interaction of Asf1 with the CAF-1 subunit Cac2, H3/H4 forms a tight complex with CAF-1 exclusive of Asf1, with an affinity weaker than Asf1–H3/H4 or H3/H4–DNA interactions. Unlike Asf1, monomeric CAF-1 binds to multiple H3/H4 dimers, which ultimately promotes the formation of (H3/H4)2 tetramers on DNA. Thus, transition of H3/H4 from the Asf1-associated dimer to the DNA-associated tetramer is promoted by CAF-1-induced H3/H4 oligomerization. PMID:23034810

Potential Size of and Value Proposition for H2@Scale Concept

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruth, Mark F; Jadun, Paige; Pivovar, Bryan S

The H2@Scale concept is focused on developing hydrogen as an energy carrier and using hydrogen's properties to improve the national energy system. Specifically hydrogen has the abilities to (1) supply a clean energy source for industry and transportation and (2) increase the profitability of variable renewable electricity generators such as wind turbines and solar photovoltaic (PV) farms by providing value for otherwise potentially-curtailed electricity. Thus the concept also has the potential to reduce oil dependency by providing a low-carbon fuel for fuel cell electric vehicles (FCEVs), reduce emissions of carbon dioxide and pollutants such as NOx, and support domestic energymore » production, manufacturing, and U.S. economic competitiveness. The analysis reported here focuses on the potential market size and value proposition for the H2@Scale concept. It involves three analysis phases: 1. Initial phase estimating the technical potential for hydrogen markets and the resources required to meet them; 2. National-scale analysis of the economic potential for hydrogen and the interactions between willingness to pay by hydrogen users and the cost to produce hydrogen from various sources; and 3. In-depth analysis of spatial and economic issues impacting hydrogen production and utilization and the markets. Preliminary analysis of the technical potential indicates that the technical potential for hydrogen use is approximately 60 million metric tons (MMT) annually for light duty FCEVs, heavy duty vehicles, ammonia production, oil refining, biofuel hydrotreating, metals refining, and injection into the natural gas system. The technical potential of utility-scale PV and wind generation independently are much greater than that necessary to produce 60 MMT / year hydrogen. Uranium, natural gas, and coal reserves are each sufficient to produce 60 MMT / year hydrogen in addition to their current uses for decades to centuries. National estimates of the economic potential of

Working safely with H5N1 viruses.

PubMed

García-Sastre, Adolfo

2012-01-01

Research on H5N1 influenza viruses has received much attention recently due to the possible dangers associated with newly developed avian H5N1 viruses that were derived from highly pathogenic avian viruses and are now transmissible among ferrets via respiratory droplets. An appropriate discussion, based on scientific facts about the risks that such viruses pose and on the biocontainment facilities and practices necessary for working safely with these viruses, is needed. Selecting the right level of biocontainment is critical for minimizing the risks associated with H5N1 research while simultaneously allowing an appropriately fast pace of discovery. Rational countermeasures for preventing the spread of influenza can be developed only by gaining a thorough knowledge of the molecular mechanisms at work in host specificity and transmission.

Histone H3.3 maintains genome integrity during mammalian development

PubMed Central

Jang, Chuan-Wei; Shibata, Yoichiro; Starmer, Joshua; Yee, Della; Magnuson, Terry

2015-01-01

Histone H3.3 is a highly conserved histone H3 replacement variant in metazoans and has been implicated in many important biological processes, including cell differentiation and reprogramming. Germline and somatic mutations in H3.3 genomic incorporation pathway components or in H3.3 encoding genes have been associated with human congenital diseases and cancers, respectively. However, the role of H3.3 in mammalian development remains unclear. To address this question, we generated H3.3-null mouse models through classical genetic approaches. We found that H3.3 plays an essential role in mouse development. Complete depletion of H3.3 leads to developmental retardation and early embryonic lethality. At the cellular level, H3.3 loss triggers cell cycle suppression and cell death. Surprisingly, H3.3 depletion does not dramatically disrupt gene regulation in the developing embryo. Instead, H3.3 depletion causes dysfunction of heterochromatin structures at telomeres, centromeres, and pericentromeric regions of chromosomes, leading to mitotic defects. The resulting karyotypical abnormalities and DNA damage lead to p53 pathway activation. In summary, our results reveal that an important function of H3.3 is to support chromosomal heterochromatic structures, thus maintaining genome integrity during mammalian development. PMID:26159997

Study of the H2O/Al2O3 Interface and the Acting Mechanism of Water in the Working Electrolyte

NASA Astrophysics Data System (ADS)

Jia, Ming; Li, Qiang; Li, Lixiang; Cao, Liang; Yang, Juan; Zhou, Xiangyang; Ai, Liang

2018-04-01

Using a working electrolyte containing mixed solvents of ethylene glycol and N,N-dimethylformamide, this paper presents a study of the reactions on the H2O/Al2O3 interface with sum frequency vibrational spectroscopy and the effects of different water content on the performance of the working electrolyte and an aluminum electrolytic capacitor and summarizes the rules of the variations in the performance parameters of the working electrolyte and aluminum electrolytic capacitor with respect to the water content. The results demonstrate that, when the water content is increased from 2.5 to 15%, the conductivity of the working electrolyte increased by 930 μS/cm, and the sparking voltage decreased by 27 V. Also, the increased water content causes lower oxidation efficiency and lower thermal stability. The leakage current of the aluminum electrolytic capacitor after high-temperature storage increases with an increase in the water content, and the attenuation rate of capacitor's the low-temperature capacitance decreases with an increase in the water content.

H2CO3 forms via HCO3- in water.

PubMed

Stirling, András; Pápai, Imre

2010-12-23

According to the generally accepted picture of CO(2) dissolution in water, the formation of H(2)CO(3) proceeds in a single step that involves the attack of a water oxygen on the CO(2) carbon in concert with a proton transfer to a CO(2) oxygen. In the present work, a series of ab initio molecular dynamics simulations have been carried out along with the metadynamics technique which reveals a stepwise mechanism: the reaction of a water molecule with CO(2) yields HCO(3)(-) as an intermediate and a hydronium ion, whereas the protonation of the CO(2) moiety occurs in a separate step representing a well-defined activation barrier toward the H(2)CO(3) molecule. This alternative scenario was already taken into consideration decades ago, but subsequent experiments and calculations have given preference to the concerted mechanism. Employing extended periodic models of the CO(2)-water system that mimic the bulk aqueous environment, the present simulations yield the complete free energy profile of the stepwise mechanism and provide a detailed microscopic mechanism of the elementary steps. HCO(3)(-) formation is found to be the rate-determining step of the entire CO(2) hydration process.

An essential role of variant histone H3.3 for ectomesenchyme potential of the cranial neural crest.

PubMed

Cox, Samuel G; Kim, Hyunjung; Garnett, Aaron Timothy; Medeiros, Daniel Meulemans; An, Woojin; Crump, J Gage

2012-09-01

The neural crest (NC) is a vertebrate-specific cell population that exhibits remarkable multipotency. Although derived from the neural plate border (NPB) ectoderm, cranial NC (CNC) cells contribute not only to the peripheral nervous system but also to the ectomesenchymal precursors of the head skeleton. To date, the developmental basis for such broad potential has remained elusive. Here, we show that the replacement histone H3.3 is essential during early CNC development for these cells to generate ectomesenchyme and head pigment precursors. In a forward genetic screen in zebrafish, we identified a dominant D123N mutation in h3f3a, one of five zebrafish variant histone H3.3 genes, that eliminates the CNC-derived head skeleton and a subset of pigment cells yet leaves other CNC derivatives and trunk NC intact. Analyses of nucleosome assembly indicate that mutant D123N H3.3 interferes with H3.3 nucleosomal incorporation by forming aberrant H3 homodimers. Consistent with CNC defects arising from insufficient H3.3 incorporation into chromatin, supplying exogenous wild-type H3.3 rescues head skeletal development in mutants. Surprisingly, embryo-wide expression of dominant mutant H3.3 had little effect on embryonic development outside CNC, indicating an unexpectedly specific sensitivity of CNC to defects in H3.3 incorporation. Whereas previous studies had implicated H3.3 in large-scale histone replacement events that generate totipotency during germ line development, our work has revealed an additional role of H3.3 in the broad potential of the ectoderm-derived CNC, including the ability to make the mesoderm-like ectomesenchymal precursors of the head skeleton.

An Essential Role of Variant Histone H3.3 for Ectomesenchyme Potential of the Cranial Neural Crest

PubMed Central

Cox, Samuel G.; Kim, Hyunjung; Garnett, Aaron Timothy; Medeiros, Daniel Meulemans; An, Woojin; Crump, J. Gage

2012-01-01

The neural crest (NC) is a vertebrate-specific cell population that exhibits remarkable multipotency. Although derived from the neural plate border (NPB) ectoderm, cranial NC (CNC) cells contribute not only to the peripheral nervous system but also to the ectomesenchymal precursors of the head skeleton. To date, the developmental basis for such broad potential has remained elusive. Here, we show that the replacement histone H3.3 is essential during early CNC development for these cells to generate ectomesenchyme and head pigment precursors. In a forward genetic screen in zebrafish, we identified a dominant D123N mutation in h3f3a, one of five zebrafish variant histone H3.3 genes, that eliminates the CNC–derived head skeleton and a subset of pigment cells yet leaves other CNC derivatives and trunk NC intact. Analyses of nucleosome assembly indicate that mutant D123N H3.3 interferes with H3.3 nucleosomal incorporation by forming aberrant H3 homodimers. Consistent with CNC defects arising from insufficient H3.3 incorporation into chromatin, supplying exogenous wild-type H3.3 rescues head skeletal development in mutants. Surprisingly, embryo-wide expression of dominant mutant H3.3 had little effect on embryonic development outside CNC, indicating an unexpectedly specific sensitivity of CNC to defects in H3.3 incorporation. Whereas previous studies had implicated H3.3 in large-scale histone replacement events that generate totipotency during germ line development, our work has revealed an additional role of H3.3 in the broad potential of the ectoderm-derived CNC, including the ability to make the mesoderm-like ectomesenchymal precursors of the head skeleton. PMID:23028350

The concepts of work, study, and leisure of parents and children.

PubMed

Nota, Laura; Ginevra, Maria Cristina

2014-01-01

The present work examines how a group of Italian parents and their adolescent children view work, study, and leisure in order to check for possible relations between the ideas of parents and their children's. A total of 160 adolescents and 160 parents were recruited. Semi-structured interviews that assessed the participants' concepts about work, study, and leisure were conducted. The analyses carried out demonstrate that there are connections between the parents' and adolescents' perceptions regarding work, study, and leisure. The results confirm the importance of considering both constructs and the parents' perspectives on them, and of involving parents in their children vocational guidance actions.

Theoretical study on magnetism induced by H vacancy in isolated Alq3 and Gaq3 molecules

NASA Astrophysics Data System (ADS)

Ju, Lin; Xu, Tongshuai; Zhang, Yongjia; Sun, Li

2017-10-01

The magnetism induced by H vacancy in isolated Alq3 and Gaq3 molecules has been studied based on density functional theory. The isolated stoichiometric Alq3 and Gaq3 molecules are non-magnetic. With an H vacancy, both Alq3 and Gaq3 molecules could show magnetism, which are mainly due to the polarization of the C 2p electrons and the magnetic moments are mainly distributed at most nearby C atoms of H vacancies. This is because the unpaired electron on the C atom appears, when the H atom nearby is removed. Six cases of the H vacancy introduced in the Alq3 and Gaq3 molecules are considered, respectively. By comparing the relative defect formation energy, the V H3 vacancy is most likely to appear in the two kinds of molecules. In addition, for the ground state configuration of isolated Alq3 and Gaq3 molecules with two H vacancies, the energy of the ferromagnetic state is lower than that of the antiferromagnetic state, which means that the ferromagnetic state is stable. The ferromagnetic mechanism can be explained by the Heisenberg direct exchange interaction between two the polarized C atoms. Our work opens a new way to synthesize organic magnetic materials and perfects the theory of organic ferromagnetism by introducing the d 0 ferromagnetism.

Student ability to apply the concepts of work and energy to extended systems

NASA Astrophysics Data System (ADS)

Lindsey, Beth A.; Heron, Paula R. L.; Shaffer, Peter S.

2009-11-01

We report results from an investigation of student ability to apply the concepts of work and energy to situations in which the internal structure of a system cannot be ignored, that is, the system cannot be treated as a particle. Students in introductory calculus-based physics courses were asked written and online questions after relevant instruction by lectures, textbook, and laboratory. Several difficulties were identified. Some related to student ability to calculate the work done on a system. Failure to associate work with the change in energy of a system was also widespread. The results have implications for instruction that aims for a rigorous treatment of energy concepts that is consistent with the first law of thermodynamics. The findings are guiding the development of two tutorials to supplement instruction.

3-Methyl-7-(2-thienyl)pyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione: pi-stacked bilayers built from N-H...O, C-H...O and C-H...pi hydrogen bonds.

PubMed

Trilleras, Jorge; Quiroga, Jairo; Cobo, Justo; Glidewell, Christopher

2009-06-01

In the title compound, C(12)H(9)N(3)O(2)S, the thienyl substituent is disordered over two sets of sites with occupancies of 0.749 (3) and 0.251 (3). A combination of N-H...O, C-H...O and C-H...pi hydrogen bonds links the molecules into bilayers and these bilayers are themselves linked into a continuous structure by pi-pi stacking interactions.

The development of the drive object concept in Freud's work: 1905-1915.

PubMed

Compton, A

1985-01-01

In 1905 Freud established the idea of an object of an instinctual drive as the basic object concept of psychoanalysis. He also introduced the derivative concepts of object directedness, object choice, and object finding. While taking these steps he simultaneously deemphasized the importance of drive objects in sexual life, contradicted himself on whether drives are autoerotic or object-directed in infancy, and made incompatible statements about whether or not object choice occurs before puberty. Freud's clinical work, reflected especially in the major case reports and a series of papers on fantasy, led to an apparent recognition of complexity in the mental life of children far greater than had been described earlier. The increased attention to and appreciation of mental content in childhood especially augmented Freud's understanding of the role of drive objects, object directedness, and object choice in infancy. This, in turn, led him to postulate a sequence of organizations of sexual life, named according to the zonal drive source plus the mode of object directedness, a process of theory development that continued through 1924. Object choice and, to a lesser extent, object directedness are concepts derived from and dependent upon the concept of drive object. Both require, however, explanatory constructs besides drive constructs. In 1915 Freud defined the term "object" in the context of stating his drive theory. Freud used the term object with several new modifying words during this decade. No new object concept was introduced, however, in this work, although some steps in that direction appeared to be in progress.

Minnesota 4-H Science of Agriculture Challenge: Infusing Agricultural Science and Engineering Concepts into 4-H Youth Development

ERIC Educational Resources Information Center

Rice, Joshua E.; Rugg, Bradley; Davis, Sharon

2016-01-01

Youth involved in 4-H projects have been engaged in science-related endeavors for years. Since 2006, 4-H has invested considerable resources in the advancement of science learning. The new Minnesota 4-H Science of Agriculture Challenge program challenges 4-H youth to work together to identify agriculture-related issues in their communities and to…

Vicarious resilience: a new concept in work with those who survive trauma.

PubMed

Hernández, Pilar; Gangsei, David; Engstrom, David

2007-06-01

This study explores the formulation of a new concept: vicarious resilience. It addresses the question of how psychotherapists who work with survivors of political violence or kidnapping are affected by their clients'stories of resilience. It focuses on the psychotherapists' interpretations of their clients' stories, and how they make sense of the impact that these stories have had on their lives. In semistructured interviews, 12 psychotherapists who work with victims of political violence and kidnapping were interviewed about their perceptions of their clients' overcoming of adversity. A phenomenological analysis of the transcripts was used to describe the themes that speak about the effects of witnessing how clients cope constructively with adversity. These themes are discussed to advance the concept of vicarious resilience and how it can contribute to sustaining and empowering trauma therapists.

"It's Insanely Useful!" Students' Use of Instructional Concepts in Group Work and Individual Writing

ERIC Educational Resources Information Center

Rodnes, Kari Anne

2012-01-01

This study investigates students' work on analyzing a literary text, a cartoon strip, with focus on their use of instructional, analytical concepts. Excerpts from a group conversation and from individually written texts are analyzed from a sociocultural, dialogical perspective. The analysis of the conversation shows how such concepts help the…

Gold as hydrogen: Structural and electronic properties and chemical bonding in Si3Au3+/0/- and comparisons to Si3H3+/0/-

NASA Astrophysics Data System (ADS)

Kiran, Boggavarapu; Li, Xi; Zhai, Hua-Jin; Wang, Lai-Sheng

2006-10-01

A single Au atom has been shown to behave like H in its bonding to Si in several mono- and disilicon gold clusters. In the current work, we investigate the Au /H analogy in trisilicon gold clusters, Si3Au3+/0/-. Photoelectron spectroscopy and density functional calculations are combined to examine the geometric and electronic structure of Si3Au3-. We find that there are three isomers competing for the ground state of Si3Au3- as is the case for Si3H3-. Extensive structural searches show that the potential energy surfaces of the trisilicon gold clusters (Si3Au3-, Si3Au3, and Si3Au3+) are similar to those of the corresponding silicon hydrides. The lowest energy isomers for Si3Au3- and Si3Au3 are structurally similar to a Si3Au four-membered ring serving as a common structural motif. For Si3Au3+, the 2π aromatic cyclotrisilenylium auride ion, analogous to the aromatic cyclotrisilenylium ion (Si3H3+), is the most stable species. Comparison of the structures and chemical bonding between Si3Au3+/0/- and the corresponding silicon hydrides further extends the isolobal analogy between Au and H.

A mass spectrometric study of gaseous H4PO+3 and H2PO-3 ions

NASA Astrophysics Data System (ADS)

de Petris, Giulia; Occhiucci, Giorgio; Pepi, Federico

1994-09-01

H4PO+3 ions have been generated in a mass spectrometer by proton-transfer to H3PO3 from different Brønsted acids. The proton affinity of H3PO3 has been estimated by bracketing and kinetic methods to be 198.6 ± 2 kcal mol-1. Gaseous H4PO+3 ions have been structurally assessed by metastable ion kinetic energy (MIKE) and collisionally induced dissociation (CID) mass spectrometry leading to the detection of a single isomeric species. The chemistry of H2PO-3 is characterized by facile addition-elimination reactions leading to formation of polyanions. Species containing up to six P atoms have been detected.

Concept for Mars Volcanic Emission Life Scout 3-D Artist Concept

NASA Image and Video Library

2004-12-21

This artist rendition depicts a concept for a Mars orbiter that would scrutinize the martian atmosphere for chemical traces of life or environments supportive of life that might be present anywhere on the planet. 3D glasses are necessary.

Metabolism of D-[1-3H]glucose, D-[2-3H]glucose, D-[5-3H]glucose, D-[6-3H]glucose and D-[U-14C]glucose by rat and human erythrocytes incubated in the presence of H2O or D2O.

PubMed

Conget, I; Malaisse, W J

1995-02-01

The present study investigates whether heavy water affects the efficiency of 3HOH production from D-[1-3H]glucose, D-[2-3H]glucose, D-[5-3H]glucose and D-[6-3H]glucose relative to the total generation of tritiated metabolites produced by either rat or human erythrocytes. The relative 3HOH yield was close to 95% with D-[5-3H]glucose, 72% with D-[2-3H]glucose, 22-32% with D-[1-3H]glucose, and only 12% with D-[6-3H]glucose. In the latter case, the comparison of the specific radioactivity of intracellular and extracellular acidic metabolites, expressed relative to that of 14C-labelled metabolites produced from D-[U-14C]glucose, indicated that the generation of 3HOH from D-[6-3H]glucose occurs at distal metabolic steps, such as the partial reversion of the pyruvate kinase reaction or the interconversion of pyruvate and L-alanine in the reaction catalysed by glutamate-pyruvate transaminase. As a rule, the substitution of H2O by D2O only caused minor to negligible changes in the relative 3HOH yield. This implies that the unexpectedly high deuteration of 13C-labelled D-glucose metabolites recently documented in erythrocytes exposed to D2O cannot be attributed to any major interference of heavy water with factors regulating both the deuteration and detritiation efficiency, such as the enzyme-to-enzyme tunnelling of specific glycolytic intermediates.

Synthesis ofN-(2-chloro-5-methylthiophenyl)-N'-(3-methyl-thiophenyl)-N'-[3H3]methylguanidine, l brace [3H3]CNS-5161 r brace

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gibbs, Andrew R.; Morimoto, Hiromi; VanBrocklin, Henry F.

2001-09-28

The preparation of the title compound, [{sup 3}H{sub 3}]CNS-5161, was accomplished in three steps starting with the production of [{sup 3}H{sub 3}]iodomethane (CT{sub 3}I). The intermediate N-[{sup 3}H{sub 3}]methyl-3-(thiomethylphenyl)cyanamide was prepared in 77% yield by the addition of CT{sub 3}I to 3-(thiomethylphenyl)cyanamide, previously treated with sodium hydride. Reaction of this tritiated intermediate with 2-chloro-5-thiomethylaniline hydrochloride formed the guanidine compound [{sup 3}H{sub 3}]CNS-5161. Purification by HPLC gave the desired labeled product in an overall yield of 9% with greater than 96% radiochemical purity and a final specific activity of 66 Ci mmol{sup -1}.

Corporate working in health visiting: a concept analysis.

PubMed

Houston, A M; Clifton, J

2001-05-01

The aim of this paper is to examine individualized health visiting care and compare it to corporate working within a consensual management style. Corporate working has been discussed and used in many different ways since the idea first came to light at the end of the 1980s. Resource management makes it an appealing model, however, analysing how corporate working functions in the practice setting reveals the complexity of this method of service provision. This paper is based on a method of practice developed by health visitors in Haywards Heath, West Sussex, who implemented the process. The article examines individualized health visiting care and compares it to corporate working within a consensual management style. Important in this analysis are the elements of reflexivity, active listening, reflection and the application of 'praxis' within the corporate caseload approach. Rogers' evolutionary concept model was used to illuminate and explain the different ways of delivering the health visiting service. There are benefits in working corporately: shared workload, increased professional support and improved accountability. Alongside the integrated supervision of this model is the opportunity offered to practitioners to innovate. This offsets any initial difficulty experienced in setting up this method and makes it a worthwhile change of style in health visiting practice. Improved service delivery, enhanced professional growth and increased opportunity for public health work can be demonstrated as outcomes of this model. For professionals this method may prevent 'burn-out', enhance practice and increase innovation in health visiting practice. Using this method as a blueprint, practitioners can develop their own style of corporate working that offers a service that is equitable, proactive, efficient and accessible to clients.

Communications: Development and characterization of a source of rotationally cold, enriched para-H3+.

PubMed

Tom, Brian A; Mills, Andrew A; Wiczer, Michael B; Crabtree, Kyle N; McCall, Benjamin J

2010-02-28

In an effort to develop a source of H(3)(+) that is almost entirely in a single quantum state (J=K=1), we have successfully generated a plasma that is enriched to approximately 83% in para-H(3)(+) at a rotational temperature of 80 K. This enrichment is a result of the nuclear spin selection rules at work in hydrogenic plasmas, which dictate that only para-H(3)(+) will form from para-H(2), and that para-H(3)(+) can be converted to ortho-H(3)(+) by subsequent reaction with H(2). This is the first experimental study in which the H(2) and H(3) (+) nuclear spin selection rules have been observed at cold temperatures. The ions were produced from a pulsed solenoid valve source, cooled by supersonic expansion, and interrogated via continuous-wave cavity ringdown spectroscopy.

Concept of defensive medicine and litigation among Sudanese doctors working in obstetrics and gynecology.

PubMed

Ali, AbdelAziem A; Hummeida, Moawia E; Elhassan, Yasir A M; Nabag, Wisal O M; Ahmed, Mohammed Ahmed A; Adam, Gamal K

2016-02-09

Obstetrics and gynaecology always has reputation for being a highly litigious. The field of obstetrics and gynaecology is surrounded by different circumstances that stimulate the doctors to practice defensive medicine. This study was directed to assess the extent and the possible effect of defensive medicine phenomenon (in term of knowledge and prevalence) on medical decision making among different grades of obstetric and gynaecologic Sudanese doctors, and to determine any experience of medical litigations with respect to sources and factors associated with it (in term of area of work, characteristics of the area at which the doctors worked, professionalism, hospitals systems…ect). A total of 117 doctors were approached, their distribution according to job description was as follow: consultants (42.7%, 50\\117) registrars (34.2%, 40\\117) and specialists (23.1%, 27\\117). The majority 89.7% had the impression that litigation against doctors are increasing and 27.6% had a direct experience of litigation. In this study less than one half (42.7%) of the surveyed doctors knew the concept of defensive medicine and 71.8% reported practicing one or another form of defensive medicine. The different sources of the litigations reported by the doctors included: maternal death (n = 15), perinatal death (n = 5), other {misdiagnosis, intra-uterine fetal death, uterine perforation, rupture uterus} (n = 4), fetal distress (n = 3), injury to viscera (n = 3) and shoulder dystocia (n = 2). In this study the experience of medical litigation was significantly observed among those who worked in area of blame culture (90.6% Vs 56.5%, P = 0.000). In logistic regression model, there was no significant difference between those who knew the concept of defence medicine and those who didn't. There should be strategic plan to reduce the practice of defensive medicine and medical litigation against doctors.

MIMO-OFDM for a Cellular Deployment - Concepts, Real-Time Implementation and Measurements Towards 3GPP-LTE

DTIC Science & Technology

2007-09-01

CONCEPTS, REAL-TIME IMPLEMENTATION AND MEASUREMENTS TOWARDS 3GPP-LTE T. Haustein , J. Eichinger, W. Zirwas, E. Schulz Nokia Siemens...BER (bottom) in an office scenario while the UE is moved from one room to another. REFERENCES [1] V. Jungnickel, A. Forck, T. Haustein , C. Juchems...2.12.2006 [3] T. Haustein , A. Forck, H. Gäbler, V. Jungnickel and S. Schif- fermüller, „Real-Time Experiments on Channel Adaptive Transmis- sion in

H. A. Gleason's 'individualistic concept' and theory of animal communities: a continuing controversy.

PubMed

McIntosh, R P

1995-05-01

A tradition of natural history and of the lore of early twentieth-century ecology was that organisms lived together and interacted to form natural entities or communities. Before there was a recognizable science of ecology, Mobius (1877) had provided a name 'biocoenosis' for such entities. This concept persisted in the early decades of ecological science; at an extreme it was maintained that the community had integrating capabilities and organization like those of an individual organism, hence the term organismic community. In the 1950s-1970s an alternative individualist concept, derived from the ideas of H. A. Gleason (1939), gained credence which held that communities were largely a coincidence of individualistic species characteristics, continuously varying environments and different probabilities of a species arriving on a given site. During the same period, however, a body of population based theory of animal communities became dominant which perpetuated the idea of patterns in nature based on biotic interactions among species resulting in integrated communities. This theory introduced an extended terminology and mathematical models to explain the organization of species into groups of compatible species governed by rules. In the late 1970s the premises and methods of the theory came under attack and a vigorous debate ensued. The alternatives proposed were, at an extreme, null models of random aggregations of species or stochastic, individualistic aggregations of species, sensu Gleason. Extended research and debate ensued during the 1980s resulting in an explosion of studies of animal communities and a plethora of symposia and volumes of collected works concerning the nature of animal communities. The inherent complexity of communities and the traditional differences among animal ecologists about how they should be defined and delimited, at what scale of taxa, space and time to study them, and appropriate methods of study and analysis have resulted in extended

Reaction paths in the system Al 2O 3-hBN-Y

NASA Astrophysics Data System (ADS)

Reichert, K.; Oreshina, O.; Cremer, R.; Neuschütz, D.

2001-07-01

As part of the investigations on the suitability of a new concept for a tailored fiber-matrix interface in sapphire fiber reinforced NiAl matrix composites for application as a high-temperature structural material, the interfacial reactions in the system alumina-hexagonal boron nitride-yttrium (Al 2O 3-hBN-Y) have been examined in the temperature range of 1100-1300°C. For this, alumina substrates were coated with hBN by means of CVD and subsequently with sputter deposited yttrium. Afterwards the samples were annealed for up to 16 h under inert atmosphere. Grazing incidence X-ray diffraction (GIXRD) served to analyze the phases formed by diffusion processes in the reaction zone. The peak intensities in these diffraction patterns were used to evaluate the sequence of phases formed due to diffusion and reaction. After the initial formation of YN and YB 2, the phases Y 2O 3, Al 2Y, and YB 4 were observed. Even longer annealing times or higher temperatures, respectively, led to the formation of the ternary oxides YAlO 3 and Y 3Al 5O 12 as well as metallic aluminum.

BEDROOM 3. VIEW FACING EAST Camp H.M. Smith and ...

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

BEDROOM 3. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Four-Bedroom, Single-Family Type 10, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

BEDROOM 3. VIEW FACING EAST Camp H.M. Smith and ...

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

BEDROOM 3. VIEW FACING EAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Three-Bedroom Single-Family Type 7, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

The astrochemistry of H+3

NASA Astrophysics Data System (ADS)

Herbst, E.

