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1

The effect of hypusine modification on the intracellular localization of eIF5A  

SciTech Connect

Eukaryotic translation initiation factor 5A (eIF5A) is a highly conserved protein essential for eukaryotic cell proliferation and is the only protein containing hypusine, [N{sup {epsilon}}-(4-amino-2-hydroxybutyl)lysine]. eIF5A is activated by the post-translational synthesis of hypusine. eIF5A also undergoes an acetylation at specific Lys residue(s). In this study, we have investigated the effect of hypusine modification and acetylation on the subcellular localization of eIF5A. Immunocytochemical analyses showed differences in the distribution of non-hypusinated eIF5A precursor and the hypusine-containing mature eIF5A. While the precursor is found in both cytoplasm and nucleus, the hypusinated eIF5A is primarily localized in cytoplasm. eIF5A mutant proteins, defective in hypusine modification (K50A, K50R) were localized in a similar manner to the eIF5A precursor, whereas hypusine-modified mutant proteins (K47A, K47R, K68A) were localized mainly in the cytoplasm. These findings provide strong evidence that the hypusine modification of eIF5A dictates its localization in the cytoplasmic compartment where it is required for protein synthesis.

Lee, Seung Bum; Park, Jong Hwan; Kaevel, Joern; Sramkova, Monika; Weigert, Roberto [Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bldg 30 Rm 211, 9000 Rockville Pike, Bethesda, MD 20892-4340 (United States)] [Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bldg 30 Rm 211, 9000 Rockville Pike, Bethesda, MD 20892-4340 (United States); Park, Myung Hee, E-mail: mhpark@nih.gov [Oral and Pharyngeal Cancer Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bldg 30 Rm 211, 9000 Rockville Pike, Bethesda, MD 20892-4340 (United States)

2009-06-12

2

A unique modification of the eukaryotic initiation factor 5A shows the presence of the complete hypusine pathway in Leishmania donovani.  

PubMed

Deoxyhypusine hydroxylase (DOHH) catalyzes the final step in the post-translational synthesis of an unusual amino acid hypusine (N(€)-(4-amino-2-hydroxybutyl) lysine), which is present on only one cellular protein, eukaryotic initiation factor 5A (eIF5A). We present here the molecular and structural basis of the function of DOHH from the protozoan parasite, Leishmania donovani, which causes visceral leishmaniasis. The L. donovani DOHH gene is 981 bp and encodes a putative polypeptide of 326 amino acids. DOHH is a HEAT-repeat protein with eight tandem repeats of ?-helical pairs. Four conserved histidine-glutamate sequences have been identified that may act as metal coordination sites. A ~42 kDa recombinant protein with a His-tag was obtained by heterologous expression of DOHH in Escherichia coli. Purified recombinant DOHH effectively catalyzed the hydroxylation of the intermediate, eIF5A-deoxyhypusine (eIF5A-Dhp), in vitro. L. donovani DOHH (LdDOHH) showed ~40.6% sequence identity with its human homolog. The alignment of L. donovani DOHH with the human homolog shows that there are two significant insertions in the former, corresponding to the alignment positions 159-162 (four amino acid residues) and 174-183 (ten amino acid residues) which are present in the variable loop connecting the N- and C-terminal halves of the protein, the latter being present near the substrate binding site. Deletion of the ten-amino-acid-long insertion decreased LdDOHH activity to 14% of the wild type recombinant LdDOHH. Metal chelators like ciclopirox olamine (CPX) and mimosine significantly inhibited the growth of L. donovani and DOHH activity in vitro. These inhibitors were more effective against the parasite enzyme than the human enzyme. This report, for the first time, confirms the presence of a complete hypusine pathway in a kinetoplastid unlike eubacteria and archaea. The structural differences between the L. donovani DOHH and the human homolog may be exploited for structure based design of selective inhibitors against the parasite. PMID:22438895

Chawla, Bhavna; Kumar, Ravi Ranjan; Tyagi, Nidhi; Subramanian, Gowri; Srinivasan, N; Park, Myung Hee; Madhubala, Rentala

2012-01-01

3

A Unique Modification of the Eukaryotic Initiation Factor 5A Shows the Presence of the Complete Hypusine Pathway in Leishmania donovani  

PubMed Central

Deoxyhypusine hydroxylase (DOHH) catalyzes the final step in the post-translational synthesis of an unusual amino acid hypusine (N€-(4-amino-2-hydroxybutyl) lysine), which is present on only one cellular protein, eukaryotic initiation factor 5A (eIF5A). We present here the molecular and structural basis of the function of DOHH from the protozoan parasite, Leishmania donovani, which causes visceral leishmaniasis. The L. donovani DOHH gene is 981 bp and encodes a putative polypeptide of 326 amino acids. DOHH is a HEAT-repeat protein with eight tandem repeats of ?-helical pairs. Four conserved histidine-glutamate sequences have been identified that may act as metal coordination sites. A ?42 kDa recombinant protein with a His-tag was obtained by heterologous expression of DOHH in Escherichia coli. Purified recombinant DOHH effectively catalyzed the hydroxylation of the intermediate, eIF5A-deoxyhypusine (eIF5A-Dhp), in vitro. L. donovani DOHH (LdDOHH) showed ?40.6% sequence identity with its human homolog. The alignment of L. donovani DOHH with the human homolog shows that there are two significant insertions in the former, corresponding to the alignment positions 159-162 (four amino acid residues) and 174-183 (ten amino acid residues) which are present in the variable loop connecting the N- and C-terminal halves of the protein, the latter being present near the substrate binding site. Deletion of the ten-amino-acid-long insertion decreased LdDOHH activity to 14% of the wild type recombinant LdDOHH. Metal chelators like ciclopirox olamine (CPX) and mimosine significantly inhibited the growth of L. donovani and DOHH activity in vitro. These inhibitors were more effective against the parasite enzyme than the human enzyme. This report, for the first time, confirms the presence of a complete hypusine pathway in a kinetoplastid unlike eubacteria and archaea. The structural differences between the L. donovani DOHH and the human homolog may be exploited for structure based design of selective inhibitors against the parasite. PMID:22438895

Chawla, Bhavna; Kumar, Ravi Ranjan; Tyagi, Nidhi; Subramanian, Gowri; Srinivasan, N.; Park, Myung Hee; Madhubala, Rentala

2012-01-01

4

A novel mouse model for inhibition of DOHH-mediated hypusine modification reveals a crucial function in embryonic development, proliferation and oncogenic transformation.  

PubMed

The central importance of translational control by post-translational modification has spurred major interest in regulatory pathways that control translation. One such pathway uniquely adds hypusine to eukaryotic initiation factor 5A (eIF5A), and thereby affects protein synthesis and, subsequently, cellular proliferation through an unknown mechanism. Using a novel conditional knockout mouse model and a Caenorhabditis elegans knockout model, we found an evolutionarily conserved role for the DOHH-mediated second step of hypusine synthesis in early embryonic development. At the cellular level, we observed reduced proliferation and induction of senescence in 3T3 Dohh-/- cells as well as reduced capability for malignant transformation. Furthermore, mass spectrometry showed that deletion of DOHH results in an unexpected complete loss of hypusine modification. Our results provide new biological insight into the physiological roles of the second step of the hypusination of eIF5A. Moreover, the conditional mouse model presented here provides a powerful tool for manipulating hypusine modification in a temporal and spatial manner, to analyse both how this unique modification normally functions in vivo as well as how it contributes to different pathological conditions. PMID:24832488

Sievert, Henning; Pällmann, Nora; Miller, Katharine K; Hermans-Borgmeyer, Irm; Venz, Simone; Sendoel, Ataman; Preukschas, Michael; Schweizer, Michaela; Boettcher, Steffen; Janiesch, P Christoph; Streichert, Thomas; Walther, Reinhard; Hengartner, Michael O; Manz, Markus G; Brümmendorf, Tim H; Bokemeyer, Carsten; Braig, Melanie; Hauber, Joachim; Duncan, Kent E; Balabanov, Stefan

2014-08-01

5

A novel mouse model for inhibition of DOHH-mediated hypusine modification reveals a crucial function in embryonic development, proliferation and oncogenic transformation  

PubMed Central

The central importance of translational control by post-translational modification has spurred major interest in regulatory pathways that control translation. One such pathway uniquely adds hypusine to eukaryotic initiation factor 5A (eIF5A), and thereby affects protein synthesis and, subsequently, cellular proliferation through an unknown mechanism. Using a novel conditional knockout mouse model and a Caenorhabditis elegans knockout model, we found an evolutionarily conserved role for the DOHH-mediated second step of hypusine synthesis in early embryonic development. At the cellular level, we observed reduced proliferation and induction of senescence in 3T3 Dohh?/? cells as well as reduced capability for malignant transformation. Furthermore, mass spectrometry showed that deletion of DOHH results in an unexpected complete loss of hypusine modification. Our results provide new biological insight into the physiological roles of the second step of the hypusination of eIF5A. Moreover, the conditional mouse model presented here provides a powerful tool for manipulating hypusine modification in a temporal and spatial manner, to analyse both how this unique modification normally functions in vivo as well as how it contributes to different pathological conditions. PMID:24832488

Sievert, Henning; Pällmann, Nora; Miller, Katharine K.; Hermans-Borgmeyer, Irm; Venz, Simone; Sendoel, Ataman; Preukschas, Michael; Schweizer, Michaela; Boettcher, Steffen; Janiesch, P. Christoph; Streichert, Thomas; Walther, Reinhard; Hengartner, Michael O.; Manz, Markus G.; Brümmendorf, Tim H.; Bokemeyer, Carsten; Braig, Melanie; Hauber, Joachim; Duncan, Kent E.; Balabanov, Stefan

2014-01-01

6

Production of active recombinant eIF5A: reconstitution in E.coli of eukaryotic hypusine modification of eIF5A by its coexpression with modifying enzymes.  

PubMed

Eukaryotic translation initiation factor 5A (eIF5A) is the only cellular protein that contains the polyamine-modified lysine, hypusine [N(?)-(4-amino-2-hydroxybutyl)lysine]. Hypusine occurs only in eukaryotes and certain archaea, but not in eubacteria. It is formed post-translationally by two consecutive enzymatic reactions catalyzed by deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH). Hypusine modification is essential for the activity of eIF5A and for eukaryotic cell proliferation. eIF5A binds to the ribosome and stimulates translation in a hypusine-dependent manner, but its mode of action in translation is not well understood. Since quantities of highly pure hypusine-modified eIF5A is desired for structural studies as well as for determination of its binding sites on the ribosome, we have used a polycistronic vector, pST39, to express eIF5A alone, or to co-express human eIF5A-1 with DHS or with both DHS and DOHH in Escherichia coli cells, to engineer recombinant proteins, unmodified eIF5A, deoxyhypusine- or hypusine-modified eIF5A. We have accomplished production of three different forms of recombinant eIF5A in high quantity and purity. The recombinant hypusine-modified eIF5A was as active in methionyl-puromycin synthesis as the native, eIF5A (hypusine form) purified from mammalian tissue. The recombinant eIF5A proteins will be useful tools in future structure/function and the mechanism studies in translation. PMID:21131325

Park, Jong Hwan; Dias, Camila A O; Lee, Seung Bum; Valentini, Sandro R; Sokabe, Masaaki; Fraser, Christopher S; Park, Myung Hee

2011-03-01

7

Unique posttranslational modifications in eukaryotic translation factors and their roles in protozoan parasite viability and pathogenesis.  

PubMed

Protozoan parasites are one of the major causes of diseases worldwide. The vector transmitted parasites exhibit complex life cycles involving interactions between humans, protozoa, and arthropods. In order to adapt themselves to the changing microenvironments, they have to undergo complex morphological and metabolic changes. These changes can be brought about by expressing a new pool of proteins in the cell or by modifying the existing repertoire of proteins via posttranslational modifications (PTMs). PTMs involve covalent modification and processing of proteins thereby modulating their functions. Some of these changes may involve PTMs of parasite proteins to help the parasite survive within the host and the vector. Out of many PTMs known, three are unique since they occur only on single proteins: ethanolamine phosphoglycerol (EPG) glutamate, hypusine and diphthamide. These modifications occur on eukaryotic elongation factor 1A (eEF1A), eukaryotic initiation factor 5A (eIF5A) and eukaryotic elongation factor 2 (eEF2), respectively. Interestingly, the proteins carrying these unique modifications are all involved in the elongation steps of translation. Here we review these unique PTMs, which are well conserved in protozoan parasites, and discuss their roles in viability and pathogenesis of parasites. Characterization of these modifications and studying their roles in physiology as well as pathogenesis will provide new insights in parasite biology, which may also help in developing new therapeutic interventions. PMID:23201129

Mittal, Nimisha; Subramanian, Gowri; Bütikofer, Peter; Madhubala, Rentala

2013-01-01

8

Hypusine modification of the ribosome-binding protein eIF5A, a target for new anti-inflammatory drugs: understanding the action of the inhibitor GC7 on a murine macrophage cell line.  

PubMed

Inflammation is part of an important mechanism triggered by the innate immune response that rapidly responds to invading microorganisms and tissue injury. One important elicitor of the inflammatory response is the Gram-negative bacteria component lipopolysaccharide (LPS), which induces the activation of innate immune response cells, the release of proinflammatory cytokines, such as interleukin 1 and tumor necrosis factor ?(TNF-?), and the cellular generation of nitric oxide (NO) by the inducible nitric oxide synthase (iNOS). Although essential to the immune response, uncontrolled inflammatory responses can lead to pathological conditions, such as sepsis and rheumatoid arthritis. Therefore, identifying cellular targets for new anti-inflammatory treatments is crucial to improving therapeutic control of inflammation-related diseases. More recently, the translation factor eIF5A has been demonstrated to have a proinflammatory role in the release of cytokines and the production of NO. As eIF5A requires and essential and unique modification of a specific residue of lysine, changing it to hypusine, eIF5A is an interesting cellular target for anti-inflammatory treatment. The present study reviews the literature concerning the anti-inflammatory effects of inhibiting eIF5A function. We also present new data showing that the inhibition of eIF5A function by the small molecule GC7 significantly decreases TNF-? release without affecting TNF-? mRNA levels. We discuss the mechanisms by which eIF5A may interfere with TNF-? mRNA translation by binding to and regulating the function of ribosomes during protein synthesis. PMID:23701550

de Almeida, Oedem Paulo; Toledo, Thais Regina; Rossi, Danuza; Rossetto, Daniella de Barros; Watanabe, Tatiana Faria; Galvão, Fábio Carrilho; Medeiros, Alexandra Ivo; Zanelli, Cleslei Fernando; Valentini, Sandro Roberto

2014-01-01

9

Biochemical quantitation of the eIF5A hypusination in Arabidopsis thaliana uncovers ABA-dependent regulation.  

PubMed

The eukaryotic translation elongation factor eIF5A is the only protein known to contain the unusual amino acid hypusine which is essential for its biological activity. This post-translational modification is achieved by the sequential action of the enzymes deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH). The crucial molecular function of eIF5A during translation has been recently elucidated in yeast and it is expected to be fully conserved in every eukaryotic cell, however the functional description of this pathway in plants is still sparse. The genetic approaches with transgenic plants for either eIF5A overexpression or antisense have revealed some activities related to the control of cell death processes but the molecular details remain to be characterized. One important aspect of fully understanding this pathway is the biochemical description of the hypusine modification system. Here we have used recombinant eIF5A proteins either modified by hypusination or non-modified to establish a bi-dimensional electrophoresis (2D-E) profile for the three eIF5A protein isoforms and their hypusinated or unmodified proteoforms present in Arabidopsis thaliana. The combined use of the recombinant 2D-E profile together with 2D-E/western blot analysis from whole plant extracts has provided a quantitative approach to measure the hypusination status of eIF5A. We have used this information to demonstrate that treatment with the hormone abscisic acid produces an alteration of the hypusine modification system in Arabidopsis thaliana. Overall this study presents the first biochemical description of the post-translational modification of eIF5A by hypusination which will be functionally relevant for future studies related to the characterization of this pathway in Arabidopsis thaliana. PMID:24904603

Belda-Palazón, Borja; Nohales, María A; Rambla, José L; Aceña, José L; Delgado, Oscar; Fustero, Santos; Martínez, M Carmen; Granell, Antonio; Carbonell, Juan; Ferrando, Alejandro

2014-01-01

10

Biochemical quantitation of the eIF5A hypusination in Arabidopsis thaliana uncovers ABA-dependent regulation  

PubMed Central

The eukaryotic translation elongation factor eIF5A is the only protein known to contain the unusual amino acid hypusine which is essential for its biological activity. This post-translational modification is achieved by the sequential action of the enzymes deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH). The crucial molecular function of eIF5A during translation has been recently elucidated in yeast and it is expected to be fully conserved in every eukaryotic cell, however the functional description of this pathway in plants is still sparse. The genetic approaches with transgenic plants for either eIF5A overexpression or antisense have revealed some activities related to the control of cell death processes but the molecular details remain to be characterized. One important aspect of fully understanding this pathway is the biochemical description of the hypusine modification system. Here we have used recombinant eIF5A proteins either modified by hypusination or non-modified to establish a bi-dimensional electrophoresis (2D-E) profile for the three eIF5A protein isoforms and their hypusinated or unmodified proteoforms present in Arabidopsis thaliana. The combined use of the recombinant 2D-E profile together with 2D-E/western blot analysis from whole plant extracts has provided a quantitative approach to measure the hypusination status of eIF5A. We have used this information to demonstrate that treatment with the hormone abscisic acid produces an alteration of the hypusine modification system in Arabidopsis thaliana. Overall this study presents the first biochemical description of the post-translational modification of eIF5A by hypusination which will be functionally relevant for future studies related to the characterization of this pathway in Arabidopsis thaliana. PMID:24904603

Belda-Palazón, Borja; Nohales, María A.; Rambla, José L.; Aceña, José L.; Delgado, Oscar; Fustero, Santos; Martínez, M. Carmen; Granell, Antonio; Carbonell, Juan; Ferrando, Alejandro

2014-01-01

11

Characterization of a novel polyclonal anti-hypusine antibody.  

PubMed

The translation factor eIF5A is the only protein known to contain the amino acid hypusine, which is formed posttranslationally. Hypusinated eIF5A is necessary for cellular proliferation and responses to extracellular stressors, and has been proposed as a target for pharmacologic therapy. Here, we provide the first comprehensive characterization of a novel polyclonal antibody (IU-88) that specifically recognizes the hypusinated eIF5A. IU-88 will be useful for the investigation of eIF5A biology and for the development of assays recognizing hypusinated eIF5A. PMID:24024105

Nishiki, Yurika; Farb, Thomas B; Friedrich, Jessica; Bokvist, Krister; Mirmira, Raghavendra G; Maier, Bernhard

2013-01-01

12

Inactivation of eukaryotic initiation factor 5A (eIF5A) by specific acetylation of its hypusine residue by spermidine/spermine acetyltransferase 1 (SSAT1).  

PubMed

eIF5A (eukaryotic translation initiation factor 5A) is the only cellular protein containing hypusine [N?-(4-amino-2-hydroxybutyl)lysine]. eIF5A is activated by the post-translational synthesis of hypusine and the hypusine modification is essential for cell proliferation. In the present study, we report selective acetylation of the hypusine and/or deoxyhypusine residue of eIF5A by a key polyamine catabolic enzyme SSAT1 (spermidine/spermine-N1-acetyltransferase 1). This enzyme normally catalyses the N1-acetylation of spermine and spermidine to form acetyl-derivatives, which in turn are degraded to lower polyamines. Although SSAT1 has been reported to exert other effects in cells by its interaction with other cellular proteins, eIF5A is the first target protein specifically acetylated by SSAT1. Hypusine or deoxyhypusine, as the free amino acid, does not act as a substrate for SSAT1, suggesting a macromolecular interaction between eIF5A and SSAT1. Indeed, the binding of eIF5A and SSAT1 was confirmed by pull-down assays. The effect of the acetylation of hypusine on eIF5A activity was assessed by comparison of acetylated with non-acetylated bovine testis eIF5A in the methionyl-puromycin synthesis assay. The loss of eIF5A activity by this SSAT1-mediated acetylation confirms the strict structural requirement for the hypusine side chain and suggests a possible regulation of eIF5A by hypusine acetylation/deacetylation. PMID:20942800

Lee, Seung Bum; Park, Jong Hwan; Folk, John E; Deck, Jason A; Pegg, Anthony E; Sokabe, Masaaki; Fraser, Christopher S; Park, Myung Hee

2011-01-01

13

Effects of novel C-methylated spermidine analogs on cell growth via hypusination of eukaryotic translation initiation factor 5A.  

PubMed

The polyamines, putrescine, spermidine, and spermine, are ubiquitous multifunctional cations essential for cellular proliferation. One specific function of spermidine in cell growth is its role as a butylamine donor for hypusine synthesis in the eukaryotic initiation factor 5A (eIF5A). Here, we report the ability of novel mono-methylated spermidine analogs (?-MeSpd, ?-MeSpd, ?-MeSpd, and ?-MeSpd) to function in the hypusination of eIF5A and in supporting the growth of DFMO-treated DU145 cells. We also tested them as substrates and inhibitors for deoxyhypusine synthase (DHS) in vitro. Of these compounds, ?-MeSpd, ?-MeSpd, and ?-MeSpd (but not ?-MeSpd) were substrates for DHS in vitro, while they all inhibited the enzyme reaction. As racemic mixtures, only ?-MeSpd and ?-MeSpd supported long-term growth (9-18 days) of spermidine-depleted DU145 cells, whereas ?-MeSpd and ?-MeSpd did not. The S-enantiomer of ?-MeSpd, which supported long-term growth, was a good substrate for DHS in vitro, whereas the R-isomer was not. The long-term growth of DFMO-treated cells correlated with the hypusine modification of eIF5A by intracellular methylated spermidine analogs. These results underscore the critical requirement for hypusine modification in mammalian cell proliferation and provide new insights into the specificity of the deoxyhypusine synthase reaction. PMID:21861168

Hyvönen, Mervi T; Keinänen, Tuomo A; Khomutov, Maxim; Simonian, Alina; Vepsäläinen, Jouko; Park, Jong Hwan; Khomutov, Alex R; Alhonen, Leena; Park, Myung Hee

2012-02-01

14

A hypusine-eIF5A-PEAK1 switch regulates the pathogenesis of pancreatic cancer.  

PubMed

Deregulation of protein synthesis is a hallmark of cancer cell proliferation, survival, and metastatic progression. eIF5A1 and its highly related isoform eIF5A2 are translation initiation factors that have been implicated in a range of human malignancies, but how they control cancer development and disease progression is still poorly understood. Here, we investigated how eIF5A proteins regulate pancreatic ductal adenocarcinoma (PDAC) pathogenesis. eIF5A proteins are the only known proteins regulated by a distinct posttranslational modification termed hypusination, which is catalyzed by two enzymes, deoxyhypusine synthase (DHPS) and deoxyhypusine hydroxylase (DOHH). The highly selective nature of the hypusine modification and its amenability to pharmacologic inhibition make eIF5A proteins attractive therapeutic targets. We found that the expression and hypusination of eIF5A proteins are upregulated in human PDAC tissues and in premalignant pancreatic intraepithelial neoplasia tissues isolated from Pdx-1-Cre: LSL-KRAS(G12D) mice. Knockdown of eIF5A proteins in PDAC cells inhibited their growth in vitro and orthotopic tumor growth in vivo, whereas amplification of eIF5A proteins increased PDAC cell growth and tumor formation in mice. Small-molecule inhibitors of DHPS and DOHH both suppressed eIF5A hypusination, preventing PDAC cell growth. Interestingly, we found that eIF5A proteins regulate PDAC cell growth by modulating the expression of PEAK1, a nonreceptor tyrosine kinase essential for PDAC cell growth and therapy resistance. Our findings suggest that eIF5A proteins utilize PEAK1 as a downstream effector to drive PDAC pathogenesis and that pharmacologic inhibition of the eIF5A-hypusine-PEAK1 axis may provide a novel therapeutic strategy to combat this deadly disease. PMID:25261239

Fujimura, Ken; Wright, Tracy; Strnadel, Jan; Kaushal, Sharmeela; Metildi, Cristina; Lowy, Andrew M; Bouvet, Michael; Kelber, Jonathan A; Klemke, Richard L

2014-11-15

15

Cryptosporidium parvum has an active hypusine biosynthesis pathway.  

PubMed

The protozoan parasite Cryptosporidium parvum causes severe enteric infection and diarrheal disease with substantial morbidity and mortality in untreated AIDS patients and children in developing or resource-limited countries. No fully effective treatment is available. Hypusination of eIF5A is an important post-translational modification essential for cell proliferation. This modification occurs in a two step process catalyzed by deoxyhypusine synthase (DHS) followed by deoxyhypusine hydroxylase. An ORF of 1086bp was identified in the C. parvum (Cp) genome which encodes for a putative polypeptide of 362 amino acids. The recombinant CpDHS protein was purified to homogeneity and used to probe the enzyme's mechanism, structure, and inhibition profile in a series of kinetic experiments. Sequence analysis and structural modeling of CpDHS were performed to probe differences with respect to the DHS of other species. Unlike Leishmania, Trypanosomes and Entamoeba, Cryptosporidium contains only a single gene for DHS. Phylogenetic analysis shows that CpDHS is more closely related to apicomplexan DHS than kinetoplastid DHS. Important residues that are essential for the functioning of the enzyme including NAD(+) binding residues, spermidine binding residues and the active site lysine are conserved between CpDHS and human DHS. N(1)-guanyl-1,7-diaminoheptane (GC7), a potent inhibitor of DHS caused an effective inhibition of infection and growth of C. parvum in HCT-8 cells. PMID:24893338

Mittal, Nimisha; Morada, Marie; Tripathi, Pankaj; Gowri, V S; Mandal, Swati; Quirch, Alison; Park, Myung Hee; Yarlett, Nigel; Madhubala, Rentala

2014-06-01

16

Cryptosporidium parvum has an active hypusine biosynthesis pathway  

PubMed Central

The protozoan parasite Cryptosporidium parvum causes severe enteric infection and diarrheal disease with substantial morbidity and mortality in untreated AIDS patients and children in developing or resource-limited countries. No fully effective treatment is available. Hypusination of eIF5A is an important post-translational modification essential for cell proliferation. This modification occurs in a two step process catalyzed by deoxyhypusine synthase (DHS) followed by deoxyhypusine hydroxylase. An ORF of 1086 bp was identified in the C. parvum (Cp) genome which encodes for a putative polypeptide of 362 amino acids. The recombinant CpDHS protein was purified to homogeneity and used to probe the enzyme’s mechanism, structure, and inhibition profile in a series of kinetic experiments. Sequence analysis and structural modeling of CpDHS were performed to probe differences with respect to the DHS of other species. Unlike Leishmania, Trypanosomes and Entamoeba, Cryptosporidium contains only a single gene for DHS. Phylogenetic analysis shows that CpDHS is more closely related to apicomplexan DHS than kinetoplastid DHS. Important residues that are essential for the functioning of the enzyme including NAD+ binding residues, spermidine binding residues and the active site lysine are conserved between CpDHS and human DHS. N1-guanyl-1.7-diaminoheptane (GC7), a potent inhibitor of DHS caused an effective inhibition of infection and growth of C. parvum in HCT-8 cells. PMID:24893338

Mittal, Nimisha; Morada, Marie; Tripathi, Pankaj; Gowri, V.S.; Mandal, Swati; Quirch, Alison; Park, Myung Hee; Yarlett, Nigel; Madhubala, Rentala

2014-01-01

17

Effects of novel C-methylated spermidine analogs on cell growth via hypusination of eukaryotic translation initiation factor 5A  

PubMed Central

The polyamines, putrescine, spermidine and spermine, are ubiquitous multifunctional cations essential for cellular proliferation. One specific function of spermidine in cell growth is its role as a butylamine donor for hypusine synthesis in the eukaryotic initiation factor 5A (eIF5A). Here, we report a novel series of mono-methylated spermidine analogs (?-MeSpd, ?-MeSpd, ?-MeSpd, and ?-MeSpd) and their role in the hypusination of eIF5A and in supporting the growth of DFMO-treated DU145 cells. We also tested them as substrates and inhibitors for deoxyhypusine synthase (DHS) in vitro. Of these compounds, ?-MeSpd, ?-MeSpd, and ?-MeSpd (but not ?-MeSpd) were substrates for DHS in vitro, while they all inhibited the enzyme reaction. As racemic mixtures, only ?-MeSpd and ?-MeSpd supported long-term growth (9–18 days) of spermidine-depleted DU145 cells, whereas ?-MeSpd and ?-MeSpd did not. The S-enantiomer of ?-MeSpd, which supported long-term growth, was a good substrate for DHS in vitro, whereas the R isomer was not. The long-term growth of DFMO-treated cells correlated with the hypusine-modification of eIF5A by intracellular methylated spermidine analogs. These results underscore the critical requirement for hypusine modification in mammalian cell proliferation and provide new insights into the specificity of the deoxyhypusine synthase reaction. PMID:21861168

Hyvönen, Mervi T.; Keinänen, Tuomo A.; Khomutov, Maxim; Simonian, Alina; Vepsäläinen, Jouko; Park, Jong Hwan; Khomutov, Alex R.; Alhonen, Leena; Park, Myung Hee

2011-01-01

18

The hypusine-containing translation factor eIF5A.  

PubMed

In addition to the small and large ribosomal subunits, aminoacyl-tRNAs, and an mRNA, cellular protein synthesis is dependent on translation factors. The eukaryotic translation initiation factor 5A (eIF5A) and its bacterial ortholog elongation factor P (EF-P) were initially characterized based on their ability to stimulate methionyl-puromycin (Met-Pmn) synthesis, a model assay for protein synthesis; however, the function of these factors in cellular protein synthesis has been difficult to resolve. Interestingly, a conserved lysine residue in eIF5A is post-translationally modified to hypusine and the corresponding lysine residue in EF-P from at least some bacteria is modified by the addition of a ?-lysine moiety. In this review, we provide a summary of recent data that have identified a novel role for the translation factor eIF5A and its hypusine modification in the elongation phase of protein synthesis and more specifically in stimulating the production of proteins containing runs of consecutive proline residues. PMID:25029904

Dever, Thomas E; Gutierrez, Erik; Shin, Byung-Sik

2014-01-01

19

The Histone Code of Toxoplasma gondii Comprises Conserved and Unique Posttranslational Modifications  

PubMed Central

ABSTRACT Epigenetic gene regulation has emerged as a major mechanism for gene regulation in all eukaryotes. Histones are small, basic proteins that constitute the major protein component of chromatin, and posttranslational modifications (PTM) of histones are essential for epigenetic gene regulation. The different combinations of histone PTM form the histone code for an organism, marking functional units of chromatin that recruit macromolecular complexes that govern chromatin structure and regulate gene expression. To characterize the repertoire of Toxoplasma gondii histone PTM, we enriched histones using standard acid extraction protocols and analyzed them with several complementary middle-down and bottom-up proteomic approaches with the high-resolution Orbitrap mass spectrometer using collision-induced dissociation (CID), higher-energy collisional dissociation (HCD), and/or electron transfer dissociation (ETD) fragmentation. We identified 249 peptides with unique combinations of PTM that comprise the T. gondii histone code. T. gondii histones share a high degree of sequence conservation with human histones, and many modifications are conserved between these species. In addition, T. gondii histones have unique modifications not previously identified in other species. Finally, T. gondii histones are modified by succinylation, propionylation, and formylation, recently described histone PTM that have not previously been identified in parasitic protozoa. The characterization of the T. gondii histone code will facilitate in-depth analysis of how epigenetic regulation affects gene expression in pathogenic apicomplexan parasites and identify a new model system for elucidating the biological functions of novel histone PTM. PMID:24327343

Nardelli, Sheila C.; Che, Fa-Yun; Silmon de Monerri, Natalie C.; Xiao, Hui; Nieves, Edward; Madrid-Aliste, Carlos; Angel, Sergio O.; Sullivan, William J.; Angeletti, Ruth H.; Kim, Kami; Weiss, Louis M.

2013-01-01

20

A tumour suppressor network relying on the polyamine-hypusine axis.  

PubMed

Tumour suppressor genes encode a broad class of molecules whose mutational attenuation contributes to malignant progression. In the canonical situation, the tumour suppressor is completely inactivated through a two-hit process involving a point mutation in one allele and chromosomal deletion of the other. Here, to identify tumour suppressor genes in lymphoma, we screen a short hairpin RNA library targeting genes deleted in human lymphomas. We functionally identify those genes whose suppression promotes tumorigenesis in a mouse lymphoma model. Of the nine tumour suppressors we identified, eight correspond to genes occurring in three physically linked 'clusters', suggesting that the common occurrence of large chromosomal deletions in human tumours reflects selective pressure to attenuate multiple genes. Among the new tumour suppressors are adenosylmethionine decarboxylase 1 (AMD1) and eukaryotic translation initiation factor 5A (eIF5A), two genes associated with hypusine, a unique amino acid produced as a product of polyamine metabolism through a highly conserved pathway. Through a secondary screen surveying the impact of all polyamine enzymes on tumorigenesis, we establish the polyamine-hypusine axis as a new tumour suppressor network regulating apoptosis. Unexpectedly, heterozygous deletions encompassing AMD1 and eIF5A often occur together in human lymphomas and co-suppression of both genes promotes lymphomagenesis in mice. Thus, some tumour suppressor functions can be disabled through a two-step process targeting different genes acting in the same pathway. PMID:22722845

Scuoppo, Claudio; Miething, Cornelius; Lindqvist, Lisa; Reyes, José; Ruse, Cristian; Appelmann, Iris; Yoon, Seungtai; Krasnitz, Alexander; Teruya-Feldstein, Julie; Pappin, Darryl; Pelletier, Jerry; Lowe, Scott W

2012-07-12

21

A tumour suppressor network relying on the polyamine–hypusine axis  

PubMed Central

Tumour suppressor genes encode a broad class of molecules whose mutational attenuation contributes to malignant progression. In the canonical situation, the tumour suppressor is completely inactivated through a two-hit process involving a point mutation in one allele and chromosomal deletion of the other1. Here, to identify tumour suppressor genes in lymphoma, we screen a short hairpin RNA library targeting genes deleted in human lymphomas. We functionally identify those genes whose suppression promotes tumorigenesis in a mouse lymphoma model. Of the nine tumour suppressors we identified, eight correspond to genes occurring in three physically linked ‘clusters’, suggesting that the common occurrence of large chromosomal deletions in human tumours reflects selective pressure to attenuate multiple genes. Among the new tumour suppressors are adenosylmethionine decarboxylase 1 (AMD1) and eukaryotic translation initiation factor 5A (eIF5A), two genes associated with hypusine, a unique amino acid produced as a product of polyamine metabolism through a highly conserved pathway2. Through a secondary screen surveying the impact of all polyamine enzymes on tumorigenesis, we establish the polyamine–hypusine axis as a new tumour suppressor network regulating apoptosis. Unexpectedly, heterozygous deletions encompassing AMD1 and eIF5A often occur together in human lymphomas and co-suppression of both genes promotes lymphomagenesis in mice. Thus, some tumour suppressor functions can be disabled through a two-step process targeting different genes acting in the same pathway. PMID:22722845

Scuoppo, Claudio; Miething, Cornelius; Lindqvist, Lisa; Reyes, José; Ruse, Cristian; Appelmann, Iris; Yoon, Seungtai; Krasnitz, Alexander; Teruya-Feldstein, Julie; Pappin, Darryl; Pelletier, Jerry; Lowe, Scott W.

2012-01-01

22

A unique family of Mrr-like modification-dependent restriction endonucleases  

PubMed Central

Mrr superfamily of homologous genes in microbial genomes restricts modified DNA in vivo. However, their biochemical properties in vitro have remained obscure. Here, we report the experimental characterization of MspJI, a remote homolog of Escherichia coli’s Mrr and show it is a DNA modification-dependent restriction endonuclease. Our results suggest MspJI recognizes mCNNR (R = G/A) sites and cleaves DNA at fixed distances (N12/N16) away from the modified cytosine at the 3? side (or N9/N13 from R). Besides 5-methylcytosine, MspJI also recognizes 5-hydroxymethylcytosine but is blocked by 5-glucosylhydroxymethylcytosine. Several other close homologs of MspJI show similar modification-dependent endonuclease activity and display substrate preferences different from MspJI. A unique feature of these modification-dependent enzymes is that they are able to extract small DNA fragments containing modified sites on genomic DNA, for example ?32 bp around symmetrically methylated CG sites and ?31 bp around methylated CNG sites. The digested fragments can be directly selected for high-throughput sequencing to map the location of the modification on the genomic DNA. The MspJI enzyme family, with their different recognition specificities and cleavage properties, provides a basis on which many future methods can build to decode the epigenomes of different organisms. PMID:20444879

Zheng, Yu; Cohen-Karni, Devora; Xu, Derrick; Chin, Hang Gyeong; Wilson, Geoffrey; Pradhan, Sriharsa; Roberts, Richard J.

2010-01-01

23

A unique family of Mrr-like modification-dependent restriction endonucleases.  

PubMed

Mrr superfamily of homologous genes in microbial genomes restricts modified DNA in vivo. However, their biochemical properties in vitro have remained obscure. Here, we report the experimental characterization of MspJI, a remote homolog of Escherichia coli's Mrr and show it is a DNA modification-dependent restriction endonuclease. Our results suggest MspJI recognizes (m)CNNR (R = G/A) sites and cleaves DNA at fixed distances (N(12)/N(16)) away from the modified cytosine at the 3' side (or N(9)/N(13) from R). Besides 5-methylcytosine, MspJI also recognizes 5-hydroxymethylcytosine but is blocked by 5-glucosylhydroxymethylcytosine. Several other close homologs of MspJI show similar modification-dependent endonuclease activity and display substrate preferences different from MspJI. A unique feature of these modification-dependent enzymes is that they are able to extract small DNA fragments containing modified sites on genomic DNA, for example ?32 bp around symmetrically methylated CG sites and ?31 bp around methylated CNG sites. The digested fragments can be directly selected for high-throughput sequencing to map the location of the modification on the genomic DNA. The MspJI enzyme family, with their different recognition specificities and cleavage properties, provides a basis on which many future methods can build to decode the epigenomes of different organisms. PMID:20444879

Zheng, Yu; Cohen-Karni, Devora; Xu, Derrick; Chin, Hang Gyeong; Wilson, Geoffrey; Pradhan, Sriharsa; Roberts, Richard J

2010-09-01

24

The spermidine analogue GC7 (N1-guanyl-1,7-diamineoheptane) induces autophagy through a mechanism not involving the hypusination of eIF5A.  