2000-09-01

The reactions of the molecular ion H3+ are pivotal to the chemistry of dense interstellar clouds. Produced by the cosmic-ray ionizati on of molecular hydrogen, H3+ reacts with a variety of a toms and molecules to produce species that are precursors to many of the detect ed molecules in dense clouds. For example, the reaction of H3+ with atomic O leads, eventually, to the production of water, while the re action with HD leads to the production of a wide variety of deuterated isotopom ers. In this article, the chemistry of H3+ and the produc ts derived from it are discussed in the larger context of interstellar chemistr y.

H3K27me3 and H3K4me3 chromatin environment at super-induced dehydration stress memory genes of Arabidopsis thaliana.

PubMed

Liu, Ning; Fromm, Michael; Avramova, Zoya

2014-03-01

Pre-exposure to a stress may alter the plant's cellular, biochemical, and/or transcriptional responses during future encounters as a 'memory' from the previous stress. Genes increasing transcription in response to a first dehydration stress, but producing much higher transcript levels in a subsequent stress, represent the super-induced 'transcription memory' genes in Arabidopsis thaliana. The chromatin environment (histone H3 tri-methylations of Lys 4 and Lys 27, H3K4me3, and H3K27me3) studied at five dehydration stress memory genes revealed existence of distinct memory-response subclasses that responded differently to CLF deficiency and displayed different transcriptional activities during the watered recovery periods. Among the most important findings is the novel aspect of the H3K27me3 function observed at specific dehydration stress memory genes. In contrast to its well-known role as a chromatin repressive mechanism at developmentally regulated genes, H3K27me3 did not prevent transcription from the dehydration stress-responding genes. The high H3K27me3 levels present during transcriptionally inactive states did not interfere with the transition to active transcription and with H3K4me3 accumulation. H3K4me3 and H3K27me3 marks function independently and are not mutually exclusive at the dehydration stress-responding memory genes.

Comparison of (/sup 3/H)pirenzepine and (/sup 3/H)quinuclidinylbenzilate binding to muscarinic cholinergic receptors in rat brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luthin, G.R.; Wolfe, B.B.

The properties of (/sup 3/H)quinuclidinylbenzilate ( (/sup 3/H)QNB) binding and (/sup 3/H)pirenzepine ( (/sup 3/H)PZ) binding to various regions of rat brain were compared. (/sup 3/H)PZ appeared to bind with high affinity to a single site, with a Kd value of approximately 15 nM in the cerebral cortex. The rank order of potencies of muscarinic drugs to inhibit binding of either (/sup 3/H)QNB or (/sup 3/H)PZ was QNB greater than atropine . scopolamine greater than pirenzepine greater than oxotremorine greater than bethanechol. Muscarinic antagonists (except PZ) inhibited both (/sup 3/H)PZ and (/sup 3/H)QNB binding with Hill coefficients of approximately 1.more » PZ inhibited (/sup 3/H)QNB binding in cortex with a Hill coefficient of 0.7, but inhibited (/sup 3/H)PZ binding with a Hill coefficient of 1.0. Hill coefficients for agonists were less than 1. The density of (/sup 3/H)PZ binding sites was approximately half the density of (/sup 3/H)QNB binding sites in cortex, striatum and hippocampus. In pons-medulla and cerebellum, the densities of (/sup 3/H)PZ binding sites were 20 and 0%, respectively, relative to the densities of (/sup 3/H)QNB binding sites. When unlabeled PZ was used to compete for (/sup 3/H)QNB binding, the relative number of high-affinity PZ binding sites in cortex, pons and cerebellum agreed with the relative number of (/sup 3/H)PZ binding sites in those regions. The binding of (/sup 3/H)PZ and (/sup 3/H)QNB was nonadditive in cortex. GTP inhibited high-affinity oxotremorine binding, but not PZ binding. Together, these data suggest that (/sup 3/H)PZ binds to a subset of (/sup 3/H)QNB binding sites. Whether this subset reflects the existence of subtypes of muscarinic receptors or is a consequence of coupling to another membrane protein remains to be seen.« less

Mobile work station concept for assembly of large space structures (zero gravity simulation tests)

NASA Astrophysics Data System (ADS)

Heard, W. L., Jr.; Bush, H. G.; Wallsom, R. E.; Jensen, J. K.

1982-03-01

The concept presented is intended to enhance astronaut assembly of truss structure that is either too large or complex to fold for efficient Shuttle delivery to orbit. The potential of augmented astronaut assembly is illustrated by applying the result of the tests to a barebones assembly of a truss structure. If this structure were assembled from the same nestable struts that were used in the Mobile Work Station assembly tests, the spacecraft would be 55 meters in diameter and consist of about 500 struts. The struts could be packaged in less than 1/2% of the Shuttle cargo bay volume and would take up approximately 3% of the mass lift capability. They could be assembled in approximately four hours. This assembly concept for erectable structures is not only feasible, but could be used to significant economic advantage by permitting the superior packaging feature of erectable structures to be exploited and thereby reduce expensive Shuttle delivery flights.

Mobile work station concept for assembly of large space structures (zero gravity simulation tests)

NASA Technical Reports Server (NTRS)

Heard, W. L., Jr.; Bush, H. G.; Wallsom, R. E.; Jensen, J. K.

1982-01-01

The concept presented is intended to enhance astronaut assembly of truss structure that is either too large or complex to fold for efficient Shuttle delivery to orbit. The potential of augmented astronaut assembly is illustrated by applying the result of the tests to a barebones assembly of a truss structure. If this structure were assembled from the same nestable struts that were used in the Mobile Work Station assembly tests, the spacecraft would be 55 meters in diameter and consist of about 500 struts. The struts could be packaged in less than 1/2% of the Shuttle cargo bay volume and would take up approximately 3% of the mass lift capability. They could be assembled in approximately four hours. This assembly concept for erectable structures is not only feasible, but could be used to significant economic advantage by permitting the superior packaging feature of erectable structures to be exploited and thereby reduce expensive Shuttle delivery flights.

Work Domain Analysis Methodology for Development of Operational Concepts for Advanced Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hugo, Jacques

2015-05-01

This report describes a methodology to conduct a Work Domain Analysis in preparation for the development of operational concepts for new plants. This method has been adapted from the classical method described in the literature in order to better deal with the uncertainty and incomplete information typical of first-of-a-kind designs. The report outlines the strategy for undertaking a Work Domain Analysis of a new nuclear power plant and the methods to be used in the development of the various phases of the analysis. Basic principles are described to the extent necessary to explain why and how the classical method wasmore » adapted to make it suitable as a tool for the preparation of operational concepts for a new nuclear power plant. Practical examples are provided of the systematic application of the method and the various presentation formats in the operational analysis of advanced reactors.« less

Enhanced LOD Concepts for Virtual 3d City Models

NASA Astrophysics Data System (ADS)

Benner, J.; Geiger, A.; Gröger, G.; Häfele, K.-H.; Löwner, M.-O.

2013-09-01

Virtual 3D city models contain digital three dimensional representations of city objects like buildings, streets or technical infrastructure. Because size and complexity of these models continuously grow, a Level of Detail (LoD) concept effectively supporting the partitioning of a complete model into alternative models of different complexity and providing metadata, addressing informational content, complexity and quality of each alternative model is indispensable. After a short overview on various LoD concepts, this paper discusses the existing LoD concept of the CityGML standard for 3D city models and identifies a number of deficits. Based on this analysis, an alternative concept is developed and illustrated with several examples. It differentiates between first, a Geometric Level of Detail (GLoD) and a Semantic Level of Detail (SLoD), and second between the interior building and its exterior shell. Finally, a possible implementation of the new concept is demonstrated by means of an UML model.

H3 and H4 Lysine Acetylation Correlates with Developmental and Experimentally Induced Adult Experience-Dependent Plasticity in the Mouse Visual Cortex

PubMed Central

Vierci, Gabriela; Pannunzio, Bruno; Bornia, Natalia; Rossi, Francesco M.

2016-01-01

Histone posttranslational modifications play a fundamental role in orchestrating gene expression. In this work, we analyzed the acetylation of H3 and H4 histones (AcH3–AcH4) and its modulation by visual experience in the mouse visual cortex (VC) during normal development and in two experimental conditions that restore juvenile-like plasticity levels in adults (fluoxetine treatment and enriched environment). We found that AcH3–AcH4 declines with age and is upregulated by treatments restoring plasticity in the adult. We also found that visual experience modulates AcH3–AcH4 in young and adult plasticity-restored mice but not in untreated ones. Finally, we showed that the transporter vGAT is downregulated in adult plasticity-restored models. In summary, we identified a dynamic regulation of AcH3–AcH4, which is associated with high plasticity levels and enhanced by visual experience. These data, along with recent ones, indicate H3–H4 acetylation as a central hub in the control of experience-dependent plasticity in the VC. PMID:27891053

OWL2 benchmarking for the evaluation of knowledge based systems.

PubMed

Khan, Sher Afgun; Qadir, Muhammad Abdul; Abbas, Muhammad Azeem; Afzal, Muhammad Tanvir

2017-01-01

OWL2 semantics are becoming increasingly popular for the real domain applications like Gene engineering and health MIS. The present work identifies the research gap that negligible attention has been paid to the performance evaluation of Knowledge Base Systems (KBS) using OWL2 semantics. To fulfil this identified research gap, an OWL2 benchmark for the evaluation of KBS is proposed. The proposed benchmark addresses the foundational blocks of an ontology benchmark i.e. data schema, workload and performance metrics. The proposed benchmark is tested on memory based, file based, relational database and graph based KBS for performance and scalability measures. The results show that the proposed benchmark is able to evaluate the behaviour of different state of the art KBS on OWL2 semantics. On the basis of the results, the end users (i.e. domain expert) would be able to select a suitable KBS appropriate for his domain.

Material dependence of 2H(d,p)3H cross section at the very low energies

NASA Astrophysics Data System (ADS)

Kılıç, Ali İhsan; Czerski, Konrad; Kuştan-Kılıç, Fadime; Targosz-Sleczka, Natalia; Weissbach, Daniel; Huke, Armin; Ruprecht, Götz

2017-09-01

Calculations of the material dependence of 2H(d,p)3H cross section and neutron-to-proton branching ratio of d+d reactions have been performed including a concept of the 0+ threshold single particle resonance. The resonance has been assumed to explain the enhanced electron screening effect observed in the d+d reaction for different metallic targets. Here, we have included interference effects between the flat and resonance part of the cross section, which allowed us to enlighten observed suppression of the neutron channel in some metals such as Sr and Li. Since the position of the resonance depends on the screening energy that strongly depends on the local electron density. The resonance width, observed for the d+d reactions in the very hygroscopic metals (Sr and Li) and therefore probably contaminated by oxides, should be much larger than for other metals. Thus, the interference term of the cross section depending on the total resonance width provides the material dependences.

Genetic progression in microsatellite instability high (MSI-H) colon cancers correlates with clinico-pathological parameters: A study of the TGRbetaRII, BAX, hMSH3, hMSH6, IGFIIR and BLM genes.

PubMed

Calin, G A; Gafà, R; Tibiletti, M G; Herlea, V; Becheanu, G; Cavazzini, L; Barbanti-Brodano, G; Nenci, I; Negrini, M; Lanza, G

2000-05-20

Colon carcinomas with microsatellite mutator phenotype exhibit specific genetic and clinico-pathological features. This report describes the analysis of 63 "microsatellite instability-high" (MSI-H) tumors for the presence of mutations in microsatellites located in the coding regions (CDRs) of 6 genes: TGFbetaRII, BAX, hMSH3, hMSH6, IGFIIR, and BLM. The following frequencies of mutations were detected: TGFbetaRII (70%), BAX (54%), hMSH3 (36.5%), IGFIIR (22%), hMSH6 (17.5%), and BLM (16%). The overall picture revealed combinations of mutations suggestive of a progressive order of accumulation, with mutations of TGFbetaRII and BAX first, followed by frameshifts in hMSH3, hMSH6, IGFIIR, and BLM. Correlations with 12 clinico-pathological parameters revealed that tumors with frameshifts in 1 or 2 CDRs were significantly better differentiated than tumors with frameshifts in more than 2 CDRs. We also found that mutations in the hMSH3 gene were significantly associated with decreased wall invasiveness and aneuploidy, and frameshifts in the BLM gene were significantly associated with the mucinous histotype. A trend toward an association between hMSH3 and IGFIIR with the medullary and conventional adenocarcinoma histotypes, respectively, was seen. Our results strengthen the concept that mutations in target genes have a role in the tumorigenic process of MSI-H tumors, and indicate that frameshifts in microsatellites located in CDRs occur in a limited number of combinations that could determine distinct clinico-pathological traits. Copyright 2000 Wiley-Liss, Inc.

Comparison of (/sup 3/H)nicotine and (/sup 3/H)acetylcholine binding in mouse brain: regional distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sershen, H.; Reith, M.E.; Hashim, A.

1985-06-01

In a continuing study of nicotine binding sites, the authors determined the relative amount of nicotine binding and acetylcholine binding in various brain regions of C57/BL and of DBA mice. Although midbrain showed the highest and cerebellum the lowest binding for both (/sup 3/H)nicotine and (/sup 3/H)acetylcholine, the ratio of nicotine to acetylcholine binding showed a three-fold regional variation. Acetylcholine inhibition of (/sup 3/H)nicotine binding indicated that a portion of nicotine binding was not inhibited by acetylcholine. These results indicate important differences between the binding of (+/-)-(/sup 3/H)nicotine and that of (/sup 3/H)acetylcholine.

Defects in Histone H3.3 Phosphorylation and ATRX Recruitment to Misaligned Chromosomes during Mitosis Contribute to the Development of Pediatric Glioblastomas

DTIC Science & Technology

2015-09-01

somatic mutations leading to single amino acid substitutions in four genes : the p53 tumor suppressor, the histone variant H3.3, ATRX, and DAXX. As...pending minor revision. The second major impact of our work is the discovery that mutations in the H3.3 gene (K27M and G34R) – found to be driver...heterozygous mutations in this region of the H3.3 gene are particularly dangerous, and provides insights into how they drive cancer progression. b

Words and Concepts. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2007

2007-01-01

"Words and Concepts" is a computer software program that focuses on building oral language skills related to vocabulary, comprehension, word relationships, and other concepts in six units--vocabulary, categorization, word identification by function, word association, concept of same, and concept of different. It can be used by adults and…

The concept of value stream mapping to reduce of work-time waste as applied the smart construction management

NASA Astrophysics Data System (ADS)

Elizar, Suripin, Wibowo, Mochamad Agung

2017-11-01

Delays in construction sites occur due to systematic additions of time waste in various activities that are part of the construction process. Work-time waste is non-adding value activity which used to differentiate between physical construction waste found on site and other waste which occurs during the construction process. The aim of this study is identification using the concept of Value Stream Mapping (VSM) to reduce of work-time waste as applied the smart construction management.VSM analysis is a method of business process improvement. The application of VSM began in the manufacturing community. The research method base on theoretically informed case study and literature review. The data have collected using questionnaire through personal interviews from 383 respondents on construction project in Indonesia. The results show that concept of VSM can identify causes of work-time waste. Base on result of questioners and quantitative approach analysis was obtained 29 variables that influence of work-time waste or non-value-adding activities. Base on three cases of construction project founded that average 14.88% of working time was classified as waste. Finally, the concept of VSM can recommend to identification of systematic for reveal current practices and opportunities for improvement towards global challenges. The concept of value stream mapping can help optimize to reduce work-time waste and improve quality standard of construction management. The concept is also can help manager to make a decision to reduce work-time waste so as to obtain of result in more efficient for performance and sustainable construction project.

Small Change Makes a Big Splash: The Role of Working Self-Concept in the Effects of Stereotype Threat on Memory.

PubMed

Liu, Pei; Zhao, Fengqing; Zhang, Baoshan; Dang, Qingxiu

2017-10-03

Assuming that the principle of an active-self account holds true in real life, priming certain constructs could selectively activate a working self-concept, which in turn guides behavior. The current study involved two experiments that examined the relationships between stereotypic identity, working self-concept, and memory performance in older adults. Specifically, Study 1 tested whether a stereotype threat can affect older adults' working self-concept and memory performance. A modified Stroop color naming task and a separate recognition task showed that a stereotype threat prime altered the activation of the working self-concept and deteriorated the older adults' memory performance. Additionally, the working self-concept mediated the effect of stereotype threat on memory performance. Accordingly, we designed Study 2 to assess whether priming different identities can alter the working self-concept of the elderly and buffer the stereotype threat effect on memory performance. The results not only were the same as Study 1 but also revealed that activating multiple identities could mitigate the stereotype threat. These results support an active-self account and the efficacy of stereotype threat intervention. This intervention strategy may be able to be used in real situations to help the elderly alleviate stereotype threats and memory impairment.

Rapid measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides.

PubMed

Barnwal, Ravi Pratap; Rout, Ashok K; Chary, Kandala V R; Atreya, Hanudatta S

2007-12-01

We present two NMR experiments, (3,2)D HNHA and (3,2)D HNHB, for rapid and accurate measurement of 3J(H N-H alpha) and 3J(N-H beta) coupling constants in polypeptides based on the principle of G-matrix Fourier transform NMR spectroscopy and quantitative J-correlation. These experiments, which facilitate fast acquisition of three-dimensional data with high spectral/digital resolution and chemical shift dispersion, will provide renewed opportunities to utilize them for sequence specific resonance assignments, estimation/characterization of secondary structure with/without prior knowledge of resonance assignments, stereospecific assignment of prochiral groups and 3D structure determination, refinement and validation. Taken together, these experiments have a wide range of applications from structural genomics projects to studying structure and folding in polypeptides.

The fault monitoring and diagnosis knowledge-based system for space power systems: AMPERES, phase 1

NASA Technical Reports Server (NTRS)

Lee, S. C.

1989-01-01

The objective is to develop a real time fault monitoring and diagnosis knowledge-based system (KBS) for space power systems which can save costly operational manpower and can achieve more reliable space power system operation. The proposed KBS was developed using the Autonomously Managed Power System (AMPS) test facility currently installed at NASA Marshall Space Flight Center (MSFC), but the basic approach taken for this project could be applicable for other space power systems. The proposed KBS is entitled Autonomously Managed Power-System Extendible Real-time Expert System (AMPERES). In Phase 1 the emphasis was put on the design of the overall KBS, the identification of the basic research required, the initial performance of the research, and the development of a prototype KBS. In Phase 2, emphasis is put on the completion of the research initiated in Phase 1, and the enhancement of the prototype KBS developed in Phase 1. This enhancement is intended to achieve a working real time KBS incorporated with the NASA space power system test facilities. Three major research areas were identified and progress was made in each area. These areas are real time data acquisition and its supporting data structure; sensor value validations; development of inference scheme for effective fault monitoring and diagnosis, and its supporting knowledge representation scheme.

The electronic donation and frequency shifts on the YCCH⋯BH4- boron-bonded complexes (Y = H, CH3, CF3 and CCl3)

NASA Astrophysics Data System (ADS)

Pordeus, Renato Q.; Rego, Danilo G.; Oliveira, Boaz G.

2015-06-01

In this theoretical work, the tetrahydroborate ion (BH4-) was used as proton acceptor in the formation of the YCC-H⋯BH4- complexes (Y = H, CH3, CCl3 and CF3). Using B3LYP/6-311++G(d,p) level of theory, the results of structure corroborate with the analyses of infrared spectra showing that the changes in the bond lengths are in good agreement with the frequency shifts of the HCC-H, H3CCC-H, Cl3CCC-H and F3CCC-H proton donors. Based on the calculations carried out by the Quantum Theory of Atoms in Molecules (QTAIM), the reductions of electronic density corroborate with the red shifts in the frequencies of the C-H bonds. In addition to that, the C-H bonds are polarized because the contributions of s orbital diminish whereas of p increase. In line with this, the variations on the atomic radii computed via QTAIM calculations show that carbon outweigh hydrogen as follows (ΔrC > ΔrH). This scenario is indirectly supported by the Bent's rule of the chemical bonding. Although the interaction energies (corrected with BSSE and ZPE) vary between -19 and -67 kJ mol-1, these complexes interact without covalent character.

Kinetics and Mechanism of the Hydrogenation of CpCr(CO)3•/[CpCr(CO)3]2 Equilibrium to CpCr(CO)3H

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norton, Jack R.; Spataru, Tudor; Camaioni, Donald M.

2014-05-26

The kinetics of the hydrogenation of 2 CpCr(CO)3•/[CpCr(CO)3]2 to CpCr(CO)3H has been investigated. The reaction is second-order in Cr and first-order in H2, with a rate constant of 45 M 2s 1 at 25 °C in benzene. DFT calculations rule out an H2 complex as an intermediate, and suggest (a) end-on approach of H2 to one Cr of [CpCr(CO)3]2 as the Cr-Cr bond undergoes heterolytic cleavage, (b) heterolytic cleavage of the coordinated H2 between O and Cr, and (c) isomerization of the resulting O-protonated CpCr(CO)2(COH) to CpCr(CO)3H. The work at Pacific Northwest National Laboratory (PNNL) was supported by the U.S.more » Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences; Battelle operates PNNL for DOE.« less

Phase Equilibria and Transport Properties in the Systems AgNO3/RCN/H2O. R = CH3, C2H5, C3H7, C4H,, C6H5, and C6H5CH2

NASA Astrophysics Data System (ADS)

Das, Surjya P.; Wittekopf, Burghard; Weil, Konrad G.

1988-11-01

Silver nitrate can form homogeneous liquid phases with some organic nitriles and water, even when there is no miscibility between the pure liquid components. We determined the shapes of the single phase regions in the ternary phase diagram for the following systems: silver nitrate /RCN /H2O with R =CH3, C3H7, C6H5, and C6H5CH2 at room temperature and for R =C6H5 also at 60 °C and O °C. Furthermore we studied kinematic viscosities, electrical conductivities, and densities of mixtures containing silver nitrate, RCN, and water with the mole ratios X /4 /1 (0.2≦ X ≦S 3.4). In these cases also R = C2H5 and C4H9 were studied. The organic nitriles show different dependences of viscosity and conductivity on the silver nitrate content from the aliphatic ones.

The Effect of Educational Disequilibrium in Field Work on Graduate Social Work Students' Self-Concept and Mental Health

ERIC Educational Resources Information Center

Ying, Yu-Wen

2011-01-01

The author used a mixed methods design to assess field work-related educational disequilibrium and its effect on the self-concept and mental health of MSW students. Twenty-eight advanced, fourth-semester MSW students were compared with 37 entering, first-semester MSW students in practice-related sense of accomplishment. Compared with first-year…

Total reaction cross sections of electronic state-specified transition metal cations: V + +C2H6, C3H8, and C2H4 at 0.2 eV

NASA Astrophysics Data System (ADS)

Sanders, Lary; Hanton, Scott D.; Weisshaar, James C.

1990-03-01

We describe a crossed beam experiment which measures total cross sections for reaction of electronic state-specified V+ with small hydrocarbons at well-defined collision energy E=0.2 eV. The V+ state distribution created at each ionizing wavelength is directly measured by angle-integrated photoelectron spectroscopy (preceding paper). Reactant and product ions are collected and analyzed by pulsed time-of-flight mass spectrometry following a reaction time of 6 μs. Tests of the performance of the apparatus are described in detail. Our experiment defines the reactant V+ electronic state distribution and the collision energy much more precisely than previous work. For all three hydrocarbons C2H6, C3H8, and C2H4, H2 elimination products dominate at 0.2 eV. We observe a dramatic dependence of cross section on the V+ electronic term. The second excited term 3d34s(3F) is more reactive than either lower energy quintet term 3d4(5D) or 3d34s(5F) by a factor of ≥270, 80, and ≥6 for the C2H6, C3H8, and C2H4 reactions, respectively. The 3d34s(3F) reaction cross sections at 0.2 eV are 20±11 Å2, 37±19 Å2, and 2.7±1.6 Å2, respectively, compared with Langevin cross sections of ˜80 Å2. For the C2H6 and C3H8 reactions, cross sections are independent of initial spin-orbit level J within the 3F term to the limits of our accuracy. Comparison with earlier work by Armentrout and co-workers shows that electronic excitation to d3s(3F) is far more effective at promoting H2 elimination than addition of the same total kinetic energy to reactants. Electron spin is clearly a key determinant of V+ reactivity with small hydrocarbons. We suggest that triplet V+ reacts much more efficiently than quintet V+ because of its ability to conserve total electron spin along paths to insertion in a C-H bond of the hydrocarbon.

Creativity: A Saleable Work Skill. Occupation Simulation Packet. Grades 3rd-4th.

ERIC Educational Resources Information Center

Dye, Dick

This teacher's guide for grades 3 and 4 contains simulated work experiences for students using the isolated skill concept - creativity. Teacher instructions include objectives, evaluation, and sequence of activities. The guide contains pre-tests and post-tests with instructions and answer keys. Two pre-skill activities are suggested, such as…

Calling to Nursing: Concept Analysis.

PubMed

Emerson, Christie

The aims of this article are (a) to analyze the concept of a calling as it relates nursing and (b) to develop a definition of calling to nursing with the detail and clarity needed to guide reliable and valid research. The classic steps described by Walker and Avant are used for the analysis. Literature from several disciplines is reviewed including vocational psychology, Christian career counseling, sociology, organizational management, and nursing. The analysis provides an operational definition of a calling to nursing and establishes 3 defining attributes of the concept: (a) a passionate intrinsic motivation or desire (perhaps with a religious component), (b) an aspiration to engage in nursing practice, as a means of fulfilling one's purpose in life, and (c) the desire to help others as one's purpose in life. Antecedents to the concept are personal introspection and cognitive awareness. Positive consequences to the concept are improved work meaningfulness, work engagement, career commitment, personal well-being, and satisfaction. Negative consequences of having a calling might include willingness to sacrifice well-being for work and problems with work-life balance. Following the concept analysis, philosophical assumptions, contextual factors, interdisciplinary work, research opportunities, and practice implications are discussed.

Radical-molecule reaction C3H+H2O: a mechanistic study.

PubMed

Dong, Hao; Ding, Yi-Hong; Sun, Chia-Chung

2005-02-08

Despite the importance of the C(3)H radical in both combustion and interstellar space, the reactions of C(3)H toward stable molecules have never been studied. In this paper, we report our detailed mechanistic study on the radical-molecule reaction C(3)H+H(2)O at the Becke's three parameter Lee-Yang-Parr-B3LYP6-311G(d,p) and coupled cluster with single, double, and triple excitations-CCSD(T)6-311G(2d,p) (single-point) levels. It is shown that the C(3)H+H(2)O reaction initially favors formation of the carbene-insertion intermediates HCCCHOH (1a,1b) rather than the direct H- or OH-abstraction process. Subsequently, the isomers (1a,1b) can undergo a direct H- extrusion to form the well-known product propynal HCCCHO (P(5)). Highly competitively, (1a,1b) can take the successive 1,4- and 1,2-H-shift interconversion to isomer H(2)CCCHO(2a,2b) and then to isomer H(2)CCHCO(3a,3b), which can finally take a direct C-C bond cleavage to give product C(2)H(3) and CO (P(1)). The other products are kinetically much less feasible. With the overall entrance barrier 10.6 kcal/mol, the title reaction can be important in postburning processes. Particularly, our calculations suggest that the title reaction may play a role in the formation of the intriguing interstellar molecule, propynal HCCCHO. The calculated results will also be useful for the analogous C(3)H reactions such as with ammonia and alkanes.

The allocation of valenced concepts onto 3D space.

PubMed

Marmolejo-Ramos, Fernando; Tirado, Carlos; Arshamian, Edward; Vélez, Jorge Iván; Arshamian, Artin

2018-06-01

The valence-space metaphor research area investigates the metaphorical mapping of valenced concepts onto space. Research findings from this area indicate that positive, neutral, and negative concepts are associated with upward, midward, and downward locations, respectively, in the vertical plane. The same research area has also indicated that such concepts seem to have no preferential location on the horizontal plane. The approach-avoidance effect consists in decreasing the distance between positive stimuli and the body (i.e. approach) and increasing the distance between negative stimuli and the body (i.e. avoid). Thus, the valence-space metaphor accounts for the mapping of valenced concepts onto the vertical and horizontal planes, and the approach-avoidance effect accounts for the mapping of valenced concepts onto the "depth" plane. By using a cube conceived for the study of allocation of valenced concepts onto 3D space, we show in three studies that positive concepts are placed in upward locations and near the participants' body, negative concepts are placed in downward locations and far from the participants' body, and neutral concepts are placed in between these concepts in both planes.

Clinical and treatment effects on /sup 3/H-clonidine and /sup 3/H-imipramine binding in elderly depressed patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Georgotas, A.; Schweitzer, J.; McCue, R.E.

1987-06-01

/sup 3/H-clonidine and /sup 3/H-imipramine binding were measured in depressed patients, 55 years and older. There was no significant difference in either /sup 3/H-clonidine or /sup 3/H-imipramine binding between depressed patients and age- and sex-matched controls. There was no significant correlation between /sup 3/H-clonidine or /sup 3/H-imipramine binding and severity of depression before treatment. There was a significant negative correlation between the K/sub D/ of /sup 3/H-imipramine binding sites and Hamilton score over seven weeks of antidepressant treatment. There was no significant difference between receptor data of responders and nonresponders to antidepressant treatment. 19 references, 2 tables.

Evolution-informed forecasting of seasonal influenza A (H3N2).

PubMed

Du, Xiangjun; King, Aaron A; Woods, Robert J; Pascual, Mercedes

2017-10-25

Interpandemic or seasonal influenza A, currently subtypes H3N2 and H1N1, exacts an enormous annual burden both in terms of human health and economic impact. Incidence prediction ahead of season remains a challenge largely because of the virus' antigenic evolution. We propose a forecasting approach that incorporates evolutionary change into a mechanistic epidemiological model. The proposed models are simple enough that their parameters can be estimated from retrospective surveillance data. These models link amino acid sequences of hemagglutinin epitopes with a transmission model for seasonal H3N2 influenza, also informed by H1N1 levels. With a monthly time series of H3N2 incidence in the United States for more than 10 years, we demonstrate the feasibility of skillful prediction for total cases ahead of season, with a tendency to underpredict monthly peak epidemic size, and an accurate real-time forecast for the 2016/2017 influenza season. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Association of H3K9me3 and H3K27me3 repressive histone marks with breast cancer subtypes in the Nurses' Health Study.

PubMed

Healey, Megan A; Hu, Rong; Beck, Andrew H; Collins, Laura C; Schnitt, Stuart J; Tamimi, Rulla M; Hazra, Aditi

2014-10-01

Repressive histone tail modifications have been associated with molecular breast cancer subtypes. We investigated whether histone 3 lysine 9 trimethylation (H3K9me3) and histone 3 lysine 27 trimethylation (H3K27me3) were associated with tumor features and subtypes while adjusting for prospectively collected reproductive and lifestyle breast cancer risk factors. We have tissue microarray data with immunohistochemical marker information on 804 incident cases of invasive breast cancer diagnosed from 1976-2000 in the Nurses' Health Study. Tissue microarray sections were stained for global H3K9me3 and H3K27me3, and scored into four categories. Multivariate odds ratios (OR) and 95 % confidence intervals (CI) were calculated using logistic regression models for tumor features and subtypes, adjusting for breast cancer risk factors. While there were no significant associations between H3K9me3 and tumor features, H3K27me3 was significantly associated with lower grade tumors compared to high grade tumors in the multivariate model (OR = 1.95, 95 % CI 1.35-2.81, p = 0.0004). H3K27me3 was suggestively associated with estrogen receptor-positive (ER+) tumors (OR = 1.47, 95 % CI 0.97-2.23, p = 0.07). In subtype analyses, H3K27me3 was positively associated with the luminal A subtype compared to all other subtypes (OR = 1.42, 95 % CI 1.14-1.77, p = 0.002), and was inversely associated with HER2-type (OR = 0.58, 95 % CI 0.37-0.91, p = 0.02) and basal-like breast cancer (OR = 0.52, 95 % CI 0.36-0.76, p = 0.0006). In the largest immunohistochemical examination of H3K9me3 and H3K27me3 in breast cancer, we found that H3K27me3 positivity, but not H3K9me3, was associated with lower grade tumors and the luminal A subtype after adjusting for reproductive and lifestyle breast cancer risk factors.

A687V EZH2 is a driver of histone H3 lysine 27 (H3K27) hypertrimethylation.

PubMed

Ott, Heidi M; Graves, Alan P; Pappalardi, Melissa B; Huddleston, Michael; Halsey, Wendy S; Hughes, Ashley M; Groy, Arthur; Dul, Edward; Jiang, Yong; Bai, Yuchen; Annan, Roland; Verma, Sharad K; Knight, Steven D; Kruger, Ryan G; Dhanak, Dashyant; Schwartz, Benjamin; Tummino, Peter J; Creasy, Caretha L; McCabe, Michael T

2014-12-01

The EZH2 methyltransferase silences gene expression through methylation of histone H3 on lysine 27 (H3K27). Recently, EZH2 mutations have been reported at Y641, A677, and A687 in non-Hodgkin lymphoma. Although the Y641F/N/S/H/C and A677G mutations exhibit clearly increased activity with substrates dimethylated at lysine 27 (H3K27me2), the A687V mutant has been shown to prefer a monomethylated lysine 27 (H3K27me1) with little gain of activity toward H3K27me2. Herein, we demonstrate that despite this unique substrate preference, A687V EZH2 still drives increased H3K27me3 when transiently expressed in cells. However, unlike the previously described mutants that dramatically deplete global H3K27me2 levels, A687V EZH2 retains normal levels of H3K27me2. Sequencing of B-cell-derived cancer cell lines identified an acute lymphoblastic leukemia cell line harboring this mutation. Similar to exogenous expression of A687V EZH2, this cell line exhibited elevated H3K27me3 while possessing H3K27me2 levels higher than Y641- or A677-mutant lines. Treatment of A687V EZH2-mutant cells with GSK126, a selective EZH2 inhibitor, was associated with a global decrease in H3K27me3, robust gene activation, caspase activation, and decreased proliferation. Structural modeling of the A687V EZH2 active site suggests that the increased catalytic activity with H3K27me1 may be due to a weakened interaction with an active site water molecule that must be displaced for dimethylation to occur. These findings suggest that A687V EZH2 likely increases global H3K27me3 indirectly through increased catalytic activity with H3K27me1 and cells harboring this mutation are highly dependent on EZH2 activity for their survival. ©2014 American Association for Cancer Research.

The Roles of Occupational Knowledge and Vocational Self-Concept Crystallization in Students' School-to-Work Transition.

ERIC Educational Resources Information Center

Taylor, M. Susan

1985-01-01

Examined predictors of college students' school-to-work transition difficulty, level of occupational knowledge, and crystallization of vocational self-concept. Occupational knowledge predicted whether students received at least one job offer before graduation and the total number of offers. Self-concept crystallization predicted at least one…

TLNS3D/CDISC Multipoint Design of the TCA Concept

NASA Technical Reports Server (NTRS)

Campbell, Richard L.; Mann, Michael J.

1999-01-01

This paper presents the work done to date by the authors on developing an efficient approach to multipoint design and applying it to the design of the HSR TCA (High Speed Research Technology Concept Aircraft) configuration. While the title indicates that this exploratory study has been performed using the TLNS3DMB flow solver and the CDISC (Constrained Direct Iterative Surface Curvature) design method, the CDISC method could have been used with any flow solver, and the multipoint design approach does not require the use of CDISC. The goal of the study was to develop a multipoint design method that could achieve a design in about the same time as 10 analysis runs.

Perceptions of the concept of health among nurses working in mental health services: a phenomenographic study.

PubMed

Jormfeldt, Henrika; Svedberg, Petra; Fridlund, Bengt; Arvidsson, Barbro

2007-02-01

A new understanding of the concept of health is needed to meet the goal of mental health nursing, which besides reducing disease is to strengthen the patient's health. The aim of the present study was to describe perceptions of the concept of health among nurses working in mental health services. Twelve Swedish nurses working in mental health services were interviewed and data were analysed with a phenomenographic approach. The nurses expressed 10 perceptions, which constituted three description categories: autonomy, process, and participation. The result showed that health was more than absence of disease. Simultaneously, perceptions were expressed indicating that health was viewed as absence of disease, which implies that the concept is not sufficiently defined. The result emphasizes the need to clarify the concept of health if it is to be used as a goal in mental health nursing and to integrate a clarified definition of health at all hierarchical levels in mental health care services.

One-pot chemoselective synthesis of novel pyrrole-substituted pyrido [2,3-d]pyrimidines using [γ-Fe2O3@HAp-SO3H] as an efficient nanocatalyst

NASA Astrophysics Data System (ADS)

Jahanshahi, Parivash; Mamaghani, Manouchehr; Haghbin, Fereshteh; Nia, Roghayeh Hossein; Rassa, Mehdi

2018-03-01

Novel (1-methyl-1H-pyrrol-2-yl)-[2,3-d]pyrimidine derivatives were synthesized chemoselectively in good to high yields (81-90%) and short reaction times (7-14 min) by hydroxyapatite-encapsulated-γ-Fe2O3 supported sulfonic acid ([γ-Fe2O3@HAp-SO3H]) catalyzed condensation of 3-(1-methyl-1H-pyrrol-2-yl)-3-oxopropanenitrile, 6-amino-2-(alkylthio)pyrimidin-4(3H)-one and various aromatic aldehydes. The easy work-up of the products, rapidity, high efficiency and recyclability of the catalyst are advantages of this protocol. The antibacterial activity of the newly synthesized products was investigated. Some of the products showed encouraging activity.

H-II Transfer Vehicle (HTV) and the Operations Concept for Extravehicular Activity (EVA) Hardware

NASA Technical Reports Server (NTRS)

Chullen, Cinda

2010-01-01

With the retirement of the Space Shuttle fleet imminent in 2011, a new concept of operations will become reality to meet the transportation challenges of the International Space Station (ISS). The planning associated with the retirement of the Space Shuttle has been underway since the announcement in 2004. Since then, several companies and government entities have had to look for innovative low-cost commercial orbital transportation systems to continue to achieve the objectives of ISS delivery requirements. Several options have been assessed and appear ready to meet the large and demanding delivery requirements of the ISS. Options that have been identified that can facilitate the challenge include the Russian Federal Space Agency's Soyuz and Progress spacecraft, European Space Agency's Automated Transfer Vehicle (ATV), the Japan Aerospace Exploration Agency's (JAXA's) H-II Transfer Vehicle (HTV) and the Boeing Delta IV Heavy (DIV-H). The newest of these options is the JAXA's HTV. This paper focuses on the HTV, mission architecture and operations concept for Extra-Vehicular Activities (EVA) hardware, the associated launch system, and details of the launch operations approach.

A simple hydrogen-bonded chain in (3Z)-3-{1-[(5-phenyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one, and a hydrogen-bonded ribbon of centrosymmetric rings in the self-assembled adduct (3Z)-3-{1-[(5-methyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one-6-(2-hydroxyethyl)-2,5-dimethylpyrazolo[1,5-a]pyrimidin-7(4H)-one (1/1).

PubMed

Quiroga, Jairo; Portilla, Jaime; Cobo, Justo; Glidewell, Christopher

2010-01-01

(3Z)-3-{1-[(5-Phenyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one, C(15)H(15)N(3)O(2), (I), and the stoichiometric adduct (3Z)-3-{1-[(5-methyl-1H-pyrazol-3-yl)amino]ethylidene}-4,5-dihydrofuran-2(3H)-one-6-(2-hydroxyethyl)-2,5-dimethylpyrazolo[1,5-a]pyrimidin-7(4H)-one (1/1), C(10)H(13)N(3)O(2).C(10)H(13)N(3)O(2), (II), in which the two components have the same composition but different constitutions, are formed in the reactions of 2-acetyl-4-butyrolactone with 5-amino-3-phenyl-1H-pyrazole and 5-amino-3-methyl-1H-pyrazole, respectively. In each compound, the furanone component contains an intramolecular N-H...O hydrogen bond. The molecules of (I) are linked into a chain by a single intermolecular N-H...O hydrogen bond, while in (II), a combination of one O-H...N hydrogen bond, within the selected asymmetric unit, and two N-H...O hydrogen bonds link the molecular components into a ribbon containing alternating centrosymmetric R(4)(4)(20) and R(6)(6)(22) rings.

The concept of identification in the work of Freud, Ferenczi, and Abraham: a review and commentary.

PubMed

Compton, A

1985-04-01

The development of the concept of identification in the work of Freud, Ferenczi, and Abraham is reviewed and analyzed from the standpoint of the development of the psychoanalytic object concept in general. Problems in the theory are seen to be related to ambiguity of the terms, ego and object, especially as reflected in the idea of introjection. The concept of identification, on the other hand, is shown to have undergone consistent evolution and expansion.

TEXSYS. [a knowledge based system for the Space Station Freedom thermal control system test-bed

NASA Technical Reports Server (NTRS)

Bull, John

1990-01-01

The Systems Autonomy Demonstration Project has recently completed a major test and evaluation of TEXSYS, a knowledge-based system (KBS) which demonstrates real-time control and FDIR for the Space Station Freedom thermal control system test-bed. TEXSYS is the largest KBS ever developed by NASA and offers a unique opportunity for the study of technical issues associated with the use of advanced KBS concepts including: model-based reasoning and diagnosis, quantitative and qualitative reasoning, integrated use of model-based and rule-based representations, temporal reasoning, and scale-up performance issues. TEXSYS represents a major achievement in advanced automation that has the potential to significantly influence Space Station Freedom's design for the thermal control system. An overview of the Systems Autonomy Demonstration Project, the thermal control system test-bed, the TEXSYS architecture, preliminary test results, and thermal domain expert feedback are presented.

Thermodynamic data of lawsonite and zoisite in the system CaO-Al2O3-SiO2-H2O based on experimental phase equilibria and calorimetric work

NASA Astrophysics Data System (ADS)

Grevel, Klaus-Dieter; Schoenitz, Mirko; Skrok, Volker; Navrotsky, Alexandra; Schreyer, Werner

2001-08-01

The enthalpy of drop-solution in molten 2PbO.B2O3 of synthetic and natural lawsonite, CaAl2(Si2O7)(OH)2.H2O, was measured by high-temperature oxide melt calorimetry. The enthalpy of formation determined for the synthetic material is ΔfHOxides=-168.7+/-3.4 kJ mol-1, or ΔfH0298=-4,872.5+/-4.0 kJ mol-1. These values are in reasonable agreement with previously published data, although previous calorimetric work yielded slightly more exothermic data and optimisation methods resulted in slightly less exothermic values. The equilibrium conditions for the dehydration of lawsonite to zoisite, kyanite and quartz/coesite at pressures and temperatures up to 5 GPa and 850 °C were determined by piston cylinder experiments. These results, other recent phase equilibrium data, and new calorimetric and thermophysical data for lawsonite and zoisite, Ca2Al3(SiO4)(Si2O7)O(OH), were used to constrain a mathematical programming analysis of the thermodynamic data for these two minerals in the chemical system CaO-Al2O3-SiO2-H2O (CASH). The following data for lawsonite and zoisite were obtained: ΔfH0298 (lawsonite)=-4,865.68 kJ mol-1 , S0298 (lawsonite)=229.27 J K-1 mol-1 , ΔfH0298 (zoisite)=-6,888.99 kJ mol-1 , S0298 (zoisite)=297.71 J K-1 mol-1 . Additionally, a recalculation of the bulk modulus of lawsonite yielded K=120.7 GPa, which is in good agreement with recent experimental work.

Conversion coefficients for H'(3;Ω) for photons.

PubMed

Behrens, Rolf

2017-06-26

In this work, conversion coefficients for the operational quantity H'(3;Ω) have been calculated for both mono-energetic photons from 2 keV to 50 MeV for angles of incidence from 0° up to 180° in steps of 15° (to complement ICRU 57) as well as for photon reference radiation qualities (to complement ISO 4037). Finally, parameters necessary to determine the influence of the air density on the conversion coefficients have been determined.

Interconversion of η3-H2SiRR' σ-complexes and 16-electron silylene complexes via reversible H-H or C-H elimination.

PubMed

Lipke, Mark C; Neumeyer, Felix; Tilley, T Don

2014-04-23

Solid samples of η(3)-silane complexes [PhBP(Ph)3]RuH(η(3)-H2SiRR') (R,R' = Et2, 1a; PhMe, 1b; Ph2, 1c, MeMes, 1d) decompose when exposed to dynamic vacuum. Gas-phase H2/D2 exchange between isolated, solid samples of 1c-d3 and 1c indicate that a reversible elimination of H2 is the first step in the irreversible decomposition. An efficient solution-phase trap for hydrogen, the 16-electron ruthenium benzyl complex [PhBP(Ph)3]Ru[η(3)-CH2(3,5-Me2C6H3)] (3) reacts quantitatively with H2 in benzene via elimination of mesitylene to form the η(5)-cyclohexadienyl complex [PhBP(Ph)3]Ru(η(5)-C6H7) (4). This H2 trapping reaction was utilized to drive forward and quantify the elimination of H2 from 1b,d in solution, which resulted in the decomposition of 1b,d to form 4 and several organosilicon products that could not be identified. Reaction of {[PhBP(Ph)3]Ru(μ-Cl)}2 (2) with (THF)2Li(SiHMes2) forms a new η(3)-H2Si species [PhBP(Ph)3]Ru[CH2(2-(η(3)-H2SiMes)-3,5-Me2C6H2)] (5) which reacts with H2 to form the η(3)-H2SiMes2 complex [PhBP(Ph)3]RuH(η(3)-H2SiMes2) (1e). Complex 1e was identified by NMR spectroscopy prior to its decomposition by elimination of Mes2SiH2 to form 4. DFT calculations indicate that an isomer of 5, the 16-electron silylene complex [PhBP(Ph)3]Ru(μ-H)(═SiMes2), is only 2 kcal/mol higher in energy than 5. Treatment of 5 with XylNC (Xyl = 2,6-dimethylphenyl) resulted in trapping of [PhBP(Ph)3]Ru(μ-H)(═SiMes2) to form the 18-electron silylene complex [PhBP(Ph)3]Ru(CNXyl)(μ-H)(═SiMes2) (6). A closely related germylene complex [PhBP(Ph)3]Ru[CN(2,6-diphenyl-4-MeC6H2)](H)(═GeH(t)Bu) (8) was prepared from reaction of (t)BuGeH3 with the benzyl complex [PhBP(Ph)3]Ru[CN(2,6-diphenyl-4-MeC6H2)][η(1)-CH2(3,5-Me2C6H3)] (7). Single crystal XRD analysis indicated that unlike for 6, the hydride ligand in 8 is a terminal hydride that does not engage in 3c-2e Ru-H → Ge bonding. Complex 1b is an effective precatalyst for the catalytic Ge-H dehydrocoupling

Evolutionary space platform concept study. Volume 3: Programmatics for manned space platform concepts

NASA Technical Reports Server (NTRS)

1982-01-01

The programmatic data for the reference concept of the Manned Space Platform is presented. Details regarding work breakdown structure (WBS) and dictionary, the facilities and equipment required to produce the modules, the project schedule and logic diagram, a preliminary assessment of environmental impacts and details regarding the estimated costs for the reference concept are included. The proposed WBS which was developed to provide summary and system level segregation of the nonrecurring and recurring portions of the Manned Space Platform project is also included. The accompanying dictionary outlines the function and activities contained within each WBS element. The facility and equipment required to produce the various modules is discussed. Generally, required equipment is within the existing state of the art although the size of some of the items to be manufactured is a consideration. A preliminary manufacturing flow was also provided. The project schedules presented consist of the Master Project Summary Schedule, the Master Project Phasing Chart and the Logic Network.

Esperanto for histones: CENP-A, not CenH3, is the centromeric histone H3 variant.

PubMed

Earnshaw, W C; Allshire, R C; Black, B E; Bloom, K; Brinkley, B R; Brown, W; Cheeseman, I M; Choo, K H A; Copenhaver, G P; Deluca, J G; Desai, A; Diekmann, S; Erhardt, S; Fitzgerald-Hayes, M; Foltz, D; Fukagawa, T; Gassmann, R; Gerlich, D W; Glover, D M; Gorbsky, G J; Harrison, S C; Heun, P; Hirota, T; Jansen, L E T; Karpen, G; Kops, G J P L; Lampson, M A; Lens, S M; Losada, A; Luger, K; Maiato, H; Maddox, P S; Margolis, R L; Masumoto, H; McAinsh, A D; Mellone, B G; Meraldi, P; Musacchio, A; Oegema, K; O'Neill, R J; Salmon, E D; Scott, K C; Straight, A F; Stukenberg, P T; Sullivan, B A; Sullivan, K F; Sunkel, C E; Swedlow, J R; Walczak, C E; Warburton, P E; Westermann, S; Willard, H F; Wordeman, L; Yanagida, M; Yen, T J; Yoda, K; Cleveland, D W

2013-04-01

The first centromeric protein identified in any species was CENP-A, a divergent member of the histone H3 family that was recognised by autoantibodies from patients with scleroderma-spectrum disease. It has recently been suggested to rename this protein CenH3. Here, we argue that the original name should be maintained both because it is the basis of a long established nomenclature for centromere proteins and because it avoids confusion due to the presence of canonical histone H3 at centromeres.

Silica-induced initiation of circular ZC3H4 RNA/ZC3H4 pathway promotes the pulmonary macrophage activation.

PubMed

Yang, Xiyue; Wang, Jing; Zhou, Zewei; Jiang, Rong; Huang, Jie; Chen, Lulu; Cao, Zhouli; Chu, Han; Han, Bing; Cheng, Yusi; Chao, Jie

2018-06-01

Phagocytosis of silicon dioxide (SiO 2 ) into lung cells causes an inflammatory cascade that results in fibroblast proliferation and migration, followed by fibrosis. Circular RNAs (circRNAs) are a subclass of noncoding RNAs that are present within mammalian cells; however, researchers have not determined whether circRNAs are involved in the pathophysiologic process of silicosis. To elucidate the role of these RNAs in SiO 2 -induced inflammation in pulmonary macrophages, we investigated the upstream molecular mechanisms and functional effects of circRNAs on cell apoptosis, proliferation, and migration. Primary cultures of alveolar macrophages from healthy donors and from patients and the RAW264.7 macrophage cell line were used to explore the functions of circZC3H4 RNA in macrophage activation. The experimental results indicated the following: 1) SiO 2 concomitantly increased circZC3H4 RNA expression and increased ZC3H4 protein levels; 2) circular ZC3H4 (circZC3H4) RNA and ZC3H4 protein participated in SiO 2 -induced macrophage activation; and 3) SiO 2 -activated macrophages promoted fibroblast proliferation and migration via the circZC3H4 RNA/ZC3H4 pathway. The up-regulation of the ZC3H4 protein was confirmed in tissue samples from patients with silicosis. Our study elucidates a link between SiO 2 -induced macrophage activation and the circZC3H4 RNA/ZC3H4 pathway, thereby providing novel insight into the potential use of ZC3H4 to develop novel therapeutic strategies for silicosis.-Yang, X., Wang, J., Zhou, Z., Jiang, R., Huang, J., Chen, L., Cao, Z., Chu, H., Han, B., Cheng, Y., Chao, J. Silica-induced initiation of circular ZC3H4 RNA/ZC3H4 pathway promotes the pulmonary macrophage activation.

Structurally characterized 1,1,3,3-tetramethylguanidine solvated magnesium aryloxide complexes: [Mg(mu-OEt)(DBP)(H-TMG)]2, [Mg(mu-OBc)(DBP)(H-TMG)]2, [Mg(mu-TMBA)(DBP)(H-TMG)]2, [Mg(mu-DPP)(DBP)(H-TMG)]2, [Mg(BMP)2(H-TMG)2], [Mg(O-2,6-Ph2C6H3)2 (H-TMG)2].

PubMed

Monegan, Jessie D; Bunge, Scott D

2009-04-06

The synthesis and structural characterization of several 1,1,3,3-tetramethylguanidine (H-TMG) solvated magnesium aryloxide complexes are reported. Bu(2)Mg was successfully reacted with H-TMG, HOC(6)H(3)(CMe(3))(2)-2,6 (H-DBP), and either ethanol, a carboxylic acid, or diphenyl phosphate in a 1:1 ratio to yield the corresponding [Mg(mu-L)(DBP)(H-TMG)](2) where L = OCH(2)CH(3) (OEt, 1), O(2)CC(CH(3))(3) (OBc, 2), O(2)C(C(6)H(2)-2,4,6-(CH(3))(3)) (TMBA, 3), or O(2)P(OC(6)H(5))(2) (DPP, 4). Bu(2)Mg was also reacted with two equivalents of H-TMG and HOC(6)H(3)(CMe(3))-2-(CH(3))-6 (BMP) or HO-2,6-Ph(2)C(6)H(3) to yield [Mg(BMP)(2)(H-TMG)(2)] (5) and [Mg(O-2,6-Ph(2)C(6)H(3))(2)(H-TMG)(2)] (6). Compounds 1-6 were characterized by single-crystal X-ray diffraction. Polymerization of l- and rac-lactide with 1 was found to generate polylactide (PLA). A discussion concerning the relevance of compounds 2 - 4 to the structure of Mg-activated phosphatase enzymes is also provided. The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, FT-IR spectroscopy, and (1)H, (13)C and (31)P NMR studies.

Electrical conductivity of aluminum hydride AlH3 at high pressure and temperature

NASA Astrophysics Data System (ADS)

Shakhray, Denis; Molodets, Alexander; Fortov, Vladimir; Khrapak, Aleksei

2009-06-01

A study of electrophysical and thermodynamic properties of alane AlH3 under multi shock compression has been carried out. The increase in specific electroconductivity of alane at shock compression up to pressure 100 GPa have been measured. High pressures and temperatures were obtained with explosive device, which accelerates the stainless impactor up to 3 km/sec. The impact shock is split into a shock wave reverberating in alane between two stiff metal anvils. The conductivity of shocked alane increases in the range up to 60-75 GPa and is about 30 1/Ohm*cm. In this region the semiconductor regime is true for shocked alane. The conductivity of alane achieves approximately 500 1/Ohm*cm at 80-90 GPa. In this region conductivity is interpreted in frames of the conception of the ``dielectric catastrophe'', taking into consideration significant difference between electronic states of isolated AlH3 molecule and condensed alane.

Review of Propulsion Technologies for N+3 Subsonic Vehicle Concepts

NASA Technical Reports Server (NTRS)

Ashcraft, Scott W.; Padron, Andres S.; Pascioni, Kyle A.; Stout, Gary W., Jr.; Huff, Dennis L.

2011-01-01

NASA has set aggressive fuel burn, noise, and emission reduction goals for a new generation (N+3) of aircraft targeting concepts that could be viable in the 2035 timeframe. Several N+3 concepts have been formulated, where the term "N+3" indicate aircraft three generations later than current state-of-the-art aircraft, "N". Dramatic improvements need to be made in the airframe, propulsion systems, mission design, and the air transportation system in order to meet these N+3 goals. The propulsion system is a key element to achieving these goals due to its major role with reducing emissions, fuel burn, and noise. This report provides an in-depth description and assessment of propulsion systems and technologies considered in the N+3 subsonic vehicle concepts. Recommendations for technologies that merit further research and development are presented based upon their impact on the N+3 goals and likelihood of being operational by 2035.

Context dependency of Set1/COMPASS-mediated histone H3 Lys4 trimethylation

PubMed Central

Thornton, Janet L.; Westfield, Gerwin H.; Takahashi, Yoh-hei; Cook, Malcolm; Gao, Xin; Woodfin, Ashley R.; Lee, Jung-Shin; Morgan, Marc A.; Jackson, Jessica; Smith, Edwin R.; Couture, Jean-Francois; Skiniotis, Georgios; Shilatifard, Ali

2014-01-01

The stimulation of trimethylation of histone H3 Lys4 (H3K4) by H2B monoubiquitination (H2Bub) has been widely studied, with multiple mechanisms having been proposed for this form of histone cross-talk. Cps35/Swd2 within COMPASS (complex of proteins associated with Set1) is considered to bridge these different processes. However, a truncated form of Set1 (762-Set1) is reported to function in H3K4 trimethylation (H3K4me3) without interacting with Cps35/Swd2, and such cross-talk is attributed to the n-SET domain of Set1 and its interaction with the Cps40/Spp1 subunit of COMPASS. Here, we used biochemical, structural, in vivo, and chromatin immunoprecipitation (ChIP) sequencing (ChIP-seq) approaches to demonstrate that Cps40/Spp1 and the n-SET domain of Set1 are required for the stability of Set1 and not the cross-talk. Furthermore, the apparent wild-type levels of H3K4me3 in the 762-Set1 strain are due to the rogue methylase activity of this mutant, resulting in the mislocalization of H3K4me3 from the promoter-proximal regions to the gene bodies and intergenic regions. We also performed detailed screens and identified yeast strains lacking H2Bub but containing intact H2Bub enzymes that have normal levels of H3K4me3, suggesting that monoubiquitination may not directly stimulate COMPASS but rather works in the context of the PAF and Rad6/Bre1 complexes. Our study demonstrates that the monoubiquitination machinery and Cps35/Swd2 function to focus COMPASS's H3K4me3 activity at promoter-proximal regions in a context-dependent manner. PMID:24402317

Ruthenium(II)-Catalyzed C-H Activation of Imidamides and Divergent Couplings with Diazo Compounds: Substrate-Controlled Synthesis of Indoles and 3H-Indoles.