PubMed

The exogenous administration of spermidine promotes longevity in many model organisms. It has been proposed that this anti-age activity of spermidine is related to this polyamine's ability to promote autophagy. Since spermidine is the substrate for the eIF5A post-translational modification by hypusination, we asked ourselves whether mature eIF5A may represent the link between spermidine and autophagy induction. To test this hypothesis, we inhibited the conversion of native eIF5A by a pharmacological approach, using the N1-guanyl-1,7-diamineoheptane (GC7), a spermidine analogue which competitively and reversibly inhibits deoxyhypusine synthase (DHS). In addition, we also employed genetic approaches by ablating both the eIF5A protein itself and DHS, the rate limiting enzyme catalyzing the conversion of lysine to hypusine. Collectively the data presented in this study demonstrate that the mature eIF5A (hypusinated form) is not involved in the autophagic pathway and that the inhibitor of DHS, GC7, produces off-target effect(s) resulting in marked induction of basal autophagy. These data are relevant in light of the fact that GC7 is considered a potent and selective inhibitor of DHS and is a potential candidate drug for cancer, diabetes and HIV therapy. PMID:25218134

Oliverio, Serafina; Corazzari, Marco; Sestito, Claudia; Piredda, Lucia; Ippolito, Giuseppe; Piacentini, Mauro

2014-12-01

25

Development of orthogonally protected hypusine for solid-phase Peptide synthesis.  

PubMed

An orthogonally protected hypusine reagent was developed for solid-phase synthesis of hypusinated peptides using the Fmoc/t-Bu protection strategy. The reagent was synthesized in an overall yield of 27% after seven steps from Cbz-Lys-OBzl and (R)-3-hydroxypyrrolidin-2-one. The side-chain protecting groups (Boc and t-Bu) are fully compatible with standard Fmoc chemistry and can be readily removed during the peptide cleavage step. The utility of the reagent was demonstrated by solid-phase synthesis of hypusinated peptides. PMID:25769022

Song, Aimin; Tom, Jeffrey; Yu, Zhiyong; Pham, Victoria; Tan, Dajin; Zhang, Dengxiong; Fang, Guoyong; Yu, Tao; Deshayes, Kurt

2015-04-01

26

De novo sequencing of unique sequence tags for discovery of post-translational modifications of proteins  

SciTech Connect

De novo sequencing has a promise to discover the protein post-translation modifications; however, such approach is still in their infancy and not widely applied for proteomics practices due to its limited reliability. In this work, we describe a de novo sequencing approach for discovery of protein modifications through identification of the UStags (Anal. Chem. 2008, 80, 1871-1882). The de novo information was obtained from Fourier-transform tandem mass spectrometry for peptides and polypeptides in a yeast lysate, and the de novo sequences obtained were filtered to define a more limited set of UStags. The DNA-predicted database protein sequences were then compared to the UStags, and the differences observed across or in the UStags (i.e., the UStags’ prefix and suffix sequences and the UStags themselves) were used to infer the possible sequence modifications. With this de novo-UStag approach, we uncovered some unexpected variances of yeast protein sequences due to amino acid mutations and/or multiple modifications to the predicted protein sequences. Random matching of the de novo sequences to the predicted sequences were examined with use of two random (false) databases, and ~3% false discovery rates were estimated for the de novo-UStag approach. The factors affecting the reliability (e.g., existence of de novo sequencing noise residues and redundant sequences) and the sensitivity are described. The de novo-UStag complements the UStag method previously reported by enabling discovery of new protein modifications.

Shen, Yufeng; Tolic, Nikola; Hixson, Kim K.; Purvine, Samuel O.; Anderson, Gordon A.; Smith, Richard D.

2008-10-15

27

Unique Structural Modifications Are Present in the Lipopolysaccharide from Colistin-Resistant Strains of Acinetobacter baumannii  

PubMed Central

Acinetobacter baumannii is a nosocomial opportunistic pathogen that can cause severe infections, including hospital-acquired pneumonia, wound infections, and sepsis. Multidrug-resistant (MDR) strains are prevalent, further complicating patient treatment. Due to the increase in MDR strains, the cationic antimicrobial peptide colistin has been used to treat A. baumannii infections. Colistin-resistant strains of A. baumannii with alterations to the lipid A component of lipopolysaccharide (LPS) have been reported; specifically, the lipid A structure was shown to be hepta-acylated with a phosphoethanolamine (pEtN) modification present on one of the terminal phosphate residues. Using a tandem mass spectrometry platform, we provide definitive evidence that the lipid A isolated from colistin-resistant A. baumannii MAC204 LPS contains a novel structure corresponding to a diphosphoryl hepta-acylated lipid A structure with both pEtN and galactosamine (GalN) modifications. To correlate our structural studies with clinically relevant samples, we characterized colistin-susceptible and -resistant isolates obtained from patients. These results demonstrated that the clinical colistin-resistant isolate had the same pEtN and GalN modifications as those seen in the laboratory-adapted A. baumannii strain MAC204. In summary, this work has shown complete structure characterization including the accurate assignment of acylation, phosphorylation, and glycosylation of lipid A from A. baumannii, which are important for resistance to colistin. PMID:23877686

Pelletier, Mark R.; Casella, Leila G.; Jones, Jace W.; Adams, Mark D.; Zurawski, Daniel V.; Hazlett, Karsten R. O.; Doi, Yohei

2013-01-01

28

The human mitochondrial tRNAMet: Structure/function relationship of a unique modification in the decoding of unconventional codons  

PubMed Central

Human mitochondrial mRNAs utilize the universal AUG and the unconventional isoleucine AUA codons for methionine. In contrast to translation in the cytoplasm, human mitochondria use one tRNA, hmtRNAMetCAU, to read AUG and AUA codons at both the peptidyl- (P-), and aminoacyl-(A-) sites of the ribosome. The hmtRNAMetCAU has a unique post-transcriptional modification, 5-formylcytidine, at the wobble position 34 (f5C34), and a cytidine substituting for the invariant uridine at position 33 of the canonical “U-turn” in tRNAs. The structure of the tRNA's anticodon stem and loop domain (hmtASLMetCAU), determined by NMR restrained molecular modeling, revealed how the f5C34 modification facilitates the decoding of AUA at the P- and A-sites. The f5C34 defined a reduced conformational space for the nucleoside, in what appears to have restricted the conformational dynamics of the anticodon bases of the modified hmtASLMetCAU. The hmtASLMetCAU exhibited a “C-turn” conformation that has some characteristics of the U-turn motif. Codon binding studies with both E. coli and bovine mitochondrial ribosomes revealed that the f5C34 facilitates AUA binding in the A-site and suggested that the modification favorably alters the ASL's binding kinetics. Mitochondrial translation by many organisms including humans sometimes initiates with the universal isoleucine codons AUU and AUC. The f5C34 enabled P-site codon binding to these normally isoleucine codons. Thus, the physicochemical properties of this one modification, f5C34, expand codon recognition from the traditional AUG to the non-traditional, synonymous codons AUU and AUC as well as AUA, in the reassignment of universal codons in the mitochondria. PMID:21168417

Bilbille, Yann; Gustilo, Estella M.; Harris, Kimberly A.; Jones, Christie N.; Lusic, Hrvoje; Kaiser, Robert J.; Delaney, Michael O.; Spremulli, Linda L.; Deiters, Alexander; Agris, Paul F.

2011-01-01

29

G-rich VEGF aptamer with locked and unlocked nucleic acid modifications exhibits a unique G-quadruplex fold  

PubMed Central

The formation of a single G-quadruplex structure adopted by a promising 25 nt G-rich vascular endothelial growth factor aptamer in a K+ rich environment was facilitated by locked nucleic acid modifications. An unprecedented all parallel-stranded monomeric G-quadruplex with three G-quartet planes exhibits several unique structural features. Five consecutive guanine residues are all involved in G-quartet formation and occupy positions in adjacent DNA strands, which are bridged with a no-residue propeller-type loop. A two-residue D-shaped loop facilitates inclusion of an isolated guanine residue into the vacant spot within the G-quartet. The remaining two G-rich tracts of three residues each adopt parallel orientation and are linked with edgewise and propeller loops. Both 5? with 3 nt and 3? with 4 nt overhangs display well-defined conformations, with latter adopting a basket handle topology. Locked residues contribute to thermal stabilization of the adopted structure and formation of structurally pre-organized intermediates that facilitate folding into a single G-quadruplex. Understanding the impact of chemical modifications on folding, thermal stability and structural polymorphism of G-quadruplexes provides means for the improvement of vascular endothelial growth factor aptamers and advances our insights into driving nucleic acid structure by locking or unlocking the conformation of sugar moieties of nucleotides in general. PMID:23935071

Maruši?, Maja; Veedu, Rakesh N.; Wengel, Jesper; Plavec, Janez

2013-01-01

30

Hypusine-containing proteins and their modifying enzymes  

SciTech Connect

The aim of this study is to purify and characterize this protein and to investigate general properties of its modifying enzymes. I developed a simple four-step procedure for purifying the hyp-18K protein. This procedure resulted in an 800-fold purification of the radio-labeled protein from NB-15 mouse neuroblastoma cells. Two hypusine-containing proteins with an apparent molecular weight of 18 kDa and 20 kDa were also identified by metabolic labeling in chick embryo fibroblasts. The hyp-18K in both NB cells and chick embryo fibroblastes exhibited two isoforms: acidic form (hyp-18K{sup a}) and basic form (hyp-18K{sup b}). I also purified both hyp-20K and hyp-18K isoforms from chick embryos to homogeneity. V8 protease peptide map analysis indicated that hyp-18K{sup b} isolated from chick embryos was identical, while hyp-18K{sup a} and hyp-20K were similar, to elF-4D. The chick embryo hyp-18K{sup b}, but not hyp-18K{sup a}, co-migrated with elF-4D. When NB cell lysates were incubated with ({sup 3}H)spermidine at pH 9.5, only hyp-18K{sup b} was labeled. Lysates, labeled at pH 9.5 and then adjusted to pH 7.2, gave both hyp-18K{sup a} and hyp-18K{sup b}. These data provided evidence that hyp-18K{sup a} is derived from hyp-18K{sup b}.

Dou, Q.

1988-01-01

31

Structural and functional effects of selective chemical modifications of Scapharca inaequivalvis haemoglobins in relation to their unique assembly.  

PubMed Central

The structural and functional roles of lysyl and thiol groups in the dimeric (HbI) and tetrameric (HbII) haemoglobins from the mollusc Scapharca inaequivalvis have been assessed. In these haemoglobins a unique mode of assembly (the haem-carrying E and F helices form the intersubunit contact of the dimeric unit) is associated with co-operative oxygen binding. Extensive acylation is accompanied by significant haem oxidation. Modification of one or two lysyl residues per chain (corresponding to approximately 20% of the total residues) does not affect the structural and functional properties of both haemoglobins, in line with the proposal that the intersubunit contacts are rich in hydrophobic residues. The modification of the thiol groups does not influence the state of association in both HbI and HbII, despite the location of the cysteine residue common to all polypeptide chains in the vicinity of the major intersubunit contact. The effect on the functional properties depends on the size of the thiol reagent: p-chloromercuribenzoate and phenylmercuric acetate increase the oxygen affinity about 20-fold, but iodoacetamide and mercuric chloride have no effect. Moreover, electrophoresis experiments indicate that p-chloromercuribenzoate is bound in a co-operative fashion, the degree of co-operativity being much higher in the dimeric HbI. Thus, only in HbII are intermediates containing substoichiometric amounts of p-chloromercuribenzoate formed in significant amounts. Their oxygen binding properties show that reaction of only one thiol group/tetramer suffices to alter the oxygen affinity of the molecule. Images Fig. 1. Fig. 3. Fig. 4. PMID:3593205

Boffi, A; Gattoni, M; Santucci, R; Vecchini, P; Ascoli, F; Chiancone, E

1987-01-01

32

Modification of NASA Langley 8 foot high temperature tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems  

NASA Technical Reports Server (NTRS)

A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988.

Kelly, H. N.; Wieting, A. R.

1984-01-01

33

Modification of NASA Langley 8 Foot High Temperature Tunnel to provide a unique national research facility for hypersonic air-breathing propulsion systems  

NASA Technical Reports Server (NTRS)

A planned modification of the NASA Langley 8-Foot High Temperature Tunnel to make it a unique national research facility for hypersonic air-breathing propulsion systems is described, and some of the ongoing supporting research for that modification is discussed. The modification involves: (1) the addition of an oxygen-enrichment system which will allow the methane-air combustion-heated test stream to simulate air for propulsion testing; and (2) supplemental nozzles to expand the test simulation capability from the current nominal Mach number to 7.0 include Mach numbers 3.0, 4.5, and 5.0. Detailed design of the modifications is currently underway and the modified facility is scheduled to be available for tests of large scale propulsion systems by mid 1988.

Kelly, H. N.; Wieting, A. R.

1984-01-01

34

Characterization of Unique Modification of Flagellar Rod Protein FlgG by Campylobacter jejuni Lipid A Phosphoethanolamine Transferase, Linking Bacterial Locomotion and Antimicrobial Peptide Resistance*  

PubMed Central

Gram-negative bacteria assemble complex surface structures that interface with the surrounding environment and are involved in pathogenesis. Recent work in Campylobacter jejuni identified a gene encoding a novel phosphoethanolamine (pEtN) transferase Cj0256, renamed EptC, that serves a dual role in modifying the flagellar rod protein, FlgG, and the lipid A domain of C. jejuni lipooligosaccharide with a pEtN residue. In this work, we characterize the unique post-translational pEtN modification of FlgG using collision-induced and electron transfer dissociation mass spectrometry, as well as a genetic approach using site-directed mutagenesis to determine the site of modification. Specifically, we show that FlgG is modified with pEtN at a single site (Thr75) by EptC and demonstrate enzyme specificity by showing that EptC is unable to modify other amino acids (e.g. serine and tyrosine). Using Campylobacter strains expressing site-directed FlgG mutants, we also show that defects in motility arise directly from the loss of pEtN modification of FlgG. Interestingly, alignments of FlgG from most epsilon proteobacteria reveal a conserved site of modification. Characterization of EptC and its enzymatic targets expands on the increasingly important field of prokaryotic post-translational modification of bacterial surface structures and the unidentified role they may play in pathogenesis. PMID:22158617

Cullen, Thomas W.; Madsen, James A.; Ivanov, Petko L.; Brodbelt, Jennifer S.; Trent, M. Stephen

2012-01-01

35

eIF5A and EF-P: two unique translation factors are now traveling the same road.  

PubMed

Translational control is extremely important in all organisms, and some of its aspects are highly conserved among all primary kingdoms, such as those related to the translation elongation step. The previously classified translation initiation factor 5A (eIF5A) and its bacterial homologue elongation factor P (EF-P) were discovered in the late 70's and have recently been the object of many studies. eIF5A and EF-P are the only cellular proteins that undergo hypusination and lysinylation, respectively, both of which are unique posttranslational modifications. Herein, we review all the important discoveries related to the biochemical and functional characterization of these factors, highlighting the implication of eIF5A in translation elongation instead of initiation. The findings that eIF5A and EF-P are important for specific cellular processes and play a role in the relief of ribosome stalling caused by specific amino acid sequences, such as those containing prolines reinforce the hypothesis that these factors are involved in specialized translation. Although there are some divergences between these unique factors, recent studies have clarified that they act similarly during protein synthesis. Further studies may reveal their precise mechanism of ribosome activity modulation as well as the mRNA targets that require eIF5A and EF-P for their proper translation. PMID:24402910

Rossi, Danuza; Kuroshu, Reginaldo; Zanelli, Cleslei Fernando; Valentini, Sandro Roberto

2014-01-01

36

The unique organization of the rpoB region of Spiroplasma citri: a restriction and modification system gene is adjacent to rpoB.  

PubMed

A 6.5-kb DNA fragment containing the gene (rpoB) encoding the RNA polymerase (RNAP) beta subunit, from the mollicute Spiroplasma citri (Sc), was cloned and sequenced. The classical eubacterial organization, with the genes (rplK, A, J and L) encoding ribosomal proteins L11, L1, L10 and L12 located immediately upstream from rpoB, was not found in the Sc DNA. Instead, an open reading frame (hsdS) potentially encoding a component of a type I restriction and modification system was identified upstream from rpoB, and sequences showing similarities with insertion elements were found between hsdS and rpoB. PMID:8675039

Laigret, F; Gaurivaud, P; Bové, J M

1996-05-24

37

Genetic modification and genetic determinism  

Microsoft Academic Search

In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and

David B. Resnik; Daniel B. Vorhaus

2006-01-01

38

Genetic modification and genetic determinism  

PubMed Central

In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions. PMID:16800884

Resnik, David B; Vorhaus, Daniel B

2006-01-01

39

A rapid and robust assay for the determination of the amino acid hypusine as a possible biomarker for a high-throughput screening of antimalarials and for the diagnosis and therapy of different diseases.  

PubMed

Eukaryotic initiation factor 5A (eIF5A) has recently been identified as a biomarker of prognostic significance and therapeutic potential for the treatment in hepatocellular carcinoma. This prompted us to establish a rapid and robust assay to determine deoxyhypusine and hypusine formed with the purified enzymes deoxyhypusine synthase (DHS) and deoxyhypusine hydroxylase (DOHH) from Plasmodium to develop a rapid screening assay for antimalarial drugs. The peptide hydrolysate obtained from hypusinylated eIF5A was analyzed by ultra performance liquid chromatography (UPLC) with retention times for deoxyhypusine of 7.44 min and for hypusine of 7.30 min, respectively. The limit of detection for both compounds was 0.144 ng/?l. Determination of the specific activity of Plasmodium DOHH resulted in a twofold higher specific activity than its human counterpart. Following the iron-complexing strategy of the ferrous iron which is present in the active site of Plasmodium DOHH, a series of iron chelating compounds was tested. 2,2'-Dipyridyl and mimosine abolished DOHH activity completely while 4-oxo-piperidine-carboxylates i.e. the nitrophenylether JK8-2 and EHW 437, the oxime ether of the piperidine aldehyde, showed no inhibition although they were highly active in in vitro cultures of Plasmodium and in vivo in a rodent mouse model. The method allows a high-throughput screening (HPTS) of antimalarial drugs and the evaluation of eIF5A as a biomarker. PMID:21360085

Kaiser, Annette; Khomutov, Alex R; Simonian, Alina; Agostinelli, Enzo

2012-05-01

40

Histone modification in Drosophila.  

PubMed

Post-translational modifications (PTMs) of nucleosomal core histones play roles in basic biological processes via altering chromatin structure and creating target sites for proteins acting on chromatin. Several features make Drosophila a uniquely effective model for studying PTMs. Position effect variegation, polycomb repression, dosage compensation and several other processes extensively studied by the powerful tools of Drosophila genetics as well as polytene chromosome cytology reveal information on the dynamic changes of histone PTMs and factors that deposit, remove and recognize these. Recent determination of the genome-wide distribution of more than 20 different histone PTM types has resulted in a highly detailed view of chromatin landscape. This review samples from the wealth of data these analyses have provided together with data resulting from gene-targeted studies on the distribution and role of specific histone modifications and modifiers. As an example of the complex interactions among PTMs, we will also discuss crosstalk involving specific phosphorylated and acetylated histone forms. PMID:22806479

Boros, Imre M

2012-07-01

41

Black Hole Uniqueness Theorems  

Microsoft Academic Search

It is nearly 30 years since Werner Israel published his uniqueness theorem for the Schwarzschild black hole. This result, which surprised the cognoscenti at first, was quickly recognized as being of major importance. It soon initiated a flurry of research on uniqueness and no-hair theorems and encouraged subsequent developments such as the formulation of black hole thermodynamics. Research related to

D C Robinson

1997-01-01

42

Unique Graviton Exchange Signatures at Linear Colliders  

SciTech Connect

Many types of new physics can lead to contact interaction-like modifications in e{sup +}e{sup -} processes below direct production threshold. We examine the possibility of uniquely identifying the effects of graviton exchange from amongst this large set of models by using the moments of the angular distribution of the final state particles. In the case of e{sup +}e{sup -} {yields} f{bar f}(W{sup +}W{sup -}) we demonstrate that this technique allows for the unique identification of the graviton exchange signature at the 5{sigma} level for mass scales as high as 6(2.5){radical}s.

Rizzo, Thomas G.

2002-09-06

43

Post-translational modification by ?-lysylation is required for activity of Escherichia coli elongation factor P (EF-P).  

PubMed

Bacterial elongation factor P (EF-P) is the ortholog of archaeal and eukaryotic initiation factor 5A (eIF5A). EF-P shares sequence homology and crystal structure with eIF5A, but unlike eIF5A, EF-P does not undergo hypusine modification. Recently, two bacterial genes, yjeA and yjeK, encoding truncated homologs of class II lysyl-tRNA synthetase and of lysine-2,3-aminomutase, respectively, have been implicated in the modification of EF-P to convert a specific lysine to a hypothetical ?-lysyl-lysine. Here we present biochemical evidence for ?-lysyl-lysine modification in Escherichia coli EF-P and for its role in EF-P activity by characterizing native and recombinant EF-P proteins for their modification status and activity in vitro. Mass spectrometric analyses confirmed the lysyl modification at lysine 34 in native and recombinant EF-P proteins. The ?-lysyl-lysine isopeptide was identified in the exhaustive Pronase digests of native EF-P and recombinant EF-P isolated from E. coli coexpressing EF-P, YjeA, and YjeK but not in the digests of proteins derived from the vectors encoding EF-P alone or EF-P together with YjeA, indicating that both enzymes, YjeA and YjeK, are required for ?-lysylation of EF-P. Endogenous EF-P as well as the recombinant EF-P preparation containing ?-lysyl-EF-P stimulated N-formyl-methionyl-puromycin synthesis ?4-fold over the preparations containing unmodified EF-P and/or ?-lysyl-EF-P. The mutant lacking the modification site lysine (K34A) was inactive. This is the first report of biochemical evidence for the ?-lysylation of EF-P in vivo and the requirement for this modification for the activity of EF-P. PMID:22128152

Park, Jong-Hwan; Johansson, Hans E; Aoki, Hiroyuki; Huang, Bill X; Kim, Hee-Yong; Ganoza, M Clelia; Park, Myung Hee

2012-01-20

44

Blocking eIF5A modification in cervical cancer cells alters the expression of cancer-related genes and suppresses cell proliferation.  

PubMed

Cancer etiology is influenced by alterations in protein synthesis that are not fully understood. In this study, we took a novel approach to investigate the role of the eukaryotic translation initiation factor eIF5A in human cervical cancers, where it is widely overexpressed. eIF5A contains the distinctive amino acid hypusine, which is formed by a posttranslational modification event requiring deoxyhypusine hydroxylase (DOHH), an enzyme that can be inhibited by the drugs ciclopirox and deferiprone. We found that proliferation of cervical cancer cells can be blocked by DOHH inhibition with either of these pharmacologic agents, as well as by RNA interference-mediated silencing of eIF5A, DOHH, or another enzyme in the hypusine pathway. Proteomic and RNA analyses in HeLa cervical cancer cells identified two groups of proteins in addition to eIF5A that were coordinately affected by ciclopirox and deferiprone. Group 1 proteins (Hsp27, NM23, and DJ-1) were downregulated at the translational level, whereas group 2 proteins (TrpRS and PRDX2) were upregulated at the mRNA level. Further investigations confirmed that eIF5A and DOHH are required for Hsp27 expression in cervical cancer cells and for regulation of its key target I?B and hence NF-?B. Our results argue that mature eIF5A controls a translational network of cancer-driving genes, termed the eIF5A regulon, at the levels of mRNA abundance and translation. In coordinating cell proliferation, the eIF5A regulon can be modulated by drugs such as ciclopirox or deferiprone, which might be repositioned to control cancer cell growth. PMID:24220243

Mémin, Elisabeth; Hoque, Mainul; Jain, Mohit R; Heller, Debra S; Li, Hong; Cracchiolo, Bernadette; Hanauske-Abel, Hartmut M; Pe'ery, Tsafi; Mathews, Michael B

2014-01-15

45

A unique green qumtz  

Microsoft Academic Search

Some unique green quartz, collected by Dana in Brazil in 1884 (NMNH 4467g), was examined. The green color, due to a broad absorption band at 2ev and a strong band extending from 2.5eV into the ultraviolet, is lost by heating to 500'C, and cannot be recovered by irradiation or by heating under reducing conditions. The usual amethyst color (absorptions at

BErry E. Pnrscorr

46

A Unique Opportunity  

NASA Technical Reports Server (NTRS)

This 3-D topographic map shows the martian crater currently cradling the Mars Exploration Rover Opportunity. It is the first look at the shape of a crater on another planet from the unique vantage point of inside the crater itself. Engineers and scientists will use this data to plot an exit route for Opportunity once it is ready to roll out of the crater; to characterize geological features of the crater; and to help pinpoint the rover's location on the surface of Mars. The crater is estimated to be 3 meters (9.8 feet) deep and 22 (72.2) meters across. The map consists of data from the rover's panoramic camera.

2004-01-01

47

Uniqueness of the SVM Solution  

Microsoft Academic Search

We give necessary and sufficient conditions for uniqueness of thesupport vector solution for the problems of pattern recognition andregression estimation, for a general class of cost functions. We showthat if the solution is not unique, all support vectors are necessarilyat bound, and we give some simple examples of non-unique solutions.We note that uniqueness of the primal (dual) solution doesnot necessarily

Christopher J. C. Burges; David J. Crisp

1999-01-01

48

Is Life Unique?  

PubMed Central

Is life physicochemically unique? No. Is life unique? Yes. Life manifests innumerable formalisms that cannot be generated or explained by physicodynamics alone. Life pursues thousands of biofunctional goals, not the least of which is staying alive. Neither physicodynamics, nor evolution, pursue goals. Life is largely directed by linear digital programming and by the Prescriptive Information (PI) instantiated particularly into physicodynamically indeterminate nucleotide sequencing. Epigenomic controls only compound the sophistication of these formalisms. Life employs representationalism through the use of symbol systems. Life manifests autonomy, homeostasis far from equilibrium in the harshest of environments, positive and negative feedback mechanisms, prevention and correction of its own errors, and organization of its components into Sustained Functional Systems (SFS). Chance and necessity—heat agitation and the cause-and-effect determinism of nature’s orderliness—cannot spawn formalisms such as mathematics, language, symbol systems, coding, decoding, logic, organization (not to be confused with mere self-ordering), integration of circuits, computational success, and the pursuit of functionality. All of these characteristics of life are formal, not physical. PMID:25382119

Abel, David L.

2011-01-01

49

Is life unique?  

PubMed

Is life physicochemically unique? No. Is life unique? Yes. Life manifests innumerable formalisms that cannot be generated or explained by physicodynamics alone. Life pursues thousands of biofunctional goals, not the least of which is staying alive. Neither physicodynamics, nor evolution, pursue goals. Life is largely directed by linear digital programming and by the Prescriptive Information (PI) instantiated particularly into physicodynamically indeterminate nucleotide sequencing. Epigenomic controls only compound the sophistication of these formalisms. Life employs representationalism through the use of symbol systems. Life manifests autonomy, homeostasis far from equilibrium in the harshest of environments, positive and negative feedback mechanisms, prevention and correction of its own errors, and organization of its components into Sustained Functional Systems (SFS). Chance and necessity-heat agitation and the cause-and-effect determinism of nature's orderliness-cannot spawn formalisms such as mathematics, language, symbol systems, coding, decoding, logic, organization (not to be confused with mere self-ordering), integration of circuits, computational success, and the pursuit of functionality. All of these characteristics of life are formal, not physical. PMID:25382119

Abel, David L

2011-01-01

50

Plasma-surface modification of biomaterials  

Microsoft Academic Search

Plasma-surface modification (PSM) is an effective and economical surface treatment technique for many materials and of growing interests in biomedical engineering. This article reviews the various common plasma techniques and experimental methods as applied to biomedical materials research, such as plasma sputtering and etching, plasma implantation, plasma deposition, plasma polymerization, laser plasma deposition, plasma spraying, and so on. The unique

P. K. Chu; J. Y. Chen; L. P. Wang; N. Huang

2002-01-01

51

Utilization of waste tires employing novel surface-modification technology  

Microsoft Academic Search

Air Products and Chemicals, Inc. is developing unique technology for the recycle of scrap tires. The approach involves surface-modification of ground tire rubber particles to facilitate their incorporation into novel composites. This form of recycling represents the highest value-added and greatest energy conservation potential of all tire recycle technologies. Furthermore, it is environmentally innocuous. Research and development of this unique

Bauman

1989-01-01

52

Uniqueness Theorem for Black Objects  

SciTech Connect

We shall review the current status of uniqueness theorem for black objects in higher dimensional spacetime. At the beginning we consider static charged asymptotically flat spacelike hypersurface with compact interior with both degenerate and non-degenerate components of the event horizon in n-dimensional spacetime. We gave some remarks concerning partial results in proving uniqueness of stationary axisymmetric multidimensional solutions and winding numbers which can uniquely characterize the topology and symmetry structure of black objects.

Rogatko, Marek [Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, pl. Marii Curie-Sklodowskiej 1 (Poland)

2010-06-23

53

Posterior cortical atrophy: Unique features  

Microsoft Academic Search

Posterior cortical atrophy (PCA) is a visual-cognitive syndrome caused by Creutzfeldt-Jakob disease (CJD), Alzheimer's disease (AD), or subcortical gliosis. We report a case of posterior cortical atrophy unique in (1) comprehensive documentation of clinical, radiologic, electroencephalograph, metabolic and histopathologic findings, (2) repeated clinical and laboratory assessment, and (3) establishment of unique occipital subcortical gliosis in a patient with AD. Clinical

T. Tom; J. L. Cummings; J. Pollak

1998-01-01

54

Diabetes: Unique to Older Adults  

MedlinePLUS Videos and Cool Tools

... Incontinence Related Video Join our e-newsletter! Aging & Health A to Z Diabetes Unique to Older Adults ... their disease or condition in conjunction with other health issues. As older adults live longer, they may ...

55

Dementia: Unique to Older Adults  

MedlinePLUS

... our e-newsletter! Aging & Health A to Z Dementia Unique to Older Adults This section provides information ... Managing Additional Health Problems in Older Adults with Dementia Dementia is rare in adults younger than 60. ...

56

Histone onco-modifications  

Microsoft Academic Search

Post-translational modification of histones provides an important regulatory platform for processes such as gene expression, DNA replication and repair, chromosome condensation and segregation and apoptosis. Disruption of these processes has been linked to the multistep process of carcinogenesis. We review the aberrant covalent histone modifications observed in cancer, and discuss how these epigenetic changes, caused by alterations in histone-modifying enzymes,

J Füllgrabe; E Kavanagh; B Joseph

2011-01-01

57

Modifications of mitosis  

SciTech Connect

Chapter 15, discusses modifications of mitosis, including endoreduplication, polyteny, endomitosis, C-mitosis, restitution, amitosis and multipolar mitoses. Apart from multipolar mitosis, all other mitotic modifications are characterized by an absent or defective spindle, and in most cases these result in the duplication of the chromosome number. 29 refs., 4 figs.

NONE

1993-12-31

58

Oxidative DNA modifications  

Microsoft Academic Search

Oxidative DNA modifications are frequent in mammalian DNA and have been suggested an important mechanism in carcinogenesis, diabetes and ageing. The foundations for this suggestion are:Evidence for the importance of oxidative DNA modifications in cancer development is: high levels of oxidative lesions in cancer tissue; highly conserved and specific DNA repair systems targeting oxidative lesions; high levels of oxidative DNA

Henrik E. Poulsen

2005-01-01

59

Permit application modifications  

SciTech Connect

This document contains the Permit Application Modifications for the Y-12 Industrial Landfill V site on the Oak Ridge Reservation. These modifications include the assessment of stability of the proposed Landfill V under static and loading conditions. Analyses performed include the general slope stability, veneer stability of the bottom liner and cover system, and a liquefaction potential assessment of the foundation soils.

NONE

1995-11-01

60

Enzymatic modification of schizophyllan  

Technology Transfer Automated Retrieval System (TEKTRAN)

An enzymatic method was developed for the progressive modification of the polysaccharide schizophyllan. Fungal strains Hypocrea nigricans NRRL 62555, Penicillium crustosum NRRL 62558, and Penicillium simplicissimum NRRL 62550 were previously identified as novel sources of ß-endoglucanase with specif...

61

The bacterial magnetosome: a unique prokaryotic organelle.  

PubMed

The bacterial magnetosome is a unique prokaryotic organelle comprising magnetic mineral crystals surrounded by a phospholipid bilayer. These inclusions are biomineralized by the magnetotactic bacteria which are ubiquitous, aquatic, motile microorganisms. Magnetosomes cause cells of magnetotactic bacteria to passively align and swim along the Earth's magnetic field lines, as miniature motile compass needles. These specialized compartments consist of a phospholipid bilayer membrane surrounding magnetic crystals of magnetite (Fe3O4) or greigite (Fe3S4). The morphology of these membrane-bound crystals varies by species with a nominal magnetic domain size between 35 and 120 nm. Almost all magnetotactic bacteria arrange their magnetosomes in a chain within the cell there by maximizing the magnetic dipole moment of the cell. It is presumed that magnetotactic bacteria use magnetotaxis in conjunction with chemotaxis to locate and maintain an optimum position for growth and survival based on chemistry, redox and physiology in aquatic habitats with vertical chemical concentration and redox gradients. The biosynthesis of magnetosomes is a complex process that involves several distinct steps including cytoplasmic membrane modifications, iron uptake and transport, initiation of crystallization, crystal maturation and magnetosome chain formation. While many mechanistic details remain unresolved, magnetotactic bacteria appear to contain the genetic determinants for magnetosome biomineralization within their genomes in clusters of genes that make up what is referred to as the magnetosome gene island in some species. In addition, magnetosomes contain a unique set of proteins, not present in other cellular fractions, which control the biomineralization process. Through the development of genetic systems, proteomic and genomic work, and the use of molecular and biochemical tools, the functions of a number of magnetosome membrane proteins have been demonstrated and the molecular mechanism for the biomineralization of magnetosomes in these organisms is beginning to be revealed. PMID:23615196

Lower, Brian H; Bazylinski, Dennis A

2013-01-01

62

UNIQUE MITOCHONDRIAL GENETICS OF CUCUMIS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Cucumis mitochondrial (mt) genome is unique for its enormous size and paternal transmission. Recombination among inverted and direct repeats in the cucumber mt DNA produce paternally transmitted mosaic (MSC) phenotypes with altered mt gene expression. We used MSC to reveal phenotypic variation...

63

Tyrosine Modifications in Aging  

PubMed Central

Abstract Significance: The understanding of physiological and pathological processes involving protein oxidation, particularly under conditions of aging and oxidative stress, can be aided by proteomic identification of proteins that accumulate oxidative post-translational modifications only if these detected modifications are connected to functional consequences. The modification of tyrosine (Tyr) residues can elicit significant changes in protein structure and function, which, in some cases, may contribute to biological aging and age-related pathologies, such as atherosclerosis, neurodegeneration, and cataracts. Recent Advances: Studies characterizing proteins in which Tyr has been modified to 3-nitrotyrosine, 3,4-dihydroxyphenylalanine, 3,3?-dityrosine and other cross-links, or 3-chlorotyrosine are reviewed, with an emphasis on structural and functional consequences. Critical Issues: Distinguishing between inconsequential modifications and functionally significant ones requires careful biochemical and biophysical analysis of target proteins, as well as innovative methods for isolating the effects of the multiple modifications that often occur under oxidizing conditions. Future Directions: The labor-intensive task of isolating and characterizing individual modified proteins must continue, especially given the expanding list of known modifications. Emerging approaches, such as genetic and metabolic incorporation of unnatural amino acids, hold promise for additional focused studies of this kind. Antioxid. Redox Signal. 17, 1571–1579. PMID:22424390

Feeney, Maria B.

2012-01-01

64

Utilization of waste tires employing novel surface-modification technology  

SciTech Connect

Air Products and Chemicals, Inc. is developing unique technology for the recycle of scrap tires. The approach involves surface-modification of ground tire rubber particles to facilitate their incorporation into novel composites. This form of recycling represents the highest value-added and greatest energy conservation potential of all tire recycle technologies. Furthermore, it is environmentally innocuous. Research and development of this unique technology is partially funded through a cost-shared contract with the US Department of Energy. 4 figs.

Bauman, B.D. (Air Products and Chemicals, Inc., Allentown, PA (USA))

1989-01-01

65

Modifications of gravity.  

PubMed

General relativity (GR) is a phenomenologically successful theory that rests on firm foundations, but has not been tested on cosmological scales. The deep mystery of dark energy (and possibly even the requirement of cold dark matter (CDM)) has increased the need for testing modifications to GR, as the inference of such otherwise undetected fluids depends crucially on the theory of gravity. Here, I discuss a general scheme for constructing consistent and covariant modifications to the Einstein equations. This framework is such that there is a clear connection between the modification and the underlying field content that produces it. I argue that this is mandatory for distinguishing modifications of gravity from conventional fluids. I give a non-trivial example, a simple metric-based modification of the fluctuation equations for which the background is exact ?CDM, but differs from it in the perturbations. I show how this can be generalized and solved in terms of two arbitrary functions. Finally, I discuss future prospects and directions of research. PMID:22084286

Skordis, Constantinos

2011-12-28

66

Social Aspects of Weather Modification  

Microsoft Academic Search

A description of the social context and citizen response to three weather modification projects provides an introduction to the discussion of a variety of social and economic issues related to planned weather modification. Various interest groups have markedly different perspectives on weather modification. Most persons subject to the consequences of weather modification have no opportunity to participate in the associated

J. Eugene Haas

1973-01-01

67

Toy Modification Note. Revised.  

ERIC Educational Resources Information Center

Described are toy modifications which enable handicapped individuals to operate battery-powered toys. A battery interrupter is explained as a device which fits between the batteries in a toy and provides the ability to have a separate on-off switch which can be custom designed to fit a handicapped user's needs. Construction and use of three types…

Vanderheiden, Gregg C.; And Others

68

Some Uniqueness Results for PARAFAC2.  

ERIC Educational Resources Information Center

Some uniqueness properties are presented for the PARAFAC2 model for covariance matrices, focusing on uniqueness in the rank two case of PARAFAC2. PARAFAC2 is shown to be usually unique with four matrices, but not unique with three unless a certain additional assumption is introduced. (SLD)

ten Berge, Jos M. F.; Kiers, Henk A. L.

1996-01-01

69

Uniquely Represented Data Structures for Computational Geometry  

Microsoft Academic Search

We present new techniques for the construction of uniquely represented data structures in a RAM, and use them to construct efficient uniquely represented data structures for orthogonal range queries, line intersection tests, point location, and 2-D dynamic convex hull. Uniquely represented data structures represent each logical state with a unique machine state. Such data structures are strongly history-independent. This eliminates

Guy E. Blelloch; Daniel Golovin; Virginia Vassilevska

2008-01-01

70

Chemical modification of proteins at cysteine: opportunities in chemistry and biology.  