PubMed

Li, Yunyun; Qi, Zisong; Wang, He; Yang, Xifa; Li, Xingwei

2016-09-19

Indoles are an important structural motif that is commonly found in biologically active molecules. In this work, conditions for divergent couplings between imidamides and acceptor-acceptor diazo compounds were developed that afforded NH indoles and 3H-indoles under ruthenium catalysis. The coupling of α-diazoketoesters afforded NH indoles by cleavage of the C(N2 )-C(acyl) bond whereas α-diazomalonates gave 3H-indoles by C-N bond cleavage. This reaction constitutes the first intermolecular coupling of diazo substrates with arenes by ruthenium-catalyzed C-H activation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification and Characterization of Switchgrass Histone H3 and CENH3 Genes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miao, Jiamin; Frazier, Taylor; Huang, Linkai

Switchgrass is one of the most promising energy crops and only recently has been employed for biofuel production. The draft genome of switchgrass was recently released; however, relatively few switchgrass genes have been functionally characterized. CENH3, the major histone protein found in centromeres, along with canonical H3 and other histones, plays an important role in maintaining genome stability and integrity. Despite their importance, the histone H3 genes of switchgrass have remained largely uninvestigated. In this study, we identified 17 putative switchgrass histone H3 genes in silico. Of these genes, 15 showed strong homology to histone H3 genes including six H3.1more » genes, three H3.3 genes, four H3.3-like genes and two H3.1-like genes. The remaining two genes were found to be homologous to CENH3. RNA-seq data derived from lowland cultivar Alamo and upland cultivar Dacotah allowed us to identify SNPs in the histone H3 genes and compare their differential gene expression. Interestingly, we also found that overexpression of switchgrass histone H3 and CENH3 genes in N. benthamiana could trigger cell death of the transformed plant cells. Localization and deletion analyses of the histone H3 and CENH3 genes revealed that nuclear localization of the N-terminal tail is essential and sufficient for triggering the cell death phenotype. Lastly, our results deliver insight into the mechanisms underlying the histone-triggered cell death phenotype and provide a foundation for further studying the variations of the histone H3 and CENH3 genes in switchgrass.« less

Identification and Characterization of Switchgrass Histone H3 and CENH3 Genes

DOE PAGES

Miao, Jiamin; Frazier, Taylor; Huang, Linkai; ...

2016-07-12

Switchgrass is one of the most promising energy crops and only recently has been employed for biofuel production. The draft genome of switchgrass was recently released; however, relatively few switchgrass genes have been functionally characterized. CENH3, the major histone protein found in centromeres, along with canonical H3 and other histones, plays an important role in maintaining genome stability and integrity. Despite their importance, the histone H3 genes of switchgrass have remained largely uninvestigated. In this study, we identified 17 putative switchgrass histone H3 genes in silico. Of these genes, 15 showed strong homology to histone H3 genes including six H3.1more » genes, three H3.3 genes, four H3.3-like genes and two H3.1-like genes. The remaining two genes were found to be homologous to CENH3. RNA-seq data derived from lowland cultivar Alamo and upland cultivar Dacotah allowed us to identify SNPs in the histone H3 genes and compare their differential gene expression. Interestingly, we also found that overexpression of switchgrass histone H3 and CENH3 genes in N. benthamiana could trigger cell death of the transformed plant cells. Localization and deletion analyses of the histone H3 and CENH3 genes revealed that nuclear localization of the N-terminal tail is essential and sufficient for triggering the cell death phenotype. Lastly, our results deliver insight into the mechanisms underlying the histone-triggered cell death phenotype and provide a foundation for further studying the variations of the histone H3 and CENH3 genes in switchgrass.« less

Math anxiety and math performance in children: The mediating roles of working memory and math self-concept.

PubMed

Justicia-Galiano, M José; Martín-Puga, M Eva; Linares, Rocío; Pelegrina, Santiago

2017-12-01

Numerous studies, most of them involving adolescents and adults, have evidenced a moderate negative relationship between math anxiety and math performance. There are, however, a limited number of studies that have addressed the mechanisms underlying this relation. This study aimed to investigate the role of two possible mediational mechanisms between math anxiety and math performance. Specifically, we sought to test the simultaneous mediating role of working memory and math self-concept. A total of 167 children aged 8-12 years participated in this study. Children completed a set of questionnaires used to assess math and trait anxiety, math self-concept as well as measures of math fluency and math problem-solving. Teachers were asked to rate each student's math achievement. As measures of working memory, two backward span tasks were administered to the children. A series of multiple mediation analyses were conducted. Results indicated that both mediators (working memory and math self-concept) contributed to explaining the relationship between math anxiety and math achievement. Results suggest that working memory and self-concept could be worth considering when designing interventions aimed at helping students with math anxiety. Longitudinal designs could also be used to better understand the mediational mechanisms that may explain the relationship between math anxiety and math performance. © 2017 The British Psychological Society.

Commercial valerian interactions with [3H]Flunitrazepam and [3H]MK-801 binding to rat synaptic membranes.

PubMed

Ortiz, José G; Rassi, Nicole; Maldonado, Patricia M; González-Cabrera, Silvia; Ramos, Igmeris

2006-09-01

Valeriana officinalis extracts are used in folkloric medicine for their sedative, hypnotic and tranquilizer effects. Using [3H]flunitrazepam binding as an indicator, the interactions of commercial Valerian extracts with GABA(A) receptors were examined. There was considerable fluctuation among the different extracts, some mildly enhanced [3H]flunitrazepam binding, others had no effect and others had inhibitory effects, independent of standardization by valerenic acid. Central depression can also be accomplished by a reduction of excitatory transmission. Valerian extracts had modest inhibitory effects on [3H]MK-801 binding, an indicator of NMDA-Valerian interactions. Spectral analyses (UV region) did not show marked differences among the different extracts. The inhibitory effects of one of the extracts on [3H]flunitrazepam binding was somewhat stable, while on [3H]MK-801 binding the inhibitory effects were lost within months. These results suggest that particular care should be taken in analysing and interpreting results from commercial Valerian preparations. Copyright (c) 2006 John Wiley & Sons, Ltd.

Identification of two H3-histamine receptor subtypes

DOE Office of Scientific and Technical Information (OSTI.GOV)

West, R.E. Jr.; Zweig, A.; Shih, N.Y.

The H3-histamine receptor provides feedback inhibition of histamine synthesis and release as well as inhibition of other neurotransmitter release. We have characterized this receptor by radioligand binding studies with the H3 agonist N alpha-(3H)methylhistamine ((3H)NAMHA). The results of (3H)NAMHA saturation binding and NAMHA inhibition of (3H)NAMHA binding were consistent with an apparently single class of receptors (KD = 0.37 nM, Bmax = 73 fmol/mg of protein) and competition assays with other agonists and the antagonists impromidine and dimaprit disclosed only a single class of sites. In contrast, inhibition of (3H)NAMHA binding by the specific high affinity H3 antagonist thioperamide revealedmore » two classes of sites (KiA = 5 nM, BmaxA = 30 fmol/mg of protein; KiB = 68 nM, BmaxB = 48 fmol/mg of protein). Burimamide, another antagonist that, like thioperamide, contains a thiourea group, likewise discriminated between two classes of sites. In addition to differences between some antagonist potencies for the two receptors, there is a differential guanine nucleotide sensitivity of the two. The affinity of the H3A receptor for (3H) NAMHA was reduced less than 2-fold, whereas (3H)NAMHA binding to the H3B receptor was undetectable in the presence of guanosine 5'-O-(3-thiotriphosphate). The distinction between H3A and H3B receptor subtypes, the former a high affinity and the latter a low affinity thioperamide site, draws support from published in vitro data.« less

Artificial Intelligence, Expert Systems, Natural Language Interfaces, Knowledge Engineering and the Librarian.

ERIC Educational Resources Information Center

Davies, Jim

This paper begins by examining concepts of artificial intelligence (AI) and discusses various definitions of the concept that have been suggested in the literature. The nesting relationship of expert systems within the broader framework of AI is described, and expert systems are characterized as knowledge-based systems (KBS) which attempt to solve…

R-matrix description of particle energy spectra produced by low-energy 3H + 3H reactions

DOE PAGES

Brune, C. R.; Caggiano, J. A.; Sayre, D. B.; ...

2015-07-20

An R-matrix model for three-body final states is presented and applied to a recent measurement of the neutron energy spectrum from the 3H + 3H→ 2n + α reaction. The calculation includes the n alpha and n n interactions in the final state, angular momentum conservation, antisymmetrization, and the interference between different channels. A good fit to the measured spectrum is obtained, where clear evidence for the 5He ground state is observed. The model is also used to predict the alpha-particle spectrum from 3H + 3H as well as particle spectra from 3He + 3He. The R-matrix approach presented heremore » is very general, and can be adapted to a wide variety of problems with three-body final states.« less

40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN P...

40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Boric acid (H3BO3), zinc salt (2=3... Substances § 721.3031 Boric acid (H3BO3), zinc salt (2=3). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as boric acid (H3BO3), zinc salt (2=3) (PMN P...

Concept-Oriented Reading Instruction (CORI). What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2010

2010-01-01

"Concept-Oriented Reading Instruction" is a reading comprehension instructional program for grades 3-9 that integrates reading and science through activities and the use of science books during reading instruction. The program supplements a school's standard science and reading curricula and offers instruction in reading strategies,…

Insertion of bentonite with Organometallic [Fe3O(OOC6H5)6(H2O)3(NO3).nH2O] as Adsorbent of Congo Red

NASA Astrophysics Data System (ADS)

Said, Muhammad; Paluta Utami, Hasja; Hayati, Ferlina

2018-01-01

The adsorption of Congo red using bentonite inserted organometallic has been investigated. The insertion bentonite was characterized using FT-IR Spectrophotometer, XRD and XRF analysis. The FT-IR characterization showed the higher intensity of peak wavenumber at 470.6 cm-1 for Fe3O on the ratio 1:3. While the XRD characterization showed the shift of diffraction angle of 2θ was 5.2° and has a basal spacing of 16.8 Å. In the XRF characterization, the insertion process of organometallic occurred optimally with the percentage of metal oxide reached 71.75 %. The adsorption process of bentonite inserted organometallic compound [Fe3O(OOC6H5)6(H2O)3(NO3)·nH2O] showed the adsorption rate (k) is 0.050 min-1, the largest adsorption capacity (b) at 70°C is 4.48 mol/g, the largest adsorption energy at temperature 30°C which is 6.4 kJ/mol Organometallic compounds. The value of the enthalpy (ΔH) and entropy (ΔS) decreased with increasing concentrations of the Congo red. Effect of pH on the adsorption on at pH 3 shows the biggest of number Congo red absorbed is 19.52 mg/L for insertion of bentonite.

Laboratory Measurements for H3+ Deuteration Reactions

NASA Astrophysics Data System (ADS)

Bowen, Kyle; Hillenbrand, Pierre-Michel; Urbain, Xavier; Savin, Daniel Wolf

2018-06-01

Deuterated molecules are important chemical tracers of protostellar cores. At the ~106 cm-3 particle densities and ~20 K temperatures typical for protostellar cores, most molecules freeze onto dust grains. A notable exception is H3+ and its isotopologues. These become important carriers of positive charge in the gas, can couple to any ambient magnetic field, and can thereby alter the cloud dynamics. Knowing the total abundance of H3+ and its isotopologues is important for studying the evolution of protostellar cores. However, H3+ and D3+ have no dipole moment. They lack a pure rotational spectrum and are not observable at protostellar core temperatures. Fortunately H2D+ and D2H+ have dipole moments and a pure rotational spectrum that can be excited in protostellar cores. Observations of these two molecules, combined with astrochemical models, provide information about the total abundance of H3+ and all its isotopologues. The inferred abundances, though, rely on accurate astrochemical data for the deuteration of H3+ and its isotopologues.Here we present laboratory measurements of the rate coefficients for three important deuterating reactions, namely D + H3+/H2D+/D2H+ → H + H2D+/ D2H+/D3+. Astrochemical models currently rely on rate coefficients from classical (Langevin) or semi-classical methods for these reactions, as fully quantum-mechanical calculations are beyond current computational capabilities. Laboratory studies are the most tractable means of providing the needed data. For our studies we used our novel dual-source, merged fast-beams apparatus, which enables us to study reactions of neutral atoms and molecular ions. Co-propagating beams allow us to measure experimental rate coefficients as a function of collision energy. We extract cross section data from these results, which we then convolve with a Maxwell-Boltzmann distribution to generate thermal rate coefficients. Here we present our results for these three reactions and discuss some implications.

Precision Saturated Absorption Spectroscopy of H3+

NASA Astrophysics Data System (ADS)

Guan, Yu-chan; Liao, Yi-Chieh; Chang, Yung-Hsiang; Peng, Jin-Long; Shy, Jow-Tsong

2016-06-01

In our previous work on the Lamb dips of the νb{2} fundamental band of H3+, the saturated absorption spectrum was obtained by the third-derivative spectroscopy using frequency modulation [1]. However, the frequency modulation also causes error in absolute frequency determination. To solve this problem, we have built an offset-locking system to lock the OPO pump frequency to an iodine-stabilized Nd:YAG laser. With this modification, we are able to scan the OPO idler frequency precisely and obtain the profile of the Lamb dips. Double modulation (amplitude modulation of the idler power and concentration modulation of the ion) is employed to subtract the interference fringes of the signal and increase the signal-to-noise ratio effectively. To Determine the absolute frequency of the idler wave, the pump wave is offset locked on the R(56) 32-0 a10 hyperfine component of 127I2, and the signal wave is locked on a GPS disciplined fiber optical frequency comb (OFC). All references and lock systems have absolute frequency accuracy better than 10 kHz. Here, we demonstrate its performance by measuring one transition of methane and sixteen transitions of H3+. This instrument could pave the way for the high-resolution spectroscopy of a variety of molecular ions. [1] H.-C. Chen, C.-Y. Hsiao, J.-L. Peng, T. Amano, and J.-T. Shy, Phys. Rev. Lett. 109, 263002 (2012).

Ab-initio study of the energetics and thermodynamics of the reaction CH3H + O( 3P) → CF3H … O → CF3 + OH

NASA Astrophysics Data System (ADS)

Kreye, W. C.

1996-07-01

Ab-initio computations at 298.15 K were made of the activation quantities ΔH ‡, ΔS ‡, and ΔG ‡ and of the reaction quantities ΔHr and ΔSr for CF3H + O( 3P) → CF3H … O → .CF3.OH. CF 3H … O is the transition state (TS). GAUSSIAN92 was used and energies computed at a slightly modified Gaussian-2 level. Two potential surfaces for the TS had symmetries 3A' and 3A″. The two rate constants included a semi-classical, quantum-mechanical-tunneling transmission coefficient. The ab-initio ΔH ‡and ΔH r values were in excellent agreement (± 1 kcal/mol) with experiment; but the ΔS ‡, ΔG ‡, and ΔS r values yielded somewhat poorer agreement. Experimental and ab-initio structures were in excellent agreement.

Ab initio Quantum Chemical Studies of Reactions in Astrophysical Ices. Reactions Involving CH3OH, CO2, CO, HNCO in H2CO/NH3/H2O Ices

NASA Technical Reports Server (NTRS)

Woon, David E.

2006-01-01

While reactions between closed shell molecules generally involve prohibitive barriers in the gas phase, prior experimental and theoretical studies have demonstrated that some of these reactions are significantly enhanced when confined within an icy grain mantle and can occur efficiently at temperatures below 100 K with no additional energy processing. The archetypal case is the reaction of formaldehyde (H2CO) and ammonia (NH3) to yield hydroxymethylamine (NH2CH2OH). In the present work we have characterized reactions involving methanol (CH3OH), carbon dioxide (CO2), carbon monoxide (CO), and isocyanic acid (HNCO) in search of other favorable cases. Most of the emphasis is on CH3OH, which was investigated in the two-body reaction with one H2CO and the three-body reaction with two H2CO molecules. The addition of a second H2CO to the product of the reaction between CH3OH and H2CO was also considered as an alternative route to longer polyoxymethylene polymers of the -CH2O- form. The reaction between HNCO and NH3 was studied to determine if it can compete against the barrierless charge transfer process that yields OCN(-) and NH4(+). Finally, the H2CO + NH3 reaction was revisited with additional benchmark calculations that confirm that little or no barrier is present when it occurs in ice.

How to calculate H3 better.

PubMed

Pavanello, Michele; Tung, Wei-Cheng; Adamowicz, Ludwik

2009-11-14

Efficient optimization of the basis set is key to achieving a very high accuracy in variational calculations of molecular systems employing basis functions that are explicitly dependent on the interelectron distances. In this work we present a method for a systematic enlargement of basis sets of explicitly correlated functions based on the iterative-complement-interaction approach developed by Nakatsuji [Phys. Rev. Lett. 93, 030403 (2004)]. We illustrate the performance of the method in the variational calculations of H(3) where we use explicitly correlated Gaussian functions with shifted centers. The total variational energy (-1.674 547 421 Hartree) and the binding energy (-15.74 cm(-1)) obtained in the calculation with 1000 Gaussians are the most accurate results to date.

Enantioselective C(sp3)‒H bond activation by chiral transition metal catalysts.

PubMed

Saint-Denis, Tyler G; Zhu, Ru-Yi; Chen, Gang; Wu, Qing-Feng; Yu, Jin-Quan

2018-02-16

Organic molecules are rich in carbon-hydrogen bonds; consequently, the transformation of C-H bonds to new functionalities (such as C-C, C-N, and C-O bonds) has garnered much attention by the synthetic chemistry community. The utility of C-H activation in organic synthesis, however, cannot be fully realized until chemists achieve stereocontrol in the modification of C-H bonds. This Review highlights recent efforts to enantioselectively functionalize C(sp 3 )-H bonds via transition metal catalysis, with an emphasis on key principles for both the development of chiral ligand scaffolds that can accelerate metalation of C(sp 3 )-H bonds and stereomodels for asymmetric metalation of prochiral C-H bonds by these catalysts. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

CAL3JHH: a Java program to calculate the vicinal coupling constants (3J H,H) of organic molecules.

PubMed

Aguirre-Valderrama, Alonso; Dobado, José A

2008-12-01

Here, we present a free web-accessible application, developed in the JAVA programming language for the calculation of vicinal coupling constant (3J(H,H)) of organic molecules with the H-Csp3-Csp3-H fragment. This JAVA applet is oriented to assist chemists in structural and conformational analyses, allowing the user to calculate the averaged 3J(H,H) values among conformers, according to its Boltzmann populations. Thus, the CAL3JHH program uses the Haasnoot-Leeuw-Altona equation, and, by reading the molecule geometry from a protein data bank (PDB) file format or from multiple pdb files, automatically detects all the coupled hydrogens, evaluating the data needed for this equation. Moreover, a "Graphical viewer" menu allows the display of the results on the 3D molecule structure, as well as the plotting of the Newman projection for the couplings.

Molecular turnover, the H3.3 dilemma and organismal aging (hypothesis)

PubMed Central

Saade, Evelyne; Pirozhkova, Iryna; Aimbetov, Rakhan; Lipinski, Marc; Ogryzko, Vasily

2015-01-01

The H3.3 histone variant has been a subject of increasing interest in the field of chromatin studies due to its two distinguishing features. First, its incorporation into chromatin is replication independent unlike the replication-coupled deposition of its canonical counterparts H3.1/2. Second, H3.3 has been consistently associated with an active state of chromatin. In accordance, this histone variant should be expected to be causally involved in the regulation of gene expression, or more generally, its incorporation should have downstream consequences for the structure and function of chromatin. This, however, leads to an apparent paradox: In cells that slowly replicate in the organism, H3.3 will accumulate with time, opening the way to aberrant effects on heterochromatin. Here, we review the indications that H3.3 is expected both to be incorporated in the heterochromatin of slowly replicating cells and to retain its functional downstream effects. Implications for organismal aging are discussed. PMID:25720734

Final Report for the Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2030 to 2035 Period, N+3 Supersonic Program

NASA Technical Reports Server (NTRS)

Morgenstern, John; Norstrud, Nicole; Stelmack, Marc; Skoch, Craig

2010-01-01

The N+3 Final Report documents the work and progress made by Lockheed Martin Aeronautics in response to the NASA sponsored program "N+3 NRA Advanced Concept Studies for Supersonic Commercial Transports Entering Service in the 2030 to 2035 Period." The key technical objective of this effort was to generate promising supersonic concepts for the 2030 to 2035 timeframe and to develop plans for maturing the technologies required to make those concepts a reality. The N+3 program is aligned with NASA's Supersonic Project and is focused on providing alternative system-level solutions capable of overcoming the efficiency, environmental, and performance barriers to practical supersonic flight

3-Helium in Obscure H II Regions

NASA Astrophysics Data System (ADS)

Bania, T. M.; Rood, R. T.; Balser, D. S.

1999-05-01

The light isotope of helium, (3) He, can serve as a probe of cosmology, the evolution of low mass stars, and the chemical evolution of the Galaxy. Its abundance can be determined via measurements of the 3.46 cm hyperfine transition of (3) He(+) . Potentially observable sources of ionized gas include H ii regions and planetary nebulae. The selection of (3) He targets is counter-intuitive because the (3) He(+) hyperfine line strength is proportional to the source density, while one usually thinks of H ii regions in terms of radio continuum or recombination line strength both of which depend on the square of the density. The (3) He(+) line strength depends on the (3) He(+) abundance ratio and a number of other factors: $ TL(A}({) (3) He(+)) ~ frac {N((3) He(+)}{N() H(+)}) frac {({TC(A}}D)({1/2)) Te(1/4) (theta_obs (2) - theta_beam (2})({3/4}}{Delta {v}({)) (3) He(+)) [ln(5.717 x 10(-3}Te({3/2})]^{1/2)) theta_obs } where T_L^A and Delta v are the antenna temperature and FWHM of the ^3He^+ line, D is the nebular distance, T_C^A and theta_obs are the antenna temperature and observed FWHM angular size of the continuum emission, theta_beam is the telescope's FWHM beam, and Te is the nebular electron temperature. For H {sc ii} regions much larger than the telescope beam we can select targets using the criterion: TLA(^3He^+)\\sim\\sqrt{TCA D\\theta_obs}. This is the case since we can neglect the weak dependence on T_e and because we do not know either ^3He^{+}/H^+ or Delta v. Thus big, distant H ii regions could be potential ^3He^+ targets even if their continuum emission is weak. Armed with this knowledge we included H ii regions like S209 in our early observing list along with more famous sources like W43. Still we did not have the temerity to push this reasoning to the limit. We have now found, however, that this selection criterion is valid for even the wimpiest known H ii regions. Here we report on the detection of ^3He^+$ emission in 8 distant, low density H ii regions.

Nqrs Data for H4I3Li2NO9 [H4INO3·2(ILiO3)] (Subst. No. 2278)

NASA Astrophysics Data System (ADS)

Chihara, H.; Nakamura, N.

This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for H4I3Li2NO9 [H4INO3·2(ILiO3)] (Subst. No. 2278)

Nqrs Data for H6I3InO12 [I3InO9·3(H2O)] (Subst. No. 2289)

NASA Astrophysics Data System (ADS)

Chihara, H.; Nakamura, N.

This document is part of Subvolume B 'Substances Containing C10H16 … Zn' of Volume 48 'Nuclear Quadrupole Resonance Spectroscopy Data' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains an extract of Section '3.2 Data tables' of the Chapter '3 Nuclear quadrupole resonance data' providing the NQRS data for H6I3InO12 [I3InO9·3(H2O)] (Subst. No. 2289)

Al6H18: A baby crystal of γ-AlH3

NASA Astrophysics Data System (ADS)

Kiran, B.; Kandalam, Anil K.; Xu, Jing; Ding, Y. H.; Sierka, M.; Bowen, K. H.; Schnöckel, H.

2012-10-01

Using global-minima search methods based on the density functional theory calculations of (AlH3)n (n = 1-8) clusters, we show that the growth pattern of alanes for n ≥ 4 is dominated by structures containing hexa-coordinated Al atoms. This is in contrast to the earlier studies where either linear or ring structures of AlH3 were predicted to be the preferred structures in which the Al atoms can have a maximum of five-fold coordination. Our calculations also reveal that the Al6H18 cluster, with its hexa-coordination of the Al atoms, resembles the unit-cell of γ-AlH3, thus Al6H18 is designated as the "baby crystal." The fragmentation energies of the (AlH3)n (n = 2-8) along with the dimerization energies for even n clusters indicate an enhanced stability of the Al6H18 cluster. Both covalent (hybridization) and ionic (charge) contribution to the bonding are the driving factors in stabilizing the isomers containing hexa-coordinated Al atoms.

Modelling disorder in 3,3' -dimethoxybensil, C[subscript 16]H[subscript 14]O[subscript 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goossens, Darren J.; Welberry, T.Richard; Heerdegen, Aidan P.

2008-06-18

This work is part of an extended study of benzil (C{sub 14}H{sub 10}O{sub 2}) and some of its derivatives which aims to understand the role of molecular flexibility in crystal packing and polymorphism. Significant steps have been made in modelling the structured thermal diffuse scattering from 3,3'-dimethoxybenzil, C{sub 16}H{sub 1}4O{sub 4}. It appears that the structure can be considered as a stack of layers of molecules in which interactions are strongest within the layers. The layers interact weakly along the a direction but more strongly along c, so shearing of the planes relative to each other is energetically likely. Themore » molecule must be treated as flexible for a good model to be found.« less

Concept development of a Mach 3.0 high-speed civil transport

NASA Technical Reports Server (NTRS)

Robins, A. Warner; Dollyhigh, Samuel M.; Beissner, Fred L., Jr.; Geiselhart, Karl; Martin, Glenn L.; Shields, E. W.; Swanson, E. E.; Coen, Peter G.; Morris, Shelby J., Jr.

1988-01-01

A baseline concept for a Mach 3.0 high-speed civil transport concept was developed as part of a national program with the goal that concepts and technologies be developed which will enable an effective long-range high-speed civil transport system. The Mach 3.0 concept reported represents an aggressive application of advanced technology to achieve the design goals. The level of technology is generally considered to be that which could have a demonstrated availability date of 1995 to 2000. The results indicate that aircraft are technically feasible that could carry 250 passengers at Mach 3.0 cruise for a 6500 nautical mile range at a size, weight and performance level that allows it to fit into the existing world airport structure. The details of the configuration development, aerodynamic design, propulsion system design and integration, mass properties, mission performance, and sizing are presented.

Revolutionary/Unconventional Aeropropulsion Technology Evaluation through Thermodynamic Work Potential: A Revolutionary Aeropropulsion Concepts Program Research Initiative

NASA Technical Reports Server (NTRS)

Mavris, Dimitri; Danner, Travis; Roth, Bryce

2002-01-01

This report is intended as a status report for activities covered May through July 2002 under the auspices of NASA Glenn's Revolutionary Aeropropulsion Concepts (RAC) project. This is the first phase I quarterly report and as such, considerable focus will be given to defining the basic need and motivation driving this research effort. In addition, background research has been ongoing for the past several months and has culminated in considerable information pertaining to the state-of-the-art in work potential analysis methods. This work is described in detail herein. Finally, the proposed analysis approach is described, as are the various ancillary concepts required for its implementation.

40. OUTLET WORKS: VIBRATION ABSORBER FOR STANDBY UNIT, Sheet H7, ...

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

40. OUTLET WORKS: VIBRATION ABSORBER FOR STANDBY UNIT, Sheet H-7, September, 1940. File no. SA 342/79. - Prado Dam, Outlet Works, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

Uptake of /sup 3/H-choline and synthesis of /sup 3/H-acetylcholine by human penile corpus cavernosum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blanco, R.; Saenz de Tejada, I.; Azadzoi, K.

1986-03-05

The neuroeffectors which relax penile smooth muscle and lead to erection are unknown; physiological studies of human corpus cavernosum, in vitro, have suggested a significant role of cholinergic neurotransmission. To further characterize the importance of cholinergic nerves, biopsies of human corpus cavernosum were obtained at the time of penile prosthesis implantation. Tissues were incubated in /sup 3/H-choline (10/sup -5/M, 80 Ci/mmol) in oxygenated physiological salt solution at 37/sup 0/C, pH 7.4 for 1 hour. Radiolabelled compounds were extracted with perchloric acid (0.4 M) and acetylcholine and choline were separated by HPLC; /sup 14/C-acetylcholine was used as internal standard. /sup 3/H-cholinemore » was accumulated by the tissues (20 +/- 1.9 fmol/mg), and /sup 3/H-acetylcholine was synthesized (4.0 +/- 1.1 fmol/mg). In control experiments, heating of the tissue blocked synthesis of /sup 3/H-acetylcholine. Inhibition of high affinity choline transport by hemicholinium-3 (10/sup -5/M) diminished tissue accumulation of /sup 3/H-choline and significantly reduced the synthesis of /sup 3/H-acetylcholine (0.5 +/ 0.2 fmol/mg, p < 0.05). These results provide direct evidence of neuronal accumulation of choline and enzymatic conversion to acetylcholine in human corpus cavernosum. Taken together with the physiological studies, it can be concluded that cholinergic neurotransmission in human corpus cavernosum plays a role in penile erection.« less

The 3H(d,gamma) Reaction and the 3 H(d,gamma)/ 3H(d, n) Branching Ratio for Ec.m. 300 keV

NASA Astrophysics Data System (ADS)

Parker, Cody E.

The 3H(d, gamma)5He reaction and the 3H(d, gamma)/3H(d, n) branching ratio have been measured using a 500-keV pulsed deuteron beam incident on a titanium tritide target of stopping thickness at the Edwards Accelerator Laboratory. The time-of-flight technique has been used to distinguish the gamma-rays from neutrons in the bismuth germinate (BGO) gamma-ray detector. A stilbene scintillator and an NE-213 scintillator have been used to detect the neutrons from the 3H(d, n)alpha reaction using both the pulse-shape discrimination and time-of-flight techniques. A target holder with an ion-implanted silicon detector at a fixed angle of 135° to the beam axis to simultaneously measure alpha-particles as a normalization for the number of neutrons was incorporated to reduce the uncertainty in the neutron yield over the preliminary measurement. The gamma-rays have been measured at laboratory angles of 0°, 4°, 9°, and 15°. Information about the gamma-ray energy distribution for the unbound ground state and first excited state of 5He have been obtained experimentally by comparing the BGO data to Monte Carlo simulations. The reported branching ratios for each angle contain only contributions from the ground-state gamma-ray branch.