PubMed

Chemical modification of proteins is a rapidly expanding area in chemical biology. Selective installation of biochemical probes has led to a better understanding of natural protein modification and macromolecular function. In other cases such chemical alterations have changed the protein function entirely. Additionally, tethering therapeutic cargo to proteins has proven invaluable in campaigns against disease. For controlled, selective access to such modified proteins, a unique chemical handle is required. Cysteine, with its unique reactivity, has long been used for such modifications. Cysteine has enjoyed widespread use in selective protein modification, yet new applications and even new reactions continue to emerge. This Focus Review highlights the enduring utility of cysteine in protein modification with special focus on recent innovations in chemistry and biology associated with such modifications. PMID:19235822

Chalker, Justin M; Bernardes, Gonçalo J L; Lin, Yuya A; Davis, Benjamin G

2009-05-01

71

ASPOD modifications of 1993-1994  

NASA Technical Reports Server (NTRS)

ASPOD, Autonomous Space Processors for Orbital Debris, provides a unique way of collecting the space debris that has built up over the past 37 years. For the past several years, ASPOD has gone through several different modifications. This year's concentrations were on the solar cutting array, the solar tracker, the earth based main frame/tilt table, the controls for the two robotic arms, and accurate autocad drawings of ASPOD. This final report contains the reports written by the students who worked on the ASPOD project this year.

Jackson, Jennifer J. (editor); Fogarty, Paul W.; Muller, Matthew; Martucci, Thomas A., III; Williams, Daniel; Rowney, David A.

1994-01-01

72

UNIQUENESS OF RESPONSIVE VOTING EQUILIBRIUM  

E-print Network

. f(s) g(s) = exp (s 1)2 + (s o)2 2 2 (10) = exp 1 o 2 s 21 2o 2 2 : 1 o 2 in the above exponential is positive by our hypothesis, so f(s) g(s) is increasing 8s2R. Furthermore, lims! 1 f(s)g(s) = 0 and lims!+1 f(s)g(s) = +1. Without... s? is a solution of v(s) = f(s)=g(s). 24 Proof. The result follows from the previous lemma by taking exponential of both sides. s? still satis es the expression mentioned in this lemma. Lemma 11 s? is the unique solution for the system exp 1 o...

Dalkir, Elif

2008-01-01

73

The Probabilities of Unique Events  

PubMed Central

Many theorists argue that the probabilities of unique events, even real possibilities such as President Obama's re-election, are meaningless. As a consequence, psychologists have seldom investigated them. We propose a new theory (implemented in a computer program) in which such estimates depend on an intuitive non-numerical system capable only of simple procedures, and a deliberative system that maps intuitions into numbers. The theory predicts that estimates of the probabilities of conjunctions should often tend to split the difference between the probabilities of the two conjuncts. We report two experiments showing that individuals commit such violations of the probability calculus, and corroborating other predictions of the theory, e.g., individuals err in the same way even when they make non-numerical verbal estimates, such as that an event is highly improbable. PMID:23056224

Khemlani, Sangeet S.; Lotstein, Max; Johnson-Laird, Phil

2012-01-01

74

Xyloglucan in cellulose modification  

Microsoft Academic Search

Xyloglucans are the principal polysaccharides coating and crosslinking cellulose microfibrills in the majority of land plants.\\u000a This review summarizes current knowledge of xyloglucan structures, solution properties, and the mechanism of interaction of\\u000a xyloglucans with cellulose. This knowledge base forms the platform for new biomimetic methods of cellulose surface modification\\u000a with applications within the fields of textile manufacture, papermaking, and materials

Qi Zhou; Mark W. Rutland; Tuula T. Teeri; Harry Brumer

2007-01-01

75

Transient conductive-radiative heat transfer: Discrete existence and uniqueness for a finite volume scheme  

Microsoft Academic Search

This article presents a finite volume scheme for transient nonlinear heat transport equations coupled by nonlocal interface conditions modeling diuse- gray radiation between the surfaces of (both open and closed) cavities. The model is considered in three space dimensions; modifications for the axisym- metric case are indicated. Proving a maximum principle as well as existence and uniqueness for roots to

Olaf Klein; Peter Philip

2003-01-01

76

Weather Modification: Finding Common Ground  

Microsoft Academic Search

Research and operational approaches to weather modification expressed in the National Research Council's 2003 report on ``Critical Issues in Weather Modification Research'' and in the Weather Modification Association's response to that report form the basis for this discussion. There is agreement that advances in the past few decades over a broad front of understanding physical processes and in technology have

Michael Garstang; Roelof Bruintjes; Robert Serafin; Harold Orville; Bruce Boe; William Cotton; Joseph Warburton

2005-01-01

77

Partner notification requires unique skills.  

PubMed

The success of health care workers involved in partner notification depends greatly on accepting unusual working conditions and developing unique skills. According to Katharyn Waldron, MA, HIV educator at the University of Pittsburgh, the challenge is one of both educating and gaining trust. The payoff is that people may make life-changing decisions because they are able to see beyond the day-to-day needs of another fix or trick. She suggests dressing appropriately for the locale and being concerned about safety. Many partners often want to know who gave the health care worker their name. Confidentiality works both ways--protect the identity of the index partner as well as the other partner. To persuade HIV-positive partners to share information about contacts, she suggests avoiding blame and appealing to their sense of compassion and fairness. Providing prevalence statistics for the contact's community can help in educating individuals. Also provide basic information about HIV transmission and prevention, and assure availability for further contact. PMID:11362434

1995-06-01

78

Solitons and ionospheric modification  

NASA Technical Reports Server (NTRS)

The possibility of Langmuir soliton formation and collapse during ionospheric modification is investigated. Parameters characterizing former facilities, existing facilities, and planned facilities are considered, using a combination of analytical and numerical techniques. At a spatial location corresponding to the exact classical reflection point of the modifier wave, the Langmuir wave evolution is found to be dominated by modulational instability followed by soliton formation and three-dimensional collapse. The earth's magnetic field is found to affect the shape of the collapsing soliton. These results provide an alternative explanation for some recent observations.

Sheerin, J. P.; Nicholson, D. R.; Payne, G. L.; Hansen, P. J.; Weatherall, J. C.; Goldman, M. V.

1982-01-01

79

Unique immunologic patterns in fibromyalgia  

PubMed Central

Background Fibromyalgia (FM) is a clinical syndrome characterized by chronic pain and allodynia. The diagnosis of FM has been one of exclusion as a test to confirm the diagnosis is lacking. Recent data highlight the role of the immune system in FM. Aberrant expressions of immune mediators, such as cytokines, have been linked to the pathogenesis and traits of FM. We therefore determined whether cytokine production by immune cells is altered in FM patients by comparing the cellular responses to mitogenic activators of stimulated blood mononuclear cells of a large number of patients with FM to those of healthy matched individuals. Methods Plasma and peripheral blood mononuclear cells (PBMC) were collected from 110 patients with the clinical diagnosis of FM and 91 healthy donors. Parallel samples of PBMC were cultured overnight in medium alone or in the presence of mitogenic activators; PHA or PMA in combination with ionomycin. The cytokine concentrations of IFN-?, IL-5, IL-6, IL-8, IL-10, MIP-1? , MCP-1, and MIP1-? in plasma as well as in cultured supernatants were determined using a multiplex immunoassay using bead array technology. Results Cytokine levels of stimulated PBMC cultures of healthy control subjects were significantly increased as compared to matched non-stimulated PBMC cultures. In contrast, the concentrations of most cytokines were lower in stimulated samples from patients with FM compared to controls. The decreases of cytokine concentrations in patients samples ranged from 1.5-fold for MIP-1? to 10.2-fold for IL-6 in PHA challenges. In PMA challenges, we observed 1.8 to 4-fold decreases in the concentrations of cytokines in patient samples. Conclusion The cytokine responses to mitogenic activators of PBMC isolated from patients with FM were significantly lower than those of healthy individuals, implying that cell-mediated immunity is impaired in FM patients. This novel cytokine assay reveals unique and valuable immunologic traits, which, when combined with clinical patterns, can offer a diagnostic methodology in FM. PMID:23245186

2012-01-01

80

Symbols are not uniquely human.  

PubMed

Modern semiotics is a branch of logics that formally defines symbol-based communication. In recent years, the semiotic classification of signs has been invoked to support the notion that symbols are uniquely human. Here we show that alarm-calls such as those used by African vervet monkeys (Cercopithecus aethiops), logically satisfy the semiotic definition of symbol. We also show that the acquisition of vocal symbols in vervet monkeys can be successfully simulated by a computer program based on minimal semiotic and neurobiological constraints. The simulations indicate that learning depends on the tutor-predator ratio, and that apprentice-generated auditory mistakes in vocal symbol interpretation have little effect on the learning rates of apprentices (up to 80% of mistakes are tolerated). In contrast, just 10% of apprentice-generated visual mistakes in predator identification will prevent any vocal symbol to be correctly associated with a predator call in a stable manner. Tutor unreliability was also deleterious to vocal symbol learning: a mere 5% of "lying" tutors were able to completely disrupt symbol learning, invariably leading to the acquisition of incorrect associations by apprentices. Our investigation corroborates the existence of vocal symbols in a non-human species, and indicates that symbolic competence emerges spontaneously from classical associative learning mechanisms when the conditioned stimuli are self-generated, arbitrary and socially efficacious. We propose that more exclusive properties of human language, such as syntax, may derive from the evolution of higher-order domains for neural association, more removed from both the sensory input and the motor output, able to support the gradual complexification of grammatical categories into syntax. PMID:17101209

Ribeiro, Sidarta; Loula, Angelo; de Araújo, Ivan; Gudwin, Ricardo; Queiroz, João

2007-01-01

81

Structural Modification of Nanocrystalline Ceria using Ion Beams  

SciTech Connect

Exceptional size-dependent electronic-ionic conductivity of nanostructured ceria can significantly alter materials properties in chemical, physical, electronic and optical applications. Using energetic ions, we have demonstrated effective modification of interface volume and grain size in nanocrystalline ceria from a few nm up to ~ 25 nm, which is the critical region for controlling size-dependent material property. The unique self-healing response of radiation damage at grain boundaries is applied to control the grain size at nanoscale as a function of ion dose and irradiation temperature. Structural modification by energetic ions is proposed to achieve disirable electronic-ionic conductivity.

Zhang, Yanwen [ORNL; Edmondson, Philip D [ORNL; Varga, Tamas [Pacific Northwest National Laboratory (PNNL); Moll, Sandra [Pacific Northwest National Laboratory (PNNL); Namavar, Fereydoon [University of Nebraska Medical Center; Weber, William J [ORNL

2011-01-01

82

Enzymatic modification of schizophyllan.  

PubMed

An enzymatic method was developed for the progressive modification of the polysaccharide schizophyllan. Fungal strains Hypocrea nigricans NRRL 62555, Penicillium crustosum NRRL 62558, and Penicillium simplicissimum NRRL 62550 were previously identified as novel sources of ?-endoglucanase with specificity towards schizophyllan. Concentrated enzyme preparations from these strains showed specific activities of 1.7-4.3 U ?-glucanase/mg protein. Using dilutions of these enzymes in time course digestions, schizophyllan was progressively modified to reduced molecular weight species. Glucose and oligosaccharides were found only in the more complete digestions, and thus modified schizophyllan can be produced quantitatively, without loss, to small molecules. Permethylation analysis confirmed that modified schizophyllan retains the fundamental linkage structure of native schizophyllan. Modified schizophyllan species showed progressively reduced viscosity profiles, and all exhibited pseudoplasticity in response to shear thinning. PMID:25335747

Leathers, Timothy D; Sutivisedsak, Nongnuch; Nunnally, Melinda S; Price, Neil P J; Stanley, April M

2015-03-01

83

Artificial modification meeting reminder  

NASA Astrophysics Data System (ADS)

A symposium on artificial modification of the ionosphere by high-powered radio waves (V. V. Migulin, Honorary Chairman) will be held September 19-23, 1988, at the Scandic Hotel, Tromso, Norway. The symposium, sponsored by Union Radio Scientifique Internationale Commissions (URSI) G and H, is in the URSI series which started at Suzdal in 1983. Information on the scientific program is available from V.V. Migulin, U.S.S.R. Academy of Sciences, 103907, Moscow Center, Marx Avl8, U.S.S.R.; Peter Stubbe, Max- Planck-Institut fuer Aeronomy, D-3411 Katlenburg- Lindau 3, Federal Republic of Germany; or W.E. Gordon, Rice University, Space Physics and Astronomy Dept., Houston, TX 77251. For local arrangements information, contact Asgeir Brekke, Institute Matematisk Realfag, Aurora Observatory, Box 953, N-9001, Tromso, Norway.

Gordon, W. E.

84

Uniquely Edge3-Colorable Graphs and Snarks  

Microsoft Academic Search

.  ?A cubic graph G is uniquely edge-3-colorable if G has precisely one 1-factorization. It is proved in this paper, if a uniquely edge-3-colorable, cubic graph G is cyclically 4-edge-connected, but not cyclically 5-edge-connected, then G must contain a snark as a minor. This is an approach to a conjecture that every triangle free uniquely edge-3-colorable cubic\\u000a graph must have the

John L. Goldwasser; Cun-Quan Zhang

2000-01-01

85

Unique Gene-Silencing and Structural Properties of 2;#8242;-Fluoro-Modified siRNAs  

SciTech Connect

With little or no negative impact on the activity of small interfering RNAs (siRNAs), regardless of the number of modifications or the positions within the strand, the 2'-deoxy-2'-fluoro (2'-F) modification is unique. Furthermore, the 2'-F-modified siRNA (see crystal structure) was thermodynamically more stable and more nuclease-resistant than the parent siRNA, and produced no immunostimulatory response.

Manoharan, Muthiah; Akinc, Akin; Pandey, Rajendra K.; Qin, June; Hadwiger, Philipp; John, Matthias; Mills, Kathy; Charisse, Klaus; Maier, Martin A.; Nechev, Lubomir; Greene, Emily M.; Pallan, Pradeep S.; Rozners, Eriks; Rajeev, Kallanthottathil G.; Egli, Martin (Alnylam Pharm.); (Vanderbilt); (SUNY-Binghamton)

2012-05-22

86

Are Scattering Properties of Networks Uniquely Connected to Their Shapes?  

NASA Astrophysics Data System (ADS)

Are scattering properties of networks uniquely connected to their shapes? This is a modification of the famous question of Mark Kac "Can one hear the shape of a drum: revisited. which can be asked in the case of scattering systems such as quantum graphs and microwave networks. We present the experimental approach to this problem (Hul et al., Phys Rev Lett 109:040402, 2012). Our experimental results indicate a negative answer to the above question. To demonstrate this we constructed a pair of isospectral microwave networks consisting of vertices connected by microwave coaxial cables and extended them to scattering systems by connecting leads to infinity to form isoscattering networks. We show that the amplitudes and phases of the determinants of the scattering matrices of such networks are the same within the experimental uncertainties. Additionally, we demonstrate that the scattering matrices of the networks are conjugated by the transplantation relation. The experimental results are in perfect agreement with the theoretical predictions.

Hul, Oleh; ?awniczak, Micha?; Bauch, Szymon; Sawicki, Adam; Ku?, Marek; Sirko, Leszek

87

Autoantibodies to Posttranslational Modifications in Rheumatoid Arthritis  

PubMed Central

Autoantibodies have been associated with human pathologies for a long time, particularly with autoimmune diseases (AIDs). Rheumatoid factor (RF) is known since the late 1930s to be associated with rheumatoid arthritis (RA). The discovery of anticitrullinated protein antibodies in the last century has changed this and other posttranslational modifications (PTM) relevant to RA have since been described. Such PTM introduce neoepitopes in proteins that can generate novel autoantibody specificities. The recent recognition of these novel specificities in RA provides a unique opportunity to understand human B-cell development in vivo. In this paper, we will review the three of the main classes of PTMs already associated with RA: citrullination, carbamylation, and oxidation. With the advancement of research methodologies it should be expected that other autoantibodies against PTM proteins could be discovered in patients with autoimmune diseases. Many of such autoantibodies may provide significant biomarker potential. PMID:24782594

Burska, Agata N.; Hunt, Laura; Strollo, Rocky; Ryan, Brent J.; Vital, Ed; Nissim, Ahuva; Winyard, Paul G.; Emery, Paul; Ponchel, Frederique

2014-01-01

88

Posttranscriptional modification of tRNA in thermophilic archaea (Archaebacteria).  

PubMed Central

Nucleoside modification has been studied in unfractionated tRNA from 11 thermophilic archaea (archaebacteria), including phylogenetically diverse representatives of thermophilic methanogens and sulfur-metabolizing hyperthermophiles which grow optimally in the temperature range of 56 (Thermoplasma acidophilum) to 105 degrees C (Pyrodictium occultum), and for comparison from the most thermophilic bacterium (eubacterium) known, Thermotoga maritima (80 degrees C). Nine nucleosides are found to be unique to the archaea, six of which are structurally novel in being modified both in the base and by methylation in ribose and occur primarily in tRNA from the extreme thermophiles in the Crenarchaeota of the archaeal phylogenetic tree. 2-Thiothymine occurs in tRNA from Thermococcus sp., and constitutes the only known occurrence of the thymine moiety in archaeal RNA, in contrast to its near-ubiquitous presence in tRNA from bacteria and eukarya. A total of 33 modified nucleosides are rigorously characterized in archaeal tRNA in the present study, demonstrating that the structural range of posttranscriptional modifications in archaeal tRNA is more extensive than previously known. From a phylogenetic standpoint, certain tRNA modifications occur in the archaea which are otherwise unique to either the bacterial or eukaryal domain, although the overall patterns of modification are more typical of eukaryotes than bacteria. PMID:1708763

Edmonds, C G; Crain, P F; Gupta, R; Hashizume, T; Hocart, C H; Kowalak, J A; Pomerantz, S C; Stetter, K O; McCloskey, J A

1991-01-01

89

Bone surface modifications in zooarchaeology  

Microsoft Academic Search

Cutmarks made by stone tools, conchoidal flake scars from hammerstone percussion, carnivore tooth marks, striations from sedimentary abrasion, and other surface modifications on bones from archaeological sites constitute a crucial body of evidence for investigating the role of human behaviors and of nonhuman taphonomic processes in site formation. This paper describes the various kinds of bone surface modifications produced by

1995-01-01

90

Surface modification of cellulose nanocrystals.  

PubMed

Chemical modification of cellulose nanocrystals is an increasingly popular topic in the literature. This review analyses the type of cellulose nanocrystal modification reactions that have been published in the literature thus far and looks at the steps that have been taken towards analysing the products of the nanocrystal modifications. The main categories of reactions carried out on cellulose nanocrystals are oxidations, esterifications, amidations, carbamations and etherifications. More recently nucleophilic substitutions have been used to introduce more complex functionality to cellulose nanocrystals. Multi-step modifications are also considered. This review emphasizes quantification of modification at the nanocrystal surface in terms of degree of substitution and the validity of conclusions drawn from different analysis techniques in this area. The mechanisms of the modification reactions are presented and considered with respect to the effect on the outcome of the reactions. While great strides have been made in the quality of analytical data published in the field of cellulose nanocrystal modification, there is still vast scope for improvement, both in data quality and the quality of analysis of data. Given the difficulty of surface analysis, cross-checking of results from different analysis techniques is fundamental for the development of reliable cellulose nanocrystal modification techniques. PMID:24937092

Eyley, Samuel; Thielemans, Wim

2014-07-21

91

Teaching and Learning with Individually Unique Exercises  

ERIC Educational Resources Information Center

In this article, the author describes the pedagogical benefits of giving students individually unique homework exercises from an exercise template. Evidence from a test of this approach shows statistically significant improvements in subsequent exam performance by students receiving unique problems compared with students who received traditional…

Joerding, Wayne

2010-01-01

92

Alias burying: Unique variables without destructive reads  

Microsoft Academic Search

SUMMARY An unshared object can be accessed without regard to possible conflicts with other parts of a system, whether concurrent or single-threaded. A unique variable (sometimes known as a 'free' or 'linear' variable) is one that either is null or else refers to an unshared object. Being able to declare and check which variables are unique improves a programmer's ability

John Boyland

2001-01-01

93

Constructing Dense Graphs with Unique Hamiltonian Cycles  

ERIC Educational Resources Information Center

It is not difficult to construct dense graphs containing Hamiltonian cycles, but it is difficult to generate dense graphs that are guaranteed to contain a unique Hamiltonian cycle. This article presents an algorithm for generating arbitrarily large simple graphs containing "unique" Hamiltonian cycles. These graphs can be turned into dense graphs…

Lynch, Mark A. M.

2012-01-01

94

System identification: A question of uniqueness, revisited  

NASA Technical Reports Server (NTRS)

Questions of uniqueness of parameters which were obtained from a system identification algorithm were investigated. The local properties of the surface defined by the error function were used. Static and dynamic numerical experiments on determinate and indeterminate trusses and on shear buildings illustrate the procedure. Examples are given of loading and sensor configurations which produce unique parameters

Hardee, J. E.; Matzen, V. C.

1982-01-01

95

Structural modifications of nucleosides in ionic liquids  

PubMed Central

Nucleoside chemistry represents an important research area for drug discovery, as many nucleoside analogs are prominent drugs and have been widely applied for cancer and viral chemotherapy. However, the synthesis of modified nucleosides presents a major challenge, which is further aggravated by poor solubility of these compounds in common organic solvents. Most of the currently available methods for nucleoside modification employ toxic high boiling solvents; require long reaction time and tedious workup methods. As such, there is constant effort to develop process chemistry in alternative medium to limit the use of organic solvents that are hazardous to the environment and can be deleterious to human health. One such approach is to use ionic liquids, which are ‘designer materials’ with unique and tunable physico-chemical properties. Studies have shown that methodologies using ionic liquids are highly efficient and convenient for the synthesis of nucleoside analogs, as demonstrated by the preparation of pharmaceutically important anti-viral drugs. This article summarizes recent efforts on nucleoside modification using ionic liquids. PMID:20178825

Kumar, Vineet; Parmar, Virinder S.; Malhotra, Sanjay V.

2011-01-01

96

Surface modification of bioceramics  

NASA Astrophysics Data System (ADS)

Hydroxyapatite [Ca10(PO4)6(OH)2, HAp] is a major inorganic component of bone and teeth tissues and has the excellent biocompatibility and high osteoconductivity. The interactions between HAp and protein or cell have been studied. The HAp related bioceramics such as bone substitute, coating substance of metal implants, inorganic-polymer composites, and cell culture. We described two methods; (1) surface modification of HAp using organosilane; (2) fabrication of HAp ultra-thin layer on gold surface for protein adsorption analyzed with QCM-D technique. The interfacial interaction between collagen and HAp in a nano-region was controlled by depositing the organosilane of n-octadecyltrimethoxysilane (ODS: -CH3) or aminopropyltriethoxysilane (APTS: -NH2) with a chemical vapor deposition method. The morphologies of collagen adsorbed on the surfaces of HAp and HAp deposited with APTS were similar, however that of the surface with ODS was apparently different, due to the hydrophobic interaction between the organic head group of -CH3 and residual groups of collagen. We present a method for coating gold quartz crystal microbalance with dissipation (QCM-D) sensor with ultra-thin layer of hydroxyapatite nanocrystals evenly covering and tightly bound to the surface. The hydroxyapatite sensor operated in liquid with high stability and sensitivity. The in-situ adsorption mechanism and conformational change of fibrinogen on gold, titanium and hydroxyapatite surfaces were investigated by QCM-D technique and Fourier-transform infrared spectroscopy. The study indicates that the hydroxyapatite sensor is applicable for qualitative and conformational analysis of protein adsorption.

Monkawa, Akira

97

Protein Modifications in Transcription Elongation  

PubMed Central

Posttranslational modifications (PTMs) of proteins play essential roles in regulating signaling, protein-protein modifications and subcellular localization. In this review, we focus on posttranslational modification of histones and RNA polymerase II (RNAPII) and their roles in gene transcription. A survey of the basic features of PTMs is provided followed by a more detailed account of how PTMs on histones and RNAPII regulate transcription in the model organism Saccharomyces cerevisiae. We emphasize the interconnections between histone and RNAPII PTMs and speculate upon the larger role PTMs have in regulating protein function in the cell. PMID:18718879

Fuchs, Stephen M.; Laribee, R. Nicholas; Strahl, Brian D.

2008-01-01

98

Heart Failure: Unique to Older Adults  

MedlinePLUS

Heart Failure Unique to Older Adults This section provides information to help older adults and their caregivers ... or maintain quality of life. Urinary Incontinence and Heart Failure If you have heart failure, you may ...

99

Chromatin modification mapping in nanochannels  

PubMed Central

We report the simultaneous mapping of multiple histone tail modifications on chromatin that has been confined to nanofluidic channels. In these channels, chromatin is elongated, and histone modification can be detected using fluorescently tagged monoclonal antibodies. Using reconstituted chromatin with three distinct histone sources and two histone tail modification probes (H3K4me3 and H3K9ac), we were able to distinguish chromatin from the different sources. Determined ratios of the two modifications were consistent with the bulk composition of histone mixtures. We determined that the major difficulty in transitioning the mapping method to site-specific profiling within single genomic molecules is the interference of naturally aggregating, off-the shelf antibodies with the internal structure of chromatin. PMID:24396539

Lim, Shuang Fang; Karpusenko, Alena; Blumers, Ansel L.; Streng, Diana E.; Riehn, Robert

2013-01-01

100

Module Four - The Uniqueness of the Nanoscale  

NSDL National Science Digital Library

This module covers the unique attributes of the nano-scale and some examples of these unique attributes, including small size, high surface to volume ratio, surface forces in relation to bulk forces, quantum mechanical effects, and wave properties of light. This module is from the Nanotechnology Applications and Career Knowledge (NACK), a National ATE Center. This site requires a free log-in to access.

101

Epigenetic Modifications and Diabetic Retinopathy  

PubMed Central

Diabetic retinopathy remains one of the most debilitating chronic complications, but despite extensive research in the field, the exact mechanism(s) responsible for how retina is damaged in diabetes remains ambiguous. Many metabolic pathways have been implicated in its development, and genes associated with these pathways are altered. Diabetic environment also facilitates epigenetics modifications, which can alter the gene expression without permanent changes in DNA sequence. The role of epigenetics in diabetic retinopathy is now an emerging area, and recent work has shown that genes encoding mitochondrial superoxide dismutase (Sod2) and matrix metalloproteinase-9 (MMP-9) are epigenetically modified, activates of epigenetic modification enzymes, histone lysine demethylase 1 (LSD1), and DNA methyltransferase are increased, and the micro RNAs responsible for regulating nuclear transcriptional factor and VEGF are upregulated. With the growing evidence of epigenetic modifications in diabetic retinopathy, better understanding of these modifications has potential to identify novel targets to inhibit this devastating disease. Fortunately, the inhibitors and mimics targeted towards histone modification, DNA methylation, and miRNAs are now being tried for cancer and other chronic diseases, and better understanding of the role of epigenetics in diabetic retinopathy will open the door for their possible use in combating this blinding disease. PMID:24286082

Kowluru, Renu A.; Santos, Julia M.; Mishra, Manish

2013-01-01

102

Coded OFDM by Unique Word Prefix  

E-print Network

In this paper we propose a novel transmit signal structure and an adjusted and optimized receiver for OFDM (orthogonal frequency division multiplexing). Instead of the conventional cyclic prefix we use a deterministic sequence, which we call unique word (UW), as guard interval. We show how unique words, which are already well investigated for single carrier systems with frequency domain equalization (SC/FDE), can also be introduced in OFDM symbols. Since unique words represent known sequences, they can advantageously be used for synchronization and channel estimation purposes. Furthermore, the proposed approach introduces a complex number Reed-Solomon (RS-) code structure within the sequence of subcarriers. This allows for RS-decoding or to apply a highly efficient Wiener smoother succeeding a zero forcing stage at the receiver. We present simulation results in an indoor multipath environment to highlight the advantageous properties of the proposed scheme.

Huemer, Mario; Huber, Johannes B

2010-01-01

103

Polymer surface modification by plasmas and photons  

NASA Astrophysics Data System (ADS)

Polymers have been applied successfully in fields such as adhesion, biomaterials, protective coatings, friction and wear, composites, microelectronic devices, and thin-film technology. In general, special surface properties with regard to chemical composition, hydrophilicity, roughness, crystallinity, conductivity, lubricity, and cross-linking density are required for the success of these applications. Polymers very often do not possess the surface properties needed for these applications. However, they have excellent bulk physical and chemical properties, are inexpensive, and are easy to process. For these reasons, surface modification techniques which can transform these inexpensive materials into highly valuable finished products have become an important part of the plastics and many other industries. In recent years, many advances have been made in developing surface treatments to alter the chemical and physical properties of polymer surfaces without affecting bulk properties. Common surface modification techniques include treatments by flame, corona, plasmas, photons, electron beams, ion beams, X-rays, and ?-rays. Plasma treatment is probably the most versatile surface treatment technique. Different types of gases such as argon, oxygen, nitrogen, fluorine, carbon dioxide, and water can produce the unique surface properties required by various applications. For example, oxygen-plasma treatment can increase the surface energy of polymers, whereas fluorine-plasma treatment can decrease the surface energy and improve the chemical inertness. Cross-linking at a polymer surface can be introduced by an inert-gas plasma. Modification by plasma treatment is usually confined to the top several hundred ångströms and does not affect the bulk properties. The main disadvantage of this technique is that it requires a vacuum system, which increases the cost of operation. Thin polymer films with unique chemical and physical properties are produced by plasma polymerization. This technology is still in its infancy, and the plasma chemical process is not fully understood. The films are prepared by vapor phase deposition and can be formed on practically any substrate with good adhesion between the film and the substrate. These films, which are usually highly cross-linked and pinhole-free, have very good barrier properties. Such films find great potential in biomaterial applications and in the microelectronics industry. Very high-power microwave-driven mercury lamps are available, and they are used in UV-hardening of photoresist patterns for image stabilization at high temperatures. Other applications of UV irradiation include surface photo-oxidation, increase of hydrophilicity, and photocuring of paintings. Pulsed UV-lasers are used in surface modification in many areas. Pulsed UV-laser irradiation can produce submicron periodic linear and dot patterns on polymer surfaces without photomask. These interference patterns can be used to increase surface roughness of inert polymers for improved adhesion. These images can also be transferred to silicon surfaces by reactive ion etching. Pulsed laser beams can be applied to inert polymer surfaces for increased hydrophilicity and wettability. Polymer surfaces treated by pulsed UV-laser irradiation can be positively or negatively charged to enhance chemical reactivity and processability. Pulsed UV-laser exposures with high fluence give rise to photoablation with a clean wall profile. There are many other practical applications of laser photoablation, including via-hole fabrication, and diamond-film deposition. The present review discusses all these current applications, especially in the biomedical and microelectronics areas.

Chan, C.-M.; Ko, T.-M.; Hiraoka, H.

1996-05-01

104

Unique hues as revealed by unique-hue selecting versus partial hue-matching.  

PubMed

Unique hues are usually defined as those that cannot be introspectively reduced to any other hue. According to a major dogma of color science, there are four unique hues: yellow, blue, red, and green. Yet only 55 of the 173 inexperienced observers who participated in our experiment selected exactly four Munsell papers that, according to their judgment, had a unique hue. The number of papers selected by the rest of the observers varied from zero to nine. We believe that such variability of unique hue selection is due to the ambiguity of the introspective criteria for hue uniqueness. Along with the traditional technique of unique hue selection, an alternative method based on partial hue-matching has also been used to establish the nomenclature of unique hues. The partial hue-matching method is based on observer judgments concerning the presence of a common hue in a pair of colors. Observers are not supposed to name (or make any other judgments of) this common hue. Without presupposing their number, the unique hues are derived from the observer's responses to a sample of color pairs. The results obtained by this new method generally support the classical notion of four unique hues. PMID:23471743

Logvinenko, Alexander D; Geithner, Coryn

2015-04-01

105

The problem of uniqueness in thermosphere dynamics  

NASA Technical Reports Server (NTRS)

The unique solution of tidal wave propagation within the thermosphere depends on the boundary conditions of the model. It is shown that the radiation condition leads to such a unique solution. Any other boundary values give rise to deviations from the physical solution with unrealistic physical parameters in the environment of the boundaries. The thickness of these boundary layers with unrealistic solutions is a few scale heights below the upper boundary of the model and a few tens of scale heights above the lower boundary of the model.

Volland, H.; Mayr, H. G.

1971-01-01

106

Altered Histone Modifications in Gliomas  

PubMed Central

Gliomas are the most frequently occurring primary brain tumors in adults. Although they exist in different malignant stages, including histologically benign forms and highly aggressive states, most gliomas are clinically challenging for neuro-oncologists because of their infiltrative growth patterns and inherent relapse tendency with increased malignancy. Once this disease reaches the glioblastoma multiforme stage, the prognosis of patients is dismal: median survival time is 15 months. Extensive genetic analyses of glial tumors have revealed a variety of deregulated genetic pathways involved in DNA repair, apoptosis, cell migration/adhesion, and cell cycle. Recently, it has become evident that epigenetic alterations may also be an important factor for glioma genesis. Of epigenetic marks, histone modification is a key mark that regulates gene expression and thus modulates a wide range of cellular processes. In this review, I discuss the neuro-oncological significance of altered histone modifications and modifiers in glioma patients while briefly overviewing the biological roles of histone modifications. PMID:24926467

2014-01-01

107

Altered histone modifications in gliomas.  

PubMed

Gliomas are the most frequently occurring primary brain tumors in adults. Although they exist in different malignant stages, including histologically benign forms and highly aggressive states, most gliomas are clinically challenging for neuro-oncologists because of their infiltrative growth patterns and inherent relapse tendency with increased malignancy. Once this disease reaches the glioblastoma multiforme stage, the prognosis of patients is dismal: median survival time is 15 months. Extensive genetic analyses of glial tumors have revealed a variety of deregulated genetic pathways involved in DNA repair, apoptosis, cell migration/adhesion, and cell cycle. Recently, it has become evident that epigenetic alterations may also be an important factor for glioma genesis. Of epigenetic marks, histone modification is a key mark that regulates gene expression and thus modulates a wide range of cellular processes. In this review, I discuss the neuro-oncological significance of altered histone modifications and modifiers in glioma patients while briefly overviewing the biological roles of histone modifications. PMID:24926467

Kim, Young Zoon

2014-04-01

108

Surface modification for corrosion resistance  

SciTech Connect

The raw gas environments that arise from coal gasification have chemical compositions that are low in pO{sub 2} and moderate-to-high in pS{sub 2}. Metallic materials for service in such an environment undergo predominantly sulfidation attack at temperatures of 400 to 700{degree}C. Modification of alloy compositions in bulk can alter the scaling processes and lead to improvements in corrosion resistance, but the benefits can only be attained at temperatures much higher than the service temperatures of the components. Modification of surfaces of structural components by several of the coating techniques examined in this study showed substantial benefit in corrosion resistance when tested in simulated coal gasification environments. The paper presents several examples of surface modification and their corrosion performance.

Natesan, K.

1993-06-01

109

Weather Modification A Theoretician's Viewpoint.  

NASA Astrophysics Data System (ADS)

Early progress in weather modification is attributed to a healthy interaction between theory and experiment. During the 1970s, a divergence of approaches took place. A "theoretical/experimental" approach, exemplified by the Cascade Project, focused on testing scientific hypotheses; an "observational/experimental" approach, exemplified by the Colorado River Basin Pilot Project, sought to enhance understanding of the seeding process through more detailed observations.The theoretical/experimental school soon came to focus almost exclusively on natural cloud processes, leaving the field of weather modification nearly devoid of a theoretical component. It is suggested that this theoretical component is necessary to revitalize the field of weather modification.Key questions are addressed. These include 1) identification of clouds that are amenable to seeding; 2) glaciogenic versus hygroscopic seeding; 3) optimizing critical seeding variables, such as seed particle concentration for glaciogenic seeding and seed particle size for hygroscopic seeding; and 4) seeding for hail suppression.

Young, Kenneth C.

1996-11-01

110

Manufacturer evaluations of endograft modifications.  

PubMed

The motivation to modify the design of a vascular device can arise from a number of sources. Clinical experience with the unmodified device could suggest new design modifications to improve device performance or clinical outcomes. Similarly, clinical success with a device often suggests modifications that could broaden the applicability of the device to enable treatment of different or more advanced disease states. As a specific example, both of these scenarios have arisen during the last decade in the evolution of endovascular grafts for the treatment of abdominal aortic aneurysms, with modifications enabling the treatment of patients with shorter infrarenal necks, more angulated anatomy, and smaller access vessels. These modifications have been made by manufacturers and additionally by physicians who create branched and fenestrated devices. The experience to date with the use of fenestrated devices and the development of chimney, snorkel, and periscope techniques suggests that modifications to off-the-shelf devices may provide some clinical benefit. This experience provides additional motivation for manufacturers to develop devices to address the clinical needs not met with their current product lines. For manufacturers, the device development process includes an assessment of the new device design to determine the appropriate evaluation strategy to support the safety and effectiveness of the modified device. This report provides a high-level overview of the process generally followed by device manufacturers to evaluate a proposed device modification before market release, in accordance with local country regulations and recognized international standards such as the International Organization of Standardization (ISO) standards for endovascular grafts (ISO 25539 Part 1). PMID:23446123

Waninger, Matthew S; Whirley, Robert G; Smith, Louis J; Wolf, Ben S

2013-03-01

111

Structural characteristics, dispersion, and modification of fibrous brucite  

NASA Astrophysics Data System (ADS)

Fibrous brucite has very unique structure and physical properties. Brucite fibers were exfoliated into single nanofibers by using dioctyl sodium sulfosuccinate (AOT) as a dispersant through mechanical agitation and ultrasonic dispersion; and then, the nanofibers were modified by stearic acid and (3-aminopropyl)triethoxysilane (?-APS) compound modification agent. The nanofibers were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis. It is found that AOT has good effect on the dispersion. The single fiber has a consistent morphology, and fibrous brucite is dispersed and modified without destroying the crystal structure. Infrared and thermal analysis shows that the surface modification of fibrous brucite is achieved by forming chemical bonds between the coupling agent and magnesium hydroxide.

Cao, Xi; Chuan, Xiu-yun

2014-01-01

112

The Uniqueness of Speech among Motor Systems  

ERIC Educational Resources Information Center

This paper considers evidence that the speech muscles are unique in their genetic, developmental, functional and phenotypical properties. The literature was reviewed using PubMed, ScienceDirect, ComDisDome and other literature-retrieval systems to identify studies reporting on the craniofacial and laryngeal muscles. Particular emphasis was given…

Kent, Ray

2004-01-01

113

Marketing the Uniqueness of Small Towns. Revised.  

ERIC Educational Resources Information Center

The key to marketing a town is determining and promoting the town's "differential advantage" or uniqueness that would make people want to visit or live there. Exercises to help communities gain important insights into the town's competitive edge include a brainstorming session with knowledgeable community members, a visitor questionnaire, a…

Dunn, Douglas; Hogg, David H.

114

Uniqueness of Kerr-Newman solution  

E-print Network

We show that non-degenerate multiple black hole solution of Einstein- Maxwell equations in an asymptotically flat axisymmetric spacetime cannot be in stationary equilibrium. This extends the uniqueness of Kerr-Newman solution first proved by Bunting and Mazur in a much wider desirable class. Spin-spin interaction cannot hold the black hole aparts even with electromagnetic forces.