Molecular dynamics simulation on HP1 protein binding by histone H3 tail methylation and phosphorylation

NASA Astrophysics Data System (ADS)

Jiang, Yan-Ke; Zou, Jian-Wei; Wu, Yu-Qian; Zhang, Na; Yu, Qing-Sen; Jiang, Yong-Jun

Trimethylation of histone H3 lysine 9 is important for recruiting heterochromatin protein 1 (HP1) to discrete regions of the genome, thereby regulating gene expression, chromatin packaging, and heterochromatin formation. Phosphorylation of histone H3 has been linked with mitotic chromatin condensation. During mitosis in vivo, H3 lysine 9 methylation and serine 10 phosphorylation can occur concomitantly on the same histone tail, whereas the influence of phosphorylation to trimethylation H3 tail recruiting HP1 remains controversial. In this work, molecular dynamics simulation of HP1 complexed with both trimethylated and phosphorylated H3 tail were performed and compared with the results from the previous methylated H3-HP1 trajectory. It is clear from the 10-ns dynamics simulation that two adjacent posttranslational modifications directly increase the flexibility of the H3 tail and weaken HP1 binding to chromatin. A combinatorial readout of two adjacent posttranslational modifications-a stable methylation and a dynamic phosphorylation mark-establish a regulatory mechanism of protein-protein interactions.

47. OUTLET WORKS: ELECTRICAL SYSTEM NO. 2. Sheet H2, date ...

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

47. OUTLET WORKS: ELECTRICAL SYSTEM NO. 2. Sheet H-2, date stamped May, 1939. File no. SA 342/10. - Prado Dam, Outlet Works, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

46. OUTLET WORKS: ELECTRICAL SYSTEM NO. 1. Sheet H1, date ...

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

46. OUTLET WORKS: ELECTRICAL SYSTEM NO. 1. Sheet H-1, date stamped May, 1939. File no. SA 342/9. - Prado Dam, Outlet Works, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

pH regulation in anoxic rice coleoptiles at pH 3.5: biochemical pHstats and net H+ influx in the absence and presence of NO3−

PubMed Central

Greenway, Hank; Kulichikhin, Konstantin Y.; Cawthray, Gregory R.; Colmer, Timothy D.

2012-01-01

During anoxia, cytoplasmic pH regulation is crucial. Mechanisms of pH regulation were studied in the coleoptile of rice exposed to anoxia and pH 3.5, resulting in H+ influx. Germinating rice seedlings survived a combination of anoxia and exposure to pH 3.5 for at least 4 d, although development was retarded and net K+ efflux was continuous. Further experiments used excised coleoptile tips (7–10 mm) in anoxia at pH 6.5 or 3.5, either without or with 0.2 mM NO3−, which distinguished two processes involved in pH regulation. Net H+ influx (μmol g−1 fresh weight h−1) for coleoptiles with NO3− was ∼1.55 over the first 24 h, being about twice that in the absence of NO3−, but then decreased to 0.5–0.9 as net NO3− uptake declined from ∼1.3 to 0.5, indicating reduced uptake via H+–NO3− symports. NO3− reduction presumably functioned as a biochemical pHstat. A second biochemical pHstat consisted of malate and succinate, and their concentrations decreased substantially with time after exposure to pH 3.5. In anoxic coleoptiles, K+ balancing the organic anions was effluxed to the medium as organic anions declined, and this efflux rate was independent of NO3− supply. Thus, biochemical pHstats and reduced net H+ influx across the plasma membrane are important features contributing to pH regulation in anoxia-tolerant rice coleoptiles at pH 3.5. PMID:22174442

Metallization of aluminum hydride AlH3 at high multiple-shock pressures

NASA Astrophysics Data System (ADS)

Molodets, A. M.; Shakhray, D. V.; Khrapak, A. G.; Fortov, V. E.

2009-05-01

A study of electrophysical and thermodynamic properties of alane AlH3 under multishock compression has been carried out. The increase in specific electroconductivity of alane at shock compression up to pressure 100 GPa has been measured. High pressures and temperatures were obtained with an explosive device, which accelerates the stainless impactor up to 3 km/s. A strong shock wave is generated on impact with a holder containing alane. The impact shock is split into a shock wave reverberating in alane between two stiff metal anvils. This compression loads the alane sample by a multishock manner up to pressure 80-90 GPa, heats alane to the temperature of about 1500-2000 K, and lasts 1μs . The conductivity of shocked alane increases in the range up to 60-75 GPa and is about 30(Ωcm)-1 . In this region the semiconductor regime is true for shocked alane. The conductivity of alane achieves approximately 500(Ωcm)-1 at 80-90 GPa. In this region, conductivity is interpreted in frames of the conception of the “dielectric catastrophe,” taking into consideration significant differences between the electronic states of isolated molecule AlH3 and condensed alane.

Synthetic, Infrared, 1H and 13C NMR Spectral Studies on N-(2-/3-Substituted Phenyl)-4-Substituted Benzenesulphonamides, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br, and X = CH3 or Cl

NASA Astrophysics Data System (ADS)

Gowda, B. Thimme; Shetty, Mahesha; Jayalakshmi, K. L.

2005-02-01

Twenty three N-(2-/3-substituted phenyl)-4-substituted benzenesulphonamides of the general formula, 4-X'C6H4SO2NH(2-/3-XC6H4), where X' = H, CH3, C2H5, F, Cl or Br and X = CH3 or Cl have been prepared and characterized, and their infrared spectra in the solid state, 1H and 13C NMR spectra in solution were studied. The N-H stretching vibrations, νN-H, absorb in the range 3285 - 3199 cm-1, while the asymmetric and symmetric SO2 vibrations vary in the ranges 1376 - 1309 cm-1 and 1177 - 1148 cm-1, respectively. The S-N and C-N stretching vibrations absorb in the ranges 945 - 893 cm-1 and 1304 - 1168 cm-1, respectively. The compounds do not exhibit particular trends in the variation of these frequencies on substitution either at ortho or meta positions with either a methyl group or Cl. The observed 1H and 13C chemical shifts of are assigned to protons and carbons of the two benzene rings. Incremental shifts of the ring protons and carbons due to -SO2NH(2-/3-XC6H4) groups in C6H5SO2NH(2-/3-XC6H4), and 4- X'C6H4SO2- and 4-X'C6H4SO2NH- groups in 4-X'C6H4SO2NH(C6H5) are computed and employed to calculate the chemical shifts of the ring protons and carbons in the substituted compounds, 4-X'C6H4SO2NH(2-/3-XC6H4). The computed values agree well with the observed chemical shifts.

Molecular turnover, the H3.3 dilemma and organismal aging (hypothesis).

PubMed

Saade, Evelyne; Pirozhkova, Iryna; Aimbetov, Rakhan; Lipinski, Marc; Ogryzko, Vasily

2015-06-01

The H3.3 histone variant has been a subject of increasing interest in the field of chromatin studies due to its two distinguishing features. First, its incorporation into chromatin is replication independent unlike the replication-coupled deposition of its canonical counterparts H3.1/2. Second, H3.3 has been consistently associated with an active state of chromatin. In accordance, this histone variant should be expected to be causally involved in the regulation of gene expression, or more generally, its incorporation should have downstream consequences for the structure and function of chromatin. This, however, leads to an apparent paradox: In cells that slowly replicate in the organism, H3.3 will accumulate with time, opening the way to aberrant effects on heterochromatin. Here, we review the indications that H3.3 is expected both to be incorporated in the heterochromatin of slowly replicating cells and to retain its functional downstream effects. Implications for organismal aging are discussed. © 2015 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Two new three-dimensional zinc phosphites templated by piperazine: [H2pip][Zn3(HPO3)4(H2O)2] and K[H2pip]0.5[Zn3(HPO3)4

NASA Astrophysics Data System (ADS)

Zhang, Xiao; Wang, Guo-Ming; Wang, Zong-Hua; Wang, Ying-Xia; Lin, Jian-Hua

2014-01-01

Two three-dimensional open-framework zinc phosphites with the same organically templated, [H2pip][Zn3(HPO3)4(H2O)2] (1) and K[H2pip]0.5[Zn3(HPO3)4] (2) (pip = piperazine), have been solvothermally synthesized and structurally characterized by IR, elemental analysis, thermogravimetric analysis, powder and single-crystal X-ray diffractions. Compound 1 consists of ZnO4 tetrahedra, [HPO3] pseudopyramids and [ZnO4(H2O)2] octahedra, which are linked through their vertexes to generate three-dimensional architecture with intersecting 8-membered channels along the [1 0 0], [0 0 1] and [1 0 1] directions. Compound 2 is constructed from strictly alternating ZnO4 tetrahedra and [HPO3] pseudopyramids, and exhibits (3,4)-connected inorganic framework with 8-, and 12-membered channels, in which the K+ and diprotonated H2pip2+ extra-framework cations reside, respectively. The coexistence of inorganic K+ and organic piperazine mixed templates in the structure is unique and, to the best of our knowledge, firstly observed in metal-phosphite materials. In addition, the participation of left-handed and right-handed helical chains in construction of the puckered 4.82 sheet structure in 2 is also noteworthy.

Assembling in Sequence: A Saleable Work Skill. Occupation Simulation Packet. Grades 3rd-4th.

ERIC Educational Resources Information Center

Hueston, Jean

This teacher's guide for grades 3 and 4 contains simulated work experiences for students using the isolated skill concept - assembling in sequence. Teacher instructions include objectives, evaluation, and sequence of activities. The guide contains pre-tests and post-tests with instructions and answer keys. Three pre-skill activities are suggested,…

Evidence that the atypical 5-HT3 receptor ligand, [3H]-BRL46470, labels additional 5-HT3 binding sites compared to [3H]-granisetron.

PubMed Central

Steward, L. J.; Ge, J.; Bentley, K. R.; Barber, P. C.; Hope, A. G.; Lambert, J. J.; Peters, J. A.; Blackburn, T. P.; Barnes, N. M.

1995-01-01

1. The radioligand binding characteristics of the 3H-derivative of the novel 5-HT3 receptor antagonist BRL46470 were investigated and directly compared to the well characterized 5-HT3 receptor radioligand [3H]-granisetron, in tissue homogenates prepared from rat cerebral cortex/hippocampus, rat ileum, NG108-15 cells, HEK-5-HT3As cells and human putamen. 2. In rat cerebral cortex/hippocampus, rat ileum, NG108-15 cell and HEK-5-HT3As cell homogenates, [3H]-BRL46470 bound with high affinity (Kd (nM): 1.57 +/- 0.18, 2.49 +/- 0.30, 1.84 +/- 0.27, 3.46 +/- 0.36, respectively; mean +/- s.e. mean, n = 3-4) to an apparently homogeneous saturable population of sites (Bmax (fmol mg-1 protein): 102 +/- 16, 44 +/- 4, 968 +/- 32 and 2055 +/- 105, respectively; mean +/- s.e. mean, n = 3-4) but failed to display specific binding in human putamen homogenates. 3. In the same homogenates of rat cerebral cortex/hippocampus, rat ileum, NG108-15 cells, HEK-5-HT3As cells and human putamen as used for the [3H]-BRL46470 studies, [3H]-granisetron also bound with high affinity (Kd (nM): 1.55 +/- 0.61, 2.31 +/- 0.44, 1.89 +/- 0.36, 2.03 +/- 0.42 and 6.46 +/- 2.58 respectively; mean +/- s.e. mean, n = 3-4) to an apparently homogeneous saturable population of sites (Bmax (fmol mg-1 protein): 39 +/- 4, 20 +/- 2, 521 +/- 47, 870 +/- 69 and 18 +/- 2, respectively; mean +/- s.e. mean, n = 3-4).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8528560

Synthesis and Preliminary Cytotoxicity Studies of 1-[1-(4,5-Dihydrooxazol- 2-yl)-1H-indazol-3-yl]-3-phenylurea and 3-phenylthiourea Derivatives.

PubMed

Kornicka, Anita; Saczewski, Franciszek; Bednarski, Patrick J; Korcz, Martyna; Szumlas, Piotr; Romejko, Ewa; Sakowicz, Aneta; Sitek, Lukasz; Wojciechowska, Monika

2017-01-01

N-substituted 3-amino-1H-indazoles represent an interesting class of biologically active compounds. Among them, derivatives containing phenylurea moiety are of particular interest. Such compounds have been found to possess inhibitory activity against cancer cell growth. Additionally, various oxazoline-containing compounds have also been designed as potential anticancer agents. The aim of this work was to obtain a new class of N-substituted 3-amino-1H-indazole derivatives with cytotoxic activity towards cancer cells. Two series of 1-[1-(4,5-dihydrooxazol-2-yl)-1H-indazol-3-yl]-3-phenylurea and 3- phenylthiourea derivatives 7-17 and 18-22, respectively, were prepared and screened for their potential in vitro cytotoxic activities against lung carcinoma LCLC-103H cell line using a crystal violet microtiter plate assay. All the urea derivatives, except the compound 8, were inactive at a concentration of 20 μM attainable in cancer cells, while the thiourea derivatives showed a pronounced cancer cell growth inhibitory effects. The most potent 1-[1-(4,5-dihydrooxazol-2-yl)-1H-indazol-3-yl]-3-ptolylthiourea (19) exhibited cytotoxicity on the lung cancer LCLC-103H and cervical cancer SISO cell lines at a concentration of 10 µM. Moreover, compound 19 displayed cytostatic activity against pancreas cancer DAN-G cell line. The 1-[1-(4,5-dihydrooxazol-2-yl)-1H-indazol-3-yl]-3-phenylthiourea derivatives described herein may serve as a useful scaffold for the search for novel anticancer agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

High current H2(+) and H3(+) beam generation by pulsed 2.45 GHz electron cyclotron resonance ion source.

PubMed

Xu, Yuan; Peng, Shixiang; Ren, Haitao; Zhao, Jie; Chen, Jia; Zhang, Ailin; Zhang, Tao; Guo, Zhiyu; Chen, Jia'er

2014-02-01

The permanent magnet 2.45 GHz electron cyclotron resonance ion source at Peking University can produce more than 100 mA hydrogen ion beam working at pulsed mode. For the increasing requirements of cluster ions (H2(+) and H3(+)) in linac and cyclotron, experimental study was carried out to further understand the hydrogen plasma processes in the ion source for the generation of cluster ions. The constituents of extracted beam have been analyzed varying with the pulsed duration from 0.3 ms to 2.0 ms (repetition frequency 100 Hz) at different operation pressure. The fraction of cluster ions dramatically increased when the pulsed duration was lower than 0.6 ms, and more than 20 mA pure H3(+) ions with fraction 43.2% and 40 mA H2(+) ions with fraction 47.7% were obtained when the operation parameters were adequate. The dependence of extracted ion fraction on microwave power was also measured at different pressure as the energy absorbed by plasma will greatly influence electron temperature and electron density then the plasma processes in the ion source. More details will be presented in this paper.

3-Arylpiperazinylethyl-1H-pyrrolo[2,3-d]pyrimidine-2,4(3H,7H)-dione derivatives as novel, high-affinity and selective alpha(1)-adrenoceptor ligands.

PubMed

Pittalà, Valeria; Romeo, Giuseppe; Salerno, Loredana; Siracusa, Maria Angela; Modica, Maria; Materia, Luisa; Mereghetti, Ilario; Cagnotto, Alfredo; Mennini, Tiziana; Marucci, Gabriella; Angeli, Piero; Russo, Filippo

2006-01-01

The discovery of a new series of selective and high-affinity alpha(1)-adrenoceptor (alpha(1)-AR) ligands, characterized by a 1H-pyrrolo[2,3-d]-pyrimidine-2,4(3H,7H)-dione system, is described in this paper. Some synthesized compounds, including 20, 22, and 30, displayed affinity in the nanomolar range for alpha(1)-ARs and substantial selectivity with respect to 5-HT(1A) and dopaminergic D(1) and D(2) receptors. Functional assays, performed on selected derivatives, showed antagonistic properties.

Synthesis of 3,5-Isoxazolidinediones and 1H-2,3-Benzoxazine-1,4(3H)-diones from Aliphatic Oximes and Dicarboxylic Acid Chlorides

PubMed Central

2015-01-01

The synthesis of the title compounds was carried out by reacting dicarboxylic acid chlorides with oximes in the presence of excess triethylamine. Disubstituted malonyl chlorides gave 2-alkenyl-4,4-dialkyl-3,5-isoxazolidinediones (8a–f) and 2,2′-ethylidene-bis[4,4-dialkyl-3,5-isoxazolidinedione]s (9a–f). Compounds 9 were formed from 8 and its N-unsubstituted 3,5-isoxazolidinedione decomposition product. Phthaloyl chlorides reacted with acetone oxime to yield 3-(1-methylethenyl)-1H-2,3-benzoxazine-1,4(3H)-diones (16a–e). Products 16 spontaneously decomposed to give N-unsubstituted 1H-2,3-benzoxazine-1,4(3H)-diones (17a–e) at rates that were dependent on temperature and solvent. Kinetic studies showed that two of the compounds decomposed by zero-order kinetics under neutral conditions. Butanedioyl chloride did not produce a cyclic product. PMID:24620711

Synthesis of 3,5-isoxazolidinediones and 1H-2,3-benzoxazine-1,4(3H)-diones from aliphatic oximes and dicarboxylic acid chlorides.

PubMed

Izydore, Robert A; Jones, Joseph T; Mogesa, Benjamin; Swain, Ira N; Davis-Ward, Ronda G; Daniels, Dwayne L; Kpakima, Felicia Frazier; Spaulding-Phifer, Sharnelle T

2014-04-04

The synthesis of the title compounds was carried out by reacting dicarboxylic acid chlorides with oximes in the presence of excess triethylamine. Disubstituted malonyl chlorides gave 2-alkenyl-4,4-dialkyl-3,5-isoxazolidinediones (8a-f) and 2,2'-ethylidene-bis[4,4-dialkyl-3,5-isoxazolidinedione]s (9a-f). Compounds 9 were formed from 8 and its N-unsubstituted 3,5-isoxazolidinedione decomposition product. Phthaloyl chlorides reacted with acetone oxime to yield 3-(1-methylethenyl)-1H-2,3-benzoxazine-1,4(3H)-diones (16a-e). Products 16 spontaneously decomposed to give N-unsubstituted 1H-2,3-benzoxazine-1,4(3H)-diones (17a-e) at rates that were dependent on temperature and solvent. Kinetic studies showed that two of the compounds decomposed by zero-order kinetics under neutral conditions. Butanedioyl chloride did not produce a cyclic product.

Molecular Epidemiology of Influenza A/H3N2 Viruses Circulating in Mexico from 2003 to 2012

PubMed Central

Escalera-Zamudio, Marina; Nelson, Martha I.; Cobián Güemes, Ana Georgina; López-Martínez, Irma; Cruz-Ortiz, Natividad; Iguala-Vidales, Miguel; García, Elvia Rodríguez; Barrera-Badillo, Gisela; Díaz-Quiñonez, Jose Alberto; López, Susana; Arias, Carlos F.; Isa, Pavel

2014-01-01

In this work, nineteen influenza A/H3N2 viruses isolated in Mexico between 2003 and 2012 were studied. Our findings show that different human A/H3N2 viral lineages co-circulate within a same season and can also persist locally in between different influenza seasons, increasing the chance for genetic reassortment events. A novel minor cluster was also identified, named here as Korea, that circulated worldwide during 2003. Frequently, phylogenetic characterization did not correlate with the determined antigenic identity, supporting the need for the use of molecular evolutionary tools additionally to antigenic data for the surveillance and characterization of viral diversity during each flu season. This work represents the first long-term molecular epidemiology study of influenza A/H3N2 viruses in Mexico based on the complete genomic sequences and contributes to the monitoring of evolutionary trends of A/H3N2 influenza viruses within North and Central America. PMID:25075517

Arabidopsis kinetochore null2 is an upstream component for centromeric histone H3 variant cenH3 deposition at centromeres.

PubMed

Lermontova, Inna; Kuhlmann, Markus; Friedel, Swetlana; Rutten, Twan; Heckmann, Stefan; Sandmann, Michael; Demidov, Dmitri; Schubert, Veit; Schubert, Ingo

2013-09-01

The centromeric histone H3 variant cenH3 is an essential centromeric protein required for assembly, maintenance, and proper function of kinetochores during mitosis and meiosis. We identified a kinetochore null2 (KNL2) homolog in Arabidopsis thaliana and uncovered features of its role in cenH3 loading at centromeres. We show that Arabidopsis KNL2 colocalizes with cenH3 and is associated with centromeres during all stages of the mitotic cell cycle, except from metaphase to mid-anaphase. KNL2 is regulated by the proteasome degradation pathway. The KNL2 promoter is mainly active in meristematic tissues, similar to the cenH3 promoter. A knockout mutant for KNL2 shows a reduced level of cenH3 expression and reduced amount of cenH3 protein at chromocenters of meristematic nuclei, anaphase bridges during mitosis, micronuclei in pollen tetrads, and 30% seed abortion. Moreover, knl2 mutant plants display reduced expression of suppressor of variegation 3-9 homologs2, 4, and 9 and reduced DNA methylation, suggesting an impact of KNL2 on the epigenetic environment for centromere maintenance.

Expansion of antimonato polyoxovanadates with transition metal complexes: (Co(N3C5H15)2)2[{Co(N3C5H15)2}V15Sb6O42(H2O)]·5H2O and (Ni(N3C5H15)2)2[{Ni(N3C5H15)2}V15Sb6O42(H2O)]·8H2O.

PubMed

Antonova, Elena; Näther, Christian; Kögerler, Paul; Bensch, Wolfgang

2012-02-20

Two new polyoxovanadates (Co(N(3)C(5)H(15))(2))(2)[{Co(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·5H(2)O (1) and (Ni(N(3)C(5)H(15))(2))(2)[{Ni(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)]·8H(2)O (2) (N(3)C(5)H(15) = N-(2-aminoethyl)-1,3-propanediamine) were synthesized under solvothermal conditions and structurally characterized. In both structures the [V(15)Sb(6)O(42)(H(2)O)](6-) shell displays the main structural motif, which is strongly related to the {V(18)O(42)} archetype cluster. Both compounds crystallize in the triclinic space group P1 with a = 14.3438(4), b = 16.6471(6), c = 18.9186(6) Å, α = 87.291(3)°, β = 83.340(3)°, γ = 78.890(3)°, and V = 4401.4(2) Å(3) (1) and a = 14.5697(13), b = 15.8523(16), c = 20.2411(18) Å, α = 86.702(11)°, β = 84.957(11)°, γ = 76.941(11)°, and V = 4533.0(7) Å(3) (2). In the structure of 1 the [V(15)Sb(6)O(42)(H(2)O)](6-) cluster anion is bound to a [Co(N(3)C(5)H(15))(2)](2+) complex via a terminal oxygen atom. In the Co(2+)-centered complex, one of the amine ligands coordinates in tridentate mode and the second one in bidentate mode to form a strongly distorted CoN(5)O octahedron. Similarly, in compound 2 an analogous NiN(5)O complex is joined to the [V(15)Sb(6)O(42)(H(2)O)](6-) anion via the same attachment mode. A remarkable difference between the two compounds is the orientation of the noncoordinated propylamine group leading to intermolecular Sb···O contacts in 1 and to Sb···N interactions in 2. In the solid-state lattices of 1 and 2, two additional [M(N(3)C(5)H(15))(2)](2+) complexes act as countercations and are located between the [{M(N(3)C(5)H(15))(2)}V(15)Sb(6)O(42)(H(2)O)](4-) anions. Between the anions and cations strong N-H···O hydrogen bonds are observed. In both compounds the clusters are stacked along the b axis in an ABAB fashion with cations and water molecules occupying the space between the clusters. Magnetic characterization demonstrates that the Ni(2+) and Co(2+) cations do not

The C-H Stretching Features at 3.2--3.5 μm of Polycyclic Aromatic Hydrocarbons with Aliphatic Sidegroups

NASA Astrophysics Data System (ADS)

Yang, X. J.; Li, Aigen; Glaser, R.; Zhong, J. X.

2016-07-01

The so-called “unidentified” infrared emission (UIE) features at 3.3, 6.2, 7.7, 8.6, and 11.3 μm are ubiquitously seen in a wide variety of astrophysical regions. The UIE features are characteristic of the stretching and bending vibrations of aromatic hydrocarbon materials, e.g., polycyclic aromatic hydrocarbon (PAH) molecules. The 3.3 μm aromatic C-H stretching feature is often accompanied by a weaker feature at 3.4 μm. The latter is generally thought to result from the C-H stretch of aliphatic groups attached to the aromatic systems. The ratio of the observed intensity of the 3.3 μm aromatic C-H feature to that of the 3.4 μm aliphatic C-H feature allows one to estimate the aliphatic fraction of the UIE carriers, provided that the intrinsic oscillator strengths of the 3.3 μm aromatic C-H stretch ({A}3.3) and the 3.4 μm aliphatic C-H stretch ({A}3.4) are known. While previous studies on the aliphatic fraction of the UIE carriers were mostly based on the {A}3.4/{A}3.3 ratios derived from the mono-methyl derivatives of small PAH molecules, in this work we employ density functional theory to compute the infrared vibrational spectra of PAH molecules with a wide range of sidegroups including ethyl, propyl, butyl, and several unsaturated alkyl chains, as well as all the isomers of dimethyl-substituted pyrene. We find that, except for PAHs with unsaturated alkyl chains, the corresponding {A}3.4/{A}3.3 ratios are close to that of mono-methyl PAHs. This confirms the predominantly aromatic nature of the UIE carriers previously inferred from the {A}3.4/{A}3.3 ratio derived from mono-methyl PAHs.

Nanoparticle Nucleation Is Termolecular in Metal and Involves Hydrogen: Evidence for a Kinetically Effective Nucleus of Three {Ir3H2x·P2W15Nb3O62}6- in Ir(0)n Nanoparticle Formation From [(1,5-COD)IrI·P2W15Nb3O62]8- Plus Dihydrogen.

PubMed

Özkar, Saim; Finke, Richard G

2017-04-19

The nucleation process yielding Ir(0) ∼300 nanoparticles from (Bu 4 N) 5 Na 3 [(1,5-COD)Ir·P 2 W 15 Nb 3 O 62 ] (abbreviated hereafter as (COD)Ir·POM 8- , where POM 9- = the polyoxometalate, P 2 W 15 Nb 3 O 62 9- ) under H 2 is investigated to learn the true molecularity, and hence the associated kinetically effective nucleus (KEN), for nanoparticle formation for the first time. Recent work with this prototype transition-metal nanoparticle formation system ( J. Am. Chem. Soc. 2014 , 136 , 17601 - 17615 ) revealed that nucleation in this system is an apparent second-order in the precatalyst, A = (COD)Ir·POM 8- , not the higher order implied by classic nucleation theory and its nA ⇌ A n , "critical nucleus", A n concept. Herein, the three most reasonable more intimate mechanisms of nucleation are tested: bimolecular nucleation, termolecular nucleation, and a mechanism termed "alternative termolecular nucleation" in which 2(COD)Ir + and 1(COD)Ir·POM 8- yield the transition state of the rate-determining step of nucleation. The results obtained definitively rule out a simple bimolecular nucleation mechanism and provide evidence for the alternative termolecular mechanism with a KEN of 3, Ir 3 . All higher molecularity nucleation mechanisms were also ruled out. Further insights into the KEN and its more detailed composition involving hydrogen, {Ir 3 H 2x POM} 6- , are also obtained from the established role of H 2 in the Ir(0) ∼300 formation balanced reaction stoichiometry, from the p(H 2 ) dependence of the kinetics, and from a D 2 /H 2 kinetic isotope effect of 1.2(±0.3). Eight insights and conclusions are presented. A section covering caveats in the current work, and thus needed future studies, is also included.

On the Automation of the MarkIII Data Analysis System.

NASA Astrophysics Data System (ADS)

Schwegmann, W.; Schuh, H.

1999-03-01

A faster and semiautomatic data analysis is an important contribution to the acceleration of the VLBI procedure. A concept for the automation of one of the most widely used VLBI software packages the MarkIII Data Analysis System was developed. Then, the program PWXCB, which extracts weather and cable calibration data from the station log-files, was automated supplementing the existing Fortran77 program-code. The new program XLOG and its results will be presented. Most of the tasks in the VLBI data analysis are very complex and their automation requires typical knowledge-based techniques. Thus, a knowledge-based system (KBS) for support and guidance of the analyst is being developed using the AI-workbench BABYLON, which is based on methods of artificial intelligence (AI). The advantages of a KBS for the MarkIII Data Analysis System and the required steps to build a KBS will be demonstrated. Examples about the current status of the project will be given, too.

Novel 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole derivatives: a patent review (2008 - 2011).