A. K. M. Masood-ul-Alam

2014-07-21

115

Alias Killing: Unique Variables without Destructive Reads  

Microsoft Academic Search

An unshared object can be accessed without regardto possible conflicts with other parts of a system,whether concurrent or single-threaded. A uniquevariable (sometimes known as a "free" or "linear"variable) is one that either is null or else refersto an unshared object. Being able to declare andcheck which variables are unique improves a programmer's ability to avoid program faults.

John Boyland

1999-01-01

116

Is There a Unique Black Personality?  

ERIC Educational Resources Information Center

This article reviews research from the 1940's, 1950's and 1960's on the effects of discrimination on blacks. Data from these studies indicate that adverse cultural restrictions have fostered a unique and distinctive black personality. Among traits identified are: a negative or inferior self-image, pessimism about the future, attachment to the…

Mosby, Doris P.

117

Art Libraries: Creating Access to Unique Collections  

ERIC Educational Resources Information Center

Art libraries face similar issues to other types of libraries during the digital transition but have unique twists driven by the needs of their collections. Art library information seekers may possess a sense of what an art library is: a library, set apart, to support the study of art and art history. For art libraries, it is the collection,…

Falls, Sarah E.

2009-01-01

118

Uniqueness of the orbital angular momentum operators  

Microsoft Academic Search

Summary  In a separable Hilbert space in which the three Cartesian coordinates form a complete set of commuting variables, it is proved\\u000a that Hermitian operators which satisfy the commutation relations for the angular momentum operators are unique within a unitary\\u000a transformation.

J. S. Lomont; H. E. Moses

1960-01-01

119

LCA ? Unique and Controversial Case Studies  

EPA Science Inventory

This session will focus on case studies and applications that have a unique or controversial aspect. Some of the most recent topics that seem to have significant interest include: LCA-based product declarations, LCA-based standards, LCA-based labels, alternative energy, agricul...

120

Static black hole uniqueness and Penrose inequality  

SciTech Connect

Under certain conditions, we offer a new way to prove the uniqueness of the static black hole in higher dimensional asymptotically flat spacetimes. In the proof, the Penrose inequality plays a key role in higher dimensions as well as four dimensions.

Mizuno, Ryosuke; Shiromizu, Tetsuya [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Ohashi, Seiju [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551 (Japan)

2010-02-15

121

Latent Variable Models of Need for Uniqueness.  

ERIC Educational Resources Information Center

Confirmatory factor analysis evaluated three a priori latent variable models of responses to the Need for Uniqueness Scale completed by 552 undergraduates. An oblique three-factor model best accounted for item commonality. Additional analysis suggests a model with loadings on four modestly correlated factors to explain the scale's latent…

Tepper, Kelly; Hoyle, Rick H.

1996-01-01

122

Tulane Student Designs Unique Learning Tool  

ERIC Educational Resources Information Center

A Louisiana architect has created plans for a unique supplementary learning environment consisting of five circular buildings featuring a planetarium, an indoor display of small animals in their native habitat, an indoor pond, a library, a media center, and an auditorium. (Author/MLF)

Modern Schools, 1977

1977-01-01

123

live music unique locations 1. Thiseventwillcontinueregardlessofweatherexceptinthecaseof  

E-print Network

. · After the concert, taxis collecting visitors must be on site by 10.30pm due to traffic flow. Access music unique locations concerT TiminGs · Concert car parks open at 5pm. The arena opens at 6pm

124

live music unique locations 1. Thiseventwillcontinueregardlessofweatherexceptinthecaseof  

E-print Network

concerts. pUBlic TransporT · The nearest train stations are etchingham (on the Hastings line from Charing a21 #12;live music unique locations concerT TiminGs · Concert car parks open at 4pm. The arena opens to concert car parks from 4pm. All concert-goers must park in the designated

125

live music unique locations 1. Thiseventwillcontinueregardlessofweatherexceptinthecaseof  

E-print Network

Clipstone a60 a617 a6075 a614 Kings Clipstone #12;live music unique locations concerT TiminGs · Concert car at 3.30pm on concert days in order to prepare for the concerts. · Free access to concert car parks from

126

Unique Discovery Aspects of Utilizing Botanical Sources  

Technology Transfer Automated Retrieval System (TEKTRAN)

Because of a long tradition of use in humans, botanicals have many unique advantages to offer as sources of natural products with pharmaceutical influence, especially in terms of opportunities for the development of diverse botanical products. This chapter outlines their use in screening programs, ...

127

(-)-Botryodiplodin, A Unique Ribose Analog Toxin  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many toxins owe their mechanisms of action to being structural analogs of essential metabolites, messengers or structural components. Examples range from tubo-curare to penicillin. Ribose plays a unique role in the metabolism of living organisms, whether prokaryotes or eukaryotes. It and its deri...

128

A Graduation Stole Uniquely Designed for Physics  

ERIC Educational Resources Information Center

In response to student requests, and to help celebrate the graduation of our physics majors, we have designed a graduation stole uniquely befitting physics. The design incorporates the four visible spectral lines of hydrogen--the Balmer series. Since the 2002 debut of the design, all our graduates have proudly worn their physics graduation stoles…

Day, Lawrence H.

2009-01-01

129

Toward a Unique UnderstandingToward a Unique Understanding Washington SquareWashington Square  

E-print Network

Toward a Unique UnderstandingToward a Unique Understanding ofof Washington SquareWashington Square Robert Z. Selden Jr.Robert Z. Selden Jr. Dan J. KaminskiDan J. Kaminski #12;Washington SquareWashington Square Photograph courtesy of Anthropology and Archaeology Laboratory ­ Stephen F. Austin State

Hung, I-Kuai

130

THEME 2 : MODIFICATIONS DU CONTINENT ASIE AU COURS DE LA COLLISION  

E-print Network

THEME 2 : MODIFICATIONS DU CONTINENT ASIE AU COURS DE LA COLLISION 1. La collision Inde questions fondamentales 1) Quelle est la zone de déformation ? Les deux continents se déforment grands décrochements dans la déformation Tertiaire du continent Asiatique. Fait unique, nous avons pu

Déverchère, Jacques

131

Modification of Lake Michigan Benthic Habitats by Zebra Mussels Primary Investigator: Stephen Lozano -NOAA GLERL  

E-print Network

Modification of Lake Michigan Benthic Habitats by Zebra Mussels Primary Investigator: Stephen Overview Colonization by dreissenid mussels, Dreissena polymorpha (Zebra) and Dreissena bugensis (Quagga. Preliminary results suggest that zebra mussel populations on the lake bottom reflect sound in a unique way

132

Optimization of Process Conditions for Enzymatic Modification of Alternan using Dextranase from Chaetomium erraticum  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternan is a unique branched glucan with alternating a-(1 ' 6) and a-(1 ' 3) backbone linkages. We previously described the modification of alternan to a reduced molecular weight form using dextranase from Penicillium sp. The solution viscosity properties of this modified alternan resemble those ...

133

Field Experimentation in Weather Modification  

Microsoft Academic Search

Weather modification provides a fertile field for interaction and collaboration between meteorologists and statisticians. Cloud seeding experiments, including Project Whitetop, provide a background for illustrating some of the statistical issues in meteorological field experimentation and for exposing some of the difficulties that can arise when meteorologists and statisticians look at the same experiments from different points of view. Several specific

Roscoe R. Braham Jr

1979-01-01

134

Changing Attitudes Through Behavior Modification.  

ERIC Educational Resources Information Center

This article describes the philosophy and methods used by the staff at the Granite Alternative School in changing student attitudes through behavior modification. The students involved all have a failure syndrome or low self-image, and are dropouts from traditional high schools. Among the techniques used are: (1) reinforcing good behavior (praise…

Whipple, W. Scott

135

Epigenetic modifications and human disease  

Microsoft Academic Search

Epigenetics is one of the most rapidly expanding fields in biology. The recent characterization of a human DNA methylome at single nucleotide resolution, the discovery of the CpG island shores, the finding of new histone variants and modifications, and the unveiling of genome-wide nucleosome positioning maps highlight the accelerating speed of discovery over the past two years. Increasing interest in

Anna Portela; Manel Esteller

2010-01-01

136

Plasma surface modification of polymers  

NASA Technical Reports Server (NTRS)

Thin plasma polymerization films are discussed from the viewpoint of simplicity in production stages. The application of selective, absorbent films and films used in selective permeability was tested. The types of surface modification of polymers discussed are: (1) plasma etching, (2) surface coating by plasma polymerized thin films, and (3) plasma activation surface graft polymerization.

Hirotsu, T.

1980-01-01

137

Demonstrating Allotropic Modifications of Sulfur.  

ERIC Educational Resources Information Center

Shows how a common demonstration that consists of slowly heating sulfur powder in a test tube to illustrate sulfur's allotropic modifications can convince students of conclusions about the moon Io which they often find surprising. Describes the demonstration in full. (Author/MM)

McCarty, Jillian L.; Dragojlovic, Veljko

2002-01-01

138

The Modification of Biocellular Chemical Reactions by Environmental Physicochemicals  

NASA Astrophysics Data System (ADS)

Environmental risk factors affect human biological system to different extent from modification of biochemical reaction to cellular catastrophe. There are considerable public concerns about electromagnetic fields and endocrine disruptors. Their risk assessments have not been fully achieved because of their scientific uncertainty: electromagnetic fields just modify the bioreaction in the restricted cells and endocrine disruptors are quite unique in that their expression is dependent on the exposure periods throughout a life. Thus, we here describe their molecular characterization to establish the new risk assessments for environmental physicochemicals.

Ishido, M.

139

Comprehensive Analysis of Protein Modifications by Top-down Mass Spectrometry  

PubMed Central

Mass spectrometry (MS)-based proteomics is playing an increasingly important role in cardiovascular research. Proteomics includes not only identification and quantification of proteins, but also the characterization of protein modifications such as post-translational modifications and sequence variants. The conventional bottom-up approach, involving proteolytic digestion of proteins into small peptides prior to MS analysis, is routinely used for protein identification and quantification with high throughput and automation. Nevertheless, it has limitations in the analysis of protein modifications mainly due to the partial sequence coverage and loss of connections among modifications on disparate portions of a protein. An alternative approach, top-down MS, has emerged as a powerful tool for the analysis of protein modifications. The top-down approach analyzes whole proteins directly, providing a “bird’s eye” view of all existing modifications. Subsequently, each modified protein form can be isolated and fragmented in the mass spectrometer to locate the modification site. The incorporation of the non-ergodic dissociation methods such as electron capture dissociation (ECD) greatly enhances the top-down capabilities. ECD is especially useful for mapping labile post-translational modifications which are well-preserved during the ECD fragmentation process. Top-down MS with ECD has been successfully applied to cardiovascular research with the unique advantages in unraveling the molecular complexity, quantifying modified protein forms, complete mapping of modifications with full sequence coverage, discovering unexpected modifications, and identifying and quantifying positional isomers and determining the order of multiple modifications. Nevertheless, top-down MS still needs to overcome some technical challenges to realize its full potential. Herein, we reviewed the advantages and challenges of top-down methodology with a focus on its application in cardiovascular research. PMID:22187450

Zhang, Han; Ge, Ying

2012-01-01

140

Unique biochemical and mineral composition of whale ear bones.  

PubMed

Abstract Cetaceans are obligate aquatic mammals derived from terrestrial artiodactyls. The defining characteristic of cetaceans is a thick and dense lip (pachyosteosclerotic involucrum) of an ear bone (the tympanic). This unique feature is absent in modern terrestrial artiodactyls and is suggested to be important in underwater hearing. Here, we investigate the mineralogical and biochemical properties of the involucrum, as these may hold clues to the aquatic adaptations of cetaceans. We compared bioapatites (enamel, dentine, cementum, and skeletal bone) of cetaceans with those of terrestrial artiodactyls and pachyosteosclerotic ribs of manatees (Sirenia). We investigated organic, carbonate, and mineral composition as well as crystal size and crystallinity index. In all studied variables, bioapatites of the cetacean involucrum were intermediate in composition and structure between those of tooth enamel on the one hand and those of dentine, cementum, and skeletal bone on the other. We also studied the amino acid composition of the cetacean involucrum relative to that of other skeletal bone. The central involucrum had low glycine and hydroxyproline concentrations but high concentrations of nonessential amino acids, unlike most bone samples but similar to the tympanic of hippos and the (pachyosteosclerotic) ribs of manatees. These amino acid results are evidence of rapid bone development. We hypothesize that the mineralogical and amino acid composition of cetacean bullae differs from that of other bone because of (1) functional modifications for underwater sound reception and (2) structural adaptations related to rapid ossification. PMID:24940922

Kim, Sora L; Thewissen, J G M; Churchill, Morgan M; Suydam, Robert S; Ketten, Darlene R; Clementz, Mark T

2014-01-01

141

Unique device identification system. Final rule.  

PubMed

The Food and Drug Administration (FDA) is issuing a final rule to establish a system to adequately identify devices through distribution and use. This rule requires the label of medical devices to include a unique device identifier (UDI), except where the rule provides for an exception or alternative placement. The labeler must submit product information concerning devices to FDA's Global Unique Device Identification Database (GUDID), unless subject to an exception or alternative. The system established by this rule requires the label and device package of each medical device to include a UDI and requires that each UDI be provided in a plain-text version and in a form that uses automatic identification and data capture (AIDC) technology. The UDI will be required to be directly marked on the device itself if the device is intended to be used more than once and intended to be reprocessed before each use. PMID:24066364

2013-09-24

142

User applications unique to mobile satellites  

NASA Technical Reports Server (NTRS)

As AMSC enters the market with its mobile satellite services, it faces a sophisticated user group that has already experimented with a wide range of communications services, including cellular radio and Ku-band satellite messaging. AMSC's challenge is to define applications unique to the capabilities of its dedicated L band satellite and consistent with the provisions outlined in its FCC license. Through a carefully researched approach to its three main markets (aeronautical, land mobile, and maritime) AMSC is discovering a wellspring of interest in corporate and general aviation, trucking companies, pipeline monitoring and control companies, maritime management firms, telecommunications companies, and government agencies. A general overview is provided of AMSC's FCC license and corporate history, and the specific applications unique to each user group is discussed.

Castiel, David

1990-01-01

143

Metalworking Techniques Unlock a Unique Alloy  

NASA Technical Reports Server (NTRS)

Approached by West Hartford, Connecticut-based Abbot Ball Company, Glenn Research Center agreed to test an intriguing alloy called Nitinol 60 that had been largely unused for a half century. Using powdered metallurgy, the partners developed a method for manufacturing and working with the material, which Abbott Ball has now commercialized. Nitinol 60 provides a unique combination of qualities that make it an excellent material for ball bearings, among other applications.

2015-01-01

144

Assessing non-uniqueness: An algebraic approach  

SciTech Connect

Geophysical inverse problems are endowed with a rich mathematical structure. When discretized, most differential and integral equations of interest are algebraic (polynomial) in form. Techniques from algebraic geometry and computational algebra provide a means to address questions of existence and uniqueness for both linear and non-linear inverse problem. In a sense, the methods extend ideas which have proven fruitful in treating linear inverse problems.

Vasco, Don W.

2002-09-16

145

live music unique locations 1. Thiseventwillcontinueregardlessofweatherexceptinthecaseof  

E-print Network

· Taxis collecting concert-goers must be on site by 10.45pm. Please book your taxi, including the return Travel 01543 304831 Wolverhampton Premier cars 01902 717777 #12;live music unique locations concerT TiminGs · Concert car parks open at 5pm. The arena opens at 6pm, with live music starting at about 7.30pm

146

live music unique locations 1. Thiseventwillcontinueregardlessofweatherexceptinthecaseof  

E-print Network

Pickering Scarborough Malton Helmsley Thirsk a169 a59 a1(m) b1363 #12;live music unique locations concerT TiminGs · Concert car parks open at 5pm. The arena opens at 6pm, with live music starting at about 7 not go for a walk and have a picnic? An admission charge may apply. · Free access to concert car parks

147

B1 Cells: unique origins and functions  

Microsoft Academic Search

B-1 cells represent a distinct population of B lymphocytes with unique phenotypic, developmental and functional characteristics. We present evidence that the expression of MHC class II antigens differentiates two distinct developmental pathways which define the fetal-type (FT) and adult-type B-cell lineages. Furtherin-vivoandin-vitroanalyses suggest that B-1 cells are derived primarily if not exclusively from the FT lineage. Combining these results with

Alan M. Stall; Sandra M. Wells; Kong-Peng Lam

1996-01-01

148

Marché unique et développement des échanges  

Microsoft Academic Search

[fre] Marché unique et développement des échanges Contrairement à la théorie classique du commerce international, la première vague d'intégration européenne ne s'est pas traduite par un développement du commerce inter-branche reflétant une spécialisation accrue des pays . membres dans des produits pour lesquels ils détenaient un avantage comparatif. En revanche, le développement du commerce intra-branche reflète davantage une spécialisation des

Michael Freudenberg; Lionel Fontagné

1999-01-01

149

Unique Signal Override Plug electromagnetic test report  

SciTech Connect

The MC4039 Unique Signal Override Plug (USOP) provides the unique signal for the B90 when fielded on aircraft that are not equipped with unique signal capability. Since the USOP is field installed, the concern is that it might be susceptible to electromagnetic radiation prior to installation on the weapon. This report documents a characterization of the USOP, evaluates various techniques for attaching electromagnetic shields, and evaluates the susceptibility of a fully assembled passive-USOP. Tests conducted evaluated the electromagnetic susceptibility of the passive, unconnected USOP. During normal operation the USOP is powered directly from the weapon. During the course of this test program two prototypes were developed. The prototype 1 USOP internal circuitry contains one SA3727 chip, five diodes, three resistors, and two capacitors; these are mounted on a circular circuit board and contained inside a metal back shell cover, which serves as an electromagnetic shield. The prototype 2 design incorporated four changes. The manufacturer of the SA3727 chip was changed from Lasarray to LSI Logic, the circuit board ground was tied to the case ground through a straight wire, Cl was changed from 1 microfarad to 0.1 microfarads. and the circuit board was changed, as required. 2 refs., 17 figs., 3 tabs. (JF)

Bonn, R.H.

1990-10-01

150

Issues unique to the female runner.  

PubMed

Care and treatment of female runners will improve as further knowledge regarding the unique factors that affect them becomes available. For care and treatment to be their most effective, current and recent information needs to be disseminated among health care providers, coaches, teachers, school administrators, and parents. In young athletes, peer support and education are the most important factors in the success of detection and treatment. Individuals who have the female athlete triad are at significant risk for stress fractures and other injuries. Early detection and multidisciplinary treatment should begin after fractures are detected to reduce or prevent long-term adverse sequelae to bone. In addition, correction of menstrual dysfunction can help to prevent later fertility problems. Addressing the unique biomechanics and core strength of female runners also is essential to rehabilitate athletes past symptom resolution. A thorough understanding of the unique issues for female runners is essential for the prevention of injuries and plays an important role in the promotion of female participation in recreational and competitive running. PMID:16005400

Prather, Heidi; Hunt, Deyvani

2005-08-01

151

HHMD: the human histone modification database.  

PubMed

Histone modifications play important roles in chromatin remodeling, gene transcriptional regulation, stem cell maintenance and differentiation. Alterations in histone modifications may be linked to human diseases especially cancer. Histone modifications including methylation, acetylation and ubiquitylation probed by ChIP-seq, ChIP-chip and qChIP have become widely available. Mining and integration of histone modification data can be beneficial to novel biological discoveries. There has been no comprehensive data repository that is exclusive for human histone modifications. Therefore, we developed a relatively comprehensive database for human histone modifications. Human Histone Modification Database (HHMD, http://bioinfo.hrbmu.edu.cn/hhmd) focuses on the storage and integration of histone modification datasets that were obtained from laboratory experiments. The latest release of HHMD incorporates 43 location-specific histone modifications in human. To facilitate data extraction, flexible search options are built in HHMD. It can be searched by histone modification, gene ID, functional categories, chromosome location and cancer name. HHMD also includes a user-friendly visualization tool named HisModView, by which genome-wide histone modification map can be shown. HisModView facilitates the acquisition and visualization of histone modifications. The database also has manually curated information of histone modification dysregulation in nine human cancers. PMID:19892823

Zhang, Yan; Lv, Jie; Liu, Hongbo; Zhu, Jiang; Su, Jianzhong; Wu, Qiong; Qi, Yunfeng; Wang, Fang; Li, Xia

2010-01-01

152

Chromatin modifications associated with diabetes.  

PubMed

Accelerated rates of vascular complications are associated with diabetes mellitus. Environmental factors including hyperglycaemia contribute to the progression of diabetic complications. Epidemiological and experimental animal studies identified poor glycaemic control as a major contributor to the development of complications. These studies suggest that early exposure to hyperglycaemia can instigate the development of complications that present later in the progression of the disease, despite improved glycaemic control. Recent experiments reveal a striking commonality associated with gene-activating hyperglycaemic events and chromatin modification. The best characterised to date are associated with the chemical changes of amino-terminal tails of histone H3. Enzymes that write specified histone tail modifications are not well understood in models of hyperglycaemia and metabolic memory as well as human diabetes. The best-characterised enzyme is the lysine specific Set7 methyltransferase. The contribution of Set7 to the aetiology of diabetic complications may extend to other transcriptional events through methylation of non-histone substrates. PMID:22639343

Keating, Samuel T; El-Osta, Assam

2012-08-01

153

DNA modifications: Another stable base in DNA  

NASA Astrophysics Data System (ADS)

Oxidation of 5-methylcytosine has been proposed to mediate active and passive DNA demethylation. Tracking the history of DNA modifications has now provided the first solid evidence that 5-hydroxymethylcytosine is a stable epigenetic modification.

Brazauskas, Pijus; Kriaucionis, Skirmantas

2014-12-01

154

Capitalized Asset Management EQUIPMENT INVENTORY MODIFICATION  

E-print Network

Capitalized Asset Management EQUIPMENT INVENTORY MODIFICATION REQUEST Instructions to the Department: Submit this form for changes to University equipment assigned to your operating unit. This form of Modification ­ Request for Equipment: Addition (Attach acquisition documents) Cannibalized ­ Date: Stolen

Yamamoto, Keith

155

Materials Modification in Nanotechnology: Oxidation  

NSDL National Science Digital Library

This PowerPoint created and presented by the Nanotechnology Applications and Career Knowledge (NACK) Center introduces students to oxidation. It goes over the various types of oxide â?? native, gate, field, etc. It discusses dry vs. wet oxidation, high pressure oxidation, chemical vapor deposition and has a section on modifying dielectric constant. This is a great resource for any classroom looking at nanofabrication modifications. This and all other valuable resources from the NACK Center require a fast, easy, free log-in.

156

Modification of Alternan by Dextranase  

Technology Transfer Automated Retrieval System (TEKTRAN)

Alternan is a unique glucan with a backbone structure of alternating alpha-(1=-6) and alpha-(1=-3) linkages. Previously, we isolated strains of Penicillium sp. that modify native, high molecular weight alternan in a novel bioconversion process to a lower molecular weight form with solution viscosit...

157

The Public Decides about Weather Modification  

Microsoft Academic Search

Planned weather modification is a potentially significant phenomenon being introduced in many area of this and other countries. Evidence is beginning to accumulate suggesting that where organized resistance persists over a period of time, weather modification efforts are in fact halted. The paper briefly outlines the history of weather modification in the United States; research findings on the social aspects

Barbara C. Farhar

1977-01-01

158

Energy conservation potential of surface modification technologies  

SciTech Connect

This report assesses the energy conservation impact of surface modification technologies on the metalworking industries. The energy conservation impact of surface modification technologies on the metalworking industries is assessed by estimating their friction and wear tribological sinks and the subsequent reduction in these sinks when surface modified tools are used. Ion implantation, coatings, and laser and electron beam surface modifications are considered.

Le, H.K.; Horne, D.M.; Silberglitt, R.S.

1985-09-01

159

Complexity Classification of Some Edge Modification Problems  

E-print Network

in Section 3. Interval modification problems have important applications in physical mapping of DNA (see [5Complexity Classification of Some Edge Modification Problems Assaf Natanzon1, Ron Shamir1,shamir,rodedg@math.tau.ac.il. Abstract. In an edge modification problem one has to change the edge set of a given graph as little

Shamir, Ron

160

The Parisi Formula has a Unique Minimizer  

NASA Astrophysics Data System (ADS)

In 1979, Parisi (Phys Rev Lett 43:1754-1756, 1979) predicted a variational formula for the thermodynamic limit of the free energy in the Sherrington-Kirkpatrick model, and described the role played by its minimizer. This formula was verified in the seminal work of Talagrand (Ann Math 163(1):221-263, 2006) and later generalized to the mixed p-spin models by Panchenko (Ann Probab 42(3):946-958, 2014). In this paper, we prove that the minimizer in Parisi's formula is unique at any temperature and external field by establishing the strict convexity of the Parisi functional.

Auffinger, Antonio; Chen, Wei-Kuo

2014-11-01

161

Sordarin, an antifungal agent with a unique mode of action  

PubMed Central

Summary The sordarin family of compounds, characterized by a unique tetracyclic diterpene core including a norbornene system, inhibits protein synthesis in fungi by stabilizing the ribosome/EF2 complex. This mode of action is in contrast to typical antifungals, which target the cell membrane. This unusual bioactivity makes sordarin a promising candidate for the development of new fungicidal agents, and provided the motivation for extensive research. Three total syntheses (by the Kato, Mander and Narasaka groups), modifications of the glycosyl unit, and changes to the diterpene core (Cuevas and Ciufolini models) will also be discussed in this review. PMID:18941619

2008-01-01

162

Modification of Nanostructures via Laser Processing  

NASA Astrophysics Data System (ADS)

Modification of nanostructures via laser processing is of great interest for a wide range of applications such as aerospace and the storage of nuclear waste. The primary goal of this dissertation is to improve the understanding of nanostructures through two primary routes: the modification of aerogels and pulsed laser ablation in ethanol. A new class of materials, patterned aerogels, was fabricated by photopolymerizing selected regions of homogeneous aerogel monoliths using visible light. The characterization and fabrication of functionally graded, cellular and compositionally anisotropic aerogels and ceramics is discussed. Visible light was utilized due to it's minimal absorption and scattering by organic molecules and oxide nanoparticles within wet gels. This allowed for the fabrication of deeply penetrating, well resolved patterns. Similarly, nanoporous monoliths with a typical aerogel core and a mechanically robust exterior ceramic layer were synthesized from silica aerogels cross-linked with polyacrylonitrile. Simple variations of the exposure geometry allowed fabrication of a wide variety of anisotropic materials without requiring layering or bonding. Nanoparticle solutions were prepared by laser ablation of metal foils (Fe and Mo) in ethanol. Ablation of Fe generated Fe3O4 and Fe3C nanoparticles which were superparamagnetic with a saturation magnetization Ms = 124 emu/g. Zero field cooled (ZFC) measurements collected at an applied field of 50 Oe displayed a maximum magnetic susceptibility at 120 K with a broad distribution. Field cooled (FC) measurements showed a thermal hysteresis indicative of temperature dependent magnetic viscosity. Pulsed laser ablation of a Mo foil in ethanol generated inhomogeneous nanoparticles where Mo and MoC coexisted within the same aggregate. Formation of these unique nanoparticles is likely due to phase separation that occurs when a high temperature carbide phase cools after the laser pulse terminates. Similarly, magnetic nanoparticle suspensions were generated by pulsed laser ablation of Fe and Mo in ethanol. The formation of several carbide phases with no discernable alloy formation was seen. A decrease in magnetization with a decrease in Fe concentration was seen which was reconciled with the decreased Fe content in the system. However, at Fe concentrations below ˜ 40%, an increase in Ms and Hc was observed which was reconciled with the disappearance of the epsilon--Fe3C. TEM analysis showed the formation of core-shell nanoparticles and Energy Filtered TEM showed the distribution of Fe-based nanoparticles in the suspensions.

Franzel, Louis Avery

163

Modification of Nanostructures via Laser Processing  

NASA Astrophysics Data System (ADS)

Modification of nanostructures via laser processing is of great interest for a wide range of applications such as aerospace and the storage of nuclear waste. The primary goal of this dissertation is to improve the understanding of nanostructures through two primary routes: the modification of aerogels and pulsed laser ablation in ethanol. A new class of materials, patterned aerogels, was fabricated by photopolymerizing selected regions of homogeneous aerogel monoliths using visible light. The characterization and fabrication of functionally graded, cellular and compositionally anisotropic aerogels and ceramics is discussed. Visible light was utilized due to it's minimal absorption and scattering by organic molecules and oxide nanoparticles within wet gels. This allowed for the fabrication of deeply penetrating, well resolved patterns. Similarly, nanoporous monoliths with a typical aerogel core and a mechanically robust exterior ceramic layer were synthesized from silica aerogels cross-linked with polyacrylonitrile. Simple variations of the exposure geometry allowed fabrication of a wide variety of anisotropic materials without requiring layering or bonding. Nanoparticle solutions were prepared by laser ablation of metal foils (Fe and Mo) in ethanol. Ablation of Fe generated Fe3O4 and Fe3C nanoparticles which were superparamagnetic with a saturation magnetization Ms = 124 emu/g. Zero field cooled (ZFC) measurements collected at an applied field of 50 Oe displayed a maximum magnetic susceptibility at 120 K with a broad distribution. Field cooled (FC) measurements showed a thermal hysteresis indicative of temperature dependent magnetic viscosity. Pulsed laser ablation of a Mo foil in ethanol generated inhomogeneous nanoparticles where Mo and MoC coexisted within the same aggregate. Formation of these unique nanoparticles is likely due to phase separation that occurs when a high temperature carbide phase cools after the laser pulse terminates. Similarly, magnetic nanoparticle suspensions were generated by pulsed laser ablation of Fe and Mo in ethanol. The formation of several carbide phases with no discernable alloy formation was seen. A decrease in magnetization with a decrease in Fe concentration was seen which was reconciled with the decreased Fe content in the system. However, at Fe concentrations below ˜ 40%, an increase in Ms and Hc was observed which was reconciled with the disappearance of the epsilon--Fe 3C. TEM analysis showed the formation of core-shell nanoparticles and Energy Filtered TEM showed the distribution of Fe-based nanoparticles in the suspensions.

Franzel, Louis Avery

164

Unique Identification of Graviton Exchange Effects in e+e- Collisions  

SciTech Connect

Many types of new physics can lead to contact interaction-like modifications in e{sup +}e{sup -} processes below direct production threshold. We examine the possibility of uniquely identifying the effects of graviton exchange, which are anticipated in many extra dimensional theories, from amongst this large set of models by using the moments of the angular distribution of the final state particles. In the case of the e{sup +}e{sup -} {yields} f{bar f} process we demonstrate that this technique allows for the unique identification of the graviton exchange signature at the 5{sigma} level for mass scales as high as 6{radical}s. The extension of this method to the e{sup +}e{sup -} {yields} W{sup +}W{sup -} process is also discussed.

Rizzo, Thomas G.

2002-08-02

165

Exploiting unique structural and functional properties of malarial glycolytic enzymes for antimalarial drug development.  

PubMed

Metabolic enzymes have been known to carry out a variety of functions besides their normal housekeeping roles known as "moonlighting functions." These functionalities arise from structural changes induced by posttranslational modifications and/or binding of interacting proteins. Glycolysis is the sole source of energy generation for malaria parasite Plasmodium falciparum, hence a potential pathway for therapeutic intervention. Crystal structures of several P. falciparum glycolytic enzymes have been solved, revealing that they exhibit unique structural differences from the respective host enzymes, which could be exploited for their selective targeting. In addition, these enzymes carry out many parasite-specific functions, which could be of potential interest to control parasite development and transmission. This review focuses on the moonlighting functions of P. falciparum glycolytic enzymes and unique structural differences and functional features of the parasite enzymes, which could be exploited for therapeutic and transmission blocking interventions against malaria. PMID:25580350

Alam, Asrar; Neyaz, Md Kausar; Ikramul Hasan, Syed

2014-01-01

166

Exploiting Unique Structural and Functional Properties of Malarial Glycolytic Enzymes for Antimalarial Drug Development  

PubMed Central

Metabolic enzymes have been known to carry out a variety of functions besides their normal housekeeping roles known as “moonlighting functions.” These functionalities arise from structural changes induced by posttranslational modifications and/or binding of interacting proteins. Glycolysis is the sole source of energy generation for malaria parasite Plasmodium falciparum, hence a potential pathway for therapeutic intervention. Crystal structures of several P. falciparum glycolytic enzymes have been solved, revealing that they exhibit unique structural differences from the respective host enzymes, which could be exploited for their selective targeting. In addition, these enzymes carry out many parasite-specific functions, which could be of potential interest to control parasite development and transmission. This review focuses on the moonlighting functions of P. falciparum glycolytic enzymes and unique structural differences and functional features of the parasite enzymes, which could be exploited for therapeutic and transmission blocking interventions against malaria. PMID:25580350

Neyaz, Md. Kausar; Ikramul Hasan, Syed

2014-01-01

167

Key advances in the chemical modification of nanocelluloses.  

PubMed

Nanocelluloses, including nanocrystalline cellulose, nanofibrillated cellulose and bacterial cellulose nanofibers, have become fascinating building blocks for the design of new biomaterials. Derived from the must abundant and renewable biopolymer, they are drawing a tremendous level of attention, which certainly will continue to grow in the future driven by the sustainability trend. This growing interest is related to their unsurpassed quintessential physical and chemical properties. Yet, owing to their hydrophilic nature, their utilization is restricted to applications involving hydrophilic or polar media, which limits their exploitation. With the presence of a large number of chemical functionalities within their structure, these building blocks provide a unique platform for significant surface modification through various chemistries. These chemical modifications are prerequisite, sometimes unavoidable, to adapt the interfacial properties of nanocellulose substrates or adjust their hydrophilic-hydrophobic balance. Therefore, various chemistries have been developed aiming to surface-modify these nano-sized substrates in order to confer to them specific properties, extending therefore their use to highly sophisticated applications. This review collocates current knowledge in the research and development of nanocelluloses and emphasizes more particularly on the chemical modification routes developed so far for their functionalization. PMID:24316693

Habibi, Youssef

2014-03-01

168

Proteome-wide Identification of SUMO2 Modification Sites  

PubMed Central

Post-translational modification with small ubiquitin-like modifiers (SUMOs) alters the function of proteins involved in diverse cellular processes. SUMO-specific enzymes conjugate SUMOs to lysine residues in target proteins. Although proteomic studies have identified hundreds of sumoylated substrates, methods to identify the modified lysines on a proteomic scale are lacking. We developed a method that enabled proteome-wide identification of sumoylated lysines that involves the expression of polyhistidine (6His)-tagged SUMO2 with Thr90 mutated to Lys. Endoproteinase cleavage with Lys-C of 6His-SUMO2T90K modifed proteins from human cell lysates produced a diGly remnant on SUMO2T90K conjugated lysines enabling immunoprecipitation of SUMO2T90K modified peptides and producing a unique mass-to-charge signature. Mass spectrometry analysis of SUMO enriched peptides revealed over 1,000 sumoylated lysines in 539 proteins, including many functionally related proteins involved in cell cycle, transcription, and DNA repair. Not only can this strategy be used to study the dynamics of sumoylation and potential other similar posttranslational modifications, but also, these data provide an unprecedented resource for future research on the role of sumoylation in cellular physiology and disease. PMID:24782567

Jaffray, Ellis G.; Ibrahim, Adel F. M.; Tatham, Michael H.; Hay, Ronald T.

2014-01-01

169

Unmanned Aerial Vehicles unique cost estimating requirements  

NASA Astrophysics Data System (ADS)

Unmanned Aerial Vehicles (UAVs), also referred to as drones, are aerial platforms that fly without a human pilot onboard. UAVs are controlled autonomously by a computer in the vehicle or under the remote control of a pilot stationed at a fixed ground location. There are a wide variety of drone shapes, sizes, configurations, complexities, and characteristics. Use of these devices by the Department of Defense (DoD), NASA, civil and commercial organizations continues to grow. UAVs are commonly used for intelligence, surveillance, reconnaissance (ISR). They are also use for combat operations, and civil applications, such as firefighting, non-military security work, surveillance of infrastructure (e.g. pipelines, power lines and country borders). UAVs are often preferred for missions that require sustained persistence (over 4 hours in duration), or are “ too dangerous, dull or dirty” for manned aircraft. Moreover, they can offer significant acquisition and operations cost savings over traditional manned aircraft. Because of these unique characteristics and missions, UAV estimates require some unique estimating methods. This paper describes a framework for estimating UAV systems total ownership cost including hardware components, software design, and operations. The challenge of collecting data, testing the sensitivities of cost drivers, and creating cost estimating relationships (CERs) for each key work breakdown structure (WBS) element is discussed. The autonomous operation of UAVs is especially challenging from a software perspective.

Malone, P.; Apgar, H.; Stukes, S.; Sterk, S.

170

The Unique Nature of Mg2+ Channels  

NSDL National Science Digital Library

Considering the biological abundance and importance of Mg2+, there is a surprising lack of information regarding the proteins that transport Mg2+, the mechanisms by which they do so, and their physiological roles within the cell. The best characterized Mg2+ channel to date is the bacterial protein CorA, present in a wide range of bacterial species. The CorA homolog Mrs2 forms the mitochondrial Mg2+ channel in all eukaryotes. Physiologically, CorA is involved in bacterial pathogenesis, and the Mrs2 eukaryotic homolog is essential for cell survival. A second Mg2+ channel widespread in bacteria is MgtE. Its eukaryotic homologs are the SLC41 family of carriers. Physiological roles for MgtE and its homologs have not been established. Recently, the crystal structures for the bacterial CorA and MgtE Mg2+ channels were solved, the first structures of any divalent cation channel. As befits the unique biological chemistry of Mg2+, both structures are unique, unlike that of any other channel or transporter. Although structurally quite different, both CorA and MgtE appear to be gated in a similar manner through multiple Mg2+ binding sites in the cytosolic domain of the channels. These sites essentially serve as Mg2+ "sensors" of cytosolic Mg2+ concentration. Many questions about these channels remain, however, including the molecular basis of Mg2+ selectivity and the physiological role(s) of their eukaryotic homologs.

Andrea S Moomaw (Case Western Reserve University Pharmacology)

2008-10-18

171

I feel unique, therefore I am: The development and preliminary validation of the personal sense of uniqueness (PSU) scale  

Microsoft Academic Search

Although the concept of uniqueness has always been special in psychology, there is no psychometric tool for measuring individuals’ sense of uniqueness. The research reported herein aimed to develop and validate a self-report measurement tool to assess individuals’ sense of uniqueness. Five studies were conducted to confirm the factor structure of the personal sense of uniqueness scale and to assess

Ömer Faruk ?im?ek; Berna Yal?nçetin

2010-01-01

172

ARAC: A unique command and control resource  

SciTech Connect

The Atmospheric Release Advisory Capability (ARAC) at Lawrence Livermore National Laboratory (LLNL) is a centralized federal facility designed to provide real-time, world-wide support to military and civilian command and control centers by predicting the impacts of inadvertent or intentional releases of nuclear, biological, or chemical materials into the atmosphere. ARAC is a complete response system consisting of highly trained and experienced personnel, continually updated computer models, redundant data collection systems, and centralized and remote computer systems. With over 20 years of experience responding to domestic and international incidents, strong linkages with the Department of Defense, and the ability to conduct classified operations, ARAC is a unique command and control resource.

Bradley, M.M.; Baskett, R.L.; Ellis, J.S. [and others

1996-04-01

173

Imaging concerns unique to twin pregnancy.  

PubMed

The incidence of multiple gestations is increasing with rising maternal age and the utilization of artificial reproductive techniques. Twinning confers an increased risk to the pregnancy, with higher incidence of structural anomalies, preterm delivery, and perinatal morbidity and mortality. Certain conditions are unique to twin pregnancy, such as the twin-to-twin transfusion syndrome and the acardiac twin, secondary to vascular sharing between both the fetuses. Conjoined twinning is a phenomenon occurring because of late splitting of the zygote. Advances in imaging have increased our ability to manage multiple pregnancies with accurate prenatal diagnosis, better antenatal surveillance, and novel image-guided procedures. The purpose of this article is to provide an overview of the twinning process, including the pathophysiology, diagnostic pearls, and dilemmas and to briefly outline the outcomes and available treatment options to assist the radiologist in better management of multiple gestations. PMID:25239076

Mahalingam, Sowmya; Dighe, Manjiri

2014-01-01

174

Hausdorff dimension of unique beta expansions  

NASA Astrophysics Data System (ADS)

Given an integer N ? 2 and a real number ? > 1, let ??, N be the set of all x=\\sumi=1^? {d_i}/{?^i} with di ? {0, 1, ···, N ? 1} for all i ? 1. The infinite sequence (di) is called a ?-expansion of x. Let U?,N be the set of all x's in ??,N which have unique ?-expansions. We give explicit formula of the Hausdorff dimension of U?,N for ? in any admissible interval [?L, ?U], where ?L is a purely Parry number while ?U is a transcendental number whose quasi-greedy expansion of 1 is related to the classical Thue–Morse sequence. This allows us to calculate the Hausdorff dimension of U?,N for almost every ? > 1. In particular, this improves the main results of Gábor Kallós (1999, 2001). Moreover, we find that the dimension function f(?) = dimHU?,N fluctuates frequently for ? ? (1, N).

Kong, Derong; Li, Wenxia

2015-01-01

175

A unique case of unilateral synophthalmia.  

PubMed

Developmental anomalies resulting in a single eye (cyclopia) or fusion of the eyes (synophthalmia) are rare. Examples of unilateral synophthalmia-in which there are 1 normal and 2 fused eyes from 3 anlagen in 2 orbits, 1 lateral proboscis, and 3 optic nerves-are even more rare. Herein, I report a unique fetus with unilateral synophthalmia that was not associated with a lateral proboscis but instead had an extra cerebral hemisphere. I postulate that the unilateral synophthalmia, accessory cerebral hemisphere, and minor structural abnormalities in the skull base were the result of failure in separating a monozygous twin, a situation similar to that postulated as the cause of fetus in fetu. PMID:20528261

Proia, Alan D

2011-01-01

176

[Unique duodenal hamartomatous polyp--case report].  

PubMed

Duodenal tumors are very rare tumors, with the lower incidence among the tumors of the small bowel, whose frequence is less than 5 % of all digestive tumors. In most of the cases these tumors remain asymptomatic, sometimes the entire life. When they become symptomatic, their first manifestation is the loss of digested blood (melena), secondary anemia and obstructive symptomatology. Early diagnosis of these tumors is difficult because of the unsystematic symptomatology and becomes easy when the complications appear. In most of the cases the diagnosis is establish by the superior digestive endoscopy, followed by barium contrast studies, CT and ultrasound. We present a case of duodenal hamartomatous polip, unique, at the level of D3, in a female patient 66 years old, addressing to our service for superior digestive hemorrhage exteriorizated by melena, secondary anemia and physical asthenia; we operated the patient procedeeing a polypectomy by a duodenotomy. PMID:22712356

Alecu, L; Tulin, A; Ursut, Beatrice; Ursut, B; Oproiu, A; Obrocea, F

2012-01-01

177

Unique topological characterization of braided magnetic fields  

SciTech Connect

We introduce a topological flux function to quantify the topology of magnetic braids: non-zero, line-tied magnetic fields whose field lines all connect between two boundaries. This scalar function is an ideal invariant defined on a cross-section of the magnetic field, and measures the average poloidal magnetic flux around any given field line, or the average pairwise crossing number between a given field line and all others. Moreover, its integral over the cross-section yields the relative magnetic helicity. Using the fact that the flux function is also an action in the Hamiltonian formulation of the field line equations, we prove that it uniquely characterizes the field line mapping and hence the magnetic topology.

Yeates, A. R. [Department of Mathematical Sciences, Durham University, Durham DH1 3LE (United Kingdom); Hornig, G. [Division of Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom)

2013-01-15

178

Mushrooms—Biologically Distinct and Nutritionally Unique  

PubMed Central

Mushrooms are fungi, biologically distinct from plant- and animal-derived foods (fruits, vegetables, grains, dairy, protein [meat, fish, poultry, legumes, nuts, and seeds]) that comprise the US Department of Agriculture food patterns operationalized by consumer-focused MyPlate messages. Although mushrooms provide nutrients found in these food groups, they also have a unique nutrient profile. Classified into food grouping systems by their use as a vegetable, mushrooms’ increasing use in main entrées in plant-based diets is growing, supporting consumers’ efforts to follow dietary guidance recommendations. Mushrooms’ nutrient and culinary characteristics suggest it may be time to reevaluate food groupings and health benefits in the context of 3 separate food kingdoms: plants/botany, animals/zoology, and fungi/mycology. PMID:25435595

Feeney, Mary Jo; Miller, Amy Myrdal; Roupas, Peter

2014-01-01

179

Lupus Erythematosus Tumidus: A Unique Disease Entity  

PubMed Central

Lupus erythematosus tumidus (LET) is a photosensitive skin disease characterized by succulent, edematous, and non-scarring plaques. Histologic features include perivascular and periadnexal lymphocytic infiltration and interstitial mucin deposition. Despite being first described in 1909, there are few case reports in the current literature describing this disease and even fewer that discuss treatment. We describe a case of a 22-year-old woman with systemic lupus erythematosus (SLE) and secondary class V lupus nephritis. She was referred to Dermatology for an intermittent pruritic facial eruption that was clinically and histologically consistent with LET. There is much controversy in literature as to whether or not LET is a unique variant of cutaneous lupus erythematosus. Interestingly, the mainstay of treatment for LET, in the limited case reports and series that exist, is with antimalarial drugs, which our patient had already been taking for SLE. This case exemplifies the need for complete disease characterization, evidence-based treatment, and a multidisciplinary approach. PMID:25285251

Fernelius, Colby; Roberts, Jefferson; Denunzio, Troy; Arora, Navin S

2014-01-01

180

Adipose Depots Possess Unique Developmental Gene Signatures  

PubMed Central

We have previously demonstrated that subcutaneous and intra-abdominal adipose tissue show different patterns of expression for developmental genes (Shox2, En1, Tbx15 Hoxa5, Hoxc8, and Hoxc9), and that the expression level of Tbx15 and Hoxa5 in humans correlated with the level of obesity and fat distribution. To further explore the role of these developmental genes in adipose tissue, we have characterized their expression in different adipose depots in mice, and studied their regulation in obesity and by fasting. Developmental and adipogenic gene expression was compared in two subcutaneous and three intra-abdominal white adipose tissue (WAT) depots as well as brown adipose tissue (BAT) from lean or obese mice in a fed or fasting state. Each of these six adipose depots display a unique pattern of developmental gene expression, whereas expression of adipogenic transcription factors PPAR?2 C/EBP?, ?, and ? showed constant expression levels in all depots. Expression levels of developmental genes were similar in obese (ob/ob and high-fat diet (HFD)) and lean mice in most depots. Fasting systematically decreased expression of Hoxc8, PPAR?2, and increased C/EBP? in both lean and ob/ob mice, but produced only variable changes in the expression of other developmental and adipogenic genes. These data indicate that each fat depot has a unique developmental gene expression signature, which is largely independent of nutritional state. This finding further supports a fundamental role of developmental genes in fat distribution and the development and/or function of specific adipose tissue depots. PMID:20111017

Lee, Kevin Y.; Tran, Thien T.; Saadatirad, Parshin; Kahn, C. Ronald

2015-01-01

181

Review of Rule Modification in Sport  

PubMed Central

The goal of this qualitative review was to analyze the state of the bibliography about rule modification in sport. In the literature reviewed, there are few studies of rule modification and related aspects. Most studies omit mentioning the purpose of the modifications, but they do refer to the goals of their analysis (improving players' performance, attracting spectators and athletes, attending to commercial pressure, adapting the sport to children’s needs and interests, preventing injuries). Eighty percent of the studies did not report the outcome of the previous modifications they analyzed. More than half of the studies (60%) achieved the proposed goals. Nearly two-thirds (63.83%) analyzed the effect of rule modification on game actions occurring during the game or through a test. Most of the studies (91.5%) did not consult the participants. Three-fourths of the studies (74.46%) examined the effect of rule modification without any knowledge of a previous analysis or without any previous analysis, and 74.47% studied rule modification related to internal logic. Modifications to be introduced in a sport should be analyzed through a reflective process before their final introduction. The following points should be considered: establishing goals, respecting the basic rules without modifying them, becoming familiar with players’ and coaches’ opinions, determining the effect of the modification on a wide spectrum of variables, elaborating useful proposals for the organizations that are responsible for competitions, using more than one type of data, modifying the internal logic and, preferably, the functional rules, and following some basic stages to consolidate rule modification. Key points Rule modification involves processes that seek change in the game conditions with a certain goal in mind. The rules related to internal logic model the game actions that are characteristic of a sport. Functional rules facilitate achieving the goals. There are few valid research studies on which to base the modifications. Modifications in a sport should be validated after a reflective process before they are introduced. PMID:24149289

Arias, Jose L.; Argudo, Francisco M.; Alonso, Jose I.

2011-01-01

182

Abstract--When designing systems-on-a-chip (SoCs), a unique opportunity exists to generate custom FPGA architectures that are specific to  

E-print Network

, multi-function SoCs, and other situations that require post-fabrication customization of a Layout1 Abstract-- When designing systems-on-a-chip (SoCs), a unique opportunity exists to generate and the performance of hardware, while at the same time allowing for post- fabrication modification of the SoC

Hauck, Scott

183

Might "Unique" Factors Be "Common"? On the Possibility of Indeterminate Common-Unique Covariances  

ERIC Educational Resources Information Center

The present paper shows that the usual factor analytic structured data dispersion matrix lambda psi lambda' + delta can readily arise from a set of scores y = lambda eta + epsilon, shere the "common" (eta) and "unique" (epsilon) factors have nonzero covariance: gamma = Cov epsilon,eta) is not equal to 0. Implications of this finding are discussed…

Grayson, Dave

2006-01-01

184

Alpbach Summer School - a unique learning experience  

NASA Astrophysics Data System (ADS)

The Alpbach Summer School is a ten-day program that provides a unique opportunity for young european science and engineering students, both undergraduate and graduate, to learn how to approach the entire design process of a space mission. The theme of the 2010 Summer School was "New Space Missions to Understand Climate Change", a current, challenging, very broad and complex topic. The program was established more than 35 years ago and is organised in two interrelated parts: a series of lectures held by renowned experts in the field (in the case of this specific year, climate change and space engineering experts) that provides a technical and scientific background for the workshops that follow, the core of the Summer School. For the workshops the students are split into four international, interdisciplinary teams of about 15 students. In 2010 every team had to complete a number of tasks, four in total: (1) identify climate change research gaps and design a space mission that has not yet been flown or proposed, (2) define the science objectives and requirements of the mission, (3) design a spacecraft that meets the mission requirements, which includes spacecraft design and construction, payload definition, orbit calculations, but also the satellite launch, operation and mission costs and (4) write up a short mission proposal and present the results to an expert review panel. Achieving these tasks in only a few days in a multicultural, interdisciplinary team represents a major challenge for all participants and provides an excellent practical learning experience. Over the course of the program, students do not just learn facts about climate change and space engineering, but scientists also learn from engineers and engineers from scientists. The participants have to deepen their knowledge in an often unfamiliar field, develop organisational and team-work skills and work under pressure. Moreover, teams are supported by team and roving tutors and get the opportunity to meet and learn from international experts. This presentation will provide an overview of the Alpbach Summer School program from a student's perspective. The different stages of this unique and enriching experience will be covered. Special attention will be paid to the workshops, which, as mentioned above, are the core of the Alpbach Summer School. During these intense workshops, participants work towards the proposed goals resulting in the design proposal of a space mission. The Alpbach Summer School is organised by FFG and co-sponsored by ESA, ISSI and the national space authorities of ESA member and cooperating states.

Kern, K.; Aulinas, J.; Clifford, D.; Krejci, D.; Topham, R.

2011-12-01

185

Reading protein modifications with interaction domains  

Microsoft Academic Search

Proteins are controlled by a vast and dynamic array of post-translational modifications, many of which create binding sites for specific protein-interaction domains. We propose that these domains, working together, read the state of the proteome and therefore couple post-translational modifications to cellular organization. We also identify common strategies through which modification-dependent interactions synergize to regulate cell behaviour.

Bruce T. Seet; Ivan Dikic; Ming-Ming Zhou; Tony Pawson

2006-01-01

186

Factors Influencing Home Modification of Stroke Patients  

Microsoft Academic Search

Background: Home modification for stroke victims is often necessary to prevent falls and enable them to have a better quality of life. Up-to-date relationship between personal factors and home modifications in post-stroke patients has not been investigated. Objective: To identify significant personal factors influencing the requirement for home modification in post-stroke patients. Study design: Prospective, analytical study. Material and Method:

Wutichai Permsirivanich; Suttipong Tipchatyotin; Krisna Piravej; Uma Juntawises MSN; Vilai Kuptniratsaikul; Arinda Ma-A-Lee

2009-01-01

187

Aeolian modification of planetary surfaces  

NASA Technical Reports Server (NTRS)

Any planet or satellite having a dynamic atmosphere and a solid surface is subject to aeolian or wind processes. A survey of the solar system shows that earth, Mars, Venus, and possibly Titan meet these criteria. Attention is given to the relevance of aeolian processes to planetary geology, approaches for investigating aeolian processes, observations on Mars, conditions on Venus, and studies of Titan with the aid of the Voyager spacecraft. It is found that aeolian processes play an important role in the modification of the surfaces of earth and Mars. Indirect evidence suggests that Venus and perhaps Titan also may experience aeolian activity. Study of aeolian activity in a planetary context thus affords the opportunity to examine a fundamental process under a wide range of environmental conditions. Each planet can be viewed as a vast natural laboratory.

Greeley, R.

1982-01-01

188

Experimental modification of attribution processes.  

PubMed

Attributional style is hypothesized to be a causative factor in depression vulnerability; however, no studies to date have examined whether manipulation of attributional style influences depressed mood. The purpose of this study was to determine whether computer-based cognitive bias modification (CBM) procedures could modify attributional style and influence stress vulnerability. Participants were provided with multiple training trials that were intended to promote the use of either a positive or a negative attributional style. Compared with individuals in the negative attributional style condition, individuals in the positive attributional style condition showed decreased tendency to make self-deficient causal attributions for poor performance on a difficult anagram test. Furthermore, individuals in the positive attributional style condition reported less depressed mood in response to this academic stressor. These results suggest that attributional style is not invariable and can potentially be modified with CBM approaches. PMID:21319929

Peters, Kelly D; Constans, Joseph I; Mathews, Andrew

2011-02-01

189

Modification of mainframe BOAST II  

SciTech Connect

BOAST II is a black-oil, applied-simulation tool used routinely for performing evaluation and design work in modern petroleum reservoir engineering. Personnel from the Louisiana State University Computer Science Department worked on modifying the mainframe version of this program through the simulation of two-phase flow of slightly compressible fluids in a three-dimensional porous medium. This included the construction of a FORTRAN program that uses 3-D finite elements to approximate the governing equations. The existing finite element code was adapted so that virtually any size of element could easily be incorporated into the solution scheme. This gave increased flexibility and made it possible to utilize mesh refinement techniques. Modifications to the mainframe version also involved the development and integration of radial grid systems suitable for the investigations proposed in the project.

Tyler, J.M.; Morton, D.J.; Schenewerk, P.A.; Bourgoyne, A.T.; Kimbrell, W.C.; Dorroh, J.R.

1998-07-01

190

Lunar granites with unique ternary feldspars  

NASA Technical Reports Server (NTRS)

An unusually high concentration of granitic fragments, with textures ranging from holocrystalline to glassy, occurs throughout Boulder 1, a complex breccia of highland rocks from Apollo 17, Station 2. Among the minerals included in the granites are enigmatic K-Ca-rich feldspars that fall in the forbidden region of the ternary diagram. The great variability in chemistry and texture is probably the result of impact degradation and melting of a granitic source-rock. Studies of the breccia matrix suggest that this original granitic source-rock may have contained more pyroxenes and phosphates than most of the present clasts contain. Petrographic observations on Apollo 15 KREEP basalts indicate that granitic liquids may be produced by differentiation without immiscibility, and the association of the granites with KREEP-rich fragments in the boulder suggests that the granites represent a residual liquid from the plutonic fractional crystallization of a KREEP-rich magma. Boulder 1 is unique among Apollo 17 samples in its silica-KREEP-rich composition. We conclude that the boulder represents a source-rock unlike the bedrock of South Massif.

Ryder, G.; Stoeser, D. B.; Marvin, U. B.; Bower, J. F.

1975-01-01

191

Optimizing acne therapy with unique vehicles.  

PubMed

The science of cutaneous drug delivery is focused on overcoming the major force of resistance to drug penetration and permeation-the stratum corneum. Acne vulgaris is a multifactorial disease of the pilosebaceous unit, resulting from abnormalities in sebum production, follicular epithelial desquamation, bacterial proliferation and inflammation. Topical treatment of even mild-moderate acne requires combination topical therapy, yet often systemic therapy is needed to ultimately confer an acceptable clinical endpoint. New delivery systems have emerged in response to the limited routes of entry and therefore efficacy of topical regimens. The unique physical and optical properties of micro/nano encapsulation of known therapeutics such as benzoyl peroxide and tretinoin allow for both improved efficacy while minimizing issues of compliance and adverse events. Vehicles that offer both inherent biological reactivity and permeation enhancement have also been shown improvement over the current armament of topical drug delivery. This current and exciting path of topical drug development will likely be continued with investigative vigor. PMID:20518361

Kircik, Leon; Friedman, Adam

2010-05-01

192

Unique animal prenyltransferase with monoterpene synthase activity  

NASA Astrophysics Data System (ADS)

Monoterpenes are structurally diverse natural compounds that play an essential role in the chemical ecology of a wide array of organisms. A key enzyme in monoterpene biosynthesis is geranyl diphosphate synthase (GPPS). GPPS is an isoprenyl diphosphate synthase that catalyzes a single electrophilic condensation reaction between dimethylallyl diphosphate (C5) and isopentenyl diphosphate (C5) to produce geranyl diphosphate (GDP; C10). GDP is the universal precursor to all monoterpenes. Subsequently, monoterpene synthases are responsible for the transformation of GDP to a variety of acyclic, monocyclic, and bicyclic monoterpene products. In pheromone-producing male Ips pini bark beetles (Coleoptera: Scolytidae), the acyclic monoterpene myrcene is required for the production of the major aggregation pheromone component, ipsdienol. Here, we report monoterpene synthase activity associated with GPPS of I. pini. Enzyme assays were performed on recombinant GPPS to determine the presence of monoterpene synthase activity, and the reaction products were analyzed by coupled gas chromatography-mass spectrometry. The functionally expressed recombinant enzyme produced both GDP and myrcene, making GPPS of I. pini a bifunctional enzyme. This unique insect isoprenyl diphosphate synthase possesses the functional plasticity that is characteristic of terpene biosynthetic enzymes of plants, contributing toward the current understanding of product specificity of the isoprenoid pathway.

Gilg, Anna B.; Tittiger, Claus; Blomquist, Gary J.

2009-06-01

193

Uniquely hominid features of adult human astrocytes.  

PubMed

Defining the microanatomic differences between the human brain and that of other mammals is key to understanding its unique computational power. Although much effort has been devoted to comparative studies of neurons, astrocytes have received far less attention. We report here that protoplasmic astrocytes in human neocortex are 2.6-fold larger in diameter and extend 10-fold more GFAP (glial fibrillary acidic protein)-positive primary processes than their rodent counterparts. In cortical slices prepared from acutely resected surgical tissue, protoplasmic astrocytes propagate Ca(2+) waves with a speed of 36 microm/s, approximately fourfold faster than rodent. Human astrocytes also transiently increase cystosolic Ca(2+) in response to glutamatergic and purinergic receptor agonists. The human neocortex also harbors several anatomically defined subclasses of astrocytes not represented in rodents. These include a population of astrocytes that reside in layers 5-6 and extend long fibers characterized by regularly spaced varicosities. Another specialized type of astrocyte, the interlaminar astrocyte, abundantly populates the superficial cortical layers and extends long processes without varicosities to cortical layers 3 and 4. Human fibrous astrocytes resemble their rodent counterpart but are larger in diameter. Thus, human cortical astrocytes are both larger, and structurally both more complex and more diverse, than those of rodents. On this basis, we posit that this astrocytic complexity has permitted the increased functional competence of the adult human brain. PMID:19279265

Oberheim, Nancy Ann; Takano, Takahiro; Han, Xiaoning; He, Wei; Lin, Jane H C; Wang, Fushun; Xu, Qiwu; Wyatt, Jeffrey D; Pilcher, Webster; Ojemann, Jeffrey G; Ransom, Bruce R; Goldman, Steven A; Nedergaard, Maiken

2009-03-11

194

Unique Ganglioside Recognition Strategies for Clostridial Neurotoxins  

SciTech Connect

Botulinum neurotoxins (BoNTs) and tetanus neurotoxin are the causative agents of the paralytic diseases botulism and tetanus, respectively. The potency of the clostridial neurotoxins (CNTs) relies primarily on their highly specific binding to nerve terminals and cleavage of SNARE proteins. Although individual CNTs utilize distinct proteins for entry, they share common ganglioside co-receptors. Here, we report the crystal structure of the BoNT/F receptor-binding domain in complex with the sugar moiety of ganglioside GD1a. GD1a binds in a shallow groove formed by the conserved peptide motif E ... H ... SXWY ... G, with additional stabilizing interactions provided by two arginine residues. Comparative analysis of BoNT/F with other CNTs revealed several differences in the interactions of each toxin with ganglioside. Notably, exchange of BoNT/F His-1241 with the corresponding lysine residue of BoNT/E resulted in increased affinity for GD1a and conferred the ability to bind ganglioside GM1a. Conversely, BoNT/E was not able to bind GM1a, demonstrating a discrete mechanism of ganglioside recognition. These findings provide a structural basis for ganglioside binding among the CNTs and show that individual toxins utilize unique ganglioside recognition strategies.

Benson, Marc A.; Fu, Zhuji; Kim, Jung-Ja P.; Baldwin, Michael R. (MCW); (UMC)

2012-03-15

195

7 CFR 623.14 - Easement modifications.  

Code of Federal Regulations, 2013 CFR

...modifications. 623.14 Section 623.14 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS...

2013-01-01

196

7 CFR 623.14 - Easement modifications.  

Code of Federal Regulations, 2012 CFR

...modifications. 623.14 Section 623.14 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS...

2012-01-01

197

7 CFR 623.14 - Easement modifications.  

Code of Federal Regulations, 2014 CFR

...modifications. 623.14 Section 623.14 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS...

2014-01-01

198

7 CFR 623.14 - Easement modifications.  

Code of Federal Regulations, 2011 CFR

...modifications. 623.14 Section 623.14 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS...

2011-01-01

199

7 CFR 623.14 - Easement modifications.  

Code of Federal Regulations, 2010 CFR

...modifications. 623.14 Section 623.14 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS...

2010-01-01

200

The Unique Horn-Satisfiability Problem and Quadratic Boolean Equations  

Microsoft Academic Search

The unique satisfiability problem for general Boolean expressions has attracted interest in recent years in connection with basic complexity issues [12,13]. We investigate here Unique Horn-Satisfiability, i.e. the subclass of Unique-Sat restricted to Horn expressions. We introduce two operators,reduction andshrinking, each transforming a given Horn expression into another Horn expression involving strictly fewer variables and preserving the unique satisfiability property,

Michel Minoux; Universitd Pierre

1992-01-01

201

CRYSTAL DISSOLUTION AND PRECIPITATION IN POROUS -CONTRACTION AND UNIQUENESS  

E-print Network

-contraction property of the pore-scale model. As a direct consequence we obtain the uniqueness of (weak of weak solution, which in particular implies uniqueness of the solution. 1.1. The pore-scale modelCRYSTAL DISSOLUTION AND PRECIPITATION IN POROUS MEDIA: L1 -CONTRACTION AND UNIQUENESS T. L. van

Eindhoven, Technische Universiteit

202

Revisiting the Uniqueness of Simple Demographics in the US Population  

E-print Network

precisely the degree of privacy of in- dividuals on a scale that goes from uniquely identi- fiable to kRevisiting the Uniqueness of Simple Demographics in the US Population Philippe Golle Palo Alto% of the US population can be uniquely identified by gen- der, ZIP code and full date of birth. This short

Golle, Philippe

203

Uniqueness of the pendent drop of infinite length Emmanuel Risler  

E-print Network

Uniqueness of the pendent drop of infinite length Emmanuel Risler Abstract We prove the uniqueness. Uniqueness is then proved by an elementary perturbation argument. 1 Introduction An orientable hypersurface to increase downwards. Up to a change of scale, we can choose any positive value for , and for convenience we

Risler, Emmanuel - Pôle de Mathématiques, Institut National des Sciences Appliquées de Lyon

204

Did Euclid Need the Euclidean Algorithm to Prove Unique Factorization?  

E-print Network

Did Euclid Need the Euclidean Algorithm to Prove Unique Factorization? David Pengelley and Fred is uniquely a product of primes. The heart of this uniqueness is found in Book VII of Euclid's Elements [3]: Proposition 30 (Euclid's Lemma). If a prime divides a product, then it divides one of the factors. Euclid

Pengelley, David J.

205

Michigan Ion Beam Laboratory (MIBL) The Michigan Ion Beam Laboratory for Surface Modification and Analysis (MIBL) was completed in  

E-print Network

NERS Michigan Ion Beam Laboratory (MIBL) The Michigan Ion Beam Laboratory for Surface Modification of advancing our understanding of ion- solid interactions by providing up-to-date equipment with unique that depends on the ion charge state. A wide variety of ions can be produced by a Torvis type, a duoplasmatron

Kamat, Vineet R.

206

Evolution of a Unique Systems Engineering Capability  

SciTech Connect

The Idaho National Laboratory (INL) is a science-based, applied engineering laboratory dedicated to supporting U.S. Department of Energy missions in nuclear and energy research, science, and national security. The INL’s Systems Engineering organization supports all of the various programs under this wide array of missions. As with any multifaceted organization, strategic planning is essential to establishing a consistent culture and a value discipline throughout all levels of the enterprise. While an organization can pursue operational excellence, product leadership or customer intimacy, it is extremely difficult to excel or achieve best-in-class at all three. In fact, trying to do so has resulted in the demise of a number of organizations given the very intricate balancing act that is necessary. The INL’s Systems Engineering Department has chosen to focus on customer intimacy where the customer’s needs are first and foremost and a more total solution is the goal. Frequently a total solution requires the employment of specialized tools to manage system complexity. However, it is only after understanding customer needs that tool selection and use would be pursued. This results in using both commercial-off-the-shelf (COTS) tools and, in some cases, requires internal development of specialized tools. This paper describes how a unique systems engineering capability, through the development of customized tools, evolved as a result of this customer-focused culture. It also addresses the need for a common information model or analysis framework and presents an overview of the tools developed to manage and display relationships between entities, support trade studies through the application of utility theory, and facilitate the development of a technology roadmap to manage system risk and uncertainty.

Robert M. Caliva; James A. Murphy; Kyle B. Oswald

2011-06-01

207

Helicobacter pylori interstrain restriction-modification diversity prevents genome subversion by chromosomal DNA from competing strains  

Microsoft Academic Search

Helicobacter pylori, bacteria that colonize the human gastric mucosa, possess a large number of genes for restriction-modification (R-M) systems, and essentially, every strain possesses a unique complement of functional and partial R-M systems. Nearly half of the H.pylori strains studied possess an active type IIs R-M system, HpyII, with the recog- nition sequence GAAGA. Recombination between direct repeats that flank

Rahul A. Aras; Aaron J. Small; Takafumi Ando; Martin J. Blaser

2002-01-01

208

The Effects of Need for Uniqueness and Uniqueness Relevant Feedback on Mood, Recall, and Perceptions of Peers and the Self.  

ERIC Educational Resources Information Center

According to the Uniqueness theory, individuals characteristically desire to perceive themselves as moderately different from others. The effects of need for uniqueness and uniqueness relevant feedback on mood, recall, and perceptions of peers and the self were examined in 60 college students who participated in a two-part study. In part one of…

Case, Thomas L.; Rosen, Signey

209

Regulation of microtubule motors by tubulin isotypes and posttranslational modifications  

PubMed Central

The ‘tubulin-code’ hypothesis proposes that different tubulin genes or posttranslational modifications (PTMs), which mainly confer variation in the carboxy-terminal tail (CTT), result in unique interactions with microtubule-associated proteins for specific cellular functions. However, the inability to isolate distinct and homogenous tubulin species has hindered biochemical testing of this hypothesis. Here, we have engineered 25 ?/? tubulin heterodimers with distinct CTTs and PTMs and tested their interactions with four different molecular motors using single molecule assays. Our results show that tubulin isotypes and PTMs can govern motor velocity, processivity and microtubule depolymerization rates, with substantial changes conferred by even single amino acid variation. Revealing the importance and specificity of PTMs, we show that kinesin-1 motility on neuronal ?-tubulin (TUBB3) is increased by polyglutamylation and that robust kinesin-2 motility requires detyrosination of ?-tubulin. Our results also show that different molecular motors recognize distinctive tubulin “signatures”, which supports the premise of tubulin-code hypothesis. PMID:24633327

Sirajuddin, Minhajuddin; Rice, Luke M.; Vale, Ronald D.

2014-01-01

210

Upconversion Nanoparticles: Synthesis, Surface Modification, and Biological Applications  

PubMed Central

New generation fluorophores, also termed upconversion nanoparticles (UCNPs), have the ability to convert near infrared radiations with lower energy into visible radiations with higher energy via a non-linear optical process. Recently, these UCNPs have evolved as alternative fluorescent labels to traditional fluorophores, showing great potential for imaging and biodetection assays in both in vitro and in vivo applications. UCNPs exhibit unique luminescent properties, including high penetration depth into tissues, low background signals, large Stokes shifts, sharp emission bands, and high resistance to photo-bleaching, making UCNPs an attractive alternative source for overcoming current limitations in traditional fluorescent probes. In this review, we discuss the recent progress in the synthesis and surface modification of rare earth doped UCNPs with a specific focus on their biological applications. PMID:21419877

Wang, Meng; Abbineni, Gopal; Clevenger, April; Mao, Chuanbin; Xu, Shukun

2011-01-01

211

Dynamic uniqueness and phase transition of chains of infinite order  

E-print Network

We say that a kernel exhibits dynamic uniqueness if all the chains starting from a fixed past coincide in the future tail $\\sigma$-algebra, otherwise the kernel exhibits dynamic phase transition. We characterize dynamic uniqueness/phase transition by proving several equivalent conditions. In particular, we prove that dynamic uniqueness is equivalent to convergence in total variation distance of all the chains starting from different pasts. We also study the relationship between our definition of uniqueness and the $\\ell^2$ criteria for the uniqueness of $g$-measures. We prove that the Bramson-Kalikow and Hulse models exhibit dynamic uniqueness if and only if the kernel is in $\\ell^2$. Finally, we prove that a $g$-measure $P$ is weak Bernoulli (or, equivalently, $\\beta$-mixing) if and only if $g$ exhibits dynamic uniqueness for $P$-a.e. pasts, generalizing several results in the literature.

Christophe Gallesco; Sandro Gallo; Daniel Yasumasa Takahashi

2015-03-12

212

7 CFR 1467.13 - Modifications.  

Code of Federal Regulations, 2014 CFR

...LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.13 Modifications...modification will not adversely affect the wetland functions and values for which the easement...restoration of other lands that provide greater wetland functions and values at no...

2014-01-01

213

7 CFR 1467.13 - Modifications.  

Code of Federal Regulations, 2010 CFR

...LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.13 Modifications...modification will not adversely affect the wetland functions and values for which the easement...restoration of other lands that provide greater wetland functions and values at no...

2010-01-01

214

7 CFR 1467.13 - Modifications.  

Code of Federal Regulations, 2013 CFR

...LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.13 Modifications...modification will not adversely affect the wetland functions and values for which the easement...restoration of other lands that provide greater wetland functions and values at no...

2013-01-01

215

7 CFR 1467.13 - Modifications.  

Code of Federal Regulations, 2012 CFR

...LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.13 Modifications...modification will not adversely affect the wetland functions and values for which the easement...restoration of other lands that provide greater wetland functions and values at no...

2012-01-01

216

7 CFR 1467.13 - Modifications.  

Code of Federal Regulations, 2011 CFR

...LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.13 Modifications...modification will not adversely affect the wetland functions and values for which the easement...restoration of other lands that provide greater wetland functions and values at no...

2011-01-01

217

Modification of integrated partial payload lifting assembly  

NASA Technical Reports Server (NTRS)

The Integrated Partial Payload Lifting Assembly (IPPLA) is currently used to transport and load experimental payloads into the cargo bay of the Space Shuttle. It is unable to carry the astronaut/passenger tunnel without a structural modification. The purpose of this design is to create a removalbe modification that will allow the IPPLA to lift and carry the passenger tunnel. Modifications evaluated were full-length insert beams which would extend through the existing strongback arms. These beam proposals were eliminated because of high cost and weight. Other proposals evaluated were attachments of cantilever beams to the existing strongback areas. The cantilever proposals reduced cost and weight compared to the full-length modifications. A third method evaluated was to simply make modifications to one side of the IPPLA therefore reducing the materials of the cantilever proposals by 40 percent. The design of the modification selected was completed with two channel beams jointly welded to a centered steel plate. The extension arm modification is inserted into the existing strongback channel beams and bolted into place. Two extension arms are added to one side of the IPPLA to provide the extra length needed to accommodate the passenger tunnel. The center counterbalance will then be offset about 20 inches to center gravity and therefore maintain horizontal status. The extension arm modification was selected because of minimum cost, low weight, and minimal installation time.

Groah, Melodie; Haddock, Michael; Woodworth, Warren

1986-01-01

218

Accidental and planned weather modification in illinois  

Microsoft Academic Search

Weather modification, both planned by humans and accidentally produced by humans, is the focus of an Illinois study. Populations in Illinois and the Midwest are living in a climate that is now modified inadvertently from its natural state. State atmospheric scientists have tackled weather modification through a series of interrelated studies, experimental design studies, experimental field studies to verify changes

1977-01-01

219

Regulation of chromatin by histone modifications  

Microsoft Academic Search

Chromatin is not an inert structure, but rather an instructive DNA scaffold that can respond to external cues to regulate the many uses of DNA. A principle component of chromatin that plays a key role in this regulation is the modification of histones. There is an ever-growing list of these modifications and the complexity of their action is only just

Andrew J Bannister; Tony Kouzarides

2011-01-01

220

Behavior Modification: A Classroom Clockwork Orange?  

ERIC Educational Resources Information Center

Behavior modification, if used properly, is a powerful and useful tool. As with many tools, improper use can cause temporary or permanent damage. The educational program might include behavior modification as one tool in a battery of many tools used to promote healthy change in behavior. (CS)

Heller, Jeffry; Kiraly, John, Jr.

1974-01-01

221

Behavior Modification: Answers to Some Ethical Issues  

ERIC Educational Resources Information Center

This paper deals with several of the commonly stated ethical issues in behavior modification: (1) the dichotomy between symptoms and underlying causes; (2) symptom substitution; (3 certain behavior modification techniques such as electric shock, physical restraint, and deprivation; (4) the counselor-client relationship; and (5) principles of…

Cooke, Thomas P.; Cooke, Sharon

1974-01-01

222

A novel DNA modification by sulphur  

Microsoft Academic Search

Summary Streptomyces lividans has a novel DNA modification, which sensitises its DNA to degradation during elec- trophoresis (the Dnd phenotype). The entire gene cluster ( dnd ) involved in this modification was local- ized on an 8 kb DNA fragment and was expressed in a S. lividans deletion mutant ( dnd ) and in several heterologous hosts. Disruption of the

Xiufen Zhou; Xinyi He; Jingdan Liang; Aiying Li; Tiegang Xu; Tobias Kieser; John D. Helmann

223

Proteomic analysis of post-translational modifications  

Microsoft Academic Search

Post-translational modifications modulate the activity of most eukaryote proteins. Analysis of these modifications presents formidable challenges but their determination generates indispensable insight into biological function. Strategies developed to characterize individual proteins are now systematically applied to protein populations. The combination of function- or structure-based purification of modified 'subproteomes', such as phosphorylated proteins or modified membrane proteins, with mass spectrometry is

Matthias Mann; Ole N. Jensen

2003-01-01

224

comparator Feed CCM/DCM modification  

E-print Network

1 L D Q C R + _ + DTon _ _ + (0.5 mH) (220mF) ADC DCM comparator Feed Forward Current Sensing Corrector g + + _ ++ + _ + _ avL CCM/DCM modification Digital Controller _ Driver ADC sDCM iac vac vg iL v PFC. Modifications related to the proposed CCM/DCM predictive current control methods include

225

7 CFR 636.10 - Modifications.  

Code of Federal Regulations, 2011 CFR

...cost-share agreement if both parties agree to the modification. The WHIP plan of operations is revised in accordance with NRCS requirements... (b) Any modifications made under this section must meet WHIP program objectives and must be in compliance with this...