PubMed

Ferreira, Vitor F; da Rocha, David R; da Silva, Fernando C; Ferreira, Patrícia G; Boechat, Núbia A; Magalhães, Jorge L

2013-03-01

The triazoles represent a class of five-membered heterocyclic compounds of great importance for the preparation of new drugs with diverse biological activities because they may present several structural variations with the same numbers of carbon and nitrogen atoms. Due to the success of various triazoles that entered the pharmaceutical market and are still being used in medicines, many companies and research groups have shown interest in developing new methods of synthesis and biological evaluation of potential uses for these compounds. In this review, the authors explored aspects of patents for the 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole families, including prototypes being considered in clinical studies between 2008 and 2011. The triazoles have been studied for over a century as an important class of heterocyclic compounds and still attract considerable attention due to their broad range of biological activities. More recently, there has been considerable interest in the development of novel triazoles with anti-inflammatory, antiplatelet, antimicrobial, antimycobacterial, antitumoral and antiviral properties and activity against several neglected diseases. This review emphasizes recent perspective and advances in the therapeutically active 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole derivative patents between 2008 and 2011, covering the development of new chemical entities and new pharmaceuticals. Many studies have focused on these compounds as target structures and evaluated them in several biological targets. The preparation of 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole derivatives brings to light several issues. There is a need to find new, more efficient preparations for these triazoles that take into consideration current issues in green chemistry, energy saving and sustainability. New diseases are discovered and new viruses and bacteria continue to challenge mankind, so it is imperative to find new prototypes for these

Energy and Spectroscopic Characterization of the Isomers of C4H3-, C6H3-, and C6H5-

NASA Technical Reports Server (NTRS)

Wright, Danielle; Bera, Partha P.; Lee, Timothy J.

2015-01-01

Organic and inorganic molecules, neutral and ions have been observed in the interstellar medium. A few anions of organic molecules have also been observed recently. The Cassini spacecraft in the upper atmosphere of Titan has observed anions of large organic molecules. In this project we have studied the physical and spectroscopic properties of C4H3-, C6H3-, and C6H5-. We have optimized the geometrical structures of all low-lying isomers of the anions, calculated rotational, and harmonic vibrational frequencies of the anions mentioned above using the B3LYP density functional along with the augmented correlation consistent polar valence triple zeta (aug-cc-pVTZ) basis set. We have found many low-lying isomers on the potential energy surface of these anions.

Fission yeast translation initiation factor 3 subunit eIF3h is not essential for global translation initiation, but deletion of eif3h+ affects spore formation.

PubMed

Ray, Anirban; Bandyopadhyay, Amitabha; Matsumoto, Tomohiro; Deng, Haiteng; Maitra, Umadas

2008-11-01

The fission yeast Schizosaccharomyces pombe homologue of the p40/eIF3h subunit of mammalian translation initiation factor eIF3 has been characterized in this study. We show that this protein physically associates with the 40S ribosomal particles as a constituent of the multimeric eIF3 protein complex, which consists of all five known eIF3 core subunits (eIF3a, eIF3b, eIF3c, eIF3g and eIF3i) as well as the five non-core subunits (eIF3d, eIF3e, eIF3f, eIF3h and eIF3m) that constitute an eIF3 holocomplex in fission yeast. However, affinity purification of eIF3 from fission yeast cells expressing TAP-tagged eIF3h suggests the presence of distinct forms of eIF3 that differ in their composition of the non-core subunits. Further characterization of eIF3h shows that strains lacking eif3h(+) (eif3hDelta) are viable and show no gross defects, either in vegetative growth or in the rate of in vivo protein synthesis. Polysome profile analysis shows no apparent defects in translation initiation. Furthermore, deletion of eif3h(+) does not affect the ability of the other eIF3 subunits to remain associated with one another in a tight protein complex similar to the situation in wild-type cells. Additionally, we show that human eIF3h can functionally substitute fission yeast eIF3h in complementing in vivo a genetic deletion of eif3h(+). Interestingly, mutant eif3hDelta cells show several prominent phenotypic properties. They are hypersensitive to caffeine and highly defective in meiosis, producing either no spores or incomplete tetrads with a very high frequency. The implications of these results in relation to the functions of eIF3h in Sz. pombe are discussed. (c) 2008 John Wiley & Sons, Ltd.

Proton transfer reactions and dynamics in CH(3)OH-H(3)O(+)-H(2)O complexes.

PubMed

Sagarik, Kritsana; Chaiwongwattana, Sermsiri; Vchirawongkwin, Viwat; Prueksaaroon, Supakit

2010-01-28

Proton transfer reactions and dynamics in hydrated complexes formed from CH(3)OH, H(3)O(+) and H(2)O were studied using theoretical methods. The investigations began with searching for equilibrium structures at low hydration levels using the DFT method, from which active H-bonds in the gas phase and continuum aqueous solution were characterized and analyzed. Based on the asymmetric stretching coordinates (Deltad(DA)), four H-bond complexes were identified as potential transition states, in which the most active unit is represented by an excess proton nearly equally shared between CH(3)OH and H(2)O. These cannot be definitive due to the lack of asymmetric O-H stretching frequencies (nu(OH)) which are spectral signatures of transferring protons. Born-Oppenheimer molecular dynamics (BOMD) simulations revealed that, when the thermal energy fluctuations and dynamics were included in the model calculations, the spectral signatures at nu(OH) approximately 1000 cm(-1) appeared. In continuum aqueous solution, the H-bond complex with incomplete water coordination at charged species turned out to be the only active transition state. Based on the assumption that the thermal energy fluctuations and dynamics could temporarily break the H-bonds linking the transition state complex and water molecules in the second hydration shell, elementary reactions of proton transfer were proposed. The present study showed that, due to the coupling among various vibrational modes, the discussions on proton transfer reactions cannot be made based solely on static proton transfer potentials. Inclusion of thermal energy fluctuations and dynamics in the model calculations, as in the case of BOMD simulations, together with systematic IR spectral analyses, have been proved to be the most appropriate theoretical approaches.

Modification of the histone tetramer at the H3-H3 interface impacts tetrasome conformations and dynamics

NASA Astrophysics Data System (ADS)

Ordu, Orkide; Kremser, Leopold; Lusser, Alexandra; Dekker, Nynke H.

2018-03-01

Nucleosomes consisting of a short piece of deoxyribonucleic acid (DNA) wrapped around an octamer of histone proteins form the fundamental unit of chromatin in eukaryotes. Their role in DNA compaction comes with regulatory functions that impact essential genomic processes such as replication, transcription, and repair. The assembly of nucleosomes obeys a precise pathway in which tetramers of histones H3 and H4 bind to the DNA first to form tetrasomes, and two dimers of histones H2A and H2B are subsequently incorporated to complete the complex. As viable intermediates, we previously showed that tetrasomes can spontaneously flip between a left-handed and right-handed conformation of DNA-wrapping. To pinpoint the underlying mechanism, here we investigated the role of the H3-H3 interface for tetramer flexibility in the flipping process at the single-molecule level. Using freely orbiting magnetic tweezers, we studied the assembly and structural dynamics of individual tetrasomes modified at the cysteines close to this interaction interface by iodoacetamide (IA) in real time. While such modification did not affect the structural properties of the tetrasomes, it caused a 3-fold change in their flipping kinetics. The results indicate that the IA-modification enhances the conformational plasticity of tetrasomes. Our findings suggest that subnucleosomal dynamics may be employed by chromatin as an intrinsic and adjustable mechanism to regulate DNA supercoiling.

Sleep and cognitive function of crewmembers and mission controllers working 24-h shifts during a simulated 105-day spaceflight mission

NASA Astrophysics Data System (ADS)

Barger, Laura K.; Wright, Kenneth P.; Burke, Tina M.; Chinoy, Evan D.; Ronda, Joseph M.; Lockley, Steven W.; Czeisler, Charles A.

2014-01-01

The success of long-duration space missions depends on the ability of crewmembers and mission support specialists to be alert and maintain high levels of cognitive function while operating complex, technical equipment. We examined sleep, nocturnal melatonin levels and cognitive function of crewmembers and the sleep and cognitive function of mission controllers who participated in a high-fidelity 105-day simulated spaceflight mission at the Institute of Biomedical Problems (Moscow). Crewmembers were required to perform daily mission duties and work one 24-h extended duration work shift every sixth day. Mission controllers nominally worked 24-h extended duration shifts. Supplemental lighting was provided to crewmembers and mission controllers. Participants' sleep was estimated by wrist-actigraphy recordings. Overall, results show that crewmembers and mission controllers obtained inadequate sleep and exhibited impaired cognitive function, despite countermeasure use, while working extended duration shifts. Crewmembers averaged 7.04±0.92 h (mean±SD) and 6.94±1.08 h (mean±SD) in the two workdays prior to the extended duration shifts, 1.88±0.40 h (mean±SD) during the 24-h work shift, and then slept 10.18±0.96 h (mean±SD) the day after the night shift. Although supplemental light was provided, crewmembers' average nocturnal melatonin levels remained elevated during extended 24-h work shifts. Naps and caffeine use were reported by crewmembers during ˜86% and 45% of extended night work shifts, respectively. Even with reported use of wake-promoting countermeasures, significant impairments in cognitive function were observed. Mission controllers slept 5.63±0.95 h (mean±SD) the night prior to their extended duration work shift. On an average, 89% of night shifts included naps with mission controllers sleeping an average of 3.4±1.0 h (mean±SD) during the 24-h extended duration work shift. Mission controllers also showed impaired cognitive function during extended

A validation of the 3H/3He method for determining groundwater recharge

NASA Astrophysics Data System (ADS)

Solomon, D. K.; Schiff, S. L.; Poreda, R. J.; Clarke, W. B.

1993-09-01

Tritium and He isotopes have been measured at a site where groundwater flow is nearly vertical for a travel time of 100 years and where recharge rates are spatially variable. Because the mid-1960s 3H peak (arising from aboveground testing of thermonuclear devices) is well-defined, the vertical groundwater velocity is known with unusual accuracy at this site. Utilizing 3H and its stable daughter 3He to determine groundwater ages, we compute a recharge rate of 0.16 m/yr, which agrees to within about 5% of the value based on the depth of the 3H peak (measured both in 1986 and 1991) and two-dimensional modeling in an area of high recharge. Zero 3H/3He age occurs at a depth that is approximately equal to the average depth of the annual low water table, even though the capillary fringe extends to land surface during most of the year at the study site. In an area of low recharge (0.05 m/yr) where the 3H peak (and hence the vertical velocity) is also well-defined, the 3H/3He results could not be used to compute recharge because samples were not collected sufficiently far above the 3H peak; however, modeling indicates that the 3H/3He age gradient near the water table is an accurate measure of vertical velocities in the low-recharge area. Because 3H and 3He have different diffusion coefficients, and because the amount of mechanical mixing is different in the area of high recharge than in the low-recharge area, we have separated the dispersive effects of mechanical mixing from molecular diffusion. We estimate a longitudinal dispersivity of 0.07 m and effective diffusion coefficients for 3H (3HHO) and 3He of 2.4×10-5 and 1.3×10-4 m2/day, respectively. Although the 3H/3He age gradient is an excellent indicator of vertical groundwater velocities above the mid-1960s 3H peak, dispersive mixing and diffusive loss of 3He perturb the age gradient near and below the 3H peak.

CFD Growth of 3C-SiC on 4H/6H Mesas

NASA Technical Reports Server (NTRS)

Neudeck, Philip G.; Trunek, Andrew J.; Spry, David J.; Powell, J. Anthony; Du, Hui; Skowronski, Marek; Huang, XianRong; Dudley, Michael

2006-01-01

This article describes growth and characterization of the highest quality reproducible 3C-SiC heteroepitaxial films ever reported. By properly nucleating 3C-SiC growth on top of perfectly on-axis (0001) 4H-SiC mesa surfaces completely free of atomic scale steps and extended defects, growth of 3C-SiC mesa heterofilms completely free of extended crystal defects can be achieved. In contrast, nucleation and growth of 3C-SiC mesa heterofilms on top of 4H-SiC mesas with atomic-scale steps always results in numerous observable dislocations threading through the 3C-SiC epilayer. High-resolution X-ray diffraction and transmission electron microscopy measurements indicate non-trivial in-plane lattice mismatch between the 3C and 4H layers. This mismatch is somewhat relieved in the step-free mesa case via misfit dislocations confined to the 3C/4H interfacial region without dislocations threading into the overlying 3C-SiC layer. These results indicate that the presence or absence of steps at the 3C/4H heteroepitaxial interface critically impacts the quality, defect structure, and relaxation mechanisms of single-crystal heteroepitaxial 3C-SiC films.

Hydrogen Storage Properties of New Hydrogen-Rich BH3NH3-Metal Hydride (TiH2, ZrH2, MgH2, and/or CaH2) Composite Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Young Joon; Xu, Yimin; Shaw, Wendy J.

2012-04-19

Ammonia borane (AB = NH3BH3) is one of the most attractive materials for chemical hydrogen storage due to its high hydrogen contents of 19.6 wt.%, however, impurity levels of borazine, ammonia and diborane in conjunction with foaming and exothermic hydrogen release calls for finding ways to mitigate the decomposition reactions. In this paper we present a solution by mixing AB with metal hydrides (TiH2, ZrH2, MgH2 and CaH2) which have endothermic hydrogen release in order to control the heat release and impurity levels from AB upon decomposition. The composite materials were prepared by mechanical ball milling, and their H2 releasemore » properties were characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The formation of volatile products from decomposition side reactions, such as borazine (N3B3H6) was determined by mass spectrometry (MS). Sieverts type pressure-composition-temperature (PCT) gas-solid reaction instrument was adopted to observe the kinetics of the H2 release reactions of the combined systems and neat AB. In situ 11B MAS-NMR revealed a destabilized decomposition pathway. We found that by adding specific metal hydrides to AB we can eliminate the impurities and mitigate the heat release.« less

Influence on Levels of Information as Presented by Different Technologies on Students' Understanding of Acid, Base, and pH Concepts.

ERIC Educational Resources Information Center

Nakhleh, Mary B.; Krajcik, Joseph S.

1994-01-01

Involves secondary students in a study designed to allow investigation into how different levels of information presented by various technologies (chemical indicators, pH meters, and microcomputer-based laboratories-MBLs) affected students' understanding of acid, base, and pH concepts. Results showed that students using MBLs exhibited a greater…

3D structure of a complex of transform basins from gravity data, a case study from the central Dead Sea fault

NASA Astrophysics Data System (ADS)

Rosenthal, Michal; Schattner, Uri; Ben-Avraham, Zvi

2017-04-01

The Kinneret-Bet She'an (KBS) basin complex comprises the Sea of Galilee, Kinarot, and Bet She'an sub-basins. The complex developed at the intersection between two major tectonic boundaries: the Oligo-Miocene Azraq-Sirhan failed rift, that later developed into the southern Galilee basins and Carmel-Gilboa fault system; and the Dead Sea fault (DSF) plate boundary that developed since the Miocene. Despite numerous studies, KBS still remains one of the enigmatic basin complexes. Its structure, stratigraphy and development are vaguely understood - both inside the basin and in correlation with its surroundings. Our study presents a new and comprehensive 3D model for the structure of KBS complex. It is based on all available gravity measurements, adopted from the national gravity database, and new gravity measurements, collected in cooperation with the Geological Survey of Israel and funded by the Ministry of National Infrastructure, Energy and Water Resources. The gravity data were integrated with constraints from boreholes, surface geology, seismic surveys, potential field studies and teleseismic tomography. The dense distribution of gravity data [1] provides suitable coverage for modeling the deep structure in three dimensions. The model details the spatial distribution, depth, thickness and density of the following regional units within the KBS complex and across its surroundings: upper crust, pre-Senonian sediments, Senonian and Cenozoic sediments, Miocene volcanics, Pliocene and Quaternary volcanics. Additional local units include salt, gabbro and pyroclasts. Results indicate that the KBS complex comprises two sub-basins separated by a structural saddle: Kinneret-Kinarot ( 6-7 km deep, 45 km long) and Bet She'an ( 4 km deep, 10 km long) sub-basin. A 500 m thick layer of Miocene volcanics appears across the Bet She'an sub-basin, yet missing from the Kinneret-Kinarot sub-basin. Between the basins Zemah-1 borehole penetrated a salt unit. The model indicates that this

Investigating the Improvement of Decoding Abilities and Working Memory in Children with Incremental or Entity Personal Conceptions of Intelligence: Two Case Reports

PubMed Central

Alesi, Marianna; Rappo, Gaetano; Pepi, Annamaria

2016-01-01

One of the most significant current discussions has led to the hypothesis that domain-specific training programs alone are not enough to improve reading achievement or working memory abilities. Incremental or Entity personal conceptions of intelligence may be assumed to be an important prognostic factor to overcome domain-specific deficits. Specifically, incremental students tend to be more oriented toward change and autonomy and are able to adopt more efficacious strategies. This study aims at examining the effect of personal conceptions of intelligence to strengthen the efficacy of a multidimensional intervention program in order to improve decoding abilities and working memory. Participants included two children (M age = 10 years) with developmental dyslexia and different conceptions of intelligence. The children were tested on a whole battery of reading and spelling tests commonly used in the assessment of reading disabilities in Italy. Afterwards, they were given a multimedia test to measure motivational factors such as conceptions of intelligence and achievement goals. The children took part in the T.I.R.D. Multimedia Training for the Rehabilitation of Dyslexia (Rappo and Pepi, 2010) reinforced by specific units to improve verbal working memory for 3 months. This training consisted of specific tasks to rehabilitate both visual and phonological strategies (sound blending, word segmentation, alliteration test and rhyme test, letter recognition, digraph recognition, trigraph recognition, and word recognition as samples of visual tasks) and verbal working memory (rapid words and non-words recognition). Posttest evaluations showed that the child holding the incremental theory of intelligence improved more than the child holding a static representation. On the whole this study highlights the importance of treatment programs in which both specificity of deficits and motivational factors are both taken into account. There is a need to plan multifaceted intervention

Synthesis and fundamental properties of stable Ph(3)SnSiH(3) and Ph(3)SnGeH(3) hydrides: model compounds for the design of Si-Ge-Sn photonic alloys.

PubMed

Tice, Jesse B; Chizmeshya, Andrew V G; Groy, Thomas L; Kouvetakis, John

2009-07-06

The compounds Ph(3)SnSiH(3) and Ph(3)SnGeH(3) (Ph = C(6)H(5)) have been synthesized as colorless solids containing Sn-MH(3) (M = Si, Ge) moieties that are stable in air despite the presence of multiple and highly reactive Si-H and Ge-H bonds. These molecules are of interest since they represent potential model compounds for the design of new classes of IR semiconductors in the Si-Ge-Sn system. Their unexpected stability and high solubility also makes them a safe, convenient, and potentially useful delivery source of -SiH(3) and -GeH(3) ligands in molecular synthesis. The structure and composition of both compounds has been determined by chemical analysis and a range of spectroscopic methods including multinuclear NMR. Single crystal X-ray structures were determined and indicated that both compounds condense in a Z = 2 triclinic (P1) space group with lattice parameters (a = 9.7754(4) A, b = 9.8008(4) A, c = 10.4093(5) A, alpha = 73.35(10)(o), beta = 65.39(10)(o), gamma = 73.18(10)(o)) for Ph(3)SnSiH(3) and (a = 9.7927(2) A, b = 9.8005(2) A, c = 10.4224(2) A, alpha = 74.01(3)(o), beta = 65.48(3)(o), gamma = 73.43(3)(o)) for Ph(3)SnGeH(3). First principles density functional theory simulations are used to corroborate the molecular structures of Ph(3)SnSiH(3) and Ph(3)SnGeH(3), gain valuable insight into the relative stability of the two compounds, and provide correlations between the Si-Sn and Ge-Sn bonds in the molecules and those in tetrahedral Si-Ge-Sn solids.

The Bromodomain of Gcn5 Regulates Site Specificity of Lysine Acetylation on Histone H3*

PubMed Central

Cieniewicz, Anne M.; Moreland, Linley; Ringel, Alison E.; Mackintosh, Samuel G.; Raman, Ana; Gilbert, Tonya M.; Wolberger, Cynthia; Tackett, Alan J.; Taverna, Sean D.

2014-01-01

In yeast, the conserved histone acetyltransferase (HAT) Gcn5 associates with Ada2 and Ada3 to form the catalytic module of the ADA and SAGA transcriptional coactivator complexes. Gcn5 also contains an acetyl-lysine binding bromodomain that has been implicated in regulating nucleosomal acetylation in vitro, as well as at gene promoters in cells. However, the contribution of the Gcn5 bromodomain in regulating site specificity of HAT activity remains unclear. Here, we used a combined acid-urea gel and quantitative mass spectrometry approach to compare the HAT activity of wild-type and Gcn5 bromodomain-mutant ADA subcomplexes (Gcn5-Ada2-Ada3). Wild-type ADA subcomplex acetylated H3 lysines with the following specificity; H3K14 > H3K23 > H3K9 ≈ H3K18 > H3K27 > H3K36. However, when the Gcn5 bromodomain was defective in acetyl-lysine binding, the ADA subcomplex demonstrated altered site-specific acetylation on free and nucleosomal H3, with H3K18ac being the most severely diminished. H3K18ac was also severely diminished on H3K14R, but not H3K23R, substrates in wild-type HAT reactions, further suggesting that Gcn5-catalyzed acetylation of H3K14 and bromodomain binding to H3K14ac are important steps preceding H3K18ac. In sum, this work details a previously uncharacterized cross-talk between the Gcn5 bromodomain “reader” function and enzymatic HAT activity that might ultimately affect gene expression. Future studies of how mutations in bromodomains or other histone post-translational modification readers can affect chromatin-templated enzymatic activities will yield unprecedented insight into a potential “histone/epigenetic code.” MS data are available via ProteomeXchange with identifier PXD001167. PMID:25106422

Innatism, Concept Formation, Concept Mastery and Formal Education

ERIC Educational Resources Information Center

Winch, Christopher

2015-01-01

This article will consider the claim that the possession of concepts is innate rather than learned. Innatism about concept learning is explained through consideration of the work of Fodor and Chomsky. First, an account of concept formation is developed. Second the argument against the claim that concepts are learned through the construction of a…

Identification of threshold concepts for biochemistry.

PubMed

Loertscher, Jennifer; Green, David; Lewis, Jennifer E; Lin, Sara; Minderhout, Vicky

2014-01-01

Threshold concepts (TCs) are concepts that, when mastered, represent a transformed understanding of a discipline without which the learner cannot progress. We have undertaken a process involving more than 75 faculty members and 50 undergraduate students to identify a working list of TCs for biochemistry. The process of identifying TCs for biochemistry was modeled on extensive work related to TCs across a range of disciplines and included faculty workshops and student interviews. Using an iterative process, we prioritized five concepts on which to focus future development of instructional materials. Broadly defined, the concepts are steady state, biochemical pathway dynamics and regulation, the physical basis of interactions, thermodynamics of macromolecular structure formation, and free energy. The working list presented here is not intended to be exhaustive, but rather is meant to identify a subset of TCs for biochemistry for which instructional and assessment tools for undergraduate biochemistry will be developed. © 2014 J. Loertscher et al. CBE—Life Sciences Education © 2014 The American Society for Cell Biology. This article is distributed by The American Society for Cell Biology under license from the author(s). It is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

An observational investigation of the identity of B11244 (l-C{sub 3}H{sup +}/C{sub 3}H{sup -})

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGuire, Brett A.; Carroll, P. Brandon; Gratier, Pierre

Pety et al. have reported the detection of eight transitions of a closed-shell, linear molecule (B11244) in observations toward the Horsehead photodissociation region (PDR), which they attribute to the l-C{sub 3}H{sup +} cation. Recent high-level ab initio calculations have called this assignment into question; the anionic C{sub 3}H{sup –} molecule has been suggested as a more likely candidate. Here, we examine observations of the Horsehead PDR, Sgr B2(N), TMC-1, and IRC+10216 in the context of both l-C{sub 3}H{sup +} and C{sub 3}H{sup –}. We find no observational evidence of K{sub a} = 1 lines, which should be present were themore » carrier indeed C{sub 3}H{sup –}. Additionally, we find a strong anticorrelation between the presence of known molecular anions and B11244 in these regions. Finally, we discuss the formation and destruction chemistry of C{sub 3}H{sup –} in the context of the physical conditions in the regions. Based on these results, we conclude there is little evidence to support the claim that the carrier is C{sub 3}H{sup –}.« less

Vibrational spectroscopic analysis of 2-chloro-5-(2,5-dimethoxy-benzylidene)-1,3-diethyl-dihydro-pyrimidine-4,6(1H,5H)-dione

NASA Astrophysics Data System (ADS)

Soliman, H. S.; Eid, Kh. M.; Ali, H. A. M.; Atef, S. M.; El-Mansy, M. A. M.

2012-11-01

In the present work, a combined experimental and computational study for the optimized molecular structural parameters, FT-IR spectra, thermo-chemical parameters, total dipole moment and HOMO-LUMO energy gap for 2-chloro-5-(2,5-dimethoxy-benzylidene)-1,3-diethyl-dihydro-pyrimidine-4,6(1H,5H)-dione have been investigated using B3LYP/6-311G basis set. Our calculated results have showed that the investigated compound possesses a dipole moment of 4.9 Debye and HOMO-LUMO energy gap of 3 eV which indicate high recommendations for photovoltaic devices fabrication.

Unified Technical Concepts. Module 3: Rate.

ERIC Educational Resources Information Center

Technical Education Research Center, Waco, TX.

This concept module on rate is one of thirteen modules that provide a flexible, laboratory-based physics instructional package designed to meet the specialized needs of students in two-year, postsecondary technical schools. Each of the thirteen concept modules discusses a single physics concept and how it is applied to each energy system. This…

Human factors evaluation of level 2 and level 3 automated driving concepts : concepts of operation.

DOT National Transportation Integrated Search

2014-07-01

The Concepts of Operation document evaluates the functional framework of operations for Level 2 and Level 3 automated vehicle systems. This is done by defining the varying levels of automation, the operator vehicle interactions, and system components...

A high-yield, enzymatic synthesis of GDP-D-[3H]arabinose and GDP-L-[3H]fucose.

PubMed

Mengeling, B J; Turco, S J

1999-02-01

For assays involving glycosyltransferases or transporters, several GDP-sugars are either commercially unavailable or expensive. We describe an enzymatic synthesis of GDP-d-[3H]arabinosep and GDP-l-[3H]fucose that yields 66-95% nucleotide-sugar from the appropriate radiolabeled sugar in less than 30 min. The coupled reaction requires Mg2+, ATP, and GTP along with the appropriate radioactive monosaccharide, sugar-1-kinase, and pyrophosphorylase. The latter two activities are present in a cytosolic fraction of Crithidia fasciculata, which is easily grown at room temperature in simple culture medium without serum or added CO2. Addition of commercial yeast inorganic pyrophosphatase shifts the equilibrium of the pyrophosphorylase reaction toward nucleotide-sugar formation. To verify that these nucleotide-sugars are biologically active, we tested their ability to serve as substrates for glycosyltransferases. GDP-l-[3H]fucose functions as the donor substrate for recombinant human fucosyltransferase V, and GDP-d-[3H]arabinosep serves as the donor substrate for the arabinosyltransferase activities present in Leishmania major microsomes. Copyright 1999 Academic Press.

Synthesis and conformation analysis of 3-substituted derivatives of 1H,3H-pyrido[2,3-d] pyrimidin-4-one of expected depressive nervous system. Part III.

PubMed

Chodkowski, Andrzej; Herold, Franciszek; Kleps, Jerzy

2004-01-01

Four series of new 1-aryl (heteroaryl) piperazinylacetyl derivatives of 1H,3H-pyrido[2,3-d] pyrimidin-4-one VIIa-o were synthesised. Substrates for the synthesis of VIa-d were obtained from the respective 3H-pyrido[2.3-d]pyrimidines IVa-d in the reaction with NaBH4. Compounds VIa-d were prepared by chloroacetylation. The obtained 1-chloroacetyl derivatives in the reaction with respective aryl (heteroaryl) piperazine formed 1-aminoacetyl derivatives of 2-phenyl-1 H.3H-pyrido[2.3-d]pyrimidin-4-one compounds VII1a-n. The structure ol compounds was analysed by 1H, 13C NMR spectroscopy.

Epigenetic regulation of facultative heterochromatinisation in Planococcus citri via the Me(3)K9H3-HP1-Me(3)K20H4 pathway.

PubMed

Bongiorni, Silvia; Pasqualini, Barbara; Taranta, Monia; Singh, Prim B; Prantera, Giorgio

2007-03-15

Using RNA interference (RNAi) we have conducted a functional analysis of the HP1-like chromobox gene pchet2 during embryogenesis of the mealybug Planococcus citri. Knocking down pchet2 expression results in decondensation of the male-specific chromocenter that normally arises from the developmentally-regulated facultative heterochromatinisation of the paternal chromosome complement. Together with the disappearance of the chromocenter the staining levels of two associated histone modifications, tri-methylated lysine 9 of histone H3 [Me(3)K9H3] and tri-methylated lysine 20 of histone H4 [Me(3)K20H4], are reduced to undetectable levels. Embryos treated with double-stranded RNA (dsRNA) targeting pchet2 also exhibit chromosome abnormalities, such as aberrant chromosome condensation, and also the presence of metaphases that contain 'lagging' chromosomes. We conclude that PCHET2 regulates chromosome behavior during metaphase and is a crucial component of a Me(3)K9H3-HP1-Me(3)K20H4 pathway involved in the facultative heterochromatinisation of the (imprinted) paternal chromosome set.

Crew coordination concepts: Continental Airlines CRM training

NASA Technical Reports Server (NTRS)

Christian, Darryl; Morgan, Alice

1987-01-01

The outline of the crew coordination concepts at Continental airlines is: (1) Present relevant theory: Contained in a pre-work package and in lecture/discussion form during the work course, (2) Discuss case examples: Contained in the pre-work for study and use during the course; and (3) Simulate practice problems: Introduced during the course as the beginning of an ongoing process. These concepts which are designed to address the problem pilots have in understanding the interaction between situations and their own theories of practice are briefly discussed.

Structure-based nuclear import mechanism of histones H3 and H4 mediated by Kap123

DOE Office of Scientific and Technical Information (OSTI.GOV)

An, Sojin; Yoon, Jungmin; Kim, Hanseong

Kap123, a major karyopherin protein of budding yeast, recognizes the nuclear localization signals (NLSs) of cytoplasmic histones H3 and H4 and translocates them into the nucleus during DNA replication. Mechanistic questions include H3- and H4-NLS redundancy toward Kap123 and the role of the conserved diacetylation of cytoplasmic H4 (K5ac and K12ac) in Kap123-mediated histone nuclear translocation. Here, we report crystal structures of full-length Kluyveromyces lactis Kap123 alone and in complex with H3- and H4-NLSs. Structures reveal the unique feature of Kap123 that possesses two discrete lysine-binding pockets for NLS recognition. Structural comparison illustrates that H3- and H4-NLSs share at leastmore » one of two lysine-binding pockets, suggesting that H3- and H4-NLSs are mutually exclusive. Additionally, acetylation of key lysine residues at NLS, particularly H4-NLS diacetylation, weakens the interaction with Kap123. These data support that cytoplasmic histone H4 diacetylation weakens the Kap123-H4-NLS interaction thereby facilitating histone Kap123-H3-dependent H3:H4/Asf1 complex nuclear translocation.« less

Influence of the Organic Species and Oxoanion in the Synthesis of two Uranyl Sulfate Hydrates, (H 3 O) 2 [(UO 2 ) 2 (SO 4 ) 3 ­(H 2 O)]·7H 2 O and (H 3 O) 2 [(UO 2 ) 2 (SO 4 ) 3 (H 2 O)]·4H 2 O, and a Uranyl Selenate-Selenite [C 5 H 6 N][(UO 2 )(SeO 4 )(HSeO 3 )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jouffret, Laurent J.; Wylie, Ernest M.; Burns, Peter C.

2012-08-08

Two uranyl sulfate hydrates, (H3O)2[(UO2)2(SO4)3(H2O)]·7H2O (NDUS) and (H3O)2[(UO2)2(SO4)3(H2O)]·4H2O (NDUS1), and one uranyl selenate-selenite [C5H6N][(UO2)(SeO4)(HSeO3)] (NDUSe), were obtained and their crystal structures solved. NDUS and NDUSe result from reactions in highly acidic media in the presence of L-cystine at 373 K. NDUS crystallized in a closed vial at 278 K after 5 days and NDUSe in an open beaker at 278 K after 2 weeks. NDUS1 was synthesized from aqueous solution at room temperature over the course of a month. NDUS, NDUS1, and NDUSe crystallize in the monoclinic space group P21/n, a = 15.0249(4) Å,b = 9.9320(2) Å, c = 15.6518(4)more » Å, β = 112.778(1)°, V = 2153.52(9) Å3,Z = 4, the tetragonal space group P43212, a = 10.6111(2) Å,c = 31.644(1) Å, V = 3563.0(2) Å3, Z = 8, and in the monoclinic space group P21/n, a = 8.993(3) Å, b = 13.399(5) Å, c = 10.640(4) Å,β = 108.230(4)°, V = 1217.7(8) Å3, Z = 4, respectively.The structural units of NDUS and NDUS1 are two-dimensional uranyl sulfate sheets with a U/S ratio of 2/3. The structural unit of NDUSe is a two-dimensional uranyl selenate-selenite sheets with a U/Se ratio of 1/2. In-situ reaction of the L-cystine ligands gives two distinct products for the different acids used here. Where sulfuric acid is used, only H3O+ cations are located in the interlayer space, where they balance the charge of the sheets, whereas where selenic acid is used, interlayer C5H6N+ cations result from the cyclization of the carboxyl groups of L-cystine, balancing the charge of the sheets.« less

Small capacity, low cost (Ni-H2) design concept for commercial, military, and higher-volume aerospace applications

NASA Technical Reports Server (NTRS)

Wheeler, James R.; Cook, William D.; Smith, Ron

1991-01-01

Nickel Hydrogen (Ni/H2) batteries have become the technology of choice for both commercial and defense related satellites in geosynchronous orbits. Their use for low earth orbit (LEO) applications is not as advanced, but seems just as inevitable because of their inherent advantages over nickel cadmium batteries. These include superior energy density, longer cycle life, and better tolerance to over-charge and reversal. Ni/H2 cells have the added advantage in both construction and operation of not presenting the environmental possibility of cadmium pollution. Unfortunately, but necessarily, the design of these cells has been driven to high cost by the sophistication of the satellites and their uses. Now, using most of the same concepts but less costly materials and techniques, a low cost, small cell design was developed. Combined with the concept of the common pressure vessel, this new design promises to be ideal for the small-sat and commercial markets which, increasingly, are calling for large numbers of less expensive satellites.

Telecommuting: An Altered Work Pattern.

DTIC Science & Technology

1984-09-01

TELECOMMUtTING : AN ALTERED WORK PATTERN THES IS Carole H. Smith GS -12 AFIT /GLMI/LSM/ 84S-59 Approved for public release; distribution unlimited__ , v 184...7 7.._._.._. _ ,:. . . 70-.--.- "" .._ 7." " --------- :’’ APIT/GLM/LSU/ 84s-59 TELECOMMUTING : AN ALTERED WORK PATTERN THES IS...Electronic Services Unlimited, a New York based telecommut - ing consultant company. They introduced me to telecommut - ing concepts in the private sector

Alcohol Primes, Expectancies, and the Working Self-Concept

PubMed Central

Hicks, Joshua A.; Schlegel, Rebecca J.; Friedman, Ronald S.; McCarthy, Denis M.

2016-01-01

Previous research has shown that alcohol consumption can lead to momentary changes in the self-concept (e.g., Steele & Josephs, 1990). In two studies (n = 150), we examined whether the implicit activation of alcohol expectancies (i.e., sociability-related expectancies) would also lead to changes in self-perception. To test this idea, participants first completed a measure of sociability-related alcohol expectancies. In a subsequent laboratory session, participants were exposed to either alcohol-related primes (i.e., pictures or words associated with alcohol) or neutral primes. After the priming task, participants completed an ostensibly unrelated self-concept survey that contained words related to sociability (e.g., “outgoing”) and non-sociability related words (e.g., “clever”). For both studies, results revealed that sociability-related alcohol expectancies were positively associated with sociability-related self-concept ratings for participants exposed to alcohol primes, but not for participants exposed to the neutral primes. Implications for the role implicit self-concept activation may have on drinking behaviors are discussed. PMID:19769437

Characterizing a sewage plume using the 3H-3He dating technique

USGS Publications Warehouse

Shapiro, Stephanie Dunkle; LeBlanc, Denis; Schlosser, Peter; Ludin, Andrea

1999-01-01

An extensive 3H-3He study was performed to determine detailed characteristics of a regional flow system and a sewage plume over a distance of 4 km in a sand and gravel aquifer at Otis Air Base in Falmouth, Massachusetts. 3H-3He ages increase with depth in individual piezometer clusters and with distance along flowpaths. However, the age gradient with depth (Δt/Δz) is smaller in the plume than that in the regional waters, due to the intense recharge in the infiltration beds. The 1960s bomb peak of tritium in precipitation is archived longitudinally along a flowline through the main axis of the plume and vertically in individual piezometer clusters. On the eastern side of the sampling area, where water from Ashumet Pond forces plume water deeper into the flow system, 3H-3He ages are young at depth because the 3H-3He "clock" is reset due to outgassing of helium in the pond. A reconstruction of the tritium input functions for the regional and plume samples shows that there is no offset in the peak [3H]+[3Hetrit] concentrations for the plume and regional water, indicating that the water from supply wells for use on the base is young. The 3H-3He ages and detergent concentrations in individual wells are consistent with the beginning of use of detergents and the time period when their concentrations in sewage would have been greatest. Ages and hydraulic properties calculated using the 3H-3He data compare well with those from previous investigations and from particle-tracking simulations.

H3PO4 imbibed polyacrylamide-graft-chitosan frameworks for high-temperature proton exchange membranes

NASA Astrophysics Data System (ADS)

Yuan, Shuangshuang; Tang, Qunwei; He, Benlin; Chen, Haiyan; Li, Qinghua; Ma, Chunqing; Jin, Suyue; Liu, Zhichao

2014-03-01

Proton exchange membrane (PEM), transferring protons from anode to cathode, is a key component in a PEM fuel cell. In the current work, a new class of PEMs are synthesized benefiting from the imbibition behavior of three-dimensional (3D) polyacrylamide-graft-chitosan (PAAm-graft-chitosan) frameworks to H3PO4 aqueous solution. Interconnected 3D framework of PAAm-graft-chitosan provides tremendous space for holding proton-conducting H3PO4. The highest anhydrous proton conductivity of 0.13 S cm-1 at 165 °C is obtained. A fuel cell using a thick membrane as a PEM showed a peak power density of 405 mW cm-2 with O2 and H2 as the oxidant and fuel, respectively. Results indicate that the interconnected 3D framework provides superhighway for proton conduction. The valued merits on anhydrous proton conductivity, huge H3PO4 loading, and easy synthesis promise the new membranes to be good alternatives as high-temperature PEMs.

The association of ruminal pH and some metabolic parameters with conception rate at first artificial insemination in Thai dairy cows.

PubMed

Inchaisri, Chaidate; Chanpongsang, Somchai; Noordhuizen, Jos; Hogeveen, Henk

2013-06-01

The objective of this study was to determine the association of metabolic parameters and cow associated factors with the conception rate at first insemination (FCR) in Thai dairy cows. The investigation was performed with 529 lactations from 32 smallholder dairy farms. At 3-6 weeks after parturition, blood samples and ruminal fluid were collected. Body condition scores (BCS) of cows were scored 1 week before expected calving date and at blood sampling date. Ruminal pH was measured at 2-4 h after morning feeding in ruminal fluid collected by ruminocentesis. Serum beta-hydroxybutyrate and serum urea nitrogen were measured by kinetic enzyme method. Cows with first insemination (AI) between 41 and 114 days postpartum were identified after pregnancy diagnosis for FCR. Breed, parity, interval from calving to first AI, BCS before calving, BCS after calving, loss in BCS after calving, SBHB, SUN, ruminal pH, and postpartum problems were selected as independent variables for a model with FCR as a dependent variable. A multivariable logistic regression model was used with farm as a random effect. Overall FCR was 27.2 %. The FCR depended on interval from calving to first AI, BCS before calving, and ruminal pH. The FCR between 69 and 91 days postpartum was significantly highest (45 %). Before calving, a cow with high BCS (≥ 3.5) had significantly greater FCR than a cow with low BCS (≤ 3.25; P<0.01). An increased ruminal pH raised significantly FCR (OR=2.53; P=0.03).

Straightforward entry to pyrido[2,3-d]pyrimidine-2,4(1H,3H)-diones and their ADME properties.

PubMed

Jatczak, Martyna; Muylaert, Koen; De Coen, Laurens M; Keemink, Janneke; Wuyts, Benjamin; Augustijns, Patrick; Stevens, Christian V

2014-08-01

A straightforward synthesis of pyrido[2,3-d]pyrimidine-2,4(1H,3H)-diones was developed starting from 2-chloropyridine-3-carboxylic acid by esterification, nucleophilic aromatic substitution and amide formation in one step, and ring closure allowing their synthesis with two identical or two different group attached to nitrogen. The structural diversity of these [2,3-d]pyrimidine-2,4(1H,3H)-diones resulted in significant variation in the biopharmaceutical properties. This was reflected by the broad range in fasted state simulated intestinal fluid solubility values (12.6 μM to 13.8 mM), Caco-2 permeability coefficients (1.2 × 10(-6)cm/s to 90.7 × 10(-6)cm/s) and in vitro-predicted human in vivo intrinsic clearance values (0 to 159 ml/min/kg). Copyright © 2014 Elsevier Ltd. All rights reserved.

Visualization of the activation of the histamine H3 receptor (H3R) using novel fluorescence resonance energy transfer biosensors and their potential application to the study of H3R pharmacology.

PubMed

Liu, Ying; Zeng, Hong; Pediani, John D; Ward, Richard J; Chen, Lu-Yao; Wu, Nan; Ma, Li; Tang, Mei; Yang, Yang; An, Su; Guo, Xiao-Xi; Hao, Qian; Xu, Tian-Rui

2018-06-01

Activation of the histamine-3 receptor (H3R) is involved in memory processes and cognitive action, while blocking H3R activation can slow the progression of neurological disorders, such as Alzheimer's disease, schizophrenia and narcolepsy. To date, however, no direct way to examine the activation of H3R has been utilized. Here, we describe a novel biosensor that can visualize the activation of H3R through an intramolecular fluorescence resonance energy transfer (FRET) signal. To achieve this, we constructed an intramolecular H3R FRET sensor with cyan fluorescent protein (CFP) attached at the C terminus and yellow fluorescent protein (YFP) inserted into the third intracellular loop. The sensor was found to internalize normally on agonist treatment. We measured FRET signals between the donor CFP and the acceptor YFP in living cells in real time, the results of which indicated that H3R agonist treatment (imetit or histamine) increases the FRET signal in a time- and concentration-dependent manner with Kon and Koff values consistent with published data and which maybe correlated with decreasing cAMP levels and the promotion of ERK1/2 phosphorylation. The FRET signal was inhibited by H3R antagonists, and the introduction of mutations at F419A, F423A, L426A and L427A, once again, the promotion of ERK1/2 phosphorylation, was diminished. Thus, we have built a H3R biosensor which can visualize the activation of receptor through real-time structure changes and which can obtain pharmacological kinetic data at the same time. The FRET signals may allow the sensor to become a useful tool for screening compounds and optimizing useful ligands. © 2018 Federation of European Biochemical Societies.

Absolute detection efficiencies of low energy H, H -, H +, H 2+ and H 3+ incident on a multichannel plate detector

NASA Astrophysics Data System (ADS)

Peko, B. L.; Stephen, T. M.

2000-12-01

Measured absolute detection efficiencies are presented for H, H - and H n+ ( n=1,2,3) impacting a commercially available, dual multichannel plate (MCP) electron multiplier at kinetic energies ranging from 30 to 1000 eV. Measurements involving isotopic substitutions (D, D -, D n+) and Ar + are also presented. In addition, atomic hydrogen detection efficiencies relative to those of H + and H - are given, as they may have a more universal application. For the three charge states, H, H + and H -, the absolute detection efficiencies are markedly different at low energies and converge to a nearly uniform value of ˜70% with increasing projectile energy. The energy dependence is strongest for H +, varying nearly three orders of magnitude over the energy range studied, and weakest for H -, varying by less than one order of magnitude. In general, for the low energy positive ions at a given energy, the lighter the incident particle mass, the greater the probability of its detection.

The Meiotic Recombination Activator PRDM9 Trimethylates Both H3K36 and H3K4 at Recombination Hotspots In Vivo.

PubMed

Powers, Natalie R; Parvanov, Emil D; Baker, Christopher L; Walker, Michael; Petkov, Petko M; Paigen, Kenneth

2016-06-01

In many mammals, including humans and mice, the zinc finger histone methyltransferase PRDM9 performs the first step in meiotic recombination by specifying the locations of hotspots, the sites of genetic recombination. PRDM9 binds to DNA at hotspots through its zinc finger domain and activates recombination by trimethylating histone H3K4 on adjacent nucleosomes through its PR/SET domain. Recently, the isolated PR/SET domain of PRDM9 was shown capable of also trimethylating H3K36 in vitro, raising the question of whether this reaction occurs in vivo during meiosis, and if so, what its function might be. Here, we show that full-length PRDM9 does trimethylate H3K36 in vivo in mouse spermatocytes. Levels of H3K4me3 and H3K36me3 are highly correlated at hotspots, but mutually exclusive elsewhere. In vitro, we find that although PRDM9 trimethylates H3K36 much more slowly than it does H3K4, PRDM9 is capable of placing both marks on the same histone molecules. In accord with these results, we also show that PRDM9 can trimethylate both K4 and K36 on the same nucleosomes in vivo, but the ratio of K4me3/K36me3 is much higher for the pair of nucleosomes adjacent to the PRDM9 binding site compared to the next pair further away. Importantly, H3K4me3/H3K36me3-double-positive nucleosomes occur only in regions of recombination: hotspots and the pseudoautosomal (PAR) region of the sex chromosomes. These double-positive nucleosomes are dramatically reduced when PRDM9 is absent, showing that this signature is PRDM9-dependent at hotspots; the residual double-positive nucleosomes most likely come from the PRDM9-independent PAR. These results, together with the fact that PRDM9 is the only known mammalian histone methyltransferase with both H3K4 and H3K36 trimethylation activity, suggest that trimethylation of H3K36 plays an important role in the recombination process. Given the known requirement of H3K36me3 for double strand break repair by homologous recombination in somatic cells, we

The Meiotic Recombination Activator PRDM9 Trimethylates Both H3K36 and H3K4 at Recombination Hotspots In Vivo

PubMed Central

Powers, Natalie R.; Parvanov, Emil D.; Baker, Christopher L.; Walker, Michael; Petkov, Petko M.; Paigen, Kenneth

2016-01-01

In many mammals, including humans and mice, the zinc finger histone methyltransferase PRDM9 performs the first step in meiotic recombination by specifying the locations of hotspots, the sites of genetic recombination. PRDM9 binds to DNA at hotspots through its zinc finger domain and activates recombination by trimethylating histone H3K4 on adjacent nucleosomes through its PR/SET domain. Recently, the isolated PR/SET domain of PRDM9 was shown capable of also trimethylating H3K36 in vitro, raising the question of whether this reaction occurs in vivo during meiosis, and if so, what its function might be. Here, we show that full-length PRDM9 does trimethylate H3K36 in vivo in mouse spermatocytes. Levels of H3K4me3 and H3K36me3 are highly correlated at hotspots, but mutually exclusive elsewhere. In vitro, we find that although PRDM9 trimethylates H3K36 much more slowly than it does H3K4, PRDM9 is capable of placing both marks on the same histone molecules. In accord with these results, we also show that PRDM9 can trimethylate both K4 and K36 on the same nucleosomes in vivo, but the ratio of K4me3/K36me3 is much higher for the pair of nucleosomes adjacent to the PRDM9 binding site compared to the next pair further away. Importantly, H3K4me3/H3K36me3-double-positive nucleosomes occur only in regions of recombination: hotspots and the pseudoautosomal (PAR) region of the sex chromosomes. These double-positive nucleosomes are dramatically reduced when PRDM9 is absent, showing that this signature is PRDM9-dependent at hotspots; the residual double-positive nucleosomes most likely come from the PRDM9-independent PAR. These results, together with the fact that PRDM9 is the only known mammalian histone methyltransferase with both H3K4 and H3K36 trimethylation activity, suggest that trimethylation of H3K36 plays an important role in the recombination process. Given the known requirement of H3K36me3 for double strand break repair by homologous recombination in somatic cells, we

Cis-existence of H3K27me3 and H3K36me2 in mouse embryonic stem cells revealed by specific ions of isobaric modification chromatogram.

PubMed

Mao, Hailei; Han, Gang; Xu, Longyong; Zhu, Duming; Lin, Hanqing; Cao, Xiongwen; Yu, Yi; Chen, Charlie Degui

2015-07-21

Histone H3 lysine 27 trimethylation (H3K27me3) and H3 lysine 36 trimethylation (H3K36me3) are important epigenetic modifications correlated with transcription repression and activation, respectively. These two opposing modifications rarely co-exist in the same H3 polypeptide. However, a small but significant amount of H3 tails are modified with 5 methyl groups on K27 and K36 in mouse embryonic stem cells (mESCs) and it is unclear how the trimethylation is distributed on K27 or K36. A label-free, bottom-up mass spectrum method, named specific ions of isobaric modification chromatogram (SIMC), was established to quantify the relative abundance of K27me2-K36me3 and K27me3-K36me2 in the same histone H3 tail. By using this method, we demonstrated that the H3K27me3-K36me2 comprises about 85 % of the penta-methylated H3 tails at K27 and K36 in mESCs. Upon mESC differentiation, the abundance of H3K27me3-K36me2 significantly decreased, while the level of H3K27me2-K36me3 remains unchanged. Our study not only revealed the cis-existence of H3K27me3-K36me2 in mESCs, but also suggested that this combinatorial histone modification may assume a specific regulatory function during differentiation.

The Hopf algebra structure of the h-deformed Z3-graded quantum supergroup GLh,j(1|1)

NASA Astrophysics Data System (ADS)

Yasar, Ergün

2016-07-01

In this work, we define a new proper singular g matrix to construct a Z3-graded calculus on the h-deformed quantum superplane. Using the obtained calculus, we construct a new h-deformed Z3-graded quantum supergroup and give some features of it. Finally, we build up the Hopf algebra structure of this supergroup.

New-Concept Part-Time Employment as a Work-Family Adaptive Strategy for Women Professionals with Small Children

ERIC Educational Resources Information Center

Hill, E. Jeffrey; Martinson, Vjollca; Ferris, Maria

2004-01-01

This study investigates how the option for new-concept part-time (NPT) employment influences the ability of mothers of preschool children working in professional occupations to successfully integrate work and family responsibilities. Female NPT professionals (n=279) and female full-time (FT) professionals (n=250) were compared. The NPT group…

The composition of Saturn's atmosphere at northern temperate latitudes from Voyager IRIS spectra - NH3, PH3, C2H2, C2H6, CH3D, CH4, and the Saturnian D/H isotopic ratio

NASA Technical Reports Server (NTRS)

Courtin, R.; Gautier, D.; Marten, A.; Bezard, B.; Hanel, R.

1984-01-01

The vertical distributions and mixing ratios of minor constituents in the northern hemisphere of Saturn are investigated. Results are obtained for NH3, PH3, C2H2, C2H6, CH3D, and CH4; the D/H ratio is obtained from the CH4 and CH3D abundances. The NH3 mixing ratio in the upper atmosphere is found to be compatible with the saturated partial pressure. The inferred PH3/H2 ratio of 1.4 + or - 0.8 x 10 to the -6th is higher than the value derived from the solar P/H ratio. The stratospheric C2H2/H2 and C2H6/H2 ratios are, respectively, 2.1 + or - 1.4 x 10 to the -7th and 3.0 + or - 1.1 x 10 to the -6th; the latter decreases sharply below the 20-50 mbar level. The results for CH3D/H2 and CH4/H2 imply an enrichment of Saturn's upper atmosphere in carbon by a factor of at least three over the solar abundance. The interpretation of two NH3 lines in the five-micron window suggests a NH3/H2 ratio at the two bar level below the solar value.

Advanced Technology Subsonic Transport Study: N+3 Technologies and Design Concepts

NASA Technical Reports Server (NTRS)

Raymer, Daniel P.; Wilson, Jack; Perkins, H. Douglas; Rizzi, Arthur; Zhang, Mengmeng; RamirezPuentes, Alfredo

2011-01-01

Conceptual Research Corporation, the Science of the Possible, has completed a two-year study of concepts and technologies for future airliners in the 180-passenger class. This NASA-funded contract was primarily focused on the ambitious goal of a 70 percent reduction in fuel consumption versus the market-dominating Boeing 737-800. The study is related to the N+3 contracts awarded in 2008 by NASA s Aeronautics Research Mission Directorate to teams led by Boeing, GE Aviation, MIT, and Northrop Grumman, but with more modest goals and funding. CRC s contract featured a predominant emphasis on propulsion and fuel consumption, but since fuel consumption depends upon air vehicle design as much as on propulsion technology, the study included notional vehicle design, analysis, and parametric studies. Other NASA goals including NOx and noise reduction are of long-standing interest but were not highlighted in this study, other than their inclusion in the propulsion system provided to CRC by NASA. The B-737-800 was used as a benchmark, parametric tool, and design point of departure. It was modeled in the RDS-Professional aircraft design software then subjected to extensive parametric variations of parasitic drag, drag-due-to-lift, specific fuel consumption, and unsized empty weight. These studies indicated that the goal of a 70 percent reduction in fuel consumption could be attained with roughly a 30 percent improvement in all four parameters. The results were then fit to a Response Surface and coded for ease of use in subsequent trade studies. Potential technologies to obtain such savings were identified and discussed. More than 16 advanced concept designs were then prepared, attempting to investigate almost every possible emerging concept for application to this class airliner. A preliminary assessment of these concepts was done based on their total wetted area after design normalization of trimmed maximum lift. This assessment points towards a Tailless Airliner concept which

Guida Didattica per l'Insegnamento della Matematica. Livelli G, H = Mathematics Curriculum Guide for Italian-Speaking Students, Levels G and H. Working Draft.

ERIC Educational Resources Information Center

Chicago Board of Education, IL. Dept. of Curriculum.

The curriculum guide is for levels G and H of the mathematics segment of Chicago's bilingual education program for limited-English-speaking native Italian-speaking students. It includes specific instructional objectives and worksheets for teaching the mathematical concepts of place value, whole numbers, rational numbers, measurement, geometry, and…

Species-to-species rate coefficients for the H3+ + H2 reacting system

NASA Astrophysics Data System (ADS)

Sipilä, O.; Harju, J.; Caselli, P.

2017-10-01

Aims: We study whether or not rotational excitation can make a large difference to chemical models of the abundances of the H3+ isotopologs, including spin states, in physical conditions corresponding to starless cores and protostellar envelopes. Methods: We developed a new rate coefficient set for the chemistry of the H3+ isotopologs, allowing for rotational excitation, using previously published state-to-state rate coefficients. These new so-called species-to-species rate coefficients are compared with previously-used ground-state-to-species rate coefficients by calculating chemical evolution in variable physical conditions using a pseudo-time-dependent chemical code. Results: We find that the new species-to-species model produces different results to the ground state-to-species model at high density and toward increasing temperatures (T> 10 K). The most prominent difference is that the species-to-species model predicts a lower H3+ deuteration degree at high density owing to an increase of the rate coefficients of endothermic reactions that tend to decrease deuteration. For example at 20 K, the ground-state-to-species model overestimates the abundance of H2D+ by a factor of about two, while the abundance of D3+ can differ by up to an order of magnitude between the models. The spin-state abundance ratios of the various H3+ isotopologs are also affected, and the new model better reproduces recent observations of the abundances of ortho and para H2D+ and D2H+. The main caveat is that the applicability regime of the new rate coefficients depends on the critical densities of the various rotational transitions which vary with the abundances of the species and the temperature in dense clouds. Conclusions: The difference in the abundances of the H3+ isotopologs predicted by the species-to-species and ground state-to-species models is negligible at 10 K corresponding to physical conditions in starless cores, but inclusion of the excited states is very important in studies

Pharmacology and expression analysis of glycine transporter GlyT1 with [3H]-(N-[3-(4'-fluorophenyl)-3-(4'phenylphenoxy)propyl])sarcosine.

PubMed

Mallorga, Pierre J; Williams, Jacinta B; Jacobson, Marlene; Marques, Rosemary; Chaudhary, Ashok; Conn, P Jeffrey; Pettibone, Douglas J; Sur, Cyrille

2003-10-01

In the central nervous system, re-uptake of the neurotransmitter glycine is mediated by two different glycine transporters, GlyT1 and GlyT2. GlyT2 is found in brainstem and spinal cord, whereas GlyT1 is expressed in rat forebrain regions where it is responsible for most glycine transport activity. Initially, GlyT1 and GlyT2 were pharmacologically differentiated by sarcosine, a weak selective inhibitor of GlyT1. The recently described selective and potent GlyT1 antagonist, NFPS/ALX-5407 provided an important additional tool to further characterize GlyT1 pharmacology. In the present study, we have radiolabeled the racemic form of NFPS (N-[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)propyl])sarcosine (also known as ALX-5407) to investigate its interaction with GlyT1, as well as define GlyT1 expression in the rat central nervous system. Kinetic studies indicated that [3H]NFPS binds rapidly to rat forebrain membranes and dissociates with a t(1/2) of 28 +/- 5 min. [3H]NFPS labeled a saturable population of sites in rat forebrain with a Kd of 7.1+/-1.3 nM and a B(max) of 3.14 +/- 0.26 pmol/mg protein. Bound [3H]NFPS was fully and potently displaced by unlabeled NFPS, whereas glycine and sarcosine were weak, Na+-dependent inhibitors with IC50 of 1,008 and 190 microM, respectively. Additional saturation experiments indicated that glycine and sarcosine were non-competitive antagonists of [3H]NFPS binding. Functional studies revealed that NFPS was a non-competitive inhibitor of [3H]glycine uptake and does not interact with Na+ and Cl- binding sites of GlyT1. Overall, this work shows that [3H]NFPS is a valuable tool in studying GlyT1 expression and pharmacology and that NFPS interacts with GlyT1 at a site different from the transporter translocation and ion binding sites.