2011-01-01

226

Prevention of biofilm formation by polymer modification  

Microsoft Academic Search

Bacterial biofilm formation on synthetic polymers plays an important role in industry and in modern medicine, leading, for example, to difficult-to-treat infections caused by colonized foreign bodies. Prevention of biofilm formation is a necessary step in the successful prophylaxis of such infections. One approach is to inhibit bacterial adherence by polymer surface modification. We have investigated polymer modification by glow

B Jansen; W Kohnen

1995-01-01

227

Evaluation of cab car crashworthiness design modifications  

Microsoft Academic Search

A study was conducted to evaluate the effectiveness of structural modifications to rail cab cars for increased crashworthiness protection in train collisions. The crashworthiness benefits were calculated based on a particular design's ability to preserve the space occupied by the operators and the passengers during a collision. The influences of the modifications on vehicle weight and cost to manufacture were

D. C. Tyrell; K. J. Seversen; R. A. Mayville; R. G. Stringfellow; S. Berry; A. B. Perlman

1997-01-01

228

Unique Challenges Testing SDRs for Space  

NASA Technical Reports Server (NTRS)

This paper describes the approach used by the Space Communication and Navigation (SCaN) Testbed team to qualify three Software Defined Radios (SDR) for operation in space and the characterization of the platform to enable upgrades on-orbit. The three SDRs represent a significant portion of the new technologies being studied on board the SCAN Testbed, which is operating on an external truss on the International Space Station (ISS). The SCaN Testbed provides experimenters an opportunity to develop and demonstrate experimental waveforms and applications for communication, networking, and navigation concepts and advance the understanding of developing and operating SDRs in space. Qualifying a Software Defined Radio for the space environment requires additional consideration versus a hardware radio. Tests that incorporate characterization of the platform to provide information necessary for future waveforms, which might exercise extended capabilities of the hardware, are needed. The development life cycle for the radio follows the software development life cycle, where changes can be incorporated at various stages of development and test. It also enables flexibility to be added with minor additional effort. Although this provides tremendous advantages, managing the complexity inherent in a software implementation requires a testing beyond the traditional hardware radio test plan. Due to schedule and resource limitations and parallel development activities, the subsystem testing of the SDRs at the vendor sites was primarily limited to typical fixed transceiver type of testing. NASA s Glenn Research Center (GRC) was responsible for the integration and testing of the SDRs into the SCaN Testbed system and conducting the investigation of the SDR to advance the technology to be accepted by missions. This paper will describe the unique tests that were conducted at both the subsystem and system level, including environmental testing, and present results. For example, test waveforms were developed to measure the gain of the transmit system across the tunable frequency band. These were used during thermal vacuum testing to enable characterization of the integrated system in the wide operational temperature range of space. Receive power indicators were used for Electromagnetic Interference tests (EMI) to understand the platform s susceptibility to external interferers independent of the waveform. Additional approaches and lessons learned during the SCaN Testbed subsystem and system level testing will be discussed that may help future SDR integrators

Chelmins, David; Downey, Joseph A.; Johnson, Sandra K.; Nappier, Jennifer M.

2013-01-01

229

Unitary Evolution as a Uniqueness Criterion  

NASA Astrophysics Data System (ADS)

It is well known that the process of quantizing field theories is plagued with ambiguities. First, there is ambiguity in the choice of basic variables describing the system. Second, once a choice of field variables has been made, there is ambiguity concerning the selection of a quantum representation of the corresponding canonical commutation relations. The natural strategy to remove these ambiguities is to demand positivity of energy and to invoke symmetries, namely by requiring that classical symmetries become unitarily implemented in the quantum realm. The success of this strategy depends, however, on the existence of a sufficiently large group of symmetries, usually including time-translation invariance. These criteria are therefore generally insufficient in non-stationary situations, as is typical for free fields in curved spacetimes. Recently, the criterion of unitary implementation of the dynamics has been proposed in order to select a unique quantization in the context of manifestly non-stationary systems. Specifically, the unitarity criterion, together with the requirement of invariance under spatial symmetries, has been successfully employed to remove the ambiguities in the quantization of linearly polarized Gowdy models as well as in the quantization of a scalar field with time varying mass, propagating in a static background whose spatial topology is either of a d-sphere (with d = 1, 2, 3) or a three torus. Following Ref. 3, we will see here that the symmetry and unitarity criteria allows for a complete removal of the ambiguities in the quantization of scalar fields propagating in static spacetimes with compact spatial sections, obeying field equations with an explicitly time-dependent mass, of the form ddot ? - ? ? + s(t)? = 0 . These results apply in particular to free fields in spacetimes which, like e.g. in the closed FRW models, are conformal to a static spacetime, by means of an exclusively time-dependent conformal factor. In fact, in such cases the free field equation can be mapped to an equation of the above type, via a suitable scaling of the field...

Cortez, J.; Mena Marugán, G. A.; Olmedo, J.; Velhinho, J. M.

2015-01-01

230

Metabolic syndrome and lifestyle modification.  

PubMed

A clustering of metabolic abnormalities such as dyslipidemia, hypertension, and diabetes mellitus, all of which are major risk factors for cardiovascular disease (CVD), occurs more often than by chance. Numerous epidemiological studies, as well as basic researches, have revealed that visceral fat accumulation is closely involved in this risk clustering. This morbid condition is now well recognized as the metabolic syndrome. The concept of the metabolic syndrome, i.e., the involvement of visceral adiposity in the clustering of CVD risk factors, implies that an effective CVD risk reduction will be accomplished by an intervention to reduce visceral fat deposits. The primary strategy of the intervention is lifestyle modification, which can be put into practice in healthcare fields, without necessity of medical treatment. Now that CVD is a leading global health burden, the metabolic syndrome attracts increasing attention in the world. To take global action against the syndrome, several working groups developed its internationally unified diagnostic criteria. Most recently, the International Diabetes Federation (IDF) and the American Heart Association/National Heart, Lung, and Blood Institute (AHA/NHLBI) jointly proposed the criteria, although some cautions will be needed in their practical use. In this review, we mainly focus on the findings observed in clinical and epidemiological studies, to discuss a practical strategy of the management of the metabolic syndrome in healthcare fields. PMID:25263290

Takahara, Mitsuyoshi; Shimomura, Iichiro

2014-12-01

231

Behaviour modification of space trusses  

NASA Astrophysics Data System (ADS)

A space truss is a three dimensional structural system assembled of linear elements arranged so that forces are transferred in a three dimensional manner. Space trusses are used where large unobstructed spaces are required, such as aircraft hangars. Space trusses have the advantages of light weight, ease of assembly, ability to create multipurpose architectural spaces, and aesthetic appeal. Space trusses are designed using linear elastic theory, and their load carrying capacity is considered to be limited by the failure of a few critical members. Due to high redundancy and practical constraints, only a portion of the truss member strength is used. Modification of space truss behavior is studied by introducing nonlinearity in the chord members prior to attaining their maximum load. The amount of nonlinearity required to increase the load capacity of the truss by an economically justifiable amount is determined, and the feasibility of the proposed system was confirmed by tests on the elements and an assembled truss. Alternatively, transfer of load to understressed elements can be achieved by selective removal of internal bracing members. A means to determine the optimum selection of diagonals to be removed has been established. The above techniques were applied to four similar space trusses with different support conditions and member size distribution.

Tabatabai, Gargari Mousa

1993-01-01

232

Maximum-likelihood density modification  

PubMed Central

A likelihood-based approach to density modification is developed that can be applied to a wide variety of cases where some information about the electron density at various points in the unit cell is available. The key to the approach consists of developing likelihood functions that represent the probability that a particular value of electron density is consistent with prior expectations for the electron density at that point in the unit cell. These likelihood functions are then combined with likelihood functions based on experimental observations and with others containing any prior knowledge about structure factors to form a combined likelihood function for each structure factor. A simple and general approach to maximizing the combined likelihood function is developed. It is found that this likelihood-based approach yields greater phase improvement in model and real test cases than either conventional solvent flattening and histogram matching or a recent reciprocal-space solvent-flattening procedure [Terwilliger (1999 ?), Acta Cryst. D55, 1863–1871]. PMID:10944333

Terwilliger, Thomas C.

2000-01-01

233

Magnetic perturbations as a viable tool for edge turbulence modification  

NASA Astrophysics Data System (ADS)

A complete description of the effects of magnetic perturbation on the edge region of RFX-mod is here reported. The flexibility of the RFX-mod device [1] allows for the operation of the machine both as a reversed field pinch (RFP, with maximum current 2 MA) and as a low-current, circular ohmic tokamak (Ip,max = 0.15 MA). The present paper summarizes the most recent results obtained in both configurations with either spontaneous or induced edge radial magnetic perturbation. Emphasis will be devoted to the experimental characterization of the edge flow, focusing on the phase relation between flow and perturbed magnetic field. These informations are provided for natural and stimulated helical discharges in RFPs, and for tokamak safely operated, thanks to the unique RFX-mod MHD control system, in a wide range of edge safety factor 1.9 ? q(a) ? 3.4 with externally imposed helical boundary. For the first time a detailed comparison between this phenomenology in tokamaks and RFPs will be presented, providing experimental measurement of the streamline of E × B flow around the magnetic perturbation and of the density modulation which exhibits the same periodicity of the perturbation. Strong new indication of the modification of the small scale turbulence in presence of magnetic perturbation is reported: this modification is deeply connected to the variation of turbulence induced particle transport.

Vianello, N.; Rea, C.; Agostini, M.; Cavazzana, R.; Ciaccio, G.; De Masi, G.; Martines, E.; Mazzi, A.; Momo, B.; Spizzo, G.; Scarin, P.; Spolaore, M.; Zanca, P.; Zuin, M.; Carraro, L.; Innocente, P.; Marrelli, L.; Puiatti, M. E.; Terranova, D.

2015-01-01

234

Assay of deoxyhypusine hydroxylase activity.  

PubMed

The eukaryotic translation initiation factor 5A (eIF5A) is the only cellular protein that contains an unusual amino acid, hypusine [N (?)-(4-amino-2-hydroxybutyl)-lysine]. eIF5A and its hypusine/deoxyhypusine modification are vital for eukaryotic cell proliferation. Hypusine is formed posttranslationally by two enzymatic steps catalyzed by deoxyhypusine synthase and deoxyhypusine hydroxylase. Deoxyhypusine hydroxylase catalyzes a stereo-specific hydroxylation of the deoxyhypusine residue in the eIF5A intermediate protein, eIF5A(Dhp). The enzyme is totally specific for this protein and does not act on short peptides (<50 amino acids). The assay measures the conversion of the radiolabeled deoxyhypusine residue to a hypusine residue in eIF5A. Optimum conditions for the reaction and two detection methods for the product, hypusine-containing eIF5A, are described in this chapter. The first, and most reliable, method is the measurement of the amount of [(3)H]hypusine in the protein hydrolysate after its separation from [(3)H]deoxyhypusine, by ion exchange chromatography. This method does require specialized equipment. The second method is based on counting the total TCA soluble radioactivity after sodium periodate oxidation of the reaction mixture, since the radiolabeled 4-amino-2-hydroxy butyl moiety of the hypusine residue is cleaved and is released from protein as radiolabeled ?-propionaldehyde and formaldehyde by periodate oxidation. PMID:21318876

Park, Jong Hwan; Wolff, Edith C; Park, Myung Hee

2011-01-01

235

Two Galaxies for a Unique Event  

NASA Astrophysics Data System (ADS)

To celebrate the 100 Hours of Astronomy, ESO is sharing two stunning images of unusual galaxies, both belonging to the Sculptor group of galaxies. The images, obtained at two of ESO's observatories at La Silla and Paranal in Chile, illustrate the beauty of astronomy. ESO PR Photo 14a/09 Irregular Galaxy NGC 55 ESO PR Photo 14b/09 Spiral Galaxy NGC 7793 As part of the International Year of Astronomy 2009 Cornerstone project, 100 Hours of Astronomy, the ambitious "Around the World in 80 Telescopes" event is a unique live webcast over 24 hours, following night and day around the globe to some of the most advanced observatories on and off the planet. To provide a long-lasting memory of this amazing world tour, observatories worldwide are revealing wonderful, and previously unseen, astronomical images. For its part, ESO is releasing outstanding pictures of two galaxies, observed with telescopes at the La Silla and Paranal observatories. The first of these depicts the irregular galaxy NGC 55, a member of the prominent Sculptor group of galaxies in the southern constellation of Sculptor. The galaxy is about 70 000 light-years across, that is, a little bit smaller than our own Milky Way. NGC 55 actually resembles more our galactic neighbour, the Large Magellanic Cloud (LMC), although the LMC is seen face-on, whilst NGC 55 is edge-on. By studying about 20 planetary nebulae in this image, a team of astronomers found that NGC 55 is located about 7.5 million light-years away. They also found that the galaxy might be forming a bound pair with the gorgeous spiral galaxy NGC 300 . Planetary nebulae are the final blooming of Sun-like stars before their retirement as white dwarfs. This striking image of NGC 55, obtained with the Wide Field Imager on the 2.2-metre MPG/ESO telescope at La Silla, is dusted with a flurry of reddish nebulae, created by young, hot massive stars. Some of the more extended ones are not unlike those seen in the LMC, such as the Tarantula Nebula. The quality of the image is clearly demonstrated by the remarkable number of background galaxies seen, as well as the huge numbers of individual stars that can be counted within NGC 55. The second image shows another galaxy belonging to the Sculptor group. This is NGC 7793, which has a chaotic spiral structure, unlike the class of grand-design spiral galaxies to which our Milky Way belongs. The image shows how difficult it is to identify any particular spiral arm in these chaotic structures, although it is possible to guess at a general rotating pattern. NGC 7793 is located slightly further away than NGC 55, about 12.5 million light-years from us, and is about half the size of NGC 55. NGC 7793 was observed with one of the workhorses of the ESO Paranal Observatory, the FORS instrument, attached to the Very Large Telescope.

2009-04-01

236

Covariance Modifications to Subspace Bases  

SciTech Connect

Adaptive signal processing algorithms that rely upon representations of signal and noise subspaces often require updates to those representations when new data become available. Subspace representations frequently are estimated from available data with singular value (SVD) decompositions. Subspace updates require modifications to these decompositions. Updates can be performed inexpensively provided they are low-rank. A substantial literature on SVD updates exists, frequently focusing on rank-1 updates (see e.g. [Karasalo, 1986; Comon and Golub, 1990, Badeau, 2004]). In these methods, data matrices are modified by addition or deletion of a row or column, or data covariance matrices are modified by addition of the outer product of a new vector. A recent paper by Brand [2006] provides a general and efficient method for arbitrary rank updates to an SVD. The purpose of this note is to describe a closely-related method for applications where right singular vectors are not required. This note also describes the SVD updates to a particular scenario of interest in seismic array signal processing. The particular application involve updating the wideband subspace representation used in seismic subspace detectors [Harris, 2006]. These subspace detectors generalize waveform correlation algorithms to detect signals that lie in a subspace of waveforms of dimension d {ge} 1. They potentially are of interest because they extend the range of waveform variation over which these sensitive detectors apply. Subspace detectors operate by projecting waveform data from a detection window into a subspace specified by a collection of orthonormal waveform basis vectors (referred to as the template). Subspace templates are constructed from a suite of normalized, aligned master event waveforms that may be acquired by a single sensor, a three-component sensor, an array of such sensors or a sensor network. The template design process entails constructing a data matrix whose columns contain the master event waveform data, then performing a singular value decomposition on the data matrix to extract an orthonormal basis for the waveform suite. The template typically is comprised of a subset of the left singular vectors corresponding to the larger singular values. The application involves updating a subspace template when new data become available, i.e. when new defining events are detected for a particular source. It often is the case that the waveforms corresponding to a particular source drift over time [Harris, 2001]. The Green's functions describing propagation can be altered because of changes in the source region. For example, if the source is a mine, signals from explosions may change gradually as a pit is extended (the source moves) or the scattering topography is altered by excavation. This motivates a tracking adjustment to a subspace representation. This note also comments on SVD updates for a related problem. In realistic pipeline operations it often is the case that data from one or more channels of an array are unusable (dead channels, channels with prolific dropouts, etc.). In such cases it is desirable to modify an array subspace template to operate on data only from the remaining usable channels. Furthermore, it is desirable to modify the templates directly without recourse to the original data matrix. Usually the template design process is separate from the application of the template in a detector to a continuous data stream. Consequently, the original data matrix may not be available for template modification at detector run time.

Harris, D B

2008-11-19

237

Modification of Sr on 4004 Aluminum Alloy  

NASA Astrophysics Data System (ADS)

As a brazing foil, 4004 Al alloy has good welding performance. However, the high Si content decreases the plasticity of the alloy. To improve the plasticity of 4004 Al alloy and subsequently improve the productivity of 4004 Al foil or 434 composite foil, 4004 Al alloy was modified by Al-10%Sr master alloy. Modification effects of an additional amount of Sr, modification temperature, and holding time on 4004 aluminum alloy were studied by orthogonal design. The results showed that the greatest impact parameter of 4004 aluminum alloy modification was the additional amount of Sr, followed by holding time and modification temperature. The optimum modification parameters obtained by orthogonal design were as follows: Sr addition of 0.04%, holding time of 60 min, and modification temperature of 760°C. The effect of Sr addition on modification was analyzed in detail based on orthogonal results. With increasing of Sr addition, elongation of 4004 alloy increased at first, and decreased after reaching the maximum value.

Guo, Erjun; Cao, Guojian; Feng, Yicheng; Wang, Liping; Wang, Guojun; Lv, Xinyu

2013-05-01

238

Evolutionary Conservation of Histone Modifications in Mammals  

PubMed Central

Histone modification is an important mechanism of gene regulation in eukaryotes. Why many histone modifications can be stably maintained in the midst of genetic and environmental changes is a fundamental question in evolutionary biology. We obtained genome-wide profiles of three histone marks, H3 lysine 4 tri-methylation (H3K4me3), H3 lysine 4 mono-methylation (H3K4me1), and H3 lysine 27 acetylation (H3K27ac), for several cell types from human and mouse. We identified histone modifications that were stable among different cell types in human and histone modifications that were evolutionarily conserved between mouse and human in the same cell type. We found that histone modifications that were stable among cell types were also likely to be conserved between species. This trend was consistently observed in promoter, intronic, and intergenic regions for all of the histone marks tested. Importantly, the trend was observed regardless of the expression breadth of the nearby gene, indicating that slow evolution of housekeeping genes was not the major reason for the correlation. These regions showed distinct genetic and epigenetic properties, such as clustered transcription factor binding sites (TFBSs), high GC content, and CTCF binding at flanking sides. Based on our observations, we proposed that TFBS clustering in or near a histone modification plays a significant role in stabilizing and conserving the histone modification because TFBS clustering promotes TFBS conservation, which in turn promotes histone modification conservation. In summary, the results of this study support the view that in mammalian genomes a common mechanism maintains histone modifications against both genetic and environmental (cellular) changes. PMID:22319170

Woo, Yong H.; Li, Wen-Hsiung

2012-01-01

239

ROSAT Discovers Unique, Distant Cluster of Galaxies  

NASA Astrophysics Data System (ADS)

Brightest X-ray Cluster Acts as Strong Gravitational Lens Based on exciting new data obtained with the ROSAT X-ray satellite and a ground-based telescope at the ESO La Silla Observatory, a team of European astronomers [2] has just discovered a very distant cluster of galaxies with unique properties. It emits the strongest X-ray emission of any cluster ever observed by ROSAT and is accompanied by two extraordinarily luminous arcs that represent the gravitationally deflected images of even more distant objects. The combination of these unusual characteristics makes this cluster, now known as RXJ1347.5-1145, a most interesting object for further cosmological studies. DISCOVERY AND FOLLOW-UP OBSERVATIONS This strange cluster of galaxies was discovered during the All Sky Survey with the ROSAT X-ray satellite as a moderately intense X-ray source in the constellation of Virgo. It could not be identified with any already known object and additional ground-based observations were therefore soon after performed with the Max-Planck-Society/ESO 2.2-metre telescope at the La Silla observatory in Chile. These observations took place within a large--scale redshift survey of X-ray clusters of galaxies detected by the ROSAT All Sky Survey, a so-called ``ESO Key Programme'' led by astronomers from the Max-Planck-Institut fur Extraterrestrische Physik and the Osservatorio Astronomico di Brera. The main aim of this programme is to identify cluster X-ray sources, to determine the distance to the X-ray emitting clusters and to investigate their overall properties. These observations permitted to measure the redshift of the RXJ1347.5-1145 cluster as z = 0.45, i.e. it moves away from us with a velocity (about 106,000 km/sec) equal to about one-third of the velocity of light. This is an effect of the general expansion of the universe and it allows to determine the distance as about 5,000 million light-years (assuming a Hubble constant of 75 km/sec/Mpc). In other words, we see these galaxies as they were 5,000 million years ago. Knowing the intensity of the X-ray emission as measured by ROSAT and also the distance, the astronomers were then able to estimate the total X-ray energy emitted by this cluster. It was found to be extremely high [3], in fact higher than that of any other cluster ever observed by ROSAT. It amounts to no less than 1.5 million million times the total energy emitted by the Sun. It is believed that this strong X-ray emission originates in a hot gas located between the galaxies in the cluster. The high temperature indicates that the components of the gas move very rapidly; this is related to the strong gravitational field within the cluster. THE GRAVITATIONAL ARCS To their great surprise and delight, the astronomers also discovered two bright arcs, 5 - 6 arcseconds long and symmetrically placed about 35 arcseconds to the North-East and South-West of the brightest galaxies in the cluster (see the photo). They were detected on exposures of only 3 minutes duration with the 2.2-metre telescope and are among the brightest such arcs ever found. At the indicated distance, the arcs are situated at a projected distance of about 500,000 light-years from the centre of the cluster. It is an interesting possibility that the two arcs may in fact be two images of the same, very distant galaxy, that is situated far beyond RXJ1347.5-1145 and whose light has been bent and split by this cluster's strong gravitational field. This strange phenomenon was first discovered in the late 1970's and is referred to as gravitational lensing. Quite a few examples are now known, in most cases in the form of double or multiple images of quasars. About three dozen cases involve well visible galaxy clusters and elongated arcs, but few, if any, of these arcs are as bright as those seen in the present cluster. This particular arc configuration enables a very accurate determination of the total mass of the cluster, once the distance of the background galaxy has been measured (by obtaining spectra of the arcs and measuring their redshift). The masses of galaxy clus

1995-06-01

240

Physical modification of polyetheretherketone for orthopedic implants  

NASA Astrophysics Data System (ADS)

Polyetheretherketone (PEEK) is regarded as one of the most potential candidates for replacing current implant applications. To obtain good bone-implant interfaces, many modification methods have been developed to enable PEEK and PEEK-based composites from bio-inert to bioactive. Among them, physical methods have aroused significant attention and been widely used to modify PEEK for orthopedic implants. This review summarizes current physical modification techniques of PEEK for orthopedic applications, which include composite strategies, surface coating methods and irradiation treatments. The positive consequences of those modification methods will encourage continuing investigations and stimulate the wide range of applications of PEEK-based implants in orthopedics.

Du, Ya-Wei; Zhang, Li-Nan; Hou, Zeng-Tao; Ye, Xin; Gu, Hong-Sheng; Yan, Guo-Ping; Shang, Peng

2014-12-01

241

VDAC proteomics: post-translation modifications  

PubMed Central

Voltage-dependent anion channels are abundant mitochondrial outer membrane proteins expressed in three isoforms, VDAC1-3, and are considered as “mitochondrial gatekeepers”. Most tissues express all three isoforms. The functions of VDACs are several-fold, ranging from metabolite and energy exchange to apoptosis. Some of these functions depend on or are affected by interaction with other proteins in the cytosol and intermembrane space. Furthermore, the function of VDACs, as well as their interaction with other proteins, is affected by posttranslational modification, mainly phosphorylation. This review summarizes recent findings on posttranslational modification of VDACs and discusses the physiological outcome of these modifications. PMID:22120575

Kerner, Janos; Lee, Kwangwon; Tandler, Bernard; Hoppel, Charles L.

2014-01-01

242

Ordinary Differential Equations 1 Existence and Uniqueness Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . 1  

E-print Network

Contents Ordinary Differential Equations 1 Existence and Uniqueness Theory Theorem for Nonlinear Real Scalar Equations . . . . . . . . . . 15 Continuation of Solutions . . . . . . . . . . . . . 20 Continuity and Differentiability of Solutions . . . . . . . . . . . . . . . . . . . . . 21

Smith, Hart F.

243

Oscillations with uniquely long periods in a microfluidic bubble generator  

E-print Network

and space is still limited2,3,7 . Spatiotemporal dynamics may underlie phenomena as varied as weather8 and modification. The system comprises coupled microfluidic flow-focusing devices. A single flow-focusing device14

Prentiss, Mara

244

On the Development of a Unique Arc Jet Test Apparatus for Control Surface Seal Evaluations  

NASA Technical Reports Server (NTRS)

NASA Glenn has developed a unique test apparatus capable of evaluating control surface seal and flap designs under simulated reentry heating conditions in NASA Johnson's arc jet test facility. The test apparatus is capable of testing a variety of seal designs with a variety of control surface materials and designs using modular components. The flap angle can be varied during testing, allowing modification of the seal environment while testing is in progress. The flap angle is varied using an innovative transmission system which limits heat transfer from the hot flap structure to the motor, all while keeping the components properly aligned regardless of thermal expansion. A combination of active and passive cooling is employed to prevent thermal damage to the test fixture while still obtaining the target seal temperature.

Finkbeiner, Joshua R.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.; Robbie, Malcolm; Baker, Gus; Erker, Arthur

2004-01-01

245

Formal Design Review Foot Clamp Modification  

SciTech Connect

This report documents the Design Review performed for the foot clamp modification. The report documents the acceptability of the design, identifies the documents that were reviewed, the scope of the review and the members of the review team.

OTEN, T.C.

2000-01-24

246

Post-Translational Modifications of TRP Channels  

PubMed Central

Transient receptor potential (TRP) channels constitute an ancient family of cation channels that have been found in many eukaryotic organisms from yeast to human. TRP channels exert a multitude of physiological functions ranging from Ca2+ homeostasis in the kidney to pain reception and vision. These channels are activated by a wide range of stimuli and undergo covalent post-translational modifications that affect and modulate their subcellular targeting, their biophysical properties, or channel gating. These modifications include N-linked glycosylation, protein phosphorylation, and covalent attachment of chemicals that reversibly bind to specific cysteine residues. The latter modification represents an unusual activation mechanism of ligand-gated ion channels that is in contrast to the lock-and-key paradigm of receptor activation by its agonists. In this review, we summarize the post-translational modifications identified on TRP channels and, when available, explain their physiological role. PMID:24717323

Voolstra, Olaf; Huber, Armin

2014-01-01

247

25 CFR 134.7 - Modifications.  

Code of Federal Regulations, 2010 CFR

...ACTIVITIES PARTIAL PAYMENT CONSTRUCTION CHARGES ON INDIAN IRRIGATION PROJECTS § 134.7 Modifications. The act of July 1, 1932 (47 Stat. 564; 25 U.S.C. 386a), cancelled all irrigation assessments for construction costs against lands in Indian...

2010-04-01

248

25 CFR 134.7 - Modifications.  

Code of Federal Regulations, 2012 CFR

...ACTIVITIES PARTIAL PAYMENT CONSTRUCTION CHARGES ON INDIAN IRRIGATION PROJECTS § 134.7 Modifications. The act of July 1, 1932 (47 Stat. 564; 25 U.S.C. 386a), cancelled all irrigation assessments for construction costs against lands in Indian...

2012-04-01

249

25 CFR 134.7 - Modifications.  

Code of Federal Regulations, 2011 CFR

...ACTIVITIES PARTIAL PAYMENT CONSTRUCTION CHARGES ON INDIAN IRRIGATION PROJECTS § 134.7 Modifications. The act of July 1, 1932 (47 Stat. 564; 25 U.S.C. 386a), cancelled all irrigation assessments for construction costs against lands in Indian...

2011-04-01

250

25 CFR 134.7 - Modifications.  

Code of Federal Regulations, 2013 CFR

...ACTIVITIES PARTIAL PAYMENT CONSTRUCTION CHARGES ON INDIAN IRRIGATION PROJECTS § 134.7 Modifications. The act of July 1, 1932 (47 Stat. 564; 25 U.S.C. 386a), cancelled all irrigation assessments for construction costs against lands in Indian...

2013-04-01

251

25 CFR 134.7 - Modifications.  

Code of Federal Regulations, 2014 CFR

...ACTIVITIES PARTIAL PAYMENT CONSTRUCTION CHARGES ON INDIAN IRRIGATION PROJECTS § 134.7 Modifications. The act of July 1, 1932 (47 Stat. 564; 25 U.S.C. 386a), cancelled all irrigation assessments for construction costs against lands in Indian...

2014-04-01

252

Examples of Process Modifications that Reduce Waste  

E-print Network

The ideal approach to reducing or eliminating waste products is to avoid making them in the first place. This article will examine numerous process modifications that have accomplished that goal. We'll look at changes to raw materials, reactors...

Nelson, K. E.

253

40 CFR 58.14 - System modification.  

Code of Federal Regulations, 2010 CFR

...AMBIENT AIR QUALITY SURVEILLANCE Monitoring Network § 58.14 System modification. ...to modify the ambient air quality monitoring network that complies with the findings of the network assessments required every 5 years...

2010-07-01

254

Modification of Phenolic Oximes for Copper Extraction   

E-print Network

The thesis deals with the modification of salicylaldoxime-based reagents used in hydrometallurgical extraction, addressing rational ligand design to tune copper(II) extractant strengths and also the development of reagents ...

Forgan, Ross Stewart

2008-01-01

255

7 CFR 636.10 - Modifications.  

Code of Federal Regulations, 2010 CFR

...and the agreement is approved by the designated conservationist. (b) Any modifications made under this section must meet WHIP program objectives and must be in compliance with this part. (c) In the event a conservation practice fails through no...

2010-01-01

256

Regulation of chromatin by histone modifications  

PubMed Central

Chromatin is not an inert structure, but rather an instructive DNA scaffold that can respond to external cues to regulate the many uses of DNA. A principle component of chromatin that plays a key role in this regulation is the modification of histones. There is an ever-growing list of these modifications and the complexity of their action is only just beginning to be understood. However, it is clear that histone modifications play fundamental roles in most biological processes that are involved in the manipulation and expression of DNA. Here, we describe the known histone modifications, define where they are found genomically and discuss some of their functional consequences, concentrating mostly on transcription where the majority of characterisation has taken place. PMID:21321607

Bannister, Andrew J; Kouzarides, Tony

2011-01-01

257

ENVIRONMENTAL ASSESSMENT WASTE WATER TREATMENT MODIFICATIONS  

E-print Network

ENVIRONMENTAL ASSESSMENT FOR WASTE WATER TREATMENT MODIFICATIONS FOR IMPROVED EFFLUENT COMPLIANCE................................................38 5.3.4 Effects of the Enhanced Treatment Alternative on Water Resources........................39 5.................................................................................................. 21 4.3 Alternative 3 ­ Enhanced Effluent Treatment

Ohta, Shigemi

258

Sustainable environmental nanotechnology using nanoparticle surface modification.  

EPA Science Inventory

Reactive nanomaterials used for environmental remediation require surface modification to make them mobile in the subsurface. Nanomaterials released into the environment inadvertently without an engineered surface coating will acquire one (e.g. adsorption of natural organic matt...

259

Old Nassau Demonstration with Wilkinson Modification  

NASA Astrophysics Data System (ADS)

A modification of the Old Nassau Reaction demonstration is presented, wherein a 0.025 M silver nitrate solution is used in place of the mercury(II) chloride solution employed in the original demonstration.

Wilkinson, Lawrence E.

2004-10-01

260

Cytosine modifications in neurodevelopment and diseases  

PubMed Central

DNA methylation has been studied comprehensively and linked to both normal neurodevelopment and neurological diseases. The recent identification of several new DNA modifications, including 5-hydroxylmethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC), has given us a new perspective on the previously observed plasticity in 5mC-dependent regulatory processes. Here we review the latest research into these cytosine modifications, focusing mainly on their roles in neurodevelopment and diseases. PMID:23912899

Yao, Bing; Jin, Peng

2013-01-01

261

Aspect Modification of an EAR Application a  

NASA Astrophysics Data System (ADS)

We propose aspect modification of compiled Java programs for which source code and documentation are not available. Aspect oriented programming is used to trace the program execution and identify points, in which aspects implementing new functionalities should be applied. A special tool for aspect oriented program tracing was designed and implemented. A modification in an real Enterprise Application Archive (EAR), compiled, without source code and documentation is presented in this paper. Advantages and disadvantages of described concepts are pointed out.

Bluemke, Ilona; Billewicz, Konrad

262

Nanoscale Materials Modification for Device Applications  

Microsoft Academic Search

This chapter considers device applications of ion beams that involve nanoscale modification of materials. It is necessarily\\u000a selective and does not include broad classes of applications such as ion beam assisted deposition of thin films or tribological\\u000a modification of surfaces for improved wear, corrosion resistance or biocompatibility. Instead it aims to illustrate the diversity\\u000a of ion beam applications by providing

Robert G. Elliman

263

RF Front End Interface and AGC Modification  

NASA Technical Reports Server (NTRS)

The latest RF front end built by Burhans (Mini-L-82) was successfully interfaced to the Ohio University LORAN-C receiver. In order for the front end to operate optimally, modifications were made to existing automatic gain control (AGC) circuitry already developed for the Ohio University LORAN-C receiver. The hardware modifications to the AGC and other interface circuitry, as well as some preliminary results are discussed.

Yost, S. R.

1982-01-01

264

48 CFR 243.205-70 - Pricing of contract modifications.  

Code of Federal Regulations, 2010 CFR

...Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT CONTRACT MODIFICATIONS Change Orders 243.205-70 Pricing of contract modifications. Use the clause at...

2010-10-01

265

Equilibrium existence and uniqueness in impure public good models  

E-print Network

Equilibrium existence and uniqueness in impure public good models Matthew J. Kotchen 4420 Donald widespread application of the impure public good model, surprisingly little attention has been given public goods; Equilibrium existence and uniqueness JEL classification: C72; H41 1. Introduction Models

Kotchen, Matthew J.

266

On unique localization of multiple sources by passive sensor arrays  

Microsoft Academic Search

Necessary and sufficient conditions are derived for the unique localization of narrowband sources having the same known center frequency by passive sensor arrays. The conditions specify the maximum number of sources that can be uniquely localized by a general array that satisfies some mild geometric constraints. The conditions are expressed in terms of the number of sensors and the rank

M. Wax; I. Ziskind

1989-01-01

267

Need for Uniqueness, Need for Cognition, and Creativity.  

ERIC Educational Resources Information Center

This study examined two neglected dispositional contributions to creativity, needs for uniqueness and cognition, in 150 undergraduates. Results indicated individuals high in the needs of uniqueness and cognition evidenced more creative past accomplishments and produced richer visual and verbal products, more individualistic photo essays, and more…

Dollinger, Stephen J.

2003-01-01

268

Those with Autism May Have Unique Brain Connections, Study Shows  

MedlinePLUS

... enable JavaScript. Those With Autism May Have Unique Brain Connections, Study Shows Brains of people without the disorder show similar patterns, ... 2015 (HealthDay News) -- People with autism may have brain connections that are uniquely their own, a new ...

269

Uniqueness of Extremal Kerr and Kerr-Newman Black Holes  

E-print Network

We prove that the only four dimensional, stationary, rotating, asymptotically flat (analytic) vacuum black hole with a single degenerate horizon is given by the extremal Kerr solution. We also prove a similar uniqueness theorem for the extremal Kerr-Newman solution. This closes a longstanding gap in the black hole uniqueness theorems.

Aaron J. Amsel; Gary T. Horowitz; Donald Marolf; Matthew M. Roberts

2009-11-25

270

Uniqueness of extremal Kerr and Kerr-Newman black holes  

SciTech Connect

We prove that the only four-dimensional, stationary, rotating, asymptotically flat (analytic) vacuum black hole with a single degenerate horizon is given by the extremal Kerr solution. We also prove a similar uniqueness theorem for the extremal Kerr-Newman solution. This closes a long-standing gap in the black hole uniqueness theorems.

Amsel, Aaron J.; Horowitz, Gary T.; Marolf, Donald; Roberts, Matthew M. [Department of Physics, UCSB, Santa Barbara, California 93106 (United States)

2010-01-15

271

Why Is Pt So Unique A Chemical Physics Approach  

E-print Network

Quantum Chemical Modeling -The strength of interaction of O2 and O2 with metals is uniquely relatedWhy Is Pt So Unique A Chemical Physics Approach Philip N. Ross, Jr. Materials Sciences Division.3 V) O2 + - (O2 -)ads Inner Sphere (E0 ` + Gad/F) O2 ­ adsorption strength nic properties

272

COSPARSE ANALYSIS MODELING UNIQUENESS AND ALGORITHMS Sangnam Nam1  

E-print Network

on properties of the analysis operator and the measurement matrix. This paper also considers two pursuit and its implications. We look at the unique- ness of `cosparse' recovery problem in the analysis modelCOSPARSE ANALYSIS MODELING ­ UNIQUENESS AND ALGORITHMS Sangnam Nam1 Michael E. Davies2 Michael Elad

Paris-Sud XI, Université de

273

Regular networks can be uniquely constructed from their trees  

E-print Network

1 Regular networks can be uniquely constructed from their trees Stephen J. Willson Department with labelled leaves displays a tree T when there exists a way to select a unique parent of each hybrid vertex resulting in the tree T. Let Tr(N) denote the set of all trees displayed by the network N. In general

Willson, Stephen J.

274

UNIQUENESS IN INVERSE OBSTACLE SCATTERING FOR ELECTROMAGNETIC WAVES  

E-print Network

UNIQUENESS IN INVERSE OBSTACLE SCATTERING FOR ELECTROMAGNETIC WAVES Rainer Kress Institut f-harmonic electromagnetic waves. We will concentrate on uniqueness issues, i.e., we will investigate under what conditions to Potthast. THE INVERSE OBSTACLE SCATTERING PROBLEM The propagation of time-harmonic electromagnetic waves

Kress, Rainer

275

Consumer's Need for Uniqueness: Scale Development and Validation  

Microsoft Academic Search

Consumers acquire and display material possessions for the purpose of feeling differentiated from other people and, thus, are targeted with a variety of marketing stimuli that attempt to enhance self-perceptions of uniqueness. Because the pursuit of differentness (or counterconformity motivation) varies across individuals to influence consumer responses, we develop and validate a trait measure of consumers' need for uniqueness. Consumers'

2001-01-01

276

Hue discrimination, unique hues and naming Romain, Bachy1  

E-print Network

Hue discrimination, unique hues and naming Romain, Bachy1 ; J´er^ome, Dias2,3 ; David, Alleysson3 Corresponding : Valerie.Bonnardel@winchester.ac.uk The Hue Discrimination Curve (HDC) that characterizes between hue discrimination and appearance, observers further performed a free color naming and a unique

Alleysson, David

277

Salience of unique hues and implications for color theory.  