Functional role of hCngb3 in regulation of human cone cng channel: effect of rod monochromacy-associated mutations in hCNGB3 on channel function.

PubMed

Okada, Akira; Ueyama, Hisao; Toyoda, Futoshi; Oda, Sanae; Ding, Wei-Guang; Tanabe, Shoko; Yamade, Shinichi; Matsuura, Hiroshi; Ohkubo, Iwao; Kani, Kazutaka

2004-07-01

The human cone photoreceptor cyclic nucleotide-gated (CNG) channel comprises alpha- and beta-subunits, which are respectively encoded by hCNGA3 and hCNGB3. The purpose was to examine the functional role of hCNGB3 in modulation of human cone CNG channels and to characterize functional consequences of rod monochromacy-associated mutations in hCNGB3 (S435F and D633G). Macroscopic patch currents were recorded from human embryonic kidney (HEK) 293 cells expressing homomeric (hCNGA3 and hCNGB3) and heteromeric (hCNGA3/hCNGB3, hCNGA3/hCNGB3-S435F, and hCNGA3/hCNGB3-D633G) channels using inside-out patch-clamp technique. Both hCNGA3 homomeric and hCNGA3/hCNGB3 heteromeric channels were activated by cGMP, with half-maximally activating concentration (K(1/2)) of 11.1 +/- 1.0 and 26.2 +/- 1.9 micro M, respectively. The hCNGA3 channels appeared to be more sensitive to inhibition by extracellular Ca(2+) compared with hCNGA3/hCNGB3 channels, when assessed by the degree of outward rectification. Coexpression of either of rod monochromacy-associated mutants of hCNGB3 with hCNGA3 significantly reduced K(1/2) value for cGMP but little affected the sensitivity to extracellular Ca(2+), compared with wild-type heteromeric channels. The selectivity of hCNGA3, hCNGA3/hCNGB3, hCNGA3/hCNGB3-S435F, and hCNGA3/hCNGB3-D633G channels for monovalent cations were largely similar. Immunoprecipitation experiments showed association of hCNGA3 subunit with both of wild-type and mutant hCNGB3 subunits. The hCNGB3 plays an important modulatory role in the function of human cone CNG channels with respect to cGMP and extracellular Ca(2+) sensitivities. The rod monochromacy-associated S435F and D633G mutations in hCNGB3 evokes a significant increase in the apparent affinity for cGMP, which should alter cone function and thereby contribute at least partly to pathogenesis of the disease.

Point mutation of H3/H4 histones affects acetic acid tolerance in Saccharomyces cerevisiae.

PubMed

Liu, Xiangyong; Zhang, Xiaohua; Zhang, Zhaojie

2014-10-10

The molecular mechanism of acetic acid tolerance in yeast remains unclear despite of its importance for efficient cellulosic ethanol production. In this study, we examined the effects of histone H3/H4 point mutations on yeast acetic acid tolerance by comprehensively screening a histone H3/H4 mutant library. A total of 24 histone H3/H4 mutants (six acetic acid resistant and 18 sensitive) were identified. Compared to the wild-type strain, the histone acetic acid-resistant mutants exhibited improved ethanol fermentation performance under acetic acid stress. Genome-wide transcriptome analysis revealed that changes in the gene expression in the acetic acid-resistant mutants H3 K37A and H4 K16Q were mainly related to energy production, antioxidative stress. Our results provide novel insights into yeast acetic acid tolerance on the basis of histone, and suggest a novel approach to improve ethanol production by altering the histone H3/H4 sequences. Copyright © 2014 Elsevier B.V. All rights reserved.

40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Boric acid (H3BO3), zinc salt (2=3). 721.3031 Section 721.3031 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3031 Boric acid (H3BO...

40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Boric acid (H3BO3), zinc salt (2=3). 721.3031 Section 721.3031 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3031 Boric acid (H3BO...

40 CFR 721.3031 - Boric acid (H3BO3), zinc salt (2=3).

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Boric acid (H3BO3), zinc salt (2=3). 721.3031 Section 721.3031 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.3031 Boric acid (H3BO...

Behavioral characterization of mice lacking histamine H(3) receptors.

PubMed

Toyota, Hiroshi; Dugovic, Christine; Koehl, Muriel; Laposky, Aaron D; Weber, China; Ngo, Karen; Wu, Ying; Lee, Doo Hyun; Yanai, Kazuhiko; Sakurai, Eiko; Watanabe, Takehiko; Liu, Changlu; Chen, Jingcai; Barbier, Ann J; Turek, Fred W; Fung-Leung, Wai-Ping; Lovenberg, Timothy W

2002-08-01

Brain histamine H(3) receptors are predominantly presynaptic and serve an important autoregulatory function for the release of histamine and other neurotransmitters. They have been implicated in a variety of brain functions, including arousal, locomotor activity, thermoregulation, food intake, and memory. The recent cloning of the H(3) receptor in our laboratory has made it possible to create a transgenic line of mice devoid of H(3) receptors. This paper provides the first description of the H(3) receptor-deficient mouse (H(3)(-/-)), including molecular and pharmacologic verification of the receptor deletion as well as phenotypic screens. The H(3)(-/-) mice showed a decrease in overall locomotion, wheel-running behavior, and body temperature during the dark phase but maintained normal circadian rhythmicity. H(3)(-/-) mice were insensitive to the wake-promoting effects of the H(3) receptor antagonist thioperamide. We also observed a slightly decreased stereotypic response to the dopamine releaser, methamphetamine, and an insensitivity to the amnesic effects of the cholinergic receptor antagonist, scopolamine. These data indicate that the H(3) receptor-deficient mouse represents a valuable model for studying histaminergic regulation of a variety of behaviors and neurotransmitter systems, including dopamine and acetylcholine.

Pharmacodynamic evaluation of intragastric pH and implications for famotidine dosing in the prophylaxis of non-steroidal anti-inflammatory drug induced gastropathy-a proof of concept analysis.

PubMed

Kent, Jeffery D; Holt, Robert J; Jung, Donald; Tidmarsh, George F; Grahn, Amy Y; Ball, Julie; Peura, David A

2014-01-01

Famotidine given at a dose of 80 mg/day is effective in preventing NSAID-induced gastropathy. The aim of this proof of concept study was to compare twice a day (BID) vs 3-times a day (TID) administration of this total dose of famotidine on intragastric pH in healthy volunteers. Two analyses were undertaken: (1) a 13 subject controlled cross-over 24-h intragastric pH evaluation of the BID and TID administration of 80 mg/day of famotidine, as well as measures for drug accumulation over 5 days (EudraCT, number 2006-002930-39); and (2) a pharmacokinetic (PK)/pharmacodynamic (PD) model which predicted steady-state famotidine plasma concentrations and pH of the two regimens. For the cross-over study, gastric pH was above 3.5 for a mean of 20 min longer for TID dosing compared to BID dosing on Day 1. On Day 5, the mean time above this threshold was higher with the BID regimen by ∼25 min. For pH 4, subjects' gastric pH was above this pH value for a mean of 25 min longer for TID dosing compared to BID dosing on Day 1. For Day 5, the pH was above 4 for ∼45 min longer with the TID regimen as compared with the BID regimen. The mean 24-h gastric pH values when taken in the upright position trended higher for the TID dosing period compared to the BID regimen on Day 1. The steady-state simulation model indicated that, following TID dosing, intragastric pH will be above 3 for 24 h vs 16 h for the BID regimen. There was no evidence for plasma accumulation of famotidine with TID dosing as compared to BID dosing from either analysis. The data indicate that overall more time is spent above the acidic threshold pH values when 80 mg/day of famotidine is administered TID vs BID. Key limitations included small study size with a short duration and lack of a baseline examination, but was compensated for by the cross-over and PK/PD modeling design. Although most of the comparisons in this proof of concept study were not statistically significant these results have

AOI [3] High-Temperature Nano-Derived Micro-H 2 and - H 2S Sensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabolsky, Edward M.

2014-08-01

The emissions from coal-fired power plants remain a significant concern for air quality. This environmental challenge must be overcome by controlling the emission of sulfur dioxide (SO 2) and hydrogen sulfide (H 2S) throughout the entire coal combustion process. One of the processes which could specifically benefit from robust, low cost, and high temperature compatible gas sensors is the coal gasification process which converts coal and/or biomass into syngas. Hydrogen (H 2), carbon monoxide (CO) and sulfur compounds make up 33%, 43% and 2% of syngas, respectively. Therefore, development of a high temperature (>500°C) chemical sensor for in-situ monitoring ofmore » H 2, H 2S and SO2 2 levels during coal gasification is strongly desired. The selective detection of SO 2/H 2S in the presence of H 2, is a formidable task for a sensor designer. In order to ensure effective operation of these chemical sensors, the sensor system must inexpensively function within harsh temperature and chemical environment. Currently available sensing approaches, which are based on gas chromatography, electrochemistry, and IR-spectroscopy, do not satisfy the required cost and performance targets. This work focused on the development microsensors that can be applied to this application. In order to develop the high- temperature compatible microsensor, this work addressed various issues related to sensor stability, selectivity, and miniaturization. In the research project entitled “High-Temperature Nano-Derived Micro-H 2 and -H 2S Sensors”, the team worked to develop micro-scale, chemical sensors and sensor arrays composed of nano-derived, metal-oxide composite materials to detect gases like H 2, SO 2, and H 2S within high-temperature environments (>500°C). The research was completed in collaboration with NexTech Materials, Ltd. (Lewis Center, Ohio). NexTech assisted in the testing of the sensors in syngas with contaminate levels of H 2S. The idea of including nanomaterials as the

Vibrational spectroscopic analysis of 2-chloro-5-(2,5-dimethoxy-benzylidene)-1,3-diethyl-dihydro-pyrimidine-4,6(1H,5H)-dione.

PubMed

Soliman, H S; Eid, Kh M; Ali, H A M; Atef, S M; El-Mansy, M A M

2012-11-01

In the present work, a combined experimental and computational study for the optimized molecular structural parameters, FT-IR spectra, thermo-chemical parameters, total dipole moment and HOMO-LUMO energy gap for 2-chloro-5-(2,5-dimethoxy-benzylidene)-1,3-diethyl-dihydro-pyrimidine-4,6(1H,5H)-dione have been investigated using B3LYP/6-311G basis set. Our calculated results have showed that the investigated compound possesses a dipole moment of 4.9 Debye and HOMO-LUMO energy gap of 3 eV which indicate high recommendations for photovoltaic devices fabrication. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Comparison of penetration and metabolism of [3H]diacetoxyscirpenol, [3H]verrucarin A and [3H]T-2 toxin in skin.

PubMed

Kemppainen, B W; Riley, R T; Biles-Thurlow, S

1987-05-01

The purpose of this research was to determine the rate of cutaneous penetration and metabolism of [3H]diacetoxyscirpenol (DAS) and [3H]verrucarin A (VCA) and compare these values to previously determined values for [3H]T-2 toxin (T-2), to compare the cutaneous penetration and metabolism of DAS in human and guinea-pig skin, and to compare the effects of dose and of two vehicles, methanol and dimethylsulphoxide (DMSO), on penetration rates. DAS or VCA was applied to the epidermal surface of excised skin, and the receptor fluid bathing the dermal surface was sampled periodically for 48 hr. Whether the applied dose (581 ng/cm2) was dissolved in methanol or DMSO, the rate of penetration through human skin was lower for VCA than for DAS or T-2, the rates for the two latter compounds being similar at this dose. Metabolism of DAS occurred during penetration through excised human skin and did not occur in the receptor fluid as a result of enzymes leaching out of the skin. VCA appeared to be metabolized by human skin, but this conclusion is tentative because of the relative instability of this compound. DAS penetrated significantly (P less than 0.05) faster through excised guinea-pig skin than through human skin. Metabolism of DAS was greater in human skin than in guinea-pig skin. When compared with methanol, DMSO increased the penetration of DAS and VCA by factors of between 7 and 52. At the low dose (79 ng/cm2) DAS penetrated human and guinea-pig skin significantly (P less than 0.05) faster than T-2 using either vehicle.

Swine influenza virus vaccine serologic cross-reactivity to contemporary U.S. swine H3N2 and efficacy in pigs infected with an H3N2 similar to 2011-2012 H3N2v

USDA-ARS?s Scientific Manuscript database

Background: Swine influenza A virus (IAV) reassortment with 2009 H1N1 pandemic (H1N1pdm09) virus has been documented and new genotypes and sub-clusters of H3N2 have since expanded in the U.S. swine population. An H3N2 variant (H3N2v) virus with the H1N1pdm09 matrix gene and the remaining genes of sw...

Plio-Pleistocene facies environments from the KBS Member, Koobi Fora Formation: implications for climate controls on the development of lake-margin hominin habitats in the northeast Turkana Basin (northwest Kenya).

PubMed

Lepre, Christopher J; Quinn, Rhonda L; Joordens, Josephine C A; Swisher, Carl C; Feibel, Craig S

2007-11-01

Climate change is hypothesized as a cause of major events of Plio-Pleistocene East African hominin evolution, but the vertically discontinuous and laterally confined nature of the relevant geological records has led to difficulties with assessing probable links between the two. High-resolution sedimentary sequences from lacustrine settings can provide comprehensive data of environmental changes and detailed correlations with well-established orbital and marine records of climate. Hominin-bearing deposits from Koobi Fora Ridge localities in the northeast Turkana Basin of Kenya are an archive of Plio-Pleistocene lake-margin sedimentation though significant developmental junctures of northern African climates, East African environments, and hominin evolution. This study examines alluvial channel and floodplain, nearshore lacustrine, and offshore lacustrine facies environments for the approximately 136-m-thick KBS Member (Koobi Fora Formation) exposed at the Koobi Fora Ridge. Aspects of the facies environments record information on the changing hydrosedimentary dynamics of the lake margin and give insights into potential climatic controls. Seasonal/yearly climate changes are represented by the varve-like laminations in offshore mudstones and the slickensides, dish-shaped fractures, and other paleosol features overprinted on floodplain strata. Vertical shifts between facies environments, however, are interpreted to indicate lake-level fluctuations deriving from longer-term, dry-wet periods in monsoonal rainfall. Recurrence periods for the inferred lake-level changes range from about 10,000 to 50,000 years, and several are consistent with the average estimated timescales of orbital precession ( approximately 20,000 years) and obliquity ( approximately 40,000 years). KBS Member facies environments from the Koobi Fora Ridge document the development of lake-margin hominin habitats in the northeast Turkana Basin. Environmental changes in these habitats may be a result of

Mechanistic Study of the Stereoselective Hydroxylation of [2-2 H1 ,3-2 H1 ]Butanes Catalyzed by Cytochrome P450 BM3 Variants.

PubMed

Yang, Chung-Ling; Lin, Cheng-Hung; Luo, Wen-I; Lee, Tsu-Lin; Ramu, Ravirala; Ng, Kok Yaoh; Tsai, Yi-Fang; Wei, Guor-Tzo; Yu, Steve S-F

2017-02-21

Engineered bacterial cytochrome P450s are noted for their ability in the oxidation of inert small alkanes. Cytochrome P450 BM3 L188P A328F (BM3 PF) and A74E L188P A328F (BM3 EPF) variants are able to efficiently oxidize n-butane to 2-butanol. Esterification of the 2-butanol derived from this reaction mediated by the aforementioned two mutants gives diastereomeric excesses (de) of -56±1 and -52±1 %, respectively, with the preference for the oxidation occurring at the C-H S bond. When tailored (2R,3R)- and (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butane probes are employed as substrates for both variants, the obtained de values from (2R,3R)-[2- 2 H 1 ,3- 2 H 1 ]butane are -93 and -92 % for BM3 PF and EPF, respectively; whereas the obtained de values from (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butane are 52 and 56 % in the BM3 PF and EPF systems, respectively. The kinetic isotope effects (KIEs) for the oxidation of (2R,3R)-[2- 2 H 1 ,3- 2 H 1 ]butane are 7.3 and 7.8 in BM3 PF and EPF, respectively; whereas KIEs for (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butanes are 18 and 25 in BM3 PF and EPF, respectively. The discrepancy in KIEs obtained from the two substrates supports the two-state reactivity (TSR) that is proposed for alkane oxidation in cytochrome P450 systems. Moreover, for the first time, experimental evidence for tunneling in the oxidation mediated by P450 is given through the oxidation of the C-H R bond in (2S,3S)-[2- 2 H 1 ,3- 2 H 1 ]butane. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

GABA action in immature neocortical neurons directly depends on the availability of ketone bodies.

PubMed

Rheims, Sylvain; Holmgren, Carl D; Chazal, Genevieve; Mulder, Jan; Harkany, Tibor; Zilberter, Tanya; Zilberter, Yuri

2009-08-01

In the early postnatal period, energy metabolism in the suckling rodent brain relies to a large extent on metabolic pathways alternate to glucose such as the utilization of ketone bodies (KBs). However, how KBs affect neuronal excitability is not known. Using recordings of single NMDA and GABA-activated channels in neocortical pyramidal cells we studied the effects of KBs on the resting membrane potential (E(m)) and reversal potential of GABA-induced anionic currents (E(GABA)), respectively. We show that during postnatal development (P3-P19) if neocortical brain slices are adequately supplied with KBs, E(m) and E(GABA) are both maintained at negative levels of about -83 and -80 mV, respectively. Conversely, a KB deficiency causes a significant depolarization of both E(m) (>5 mV) and E(GABA) (>15 mV). The KB-mediated shift in E(GABA) is largely determined by the interaction of the NKCC1 cotransporter and Cl(-)/HCO3 transporter(s). Therefore, by inducing a hyperpolarizing shift in E(m) and modulating GABA signaling mode, KBs can efficiently control the excitability of neonatal cortical neurons.

Dynamics of H3K27me3 methylation and demethylation in plant development

PubMed Central

Gan, Eng-Seng; Xu, Yifeng; Ito, Toshiro

2015-01-01

Epigenetic regulation controls multiple aspects of the plant development. The N-terminal tail of histone can be differently modified to regulate various chromatin activities. One of them, the trimethylation of histone H3 lysine 27 (H3K27me3) confers a repressive chromatin state with gene silencing. H3K27me3 is dynamically deposited and removed throughout development. While components of the H3K27me3 writer, Polycomb repressive complex 2 (PRC2), have been reported for almost 2 decades, it is only recently that JUMONJI (JMJ) proteins are reported as H3K27me3 demethylases, affirming the dynamic nature of histone modifications. This review highlights recent progress in plant epigenetic research, focusing on the H3K27me3 demethylases. PMID:26313233

Ethanol intake and sup 3 H-serotonin uptake II: A study in alcoholic patients using platelets sup 3 H-paroxetine binding

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daoust, M.; Boucly, P.; Ernouf, D.

1991-01-01

The kinetic parameters of {sup 3}H-paroxetine binding and {sup 3}H-serotonin uptake were studied in platelets of alcoholic patients. There was no difference between alcoholic and non alcoholic subjects in {sup 3}H-paroxetine binding. When binding and {sup 3}H-serotonin uptake were studied, in the same plasma of the same subjects, the Vmax of serotonin uptake was increased in alcoholics. The data confirm the involvement of serotonin uptake system in alcohol dependance and suggest that serotonin uptake and paroxetine binding sites may be regulated independently in this pathology.

The SUVR4 Histone Lysine Methyltransferase Binds Ubiquitin and Converts H3K9me1 to H3K9me3 on Transposon Chromatin in Arabidopsis

PubMed Central

Veiseth, Silje V.; Rahman, Mohummad A.; Yap, Kyoko L.; Fischer, Andreas; Egge-Jacobsen, Wolfgang; Reuter, Gunter; Zhou, Ming-Ming; Aalen, Reidunn B.; Thorstensen, Tage

2011-01-01

Chromatin structure and gene expression are regulated by posttranslational modifications (PTMs) on the N-terminal tails of histones. Mono-, di-, or trimethylation of lysine residues by histone lysine methyltransferases (HKMTases) can have activating or repressive functions depending on the position and context of the modified lysine. In Arabidopsis, trimethylation of lysine 9 on histone H3 (H3K9me3) is mainly associated with euchromatin and transcribed genes, although low levels of this mark are also detected at transposons and repeat sequences. Besides the evolutionarily conserved SET domain which is responsible for enzyme activity, most HKMTases also contain additional domains which enable them to respond to other PTMs or cellular signals. Here we show that the N-terminal WIYLD domain of the Arabidopsis SUVR4 HKMTase binds ubiquitin and that the SUVR4 product specificity shifts from di- to trimethylation in the presence of free ubiquitin, enabling conversion of H3K9me1 to H3K9me3 in vitro. Chromatin immunoprecipitation and immunocytological analysis showed that SUVR4 in vivo specifically converts H3K9me1 to H3K9me3 at transposons and pseudogenes and has a locus-specific repressive effect on the expression of such elements. Bisulfite sequencing indicates that this repression involves both DNA methylation–dependent and –independent mechanisms. Transcribed genes with high endogenous levels of H3K4me3, H3K9me3, and H2Bub1, but low H3K9me1, are generally unaffected by SUVR4 activity. Our results imply that SUVR4 is involved in the epigenetic defense mechanism by trimethylating H3K9 to suppress potentially harmful transposon activity. PMID:21423664

SABRE hyperpolarisation of vitamin B3 as a function of pH.

PubMed

Olaru, A M; Burns, M J; Green, G G R; Duckett, S B

2017-03-01

In this work we describe how the signal enhancements obtained through the SABRE process in methanol- d 4 solution are significantly affected by pH. Nicotinic acid (vitamin B3, NA ) is used as the agent, and changing pH is shown to modify the level of polarisation transfer by over an order of magnitude, with significant improvements being seen in terms of the signal amplitude and relaxation rate at high pH values. These observations reveal that manipulating pH to improve SABRE enhancements levels may improve the potential of this method to quantify low concentrations of analytes in mixtures. 1 H NMR spectroscopy results link this change to the form of the SABRE catalyst, which changes with pH, resulting in dramatic changes in the magnitude of the ligand exchange rates. The presented data also uses the fact that the chemical shifts of the nicotinic acids NMR resonances are affected by pH to establish that hyperpolarised 1 H-based pH mapping with SABRE is possible. Moreover, the strong polarisation transfer field dependence shown in the amplitudes of the associated higher order longitudinal terms offers significant opportunities for the rapid detection of hyperpolarised NA in H 2 O itself without solvent suppression. 1 H and 13 C MRI images of hyperpolarised vitamin B3 in a series of test phantoms are presented that show pH dependent intensity and contrast. This study therefore establishes that when the pH sensitivity of NA is combined with the increase in signal gain provided for by SABRE hyperpolarisation, a versatile pH probe results.

The Effectiveness of Predict-Observe-Explain Technique in Probing Students' Understanding about Acid-Base Chemistry: A Case for the Concepts of pH, pOH, and Strength

ERIC Educational Resources Information Center

Kala, Nesli; Yaman, Fatma; Ayas, Alipasa

2013-01-01

The present study describes high school students' conceptions about acids and bases in terms of pH, pOH, microscopic level, strength, and concentration. A total of 27 high school students participated in the study. The data was collected using 3 POE tasks and a semi-structured interview. The data analysis demonstrated that most of the students had…

Working (longer than) 9 to 5: are there cardiometabolic health risks for young Australian workers who report longer than 38-h working weeks?

PubMed

Reynolds, Amy C; Bucks, Romola S; Paterson, Jessica L; Ferguson, Sally A; Mori, Trevor A; McArdle, Nigel; Straker, Leon; Beilin, Lawrence J; Eastwood, Peter R

2018-05-01

The average Australian working week in middle-aged and older workers exceeds government recommendations. Long working weeks are associated with poor health outcomes; however, the relationship between long working weeks and health in young Australian workers is unknown. Data were drawn from the 22-year follow-up of the Western Australian Pregnancy Cohort (Raine) Study in Perth, Western Australia. Information was available from 873 young adults about working hours per week, shift work and sleep duration. Blood samples provided measures of cardiometabolic risk (CMR) factors. Almost one-third (32.8%) of young workers reported > 38 h working weeks. This was commonly reported in mining and construction industries for males; health and social assistance, mining and retail trade industries for females. CMR factors including increased waist circumference, higher fasting plasma glucose and reduced HDL cholesterol were associated with > 38 h working weeks. These relationships were not moderated by gender or by BMI for glucose and HDL cholesterol. Total sleep time was significantly lower in both male and female workers reporting > 38 h working weeks, but did not mediate the relationships seen with CMR factors. These findings point to early associations between > 38 h working weeks and CMR risk, and highlight the potential benefit of making young employees aware of the health associations with working arrangements to reduce the longer-term relationships seen with working hours and poor cardiometabolic health in population studies.

Trithorax monomethylates histone H3K4 and interacts directly with CBP to promote H3K27 acetylation and antagonize Polycomb silencing

PubMed Central

Tie, Feng; Banerjee, Rakhee; Saiakhova, Alina R.; Howard, Benny; Monteith, Kelsey E.; Scacheri, Peter C.; Cosgrove, Michael S.; Harte, Peter J.

2014-01-01

Trithorax (TRX) antagonizes epigenetic silencing by Polycomb group (PcG) proteins, stimulates enhancer-dependent transcription, and establishes a ‘cellular memory’ of active transcription of PcG-regulated genes. The mechanisms underlying these TRX functions remain largely unknown, but are presumed to involve its histone H3K4 methyltransferase activity. We report that the SET domains of TRX and TRX-related (TRR) have robust histone H3K4 monomethyltransferase activity in vitro and that Tyr3701 of TRX and Tyr2404 of TRR prevent them from being trimethyltransferases. The trxZ11 missense mutation (G3601S), which abolishes H3K4 methyltransferase activity in vitro, reduces the H3K4me1 but not the H3K4me3 level in vivo. trxZ11 also suppresses the impaired silencing phenotypes of the Pc3 mutant, suggesting that H3K4me1 is involved in antagonizing Polycomb silencing. Polycomb silencing is also antagonized by TRX-dependent H3K27 acetylation by CREB-binding protein (CBP). We show that perturbation of Polycomb silencing by TRX overexpression requires CBP. We also show that TRX and TRR are each physically associated with CBP in vivo, that TRX binds directly to the CBP KIX domain, and that the chromatin binding patterns of TRX and TRR are highly correlated with CBP and H3K4me1 genome-wide. In vitro acetylation of H3K27 by CBP is enhanced on K4me1-containing H3 substrates, and independently altering the H3K4me1 level in vivo, via the H3K4 demethylase LSD1, produces concordant changes in H3K27ac. These data indicate that the catalytic activities of TRX and CBP are physically coupled and suggest that both activities play roles in antagonizing Polycomb silencing, stimulating enhancer activity and cellular memory. PMID:24550119

H3S10ph broadly marks early-replicating domains in interphase ESCs and shows reciprocal antagonism with H3K9me2.

PubMed

Chen, Carol C L; Goyal, Preeti; Karimi, Mohammad M; Abildgaard, Marie H; Kimura, Hiroshi; Lorincz, Matthew C

2018-01-01

Phosphorylation of histone H3 at serine 10 (H3S10ph) by Aurora kinases plays an important role in mitosis; however, H3S10ph also marks regulatory regions of inducible genes in interphase mammalian cells, implicating mitosis-independent functions. Using the fluorescent ubiquitin-mediated cell cycle indicator (FUCCI), we found that 30% of the genome in interphase mouse embryonic stem cells (ESCs) is marked with H3S10ph. H3S10ph broadly demarcates gene-rich regions in G1 and is positively correlated with domains of early DNA replication timing (RT) but negatively correlated with H3K9me2 and lamin-associated domains (LADs). Consistent with mitosis-independent kinase activity, this pattern was preserved in ESCs treated with Hesperadin, a potent inhibitor of Aurora B/C kinases. Disruption of H3S10ph by expression of nonphosphorylatable H3.3S10A results in ectopic spreading of H3K9me2 into adjacent euchromatic regions, mimicking the phenotype observed in Drosophila JIL-1 kinase mutants . Conversely, interphase H3S10ph domains expand in Ehmt1 (also known as Glp ) null ESCs, revealing that H3S10ph deposition is restricted by H3K9me2. Strikingly, spreading of H3S10ph at RT transition regions (TTRs) is accompanied by aberrant transcription initiation of genes co-oriented with the replication fork in Ehmt1 -/- and Ehmt2 -/- ESCs, indicating that establishment of repressive chromatin on the leading strand following DNA synthesis may depend upon these lysine methyltransferases. H3S10ph is also anti-correlated with H3K9me2 in interphase murine embryonic fibroblasts (MEFs) and is restricted to intragenic regions of actively transcribing genes by EHMT2. Taken together, these observations reveal that H3S10ph may play a general role in restricting the spreading of repressive chromatin in interphase mammalian cells. © 2018 Chen et al.; Published by Cold Spring Harbor Laboratory Press.