PubMed

The unique hues-blue, green, yellow, red-form the fundamental dimensions of opponent-color theories, are considered universal across languages, and provide useful mental representations for structuring color percepts. However, there is no neural evidence for them from neurophysiology or low-level psychophysics. Tapping a higher prelinguistic perceptual level, we tested whether unique hues are particularly salient in search tasks. We found no advantage for unique hues over their nonunique complementary colors. However, yellowish targets were detected faster, more accurately, and with fewer saccades than their complementary bluish targets (including unique blue), while reddish-greenish pairs were not significantly different in salience. Similarly, local field potentials in primate V1 exhibited larger amplitudes and shorter latencies for yellowish versus bluish stimuli, whereas this effect was weaker for reddish versus greenish stimuli. Consequently, color salience is affected more by early neural response asymmetries than by any possible mental or neural representation of unique hues. PMID:25761328

Wool, Lauren E; Komban, Stanley J; Kremkow, Jens; Jansen, Michael; Li, Xiaobing; Alonso, Jose-Manuel; Zaidi, Qasim

2015-01-01

278

Salience of unique hues and implications for color theory  

PubMed Central

The unique hues—blue, green, yellow, red—form the fundamental dimensions of opponent-color theories, are considered universal across languages, and provide useful mental representations for structuring color percepts. However, there is no neural evidence for them from neurophysiology or low-level psychophysics. Tapping a higher prelinguistic perceptual level, we tested whether unique hues are particularly salient in search tasks. We found no advantage for unique hues over their nonunique complementary colors. However, yellowish targets were detected faster, more accurately, and with fewer saccades than their complementary bluish targets (including unique blue), while reddish-greenish pairs were not significantly different in salience. Similarly, local field potentials in primate V1 exhibited larger amplitudes and shorter latencies for yellowish versus bluish stimuli, whereas this effect was weaker for reddish versus greenish stimuli. Consequently, color salience is affected more by early neural response asymmetries than by any possible mental or neural representation of unique hues. PMID:25589294

Wool, Lauren E.; Komban, Stanley J.; Kremkow, Jens; Jansen, Michael; Li, Xiaobing; Alonso, Jose-Manuel; Zaidi, Qasim

2015-01-01

279

Black-hole uniqueness theorems in Euclidean quantum gravity  

SciTech Connect

The Euclidean section of the classical Lorentzian black-hole solutions has been used in approximating the functional integral in the Euclidean path-integral approach to quantum gravity. In this paper the claim that classical black-hole uniqueness theorems apply to the Euclidean section is disproved. In particular, it is shown that although a Euclidean version of Israel's theorem does provide a type of uniqueness theorem for the Euclidean Schwarzschild solution, a Euclidean version of Robinson's theorem does not allow one to form conclusions about the uniqueness of the Euclidean Kerr solution. Despite the failure of uniqueness theorems, ''no-hair'' theorems are shown to exist. Implications are discussed. A precise mathematical statement of the Euclidean black-hole uniqueness conjecture is made and the proof, left as an unsolved problem in Riemannian geometry.

Lapedes, A.S.

1980-10-15

280

Phosphorylation of unique domains of Src family kinases.  

PubMed

Members of the Src family of kinases (SFKs) are non-receptor tyrosine kinases involved in numerous signal transduction pathways. The catalytic, SH3 and SH2 domains are attached to the membrane-anchoring SH4 domain through the intrinsically disordered "Unique" domains, which exhibit strong sequence divergence among SFK members. In the last decade, structural and biochemical studies have begun to uncover the crucial role of the Unique domain in the regulation of SFK activity. This mini-review discusses what is known about the phosphorylation events taking place on the SFK Unique domains, and their biological relevance. The modulation by phosphorylation of biologically relevant inter- and intra- molecular interactions of Src, as well as the existence of complex phosphorylation/dephosphorylation patterns observed for the Unique domain of Src, reinforces the important functional role of the Unique domain in the regulation mechanisms of the Src kinases and, in a wider context, of intrinsically disordered regions in cellular processes. PMID:25071818

Amata, Irene; Maffei, Mariano; Pons, Miquel

2014-01-01

281

Phosphorylation of unique domains of Src family kinases  

PubMed Central

Members of the Src family of kinases (SFKs) are non-receptor tyrosine kinases involved in numerous signal transduction pathways. The catalytic, SH3 and SH2 domains are attached to the membrane-anchoring SH4 domain through the intrinsically disordered “Unique” domains, which exhibit strong sequence divergence among SFK members. In the last decade, structural and biochemical studies have begun to uncover the crucial role of the Unique domain in the regulation of SFK activity. This mini-review discusses what is known about the phosphorylation events taking place on the SFK Unique domains, and their biological relevance. The modulation by phosphorylation of biologically relevant inter- and intra- molecular interactions of Src, as well as the existence of complex phosphorylation/dephosphorylation patterns observed for the Unique domain of Src, reinforces the important functional role of the Unique domain in the regulation mechanisms of the Src kinases and, in a wider context, of intrinsically disordered regions in cellular processes. PMID:25071818

Amata, Irene; Maffei, Mariano; Pons, Miquel

2014-01-01

282

On Time Delay Margin Estimation for Adaptive Control and Optimal Control Modification  

NASA Technical Reports Server (NTRS)

This paper presents methods for estimating time delay margin for adaptive control of input delay systems with almost linear structured uncertainty. The bounded linear stability analysis method seeks to represent an adaptive law by a locally bounded linear approximation within a small time window. The time delay margin of this input delay system represents a local stability measure and is computed analytically by three methods: Pade approximation, Lyapunov-Krasovskii method, and the matrix measure method. These methods are applied to the standard model-reference adaptive control, s-modification adaptive law, and optimal control modification adaptive law. The windowing analysis results in non-unique estimates of the time delay margin since it is dependent on the length of a time window and parameters which vary from one time window to the next. The optimal control modification adaptive law overcomes this limitation in that, as the adaptive gain tends to infinity and if the matched uncertainty is linear, then the closed-loop input delay system tends to a LTI system. A lower bound of the time delay margin of this system can then be estimated uniquely without the need for the windowing analysis. Simulation results demonstrates the feasibility of the bounded linear stability method for time delay margin estimation.

Nguyen, Nhan T.

2011-01-01

283

Guide to good practices for operations aspects of unique processes  

SciTech Connect

This Guide to Good Practices is written to enhance understanding of, and provide direction for, Operations Aspects of Facility Chemistry and Unique Processes, Chapter XIII of Department of Energy (DOE) Order 5480.19, Conduct of Operations Requirements for DOE Facilities. The practices in this guide should be considered when planning or reviewing employee training and facility management programs. Contractors are advised to adopt procedures that meet the intent of DOE Order 5480.19. Operations Aspects of Unique Processes is an element of an effective Conduct of Operations program. The complexity and array of activities performed in DOE facilities dictate the necessity for all personnel to coordinate interrelated activities affecting unique processes.

NONE

1998-12-01

284

(Non)Uniqueness of critical points in variational data assimilation  

NASA Astrophysics Data System (ADS)

In this paper we apply the 4D-Var data assimilation scheme to the initialization problem for a family of quasilinear evolution equations. The resulting variational problem is non-convex, so it need not have a unique minimizer. We comment on the implications of non-uniqueness for numerical applications, then prove uniqueness results in the following situations: (1) the observational times are sufficiently small; (2) the prior covariance is sufficiently small. We also give an example of a data set where the cost functional has a critical point of arbitrarily large Morse index, thus demonstrating that the geometry can be highly nonconvex even for a relatively mild nonlinearity.

Cox, Graham

2015-04-01

285

Extending the Black Hole Uniqueness Theorems, II. Superstring Black Holes  

E-print Network

We make use of an internal symmetry of a truncation of the bosonic sector of the superstring and N=4 supergravity theories to write down an analogue of Robinson's identity for the black holes of this theory. This allows us to prove the uniqueness of a restricted class of black hole solutions. In particular, we can apply the methods of the preceding paper to prove the uniqueness of a class of accelerating black holes (the Stringy Ernst solution and Stringy C-metric) which incorporate the possibility of the black hole accelerating within an electromagnetic flux tube. These solutions and their associated uniqueness may be useful in future instanton calculations.

Clive G. Wells

1998-08-17

286

Profiling of RNA modifications by multiplexed stable isotope labelling.  

PubMed

The combination of (15)N/(13)C stable isotope labelling (SIL) and LC-MS/MS revealed a total of 52 modifications in RNA from E. coli and yeast, including 10 previously undescribed modifications. Two modifications, N-ribosylnicotinamide and 2-methylthioadenosine, were newly detected in species hitherto thought not to contain these modifications. PMID:24567952

Kellner, Stefanie; Neumann, Jennifer; Rosenkranz, David; Lebedeva, Svetlana; Ketting, René F; Zischler, Hans; Schneider, Dirk; Helm, Mark

2014-04-01

287

Genetic Variation Stimulated by Epigenetic Modification W. Jason Cummings1  

E-print Network

Genetic Variation Stimulated by Epigenetic Modification W. Jason Cummings1 , David W. Bednarski1 modification can stimulate genetic variation. The evidence that distinct activating modifications can promote: Cummings WJ, Bednarski DW, Maizels N (2007) Genetic Variation Stimulated by Epigenetic Modification. PLo

Maizels, Nancy

288

Different Roles for Two Ubiquitin-like Domains of ISG15 in Protein Modification*S  

E-print Network

Different Roles for Two Ubiquitin-like Domains of ISG15 in Protein Modification*S Received by ISG15 (ISGylation) and the impact of Influ- enza B virus NS1 protein (NS1B) on regulation treatment. We propose that the N-terminal UbL domain of ISG15 mainly functions in the ligation step and NS1B

Tian, Weidong

289

Isolation of a deoxycytidylate methyl transferase capable of protecting DNA uniquely against cleavage by endonuclease R.Aqu I (isoschizomer of Ava I).  

PubMed Central

A sequence-specific modification methylase (M.AquI) was isolated and purified from Agmenellum quadruplicatum (Synechococcus PCC 7002). This enzyme uniquely methylates the deoxycytidylate residue in the sequence *CYCGRG indicated by the asterisk. It was shown to protect DNA against cleavage by restriction endonucleases AvaI, SmaI and XhoI, which recognize the sequences CYCGRG, CCCGGG, and CTCGAG, respectively. Images PMID:3016641

Karreman, C; Tandeau de Marsac, N; de Waard, A

1986-01-01

290

Epigenetic modifications as new targets for liver disease therapies.  

PubMed

An important discovery from the human genome mapping project was that it is comprised of a surprisingly low number of genes,with recent estimates suggesting they are as few as 25,000 [1].This supported an alternative hypothesis that our complexity in comparison with lower order species is likely to be determined by regulatory mechanisms operating at levels above the fundamental DNA sequences of the genome [2]. One set of mechanisms that dictate tissue and cellular complexity can be described by the overarching term "epigenetics". In the 1940s, Conrad Waddington described epigenetics as "the branch of biology which studies the causal interactions between genes and their products which bring the phenotype into being". Today we understand epigenetics as a gene regulatory system comprised of 3 major mechanisms including DNA modifications (e.g., methylation), use of histone variants and post-translational modifications of the amino acid tails of histones and non-coding RNAs of which microRNAs are the best characterized [3,4]. Together, these mechanisms orchestrate numerous sets of chemical reactions that switch parts of the genome on and off at specific times and locations.Epigenetic marks, or the epigenome, exhibit a high degree of cellular-specificity and developmental or environmentally driven dynamic plasticity. Due to being at the interface between genome and the environment, the epigenome evolves at a very high rate compared to genetic mutations. Indeed, the differences in the epigenome account for most of the phenotypic uniqueness between closely related species, especially primates. More interestingly,the epigenetic changes, or epimutations, within an individual are not only maintained over cellular generations, but may also be transmitted between generations, such that adaptive epimutations generated in response to a particular environmental cue can influence phenotypes in our children and grandchildren [5]. PMID:23747756

Zeybel, Müjdat; Mann, Derek A; Mann, Jelena

2013-12-01

291

ROSICS: CHEMISTRY AND PROTEOMICS OF CYSTEINE MODIFICATIONS IN REDOX BIOLOGY  

PubMed Central

Post-translational modifications (PTMs) occurring in proteins determine their functions and regulations. Proteomic tools are available to identify PTMs and have proved invaluable to expanding the inventory of these tools of nature that hold the keys to biological processes. Cysteine (Cys), the least abundant (1–2%) of amino acid residues, are unique in that they play key roles in maintaining stability of protein structure, participating in active sites of enzymes, regulating protein function and binding to metals, among others. Cys residues are major targets of reactive oxygen species (ROS), which are important mediators and modulators of various biological processes. It is therefore necessary to identify the Cys-containing ROS target proteins, as well as the sites and species of their PTMs. Cutting edge proteomic tools which have helped identify the PTMs at reactive Cys residues, have also revealed that Cys residues are modified in numerous ways. These modifications include formation of disulfide, thiosulfinate and thiosulfonate, oxidation to sulfenic, sulfinic, sulfonic acids and thiosulfonic acid, transformation to dehydroalanine (DHA) and serine, palmitoylation and farnesylation, formation of chemical adducts with glutathione, 4-hydroxynonenal and 15-deoxy PGJ2, and various other chemicals. We present here, a review of relevant ROS biology, possible chemical reactions of Cys residues and details of the proteomic strategies employed for rapid, efficient and sensitive identification of diverse and novel PTMs involving reactive Cys residues of redox-sensitive proteins. We propose a new name, “ROSics,” for the science which describes the principles of mode of action of ROS at molecular levels. © 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc. Rapid Commun. Mass Spec Rev 34:184–208, 2015. PMID:24916017

Kim, Hee-Jung; Ha, Sura; Lee, Hee Yoon; Lee, Kong-Joo

2015-01-01

292

ROSics: Chemistry and proteomics of cysteine modifications in redox biology.  

PubMed

Post-translational modifications (PTMs) occurring in proteins determine their functions and regulations. Proteomic tools are available to identify PTMs and have proved invaluable to expanding the inventory of these tools of nature that hold the keys to biological processes. Cysteine (Cys), the least abundant (1-2%) of amino acid residues, are unique in that they play key roles in maintaining stability of protein structure, participating in active sites of enzymes, regulating protein function and binding to metals, among others. Cys residues are major targets of reactive oxygen species (ROS), which are important mediators and modulators of various biological processes. It is therefore necessary to identify the Cys-containing ROS target proteins, as well as the sites and species of their PTMs. Cutting edge proteomic tools which have helped identify the PTMs at reactive Cys residues, have also revealed that Cys residues are modified in numerous ways. These modifications include formation of disulfide, thiosulfinate and thiosulfonate, oxidation to sulfenic, sulfinic, sulfonic acids and thiosulfonic acid, transformation to dehydroalanine (DHA) and serine, palmitoylation and farnesylation, formation of chemical adducts with glutathione, 4-hydroxynonenal and 15-deoxy PGJ2, and various other chemicals. We present here, a review of relevant ROS biology, possible chemical reactions of Cys residues and details of the proteomic strategies employed for rapid, efficient and sensitive identification of diverse and novel PTMs involving reactive Cys residues of redox-sensitive proteins. We propose a new name, "ROSics," for the science which describes the principles of mode of action of ROS at molecular levels. © 2014 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc. Rapid Commun. Mass Spec Rev 34:184-208, 2015. PMID:24916017

Kim, Hee-Jung; Ha, Sura; Lee, Hee Yoon; Lee, Kong-Joo

2015-04-01

293

Gamma-induced modifications of polycarbonate polymer  

NASA Astrophysics Data System (ADS)

Gamma-induced modifications in polycarbonate polymer have been studied in the dose range of 10(1)-10(6) Gy. Thin films of polycarbonate have been irradiated with different gamma doses from a Co-60 source. To monitor the modifications caused by gamma radiation, FT-IR, differential scanning calorimetry and X-ray diffraction studies have been performed. The studies have indicated that at the dose of 10(6) Gy, phenolic group forms through scissioning of ester linkage. Though the effect of radiation is most significant at the highest dose, the process of modifications starts at 10(3) Gy. Scissioning of the polymeric chain initiates a different morphological zone within the polymer matrix, and the polymer becomes more crystalline with increasing dose. Owing to chain scissioning, the mobility of the polymer increases, which in turn reduces the glass transition temperature of the polymer.

Sinha, D.; Sahoo, K. L.; Sinha, U. B.; Swu, T.; Chemseddine, A.; Fink, D.

2004-10-01

294

Identification and interrogation of combinatorial histone modifications  

PubMed Central

Histone proteins are dynamically modified to mediate a variety of cellular processes including gene transcription, DNA damage repair, and apoptosis. Regulation of these processes occurs through the recruitment of non-histone proteins to chromatin by specific combinations of histone post-translational modifications (PTMs). Mass spectrometry has emerged as an essential tool to discover and quantify histone PTMs both within and between samples in an unbiased manner. Developments in mass spectrometry that allow for characterization of large histone peptides or intact protein has made it possible to determine which modifications occur simultaneously on a single histone polypeptide. A variety of techniques from biochemistry, biophysics, and chemical biology have been employed to determine the biological relevance of discovered combinatorial codes. This review first describes advancements in the field of mass spectrometry that have facilitated histone PTM analysis and then covers notable approaches to probe the biological relevance of these modifications in their nucleosomal context. PMID:24391660

Karch, Kelly R.; DeNizio, Jamie E.; Black, Ben E.; Garcia, Benjamin A.

2013-01-01

295

On uniqueness of tangent cones for Einstein manifolds  

E-print Network

We show that for any Ricci-flat manifold with Euclidean volume growth the tangent cone at infinity is unique if one tangent cone has a smooth cross-section. Similarly, for any noncollapsing limit of Einstein manifolds with ...

Colding, Tobias

296

New Guidelines for Reducing Stroke Risks Unique to Women  

MedlinePLUS

... org Learn More New guidelines for reducing stroke risks unique to women American Heart Association/American Stroke ... org Share Related Images ASA Stroke-Women-at-Risk-infographic copyright American Heart Association Download (378.5 ...

297

Comparison of Bacillus monooxygenase genes for unique fatty acid production  

Technology Transfer Automated Retrieval System (TEKTRAN)

This paper reviews Bacillus genes encoding monooxygenase enzymes producing unique fatty acid metabolites. Specifically, it examines standard monooxygenase electron transfer schemes and related domain structures of these fused domain enzymes on route to understanding the observed oxygenase activiti...

298

Unique Energy Management Training Offers Certification and Energy Savings  

E-print Network

The Northwest Energy Education Institute1 (NEEI) has developed and presents a very unique energy efficiency training and certification program. Modeled after a similar course once offered in New Zealand, NEEI offers a two-week energy management...

Ebbage, R.

2004-01-01

299

Coexisting generalist herbivores occupy unique nutritional feeding niches  

E-print Network

Coexisting generalist herbivores occupy unique nutritional feeding niches Spencer T. Behmer in nutritional physiology to show that closely related, cooccurring and generalist-feeding herbivores (seven- tional niches provides a cryptic mechanism that helps explain how generalist herbivores with broadly

Behmer, Spencer T.

300

Unique in the Crowd: The privacy bounds of human mobility  

PubMed Central

We study fifteen months of human mobility data for one and a half million individuals and find that human mobility traces are highly unique. In fact, in a dataset where the location of an individual is specified hourly, and with a spatial resolution equal to that given by the carrier's antennas, four spatio-temporal points are enough to uniquely identify 95% of the individuals. We coarsen the data spatially and temporally to find a formula for the uniqueness of human mobility traces given their resolution and the available outside information. This formula shows that the uniqueness of mobility traces decays approximately as the 1/10 power of their resolution. Hence, even coarse datasets provide little anonymity. These findings represent fundamental constraints to an individual's privacy and have important implications for the design of frameworks and institutions dedicated to protect the privacy of individuals. PMID:23524645

de Montjoye, Yves-Alexandre; Hidalgo, César A.; Verleysen, Michel; Blondel, Vincent D.

2013-01-01

301

The unique radar properties of silicic lava domes  

NASA Technical Reports Server (NTRS)

Silicic lava domes exhibit distinct morphologic characteristics at scales of centimeters to kilometers. Multiparameter radar observations capture the unique geometric signatures of silicic domes in a set of radar scattering properties that are unlike any other natural geologic surfaces.

Plaunt, J J.; Anderson, S. W.; Crown, D. A.; Stofan, E. R.; van Zyl, J. J.

2004-01-01

302

221. View entering smart view. Note the unique snake rail ...  

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

221. View entering smart view. Note the unique snake rail fence. The pond was a manipulated landscape element. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

303

Existence, uniqueness, and parametrization of Lagrangian invariant subspaces  

E-print Network

The existence, uniqueness, and parametrization of Lagrangian invariant subspaces for Hamiltonian matrices is studied. Necessary and sufficient conditions and a complete parametrization are given. Some necessary and sufficient conditions...

Freiling, G.; Mehrmann, V.; Xu, Hongguo

2002-05-10

304

Uncoupling Transcription from Covalent Histone Modification  

PubMed Central

It is widely accepted that transcriptional regulation of eukaryotic genes is intimately coupled to covalent modifications of the underlying chromatin template, and in certain cases the functional consequences of these modifications have been characterized. Here we present evidence that gene activation in the silent heterochromatin of the yeast Saccharomyces cerevisiae can occur in the context of little, if any, covalent histone modification. Using a SIR-regulated heat shock-inducible transgene, hsp82-2001, and a natural drug-inducible subtelomeric gene, YFR057w, as models we demonstrate that substantial transcriptional induction (>200-fold) can occur in the context of restricted histone loss and negligible levels of H3K4 trimethylation, H3K36 trimethylation and H3K79 dimethylation, modifications commonly linked to transcription initiation and elongation. Heterochromatic gene activation can also occur with minimal H3 and H4 lysine acetylation and without replacement of H2A with the transcription-linked variant H2A.Z. Importantly, absence of histone modification does not stem from reduced transcriptional output, since hsp82-?TATA, a euchromatic promoter mutant lacking a TATA box and with threefold lower induced transcription than heterochromatic hsp82-2001, is strongly hyperacetylated in response to heat shock. Consistent with negligible H3K79 dimethylation, dot1? cells lacking H3K79 methylase activity show unimpeded occupancy of RNA polymerase II within activated heterochromatic promoter and coding regions. Our results indicate that large increases in transcription can be observed in the virtual absence of histone modifications often thought necessary for gene activation. PMID:24722509

Gross, David S.

2014-01-01

305

Unnatural Amino Acid Incorporation onto Adenoviral (Ad) Coat Proteins Facilitates Chemoselective Modification and Retargeting of Ad Type 5 Vectors ?  

PubMed Central

Surface modification of adenovirus vectors can improve tissue-selective targeting, attenuate immunogenicity, and enable imaging of particle biodistribution, thus significantly improving therapeutic potential. Currently, surface engineering is constrained by a combination of factors, including impact on viral fitness, limited access to functionality, or incomplete control over the site of modification. Here, we report a two-step labeling process involving an initial metabolic placement of a uniquely reactive unnatural amino acid, azidohomoalanine (Aha), followed by highly specific chemical modification. As genetic modification of adenovirus is unnecessary, vector production is exceedingly straightforward. Aha incorporation demonstrated no discernible impact on either virus production or infectivity of the resultant particles. “Click” chemical modification of surface-exposed azides was highly selective, allowing for the attachment of a wide range of functionality. Decoration of human adenovirus type 5 (hAd5) with folate, a known cancer-targeting moiety, provided an ?20-fold increase in infection of murine breast cancer cells (4T1) in a folate receptor-dependent manner. This study demonstrates that incorporation of unnatural amino acids can provide a flexible, straightforward route for the selective chemical modification of adenoviral vectors. PMID:21613404

Banerjee, Partha Sarathi; Ostapchuk, Philomena; Hearing, Patrick; Carrico, Isaac Sheridan

2011-01-01

306

BuD, a helix–loop–helix DNA-binding domain for genome modification  

PubMed Central

DNA editing offers new possibilities in synthetic biology and biomedicine for modulation or modification of cellular functions to organisms. However, inaccuracy in this process may lead to genome damage. To address this important problem, a strategy allowing specific gene modification has been achieved through the addition, removal or exchange of DNA sequences using customized proteins and the endogenous DNA-repair machinery. Therefore, the engineering of specific protein–DNA interactions in protein scaffolds is key to providing ‘toolkits’ for precise genome modification or regulation of gene expression. In a search for putative DNA-binding domains, BurrH, a protein that recognizes a 19?bp DNA target, was identified. Here, its apo and DNA-bound crystal structures are reported, revealing a central region containing 19 repeats of a helix–loop–helix modular domain (BurrH domain; BuD), which identifies the DNA target by a single residue-to-nucleotide code, thus facilitating its redesign for gene targeting. New DNA-binding specificities have been engineered in this template, showing that BuD-derived nucleases (BuDNs) induce high levels of gene targeting in a locus of the human haemoglobin ? (HBB) gene close to mutations responsible for sickle-cell anaemia. Hence, the unique combination of high efficiency and specificity of the BuD arrays can push forward diverse genome-modification approaches for cell or organism redesign, opening new avenues for gene editing. PMID:25004980

Stella, Stefano; Molina, Rafael; López-Méndez, Blanca; Juillerat, Alexandre; Bertonati, Claudia; Daboussi, Fayza; Campos-Olivas, Ramon; Duchateau, Phillippe; Montoya, Guillermo

2014-01-01

307

Denture identification using unique identification authority of India barcode  

PubMed Central

Over the years, various denture marking systems have been reported in the literature for personal identification. They have been broadly divided into surface marking and inclusion methods. In this technique, patient's unique identification number and barcode printed in the patient's Aadhaar card issued by Unique Identification Authority of India (UIDAI) are used as denture markers. This article describes a simple, quick, and economical method for identification of individual. PMID:23960418

Mahoorkar, Sudhindra; Jain, Anoop

2013-01-01

308

On the uniqueness of Kerr-Newman black holes  

Microsoft Academic Search

The uniqueness of the Kerr-Newman family of black hole metrics as stationary asymptotically flat solutions to the Einstein equations coupled to a free Maxwell field is a crucial ingredient in the study of final states of the universe in general relativity. If one imposes the additional requirement that the space-time is axial-symmetric, then said uniqueness was shown by the works

Willie Wai-Yeung Wong

2009-01-01

309

The uniqueness theorem for the universal R -matrix  

Microsoft Academic Search

Up to now, the universal R-matrix for quantized Kac-Moody algebrasHere the name \\\\lsKac-Moody algebras\\\\rs includes all semisimple finite-dimensional Lie algebras and all infinite-dimensional affine Kac-Moody algebras. is believed to be uniquely determined (for some ansatz) by properties of a quasi-cocommutativity and a quasi-triangularity. We prove here that the universal R-matrix (for the same ansatz) is uniquely determined by the property

S. M. Khoroshkin; V. N. Tolstoy

1992-01-01

310

Meteorological satellites in support of weather modification  

NASA Technical Reports Server (NTRS)

During the past several years, many weather modification programs have been incorporating meteorological satellite data into both the operations and the analysis phase of these projects. This has occurred because of the advancement of the satellite as a mesoscale measurement platform, both temporally and spatially, and as the availability of high quality data has increased. This paper surveys the applications of meteorological satellite data to both summer and winter weather modification programs. A description of the types of observations needed by the programs is given, and an assessment of how accurately satellites can determine these necessary parameters is made.

Reynolds, D. W.; Vonder Haar, T. H.; Grant, L. O.

1978-01-01

311

Epigenetic modifications in pediatric acute lymphoblastic leukemia.  

PubMed

Aberrant epigenetic modifications are well-recognized drivers for oncogenesis. Pediatric acute lymphoblastic leukemia (ALL) is no exception and serves as a model toward the significant impact these heritable alterations can have in leukemogenesis. In this brief review, we will focus on the main aspects of epigenetics, which control leukemogenesis in pediatric ALL, mainly DNA methylation, histone modification, and microRNA alterations. As we continue to gain better understanding of the driving mechanisms for pediatric ALL at both diagnosis and relapse, therapeutic interventions directed toward these pathways and mechanisms can be harnessed and introduced into clinical trials for pediatric ALL. PMID:24860797

Burke, Michael J; Bhatla, Teena

2014-01-01

312

A amphoteric copolymer profile modification agent  

SciTech Connect

This report provides a new gel profile modification agent prepared by an amphoteric copolymer (FT-213) and a novel crosslinking agent (BY), and introduces the preparations of the amphoteric polymer, the crosslinking agent and the profile modification agent, the action mechanism, the test conditions and the evaluations of the performance of the agent. The 45 well treatments in oilfields demonstrate that the agent can be prepared conveniently, the agent has better compatibility and application performances, and the treatment life is longer with the use of the agent. 80,000 tons incremental oil and 60,000 m{sup 3} decreasing water production have been achieved.

Wang HongGuan; Yu LianCheng; Tian HongKun [Scientific Research Inst. of Petroleum Exploration and Development, Beijing (China)

1995-11-01

313

Beam Distribution Modification By Alfven Modes  

SciTech Connect

Modification of a deuterium beam distribution in the presence of low amplitude Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes in a toroidal magnetic confinement device is examined. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam transport, and that the experimental amplitudes are only slightly above this threshold. The modes produce a substantial central flattening of the beam distribution.

R. B. White, N. Gorelenkov, W. W. Heidbrink, and M.A. Van Zeeland

2010-01-25

314

Beam Distribution Modification by Alfven Modes  

SciTech Connect

Modification of a deuterium beam distribution in the presence of low amplitude Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes in a toroidal magnetic confinement device is examined. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam transport, and that the experimental amplitudes are only slightly above this threshold. The modes produce a substantial central flattening of the beam distribution.

R.B. White, N. Gorelenkov, W.W. Heidbrink, and M.A. Van Zeeland

2010-04-03

315

Development of an Improved Permeability Modification Simulator  

SciTech Connect

This report describes the development of an improved permeability modification simulator performed jointly by BDM Petroleum Technologies and Schlumberger Dowell under a cooperative research and development agreement (CRADA) with the US Department of Energy. The improved simulator was developed by modifying NIPER's PC-GEL permeability modification simulator to include a radial model, a thermal energy equation, a wellbore simulator, and a fully implicit time-stepping option. The temperature-dependent gelation kinetics of a delayed gel system (DGS) is also included in the simulator.

Gao, H.W.; Elphnick, J.

1999-03-09

316

Cell Reports Chromatin Modifications as Determinants  

E-print Network

in quiescent stem cells. These findings highlight the importance of chromatin map- ping in understanding unique of distinct types of cells is established at the epigenetic level. The epigenome determines the pattern

Brunet, Anne

317

Uniqueness in the forensic identification sciences--fact or fiction?  

PubMed

Fingerprint analysts, firearms and toolmark examiners, and forensic odontologists often rely on the uniqueness proposition in order to support their theory of identification. However, much of the literature claiming to have proven uniqueness in the forensic identification sciences is methodologically weak, and suffers flaws that negate any such conclusion being drawn. The finding of uniqueness in any study appears to be an overstatement of the significance of its results, and in several instances, this claim is made despite contrary data being presented. The mathematical and philosophical viewpoint regarding this topic is that obtaining definitive proof of uniqueness is considered impossible by modern scientific methods. More importantly, there appears to be no logical reason to pursue such research, as commentators have established that uniqueness is not the essential requirement for forming forensic conclusions. The courts have also accepted this in several recent cases in the United States, and have dismissed the concept of uniqueness as irrelevant to the more fundamental question of the reliability of the forensic analysis. PMID:20832209

Page, Mark; Taylor, Jane; Blenkin, Matt

2011-03-20

318

Post-translational structural modifications of immunoglobulin G and their effect on biological activity.  

PubMed

The size, heterogeneity, and biological production process of protein therapeutics like monoclonal antibodies create unique challenges for their analysis and regulation compared with small molecules. Complete structural characterization of a molecule 1000-fold heavier than aspirin is no small feat. Biological post-translational modifications such as glycosylation further complicate their characterization and regulation. Even approved protein therapeutics are known to contain multiple structural variants in differing amounts. Structural modification occurs during production and storage as well as within patients after administration. Thus, the goals of manufacturers and regulators are to control and characterize this heterogeneity, not take on the impossible task of eliminating it. The aim of this review is to describe the structural heterogeneities known to occur with immunoglobulin G (IgG), note current detection and analytical strategies, establish their causes, and define their potential effects on the ultimate safety, purity, and potency of antibody therapeutics when known. PMID:25200070

Hmiel, Laura K; Brorson, Kurt A; Boyne, Michael T

2015-01-01

319

Bond cleavage, fragment modification and reassembly in enantioselective three-component reactions.  

PubMed

Chemical bond cleavage and reconstruction are common processes in traditional rearrangement reactions. In contrast, the process that involves bond cleavage, fragment modification and then reconstruction of the modified fragment provides an efficient way to build structurally diversified molecules. Here, we report a palladium(II)/chiral phosphoric acid catalysed three-component reaction of aryldiazoacetates, enamines and imines to afford ?-amino-?-oxo pentanoic acid derivatives in good yields with excellent diastereoselectivities and high enantioselectivities. The stereoselective reaction went through a unique process that involves cleavage of a C-N bond, modification of the resulting amino fragment and selective reassembly of the modified fragment. This innovative multi-component process represents a highly efficient way to build structurally diversified polyfunctional molecules in an atom and step economic fashion. A keto-iminium is proposed as a key intermediate and a chiral palladium/phosphate complex is proposed as an active catalyst. PMID:25586817

Zhang, Dan; Zhou, Jun; Xia, Fei; Kang, Zhenghui; Hu, Wenhao

2015-01-01

320

Bond cleavage, fragment modification and reassembly in enantioselective three-component reactions  

PubMed Central

Chemical bond cleavage and reconstruction are common processes in traditional rearrangement reactions. In contrast, the process that involves bond cleavage, fragment modification and then reconstruction of the modified fragment provides an efficient way to build structurally diversified molecules. Here, we report a palladium(II)/chiral phosphoric acid catalysed three-component reaction of aryldiazoacetates, enamines and imines to afford ?-amino-?-oxo pentanoic acid derivatives in good yields with excellent diastereoselectivities and high enantioselectivities. The stereoselective reaction went through a unique process that involves cleavage of a C–N bond, modification of the resulting amino fragment and selective reassembly of the modified fragment. This innovative multi-component process represents a highly efficient way to build structurally diversified polyfunctional molecules in an atom and step economic fashion. A keto-iminium is proposed as a key intermediate and a chiral palladium/phosphate complex is proposed as an active catalyst. PMID:25586817

Zhang, Dan; Zhou, Jun; Xia, Fei; Kang, Zhenghui; Hu, Wenhao

2015-01-01

321

Genetic modification of stem cells for transplantation  

Microsoft Academic Search

Gene modification of cells prior to their transplantation, especially stem cells, enhances their survival and increases their function in cell therapy. Like the Trojan horse, the gene-modified cell has to gain entrance inside the host's walls and survive and deliver its transgene products Using cellular, molecular and gene manipulation techniques the transplanted cell can be protected in a hostile environment

M. Ian Phillips; Yao Liang Tang

2008-01-01

322

Modification ofregional groundwater regimes by land reclamation  

E-print Network

Modification ofregional groundwater regimes by land reclamation Jiu Jimmy Jiao Department ofEarth Sciences, The University ofHong Kong, P. R. China Abstract JJ.Jiao Land reclamation has played a significant role in the urban development process in many coastal areas in the world. While reclamation

Jiao, Jiu Jimmy

323

A behavior modification approach to supervisor training  

Microsoft Academic Search

The principles underlying behavior modification are rather well-established. For some time, psychologists have turned out research demonstrating the efficacy of imitation, positive reinforcement, and practice in learning situations. Psychotherapists, in fact, have recently been reporting considerable success in changing behavior by using techniques which fall under the descriptive term \\

Melvin Sorcher

1971-01-01

324

Prespective from a weather modification experiment  

Microsoft Academic Search

This article provides some views on the statistical design and analysis of weather modification experiments. Perspectives were developed from experience with analyses of the Santa Barbara Phase I experiment summarized in Section 2, Randomization analvses are reported and compared with previously published parametric analyses. The parametric significance levels of tests for a cloud seeding effect agree well with the significance

Ralph A. Bradley; Elton Scott

1980-01-01

325

How to Train Supervisors in Behavior Modification.  

ERIC Educational Resources Information Center

This is a guide for training supervisors in the theory and application of behavior modification using material that has been implemented successfully for many years in companies throughout the country. Procedures for organizing and conducting training sessions in a supervisor training program are presented. The manual, one of four prepared to aid…

Arkin, Ronald; And Others

326

ORIGINAL CONTRIBUTION Modification of Multiple Sclerosis Phenotypes  

E-print Network

ORIGINAL CONTRIBUTION Modification of Multiple Sclerosis Phenotypes by African Ancestry at HLA. Oksenberg, PhD Background: In those with multiple sclerosis (MS), Afri- can American individuals have a more ancestry at HLA correlated with dis- ability as measured by the Multiple Sclerosis Severity Score (P .001

Reich, David

327

MODIFICATION OF VEGETABLE OILS FOR LUBRICANTS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates as base fluids in environmental-friendly lubricants. Vegetable oils have excellent lubricity, but poor oxidation and low-temperature stability. This paper presents a series of structural modifications of veget...

328

Adaptive size modification by dominant female meerkats.  

PubMed

In species of cooperative insects that live in large groups, selection for increased fecundity has led to the evolution of an increased body size among female reproductives, but whether this is also true of cooperative vertebrates is unknown. Among vertebrates, morphological modification of female breeders has only been documented in a single species; in naked mole rats (Heterocephalus glaber), acquisition of alpha status is associated with a significant increase in body size through an elongation of the lumbar vertebrae. Here we provide evidence of morphological modification among breeding females of a cooperative carnivore, the meerkat (Suricata suricatta), and demonstrate that this modification is likely to be adaptive. The same female meerkats were significantly larger when they were dominant than when they were subordinate. This increased body size was not explained by differences in age, foraging efficiency, or investment in offspring care, but may have arisen, in part, through increased levels of hormone that govern bone growth. Increases in body size are likely to result in fitness benefits, for large females delivered larger litters and had heavier offspring, both of which are known to correlate positively with measures of breeding success in meerkats. Our results suggest that the acquisition of alpha status in female meerkats is associated with an adaptive increase in body size and hence that morphological modification of female vertebrates may be more widespread than has been previously supposed. PMID:15341161

Russell, Andrew F; Carlson, Anne A; McIlrath, Grant M; Jordan, Neil R; Clutton-Brock, Tim

2004-07-01

329

A Classroom Modification of the Ames Test.  

ERIC Educational Resources Information Center

A modification of the Ames test for detecting carcinogens and mutagens using a strain of bacteria is described. A suggestion is given for checking the correctness of procedures by using particular hair dyes which have been shown to be mutogenic. (Author/SA)

Yavornitzky, Joseph; Trzeciak, Victor

1979-01-01

330

APPLICATION OF COMBUSTION MODIFICATIONS OF INDUSTRIAL EQUIPMENT  

EPA Science Inventory

The report gives results of a field test program to evaluate the effect of minor combustion modifications on pollutant emissions from a variety of industrial combustion equipment types. Tested were 22 units, including refinery process heaters; clay and cement kilns; steel and alu...

331

DNA restriction and modification systems in Salmonella  

Microsoft Academic Search

Haploid hybrids between Salmonella typhimurium Hfr and Escherichia coli Fexercise two additive types of restriction and modification (SA and SB) on phage ?. System SA had been detected previously in S. typhimurium with phage L. Independent mutants in the SA and SB systems were isolated. P22- and P1-mediated transductions in S. typhimurium and in hybrids established that the genes governing

Charles Colson; Aline Van Pal

1974-01-01

332

Genetic Modification: From Fireflies to Superbugs  

NSDL National Science Digital Library

Genetic modification, taking genes from one animal and putting them in another sounds like science fiction but has become an essential tool for modern medical research. In this short animated film, Dr Siouxsie Wiles from the University of Auckland explains how and why it is done.

Siouxsie Wiles (University of Auckland)

2012-11-08

333

Extreme exercise and oxidative DNA modification  

Microsoft Academic Search

Extreme exercise increases oxygen uptake with a potential for increased formation of reactive oxygen species. Damage to biomolecules may occur if such an increase exceeds the protective capacity of antioxidant defence mechanisms. Vigorous exercise amounting to ? 10 h a day for 30 days increased the rate of oxidative DNA modification by 33% (95% confidence limits, 3–67%; P < 0.02)

Henrik E. Poulsen; Steffen Loft; Kirsten Vistisen

1996-01-01

334

DNA methylation: Bisulphite modification and analysis  

Microsoft Academic Search

DNA methylation is an important epigenetic modification of DNA in mammalian genomes. DNA methylation patterns are established early in development, modulated during tissue-specific differentiation and disrupted in many disease states, including cancer. To understand further the biological functions of these changes, accurate and reproducible methods are required to fully analyze the DNA methylation sequence. Here, we describe the 'gold-standard' bisulphite

Aaron Statham; Clare Stirzaker; Peter L Molloy; Marianne Frommer; Susan J Clark

2006-01-01

335

Modifications to the Flexible Spacecraft Dynamics Program  

NASA Technical Reports Server (NTRS)

Modifications to existing subroutines are briefly described and a detailed description of new subroutines is given. The capability to simulate the Dynamics Explorer-B control system new developed and the formulation for this addition is given. The program variables in new labelled COMMON blocks are described in detail and the modified input and output for the d Flexible Spacecraft Dynamics Program is described.

1980-01-01

336

Covalent Modifications of the Ebola Virus Glycoprotein  

Microsoft Academic Search

The role of covalent modifications of the Ebola virus glycoprotein (GP) and the significance of the sequence identity between filovirus and avian retrovirus GPs were investigated through biochemical and functional analyses of mutant GPs. The expression and processing of mutant GPs with altered N-linked glycosylation, substitutions for conserved cysteine residues, or a deletion in the region of O-linked glycosylation were

Scott A. Jeffers; David Avram Sanders; Anthony Sanchez

2002-01-01

337

Modification of Vegetable Oils for Lubricants  

Technology Transfer Automated Retrieval System (TEKTRAN)

The current talk deals with a partial review of research for developing improved lubricants from vegetable oils through modifications of the chemical structure. The typical vegetable oil is a mixture of triesters of glycerin with linear fatty acids, most of them with one or more double bonds. The ...

338

D-21B RBCC Modification Feasibility Study  

NASA Technical Reports Server (NTRS)

This report presents a feasibility study on the modifications required to re-engine the Lockheed D-21 Drone for use as a NASA RBCC engine. An introduction, background information, engine configuration and performance, propulsion system integration, loads/thermal analysis, avionics/systems, flight test results, costs and work schedule, and some conclusions are presented.

1999-01-01

339

Naturalness and the genetic modification of animals  

Microsoft Academic Search

In the past few years it has been recognised that so-called intrinsic concerns about genetic modification (GM) of plants and animals, for food in particular, have an important role in the public perception of GM. One of these concerns is the view that GM is ‘unnatural’. This article gives an overview of the often conflicting views on the argument of

Henk Verhoog

2003-01-01

340

In-Medium Modifications of Hadron Properties  

E-print Network

The in-medium modifications of hadron properties are briefly discussed. We restrict the discussion to the lattice QCD calculations for the hadron masses, screening masses, decay constants and wave functions. We review the progress made so far and describe how to broaden its horizon.

A. Tawfik

2006-03-22

341

A Suggested Modification to Maslow's Need Hierarchy  

ERIC Educational Resources Information Center

Since its development, Maslow's need hierarchy has been criticized and applauded. This investigation was undertaken to explore a modification of the upper levels of the need hierarchy based upon the application of power, competition, and achievement to self, as well as the concept of "other directed." (Author)

Groves, David L.; And Others

1975-01-01

342

Organizational Behavior Modification in Business Settings  

Microsoft Academic Search

Design and Content analyses were performed on 20 recent applications of Organizational Behavior Modification in business settings. In performing the design analysis each application was evaluated with respect to the followin design criteria: Reliability of Measurement, Baseline, Systematic 7 ntervention, and Follow-up. Thirty percent of the ap lications performed reliability assessments. All studies incorporate a baseline measurement. Sixty percent of

Frank Andrasik

1989-01-01

343

New facility for ion beam materials characterization and modification at Los Alamos  

SciTech Connect

The Ion Beam Materials Laboratory (IBML) is a new Los Alamos laboratory devoted to the characterization and modification of the near surfaces of materials. The primary instruments of the IBML are a tandem electrostatic accelerator, a National Electrostatics Corp. Model 9SDH, coupled with a Varian CF-3000 ion implanter. The unique organizational structure of the IBML as well as the operational characteristics of the 9SDH (after approximately 3000 h of operation) and the laboratories' research capabilities will be discussed. Examples of current research results will also be presented. 5 refs., 2 figs.

Tesmer, J.R.; Maggiore, C.J.; Parkin, D.M.

1988-01-01

344

Modifications and integration of the electronic tracking board in a pediatric emergency department.  

PubMed

Electronic health records (EHRs) are used for data storage; provider, laboratory, and patient communication; clinical decision support; procedure and medication orders; and decision support alerts. Clinical decision support is part of any EHR and is designed to help providers make better decisions. The emergency department (ED) poses a unique environment to the use of EHRs and clinical decision support. Used effectively, computerized tracking boards can help improve flow, communication, and the dissemination of pertinent visit information between providers and other departments in a busy ED. We discuss the unique modifications and decisions made in the implementation of an EHR and computerized tracking board in a pediatric ED. We discuss the changing views based on provider roles, customization to the user interface including the layout and colors, decision support, tracking board best practices collected from other institutions and colleagues, and a case study of using reminders on the electronic tracking board to drive pain reassessments. PMID:23823269

Dexheimer, Judith W; Kennebeck, Stephanie

2013-07-01

345

On the uniqueness of Kerr-Newman black holes  

NASA Astrophysics Data System (ADS)

The uniqueness of the Kerr-Newman family of black hole metrics as stationary asymptotically flat solutions to the Einstein equations coupled to a free Maxwell field is a crucial ingredient in the study of final states of the universe in general relativity. If one imposes the additional requirement that the space-time is axial-symmetric, then said uniqueness was shown by the works of B. Carter, D.C. Robinson, G.L. Bunting, and P.O. Mazur during the 1970s and 80s. In the real-analytic category, the condition of axial symmetry can be removed through S. Hawking's Rigidity Theorem. The necessary construction used in Hawking's proof, however, breaks down in the smooth category as it requires solving an ill-posed hyperbolic partial differential equation. The uniqueness problem of Kerr-Newman metrics in the smooth category is considered here following the program initiated by A. Ionescu and S. Klainerman for uniqueness of the Kerr metrics among solutions to the Einstein vacuum equations. In this work, a space-time, tensorial characterization of the Kerr-Newman solutions is obtained, generalizing an earlier work of M. Mars. The characterization tensors are shown to obey hyperbolic partial differential equations. Using the general Carleman inequality of Ionescu and Klainerman, the uniqueness of Kerr-Newman metrics is proven, conditional on a rigidity assumption on the bifurcate event horizon.

Wong, Willie Wai-Yeung

346

Non-uniqueness of Solutions to the Conformal Formulation  

E-print Network

It is well-known that solutions to the conformal formulation of the Einstein constraint equations are unique in the cases of constant mean curvature (CMC) and near constant mean curvature (near-CMC). However, the new far-from-constant mean curvature (far-from-CMC) existence results due to Holst, Nagy, and Tsogtgerel in 2008, to Maxwell in 2009, and to Dahl, Gicquaud and Humbert in 2010, are based on degree theory rather than on the (uniqueness-providing) contraction arguments that had been used for all non-CMC existence results prior to 2008. In fact, Maxwell demonstrated in 2011 that solutions are non-unique in the far-from-CMC case for certain types of low-regularity mean curvature. In this article, we investigate uniqueness properties of solutions to the Einstein constraint equations on closed manifolds using tools from bifurcation theory. For positive, constant scalar curvature and constant mean curvature, we first demonstrate existence of a critical energy density for the Hamiltonian constraint with unscaled matter sources. We then show that for this choice of energy density, the linearization of the elliptic system develops a one-dimensional kernel in both the CMC and non-CMC (near and far) cases. Using Liapunov-Schmidt reduction and standard tools from nonlinear analysis, we demonstrate that solutions to the conformal formulation with unscaled data are non-unique by determining an explicit solution curve, and by analyzing its behavior in the neighborhood of a particular solution.

Michael Holst; Caleb Meier

2012-12-04

347

On uniqueness of static Einstein-Maxwell-dilaton black holes  

E-print Network

We prove uniqueness of static, asymptotically flat spacetimes with non-degenerate black holes for three special cases of Einstein-Maxwell-dilaton theory: For the coupling ``$\\alpha = 1$'' (which is the low energy limit of string theory) on the one hand, and for vanishing magnetic or vanishing electric field (but arbitrary coupling) on the other hand. Our work generalizes in a natural, but non-trivial way the uniqueness result obtained by Masood-ul-Alam who requires both $\\alpha = 1$ and absence of magnetic fields, as well as relations between the mass and the charges. Moreover, we simplify Masood-ul-Alam's proof as we do not require any non-trivial extensions of Witten's positive mass theorem. We also obtain partial results on the uniqueness problem for general harmonic maps.

Marc Mars; Walter Simon

2002-07-03

348

Effect of site-specific modification on restriction endonucleases and DNA modification methyltransferases.  

PubMed Central

Restriction endonucleases have site-specific interactions with DNA that can often be inhibited by site-specific DNA methylation and other site-specific DNA modifications. However, such inhibition cannot generally be predicted. The empirically acquired data on these effects are tabulated for over 320 restriction endonucleases. In addition, a table of known site-specific DNA modification methyltransferases and their specificities is presented along with EMBL database accession numbers for cloned genes. PMID:7937074

McClelland, M; Nelson, M; Raschke, E

1994-01-01

349

DNA modification by sulfur: analysis of the sequence recognition specificity surrounding the modification sites  

Microsoft Academic Search

The Dnd (DNA degradation) phenotype, reflecting a novel DNA modification by sulfur in Streptomyces lividans 1326, was strongly aggravated when one (dndB) of the five genes (dndABCDE) controlling it was mutated. Electrophoretic banding patterns of a plasmid (pHZ209), reflecting DNA degradation, displayed a clear change from a preferential modi- fication site in strain 1326 to more random modifications in the

Jingdan Liang; Zhijun Wang; Xinyi He; Jialiang Li; Xiufen Zhou; Zixin Deng

2007-01-01

350

Bimodal quantitative relationships between histone modifications for X-linked and autosomal loci  

PubMed Central

Gene expression is controlled by coordinated action of many epigenetic mechanisms including covalent histone modifications. Although numerous recurrent patterns of colocalized histone modifications have been associated with specific gene expression states, interrelationships between individual modifications are largely unknown. Here, we analyze quantitative relationships between colocalized histone marks during embryonic stem cell (ESC) differentiation and find that, for autosomal genes, these densities follow bimodal patterns. Analysis of repressive H3K27me3 and activating H3K4me3 modifications reveals the expected anticorrelation between them at active promoters but an unexpected positive correlation at inactive promoters. The two trends connect in a region corresponding to bivalent genes. Interestingly, this region is characterized by maximal H3K27 methylation. Resolving gene bivalency during ESC differentiation does not conform to the expected model of two marks as counteracting and competing forces. Although activated genes acquire H3K4me3 and lose H3K27me3, repressed genes lose H3K4me3 without gaining H3K27me3. The behavior of X-linked genes also deviates from expected models. Allele-specific analysis of chromatin modifications during X-chromosome inactivation (XCI) suggests that the silencing machinery focuses on active genes and depletion of H3K4me3 and that H3K27me3 is most significant during establishment of gene silencing. Our analysis reveals nontrivial relationships between H3K4me3 and H3K27me3, reveals unique aspects of gene bivalency, and demonstrates that XCI does not conform neatly to autosomal models. PMID:23564346

Sadreyev, Ruslan I.; Yildirim, Eda; Pinter, Stefan F.; Lee, Jeannie T.

2013-01-01

351

Tissue-Specific Epigenetic Modifications in Root Apical Meristem Cells of Hordeum vulgare  

PubMed Central

Epigenetic modifications of chromatin structure are essential for many biological processes, including growth and reproduction. Patterns of DNA and histone modifications have recently been widely studied in many plant species, although there is virtually no data on the spatial and temporal distribution of epigenetic markers during plant development. Accordingly, we have used immunostaining techniques to investigate epigenetic modifications in the root apical meristem of Hordeum vulgare. Histone H4 acetylation (H4K5ac), histone H3 dimethylation (H3K4me2, H3K9me2) and DNA methylation (5mC) patterns were established for various root meristem tissues. Distinct levels of those modifications were visualised in the root cap, epidermis, cortex and vascular tissues. The lateral root cap cells seem to display the highest level of H3K9me2 and 5mC. In the epidermis, the highest level of 5mC and H3K9me2 was detected in the nuclei from the boundary of the proximal meristem and the elongation zone, while the vascular tissues were characterized by the highest level of H4K5ac. Some of the modified histones were also detectable in the cytoplasm in a highly tissue-specific manner. Immunolocalisation of epigenetic modifications of chromatin carried out in this way, on longitudinal or transverse sections, provides a unique topographic context within the organ, and will provide some answers to the significant biological question of tissue differentiation processes during root development in a monocotyledon plant species. PMID:23935955

Braszewska-Zalewska, Agnieszka J.; Wolny, Elzbieta A.; Smialek, Lukasz; Hasterok, Robert

2013-01-01

352

Deoxyribonucleic acid restriction and modification systems in Salmonella: chromosomally located systems of different serotypes.  

PubMed Central

With the use of four different phages, Salmonella strains representing 85 different serotypes were examined to determine their restriction-modification phenotype. They fell into one of three groups on this basis: group 1, those which lacked the common LT system; group 2, those in which only the LT system could be recognized; and group 3. those which possessed the LT system and at least one other system shown with some serotypes to be closely linked to serB. The specificity of the serB-linked restriction-modification system was unique for each serotype, but different strains of the same serotype expressed the same specificity. Two of the systems were shown to behave in genetic crosses as functional alleles of the S. typhimurium SB system. It is possible that these serB-linked restriction-modification systems constitute a large multiallelic series of genes extending throughout the Salmonella genus and Escherichia coli. We suggest that the division of the Salmonella into the three restriction-modification groups may be significant in defining a "biological grouping" of the different serotypes within the genus which may ultimately be useful in describing the Salmonella species. From the genetic relatedness between the genes of some of the Salmonella restriction-modification systems with those of the E. coli systems, we deduce that the restriction endonuclases produced by the Salmonella serB-linked systems are of type 1. Determination of the nucleotide sequences of the recognition sites of the restriction endonucleases of selected Salmonella systems should further our understanding of specificity with these enzymes. PMID:6243623

Bullas, L R; Colson, C; Neufeld, B

1980-01-01

353

Nonlocal actin orientation models select for a unique orientation pattern  

E-print Network

Many models have been developed to study the role of branching actin networks in motility. One important component of those models is the distribution of filament orientations relative to the cell membrane. Two mean-field models previously proposed are generalized and analyzed. In particular, we find that both models uniquely select for a dominant orientation pattern. In the linear case, the pattern is the eigenfunction associated with the principal eigenvalue. In the nonlinear case, we show there exists a unique equilibrium and that the equilibrium is locally stable. Approximate techniques are then used to provide evidence for global stability.

Daniel Smith; Jian Liu

2013-10-31

354

Fetal alcohol syndrome and secondary schizophrenia: a unique neuropathologic study.  

PubMed

We report the unique neuropathologic study of an adult brain of a patient with fetal alcohol syndrome who developed the well-recognized complication of schizophrenia in adolescence. The major finding was asymmetric formation of the lateral temporal lobes, with marked enlargement of the right superior temporal gyrus, suggesting that alcohol is preferentially toxic to temporal lobe patterning during gestation. Critical maturational changes unique to adolescence can unmask psychotic symptomatology mediated by temporal lobe pathology that has been clinically dormant since birth. Elucidating the neuropathologic basis of the secondary psychiatric disorders in fetal alcohol syndrome can help provide insight into their putative developmental origins. PMID:24563476

Stoos, Catherine; Nelsen, Laura; Schissler, Kathryn A; Elliott, Amy J; Kinney, Hannah C

2015-04-01

355

The Effects of Uniqueness-Relevant Feedback and Strength of Need for Uniqueness on the Social Behaviors and Perceptions of Individual Group Discussants.  

ERIC Educational Resources Information Center

Uniqueness theory suggests that individuals are most comfortable with the thought that they are moderately different or unique from others. To test whether individuals with a high need for uniqueness are perceived as being different from those with a low need for uniqueness, 144 college students participated in a two-part study. In part one,…

Case, Thomas L.; Rosen, Sidney

356

Optical Marking of Alcohol Induced Hemoglobin Modification  

E-print Network

It has been shown that conformational modifications of Hb induced by ethanol consumption can be visualized in optical spectra studying oxygenation kinetics of hemoglobin or mixing hemoglobin with Cibacron blue dye. Better dye affinity of blood proteins extracted from alcoholised rats with respect to those from non-alcoholised ones confirms that ethanol and its metabolites induce structural pathologies in blood protein molecules. The detected changes for the case of the posterity of intoxicated animals may be explained as a post-translation modification, as well as a disturbance of the structure and function of tissue cellular gene mechanism for the blood creation. It is established that alcohol intake during first four months leads to the decrease of fractional weight of oxyhemoglobin and to the increase of methemoglobin amount in blood. Further alcohol consumption is accompanied by recovering of the normal level of hemoglobin derivatives in blood. Normalization of the fractional weight of hemoglobin derivati...

Vlokh, R; Moroz, O; Nastishin, Yu; Dudok, K; Dudok, T; Grinchishin, N; Nechiporenko, I; Hul, A

2007-01-01

357

Surface modification of magnetic nanoparticles in biomedicine  

NASA Astrophysics Data System (ADS)

Progress in surface modification of magnetic nanoparticles (MNPs) is summarized with regard to organic molecules, macromolecules and inorganic materials. Many researchers are now devoted to synthesizing new types of multi-functional MNPs, which show great application potential in both diagnosis and treatment of disease. By employing an ever-greater variety of surface modification techniques, MNPs can satisfy more and more of the demands of medical practice in areas like magnetic resonance imaging (MRI), fluorescent marking, cell targeting, and drug delivery. Project supported by the National Natural Science Foundation of China (Grant Nos. 51125001 and 51172005), the Natural Science Foundation of Beijing,China (Grant No. 2122022), the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (Grant No. 81421004), and the Doctoral Program of the Education Ministry of China (Grant No. 20120001110078).

Chu, Xin; Yu, Jing; Hou, Yang-Long

2015-01-01

358

Chitosan Modification and Pharmaceutical/Biomedical Applications  

PubMed Central

Chitosan has received much attention as a functional biopolymer for diverse applications, especially in pharmaceutics and medicine. Our recent efforts focused on the chemical and biological modification of chitosan in order to increase its solubility in aqueous solutions and absorbability in the in vivo system, thus for a better use of chitosan. This review summarizes chitosan modification and its pharmaceutical/biomedical applications based on our achievements as well as the domestic and overseas developments: (1) enzymatic preparation of low molecular weight chitosans/chitooligosaccharides with their hypocholesterolemic and immuno-modulating effects; (2) the effects of chitin, chitosan and their derivatives on blood hemostasis; and (3) synthesis of a non-toxic ion ligand—D-Glucosaminic acid from Oxidation of D-Glucosamine for cancer and diabetes therapy. PMID:20714418

Zhang, Jiali; Xia, Wenshui; Liu, Ping; Cheng, Qinyuan; Tahirou, Talba; Gu, Wenxiu; Li, Bo

2010-01-01

359

Biological and nonbiological modifications of organophosphorus compounds*  

PubMed Central

The general types of biological reaction that are most prominent in the modification of organophosphorus compounds involve the mixed-function oxidases, hydrolases, or transferases. In certain cases, more than one of these reactions may be involved at the same site on the pesticide molecule. Examples of various organophosphorus pesticides that are altered by oxidation, hydrolysis, alkyl- or aryl-group transfer, reduction, and conjugation are discussed. The increase or decrease in toxicity of a pesticide that can result from biological modification is emphasized. Non-biological transformations of organophosphorus compounds involve the effect ou the compounds of such factors as light, air, temperature, and solvent. These factors are discussed with special emphasis on desulfuration, rearrangement, and oxidation. PMID:4938021

Dauterman, W. C.

1971-01-01

360

Effective Theories and Modifications of Gravity  

E-print Network

We live at a time of contradictory messages about how successfully we understand gravity. General Relativity seems to work very well in the Earth's immediate neighborhood, but arguments abound that it needs modification at very small and/or very large distances. This essay tries to put this discussion into the broader context of similar situations in other areas of physics, and summarizes some of the lessons which our good understanding of gravity in the solar system has for proponents for its modification over very long and very short distances. The main message is that effective theories, in the technical sense of `effective', provide the natural language for testing proposals, and so are also effective in the colloquial sense.

C. P. Burgess

2010-02-23

361

Tissue modification with feedback: the smart scalpel  

NASA Astrophysics Data System (ADS)

While feedback control is widespread throughout many engineering fields, there are almost no examples of surgical instruments that utilize a real-time detection and intervention strategy. This concept of closed loop feedback can be applied to the development of autonomous or semi- autonomous minimally invasive robotic surgical systems for efficient excision or modification of diseased tissue. Spatially localized regions of the tissue are first probed to distinguish pathological from healthy tissue based on differences in histochemical and morphological properties. Energy is directed to only the diseased tissue, minimizing collateral damage by leaving the adjacent healthy tissue intact. Continuous monitoring determines treatment effectiveness and, if needed, enables real-time treatment modifications to produce optimal therapeutic outcomes. The present embodiment of this general concept is a microsurgical instrument we call the Smart Scalpel, designed to treat skin angiodysplasias such as port wine stains. Other potential Smart Scalpel applications include psoriasis treatment and early skin cancer detection and intervention.

Sebern, Elizabeth L.; Brenan, Colin J. H.; Anderson, R. Rox; Hunter, Ian W.

1998-10-01

362

Shanker formulation needs modification at high pressures  

NASA Astrophysics Data System (ADS)

It is found that the Shanker formulation widely used in the literature to study the thermal expansion of solids (at constant pressure) works under the effect of pressure (at constant temperature) up to a limited range (?30 kbar). Large deviations occur, when the pressure range is increased, demonstrating the failure of the relation under high pressure (at constant temperature). We, therefore, propose the modification in the formulation on an empirical basis. The modified relation is used to study the compression behavior of ionic solids viz. NaF, NaCl, NaBr and NaI crystals. The results obtained with the modified relation are compared with the experimental data in the light of the results obtained from Shanker formulation and Birch Murnaghan equation of state. A good agreement between theory and experiment demonstrates the validity of the modification presented in the present note.

Kumar, Manoj; Kumar, M.

2007-04-01

363

Histone modifications: implications in renal cell carcinoma  

PubMed Central

In 2012, an estimated 64,770 men and women were diagnosed with malignancy of the kidney and renal pelvis, of which 13,570 succumbed to their disease. Common genetic aberrations in renal cell carcinomas (RCCs) include loss of function of the VHL gene in clear-cell RCC, overexpression of the c-MET gene in papillary RCC type I, deficiency in the FH gene in papillary RCC type II and loss of heterozygozity of the BHD gene in chromophobe RCC. Recent studies illustrate epigenetic silencing of VHL, as well as alterations in histone modifications and their governing enzymes. The possibility of reversing these epigenetic marks has resulted in efforts to target these changes by utilizing inhibitors of HDACs, DNA methyltransferases and, recently, histone methyltransferases in preclinical and clinical studies. This article focuses on potential therapeutic interventions, and the implications of histone modifications and related enzyme alterations in RCC. PMID:23895657

Ramakrishnan, Swathi; Ellis, Leigh; Pili, Roberto

2013-01-01

364

40 CFR 790.68 - Modification of consent agreements.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Modification of consent agreements. 790.68 Section... PROCEDURES GOVERNING TESTING CONSENT AGREEMENTS AND TEST RULES Implementation, Enforcement and Modification of Consent Agreements § 790.68...

2012-07-01

365

40 CFR 790.68 - Modification of consent agreements.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Modification of consent agreements. 790.68 Section... PROCEDURES GOVERNING TESTING CONSENT AGREEMENTS AND TEST RULES Implementation, Enforcement and Modification of Consent Agreements § 790.68...

2013-07-01

366

40 CFR 790.68 - Modification of consent agreements.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Modification of consent agreements. 790.68 Section... PROCEDURES GOVERNING TESTING CONSENT AGREEMENTS AND TEST RULES Implementation, Enforcement and Modification of Consent Agreements § 790.68...

2014-07-01

367

36 CFR 294.27 - Corrections and modifications.  

Code of Federal Regulations, 2012 CFR

...27 Section 294.27 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SPECIAL AREAS Idaho Roadless Area Management § 294.27 Corrections and modifications. Correction or modification of designations...

2012-07-01

368

36 CFR 294.27 - Corrections and modifications.  

Code of Federal Regulations, 2011 CFR

...27 Section 294.27 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SPECIAL AREAS Idaho Roadless Area Management § 294.27 Corrections and modifications. Correction or modification of designations...

2011-07-01

369

23 CFR 630.110 - Modification of original agreement.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Modification of original agreement. 630.110 Section 630.110 Highways...PROCEDURES Project Authorization and Agreements § 630.110 Modification of original agreement. (a) When changes are needed to...

2010-04-01

370

46 CFR 535.406 - Modification of agreements.  

Code of Federal Regulations, 2010 CFR

...2010-10-01 false Modification of agreements. 535.406 Section 535.406 ...CARRIER AND MARINE TERMINAL OPERATOR AGREEMENTS SUBJECT TO THE SHIPPING ACT OF 1984 Filing of Agreements § 535.406 Modification of...

2010-10-01

371

18 CFR 806.8 - Waiver/modification.  

Code of Federal Regulations, 2010 CFR

...modification. 806.8 Section 806.8 Conservation of Power and Water Resources SUSQUEHANNA RIVER BASIN COMMISSION REVIEW AND APPROVAL OF PROJECTS General Provisions § 806.8 Waiver/modification. The Commission may, in its...

2010-04-01

372

"Click" Modification of Silica Surfaces and Glass Microfluidic Channels  

E-print Network

"Click" Modification of Silica Surfaces and Glass Microfluidic Channels Shaurya Prakash, Timothy M This paper demonstrates a chemical surface modification method for covalent attachment of various polymers for microfluidic chips include electrophoretic separa- tions, DNA and protein analyses, PCR amplification

373

21 CFR 640.74 - Modification of Source Plasma.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Modification of Source Plasma. 640.74 Section 640.74 Food and...FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.74 Modification of Source Plasma. (a) Upon approval by the...

2010-04-01

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21 CFR 640.74 - Modification of Source Plasma.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Modification of Source Plasma. 640.74 Section 640.74 Food and...FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.74 Modification of Source Plasma. (a) Upon approval by the...

2013-04-01

375

21 CFR 640.74 - Modification of Source Plasma.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 false Modification of Source Plasma. 640.74 Section 640.74 Food and...FOR HUMAN BLOOD AND BLOOD PRODUCTS Source Plasma § 640.74 Modification of Source Plasma. (a) Upon approval by the...

2014-04-01

376

RESEARCH ARTICLE Open Access Histone modification pattern evolution after yeast  

E-print Network

RESEARCH ARTICLE Open Access Histone modification pattern evolution after yeast gene duplication for evolutionary innovations. Many studies evidenced that genetic regulatory network evolved rapidly shortly after gene duplication. In this study, we conducted detailed analyses on yeast histone modification (HM

Gu, Xun

377

Evolutionary modification of development in mammalian teeth: Quantifying gene  

E-print Network

Evolutionary modification of development in mammalian teeth: Quantifying gene expression patterns Geographic Information Systems. We investi- gated how genetic markers for epithelial signaling centers known, usually involve little initial modification of morphology. One system that offers promise for linking

Jernvall, Jukka

378

76 FR 51878 - Modifications of Certain Derivative Contracts; Correction  

Federal Register 2010, 2011, 2012, 2013, 2014

...1545-BK14 Modifications of Certain Derivative Contracts; Correction AGENCY: Internal...a transfer or assignment of certain derivative contracts does not result in an exchange...1001-4T Modifications of certain derivative contracts...

2011-08-19

379

43 CFR 3932.10 - Lease size modification.  

Code of Federal Regulations, 2011 CFR

...Lands (Continued) BUREAU OF LAND MANAGEMENT, DEPARTMENT OF THE INTERIOR RANGE MANAGEMENT (4000) MANAGEMENT OF OIL SHALE EXPLORATION AND LEASES Lease Modifications and Readjustments § 3932.10 Lease size modification....

2011-10-01

380

13 CFR 304.3 - District modification and termination.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false District modification and termination. 304.3 Section 304.3 Business Credit and Assistance ECONOMIC DEVELOPMENT...DEPARTMENT OF COMMERCE ECONOMIC DEVELOPMENT DISTRICTS § 304.3 District modification and termination....

2012-01-01

381

13 CFR 304.3 - District modification and termination.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 false District modification and termination. 304.3 Section 304.3 Business Credit and Assistance ECONOMIC DEVELOPMENT...DEPARTMENT OF COMMERCE ECONOMIC DEVELOPMENT DISTRICTS § 304.3 District modification and termination....

2014-01-01

382

13 CFR 304.3 - District modification and termination.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false District modification and termination. 304.3 Section 304.3 Business Credit and Assistance ECONOMIC DEVELOPMENT...DEPARTMENT OF COMMERCE ECONOMIC DEVELOPMENT DISTRICTS § 304.3 District modification and termination....

2011-01-01

383

13 CFR 304.3 - District modification and termination.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false District modification and termination. 304.3 Section 304.3 Business Credit and Assistance ECONOMIC DEVELOPMENT...DEPARTMENT OF COMMERCE ECONOMIC DEVELOPMENT DISTRICTS § 304.3 District modification and termination....

2013-01-01

384

13 CFR 304.3 - District modification and termination.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false District modification and termination. 304.3 Section 304.3 Business Credit and Assistance ECONOMIC DEVELOPMENT...DEPARTMENT OF COMMERCE ECONOMIC DEVELOPMENT DISTRICTS § 304.3 District modification and termination....

2010-01-01

385

Materials Modification in Nanotechnology: Laboratory Activities  

NSDL National Science Digital Library

This page from the Nanotechnology Applications and Career Knowledge (NACK) Center presents a series of laboratory activities on materials modification in nanotechnology. An overview of the activities is provided. The laboratory exercises cover microfluidics, furnace oxidation, ion implantation simulation, siction and doping. All are available for download in .DOC file format. This and all other valuable resources from the NACK Center require a fast, easy, free log-in.

386

Epigenetic modifications in pluripotent and differentiated cells  

Microsoft Academic Search

Epigenetic modifications constitute a complex regulatory layer on top of the genome sequence. Pluripotent and differentiated cells provide a powerful system for investigating how the epigenetic code influences cellular fate. High-throughput sequencing of these cell types has yielded DNA methylation maps at single-nucleotide resolution and many genome-wide chromatin maps. In parallel to epigenome mapping efforts, remarkable progress has been made

Alexander Meissner

2010-01-01

387

Magnetic field modification of optical magnetic dipoles.  

PubMed

Acting on optical magnetic dipoles opens novel routes to govern light-matter interaction. We demonstrate magnetic field modification of the magnetic dipolar moment characteristic of resonant nanoholes in thin magnetoplasmonic films. This is experimentally shown through the demonstration of the magneto-optical analogue of Babinet's principle, where mirror imaged MO spectral dependencies are obtained for two complementary magnetoplasmonic systems: holes in a perforated metallic layer and a layer of disks on a substrate. PMID:25646869

Armelles, Gaspar; Caballero, Blanca; Cebollada, Alfonso; Garcia-Martin, Antonio; Meneses-Rodríguez, David

2015-03-11

388

Surface erosion and modification by energetic ions  

Microsoft Academic Search

Surface erosion and modification by energetic highly charged and cluster ions are important in the development of semiconductor devices, TeV accelerators, fission and fusion reactors, and in the development of extreme ultra-violet lithography devices. Gas cluster ion beam (GCIB) surface treatment can significantly mitigate the high-gradient electric vacuum breakdown of rf-cavities. GCIB can also mitigate Q-slope drop in superconducting Nb-cavities.

Z. Insepov; J. Norem; D. R. Swenson; A. Hassanein; Epion Corp

2008-01-01

389

Genetic modification of respiratory capacity in potato  

Microsoft Academic Search

Mitochondrial respiration was altered in transgenic potato (so- lanum tuberosum) lines by overexpression of the alternative oxidase Aoxl gene. Overexpressing lines showed higher levels of Aoxl mRNA, increased levels of alternative oxidase protein(s), and an ~~sual higher molecular weight PolYPePtide, which maY be a normal processing\\/modification intermediate. Evidence suggests that the alternative oxidase protein is further processed\\/modified beyond removal of

Carrie Hiser; Philipp Kapranov; Lee Mclntosh

1996-01-01

390

Laser modification of thermally sprayed coatings  

NASA Astrophysics Data System (ADS)

Experimental results are reported on the modification of thermally sprayed coatings on steels and aluminum alloys using pulsed YAG and CW CO2 lasers. In particular, results obtained for self-fluxing Ni9CrBSi powders, ZRO2 ceramic, and titanium are examined. It is shown that the laser treatment of thermally sprayed coatings significantly improves their physicomechanical properties; it also makes it possible to obtain refractory coatings on low-melting substrates with good coating-substrate adhesion.

Uglov, A. A.; Fomin, A. D.; Naumkin, A. O.; Pekshev, P. Iu.; Smurov, I. Iu.

1987-08-01

391

Organization of restriction-modification systems.  

PubMed Central

The genes for over 100 restriction-modification systems have now been cloned, and approximately one-half have been sequenced. Despite their similar function, they are exceedingly heterogeneous. The heterogeneity is evident at three levels: in the gene arrangements; in the enzyme compositions; and in the protein sequences. This paper summarizes the main features of the R-M systems that have been cloned. PMID:2041731

Wilson, G G

1991-01-01

392

Aging and Non-sirtuin Histone Modifications  

Microsoft Academic Search

\\u000a Histones, once thought of as static structural elements, are now known to be dynamic and integral elements of the machinery\\u000a responsible for regulating gene transcription. Modification of histones and\\/or DNA can alter the strength of their association\\u000a and thus, together, modulate transcriptional activity. Acetylation of histones neutralizes their positively charged, lysine-rich\\u000a amino-terminal tails, loosening the histone–DNA contacts, thus making DNA

Inga Kadish

393

Hydrothermal modification of zirconia-silica gels  

Microsoft Academic Search

Porous materials based on the complex oxides SiOâ-ZrOâ produced by various methods are of interest as acid-base catalysts and ion-exchangers. In this work the authors studied hydrothermal modification of the texture and phase composition of coprecipitated zirconia-silica gels. The porosity parameters were determined from the methanol and hexane vapor adsorption isotherms and by chromatography from thermal argon desorption. The crystal

V. V. Sidorchuk; V. M. Chertov

1987-01-01

394

Cone photoreceptor sensitivities and unique hue chromatic responses: correlation and causation imply the physiological basis of unique hues.  

PubMed

This paper relates major functions at the start and end of the color vision process. The process starts with three cone photoreceptors transducing light into electrical responses. Cone sensitivities were once expected to be Red Green Blue color matching functions (to mix colors) but microspectrometry proved otherwise: they instead peak in yellowish, greenish, and blueish hues. These physiological functions are an enigma, unmatched with any set of psychophysical (behavioral) functions. The end-result of the visual process is color sensation, whose essential percepts are unique (or pure) hues red, yellow, green, blue. Unique hues cannot be described by other hues, but can describe all other hues, e.g., that hue is reddish-blue. They are carried by four opponent chromatic response curves but the literature does not specify whether each curve represents a range of hues or only one hue (a unique) over its wavelength range. Here the latter is demonstrated, confirming that opponent chromatic responses define, and may be termed, unique hue chromatic responses. These psychophysical functions also are an enigma, unmatched with any physiological functions or basis. Here both enigmas are solved by demonstrating the three cone sensitivity curves and the three spectral chromatic response curves are almost identical sets (Pearson correlation coefficients r from 0.95-1.0) in peak wavelengths, curve shapes, math functions, and curve crossover wavelengths, though previously unrecognized due to presentation of curves in different formats, e.g., log, linear. (Red chromatic response curve is largely nonspectral and thus derives from two cones.) Close correlation combined with deterministic causation implies cones are the physiological basis of unique hues. This match of three physiological and three psychophysical functions is unique in color vision. PMID:24204755

Pridmore, Ralph W

2013-01-01

395

Discovery of GW870086: a potent anti-inflammatory steroid with a unique pharmacological profile  

PubMed Central

Background and Purpose Glucocorticoids are highly effective therapies for a range of inflammatory diseases. Advances in the understanding of the diverse molecular mechanisms underpinning glucocorticoid action suggest that anti-inflammatory molecules with reduced side effect liabilities can be discovered. Here we set out to explore whether modification of the 17? position of the steroid nucleus could generate molecules with a unique pharmacological profile and to determine whether such molecules would retain anti-inflammatory activity. Experimental Approach The pharmacological properties of GW870086 were compared with fluticasone propionate (FP) using a range of cellular and in vivo model systems, including extensive gene expression profiling. Key Results GW870086 repressed inflammatory cytokine release from lung epithelial cells in a similar manner to FP but antagonized the effect of dexamethasone on MMTV-driven reporter gene transactivation. GW870086 had a strong effect on the expression of some glucocorticoid-regulated genes (such as PTGS2), while having minimal impact on the expression of other known target genes (such as SGK). GW870086 retained the ability to strengthen tight junctions in epithelial cell culture but, unlike FP, was unable to protect the culture from elastase-mediated damage. In murine models of irritant-induced contact dermatitis and ovalbumin-induced allergic inflammation, GW870086 showed comparable anti-inflammatory efficacy to FP. Conclusion and Implications GW870086 is a potent anti-inflammatory compound with a unique ability to regulate only a subset of those genes that are normally affected by classical glucocorticoids. It has the potential to become a new topical steroid with a different safety profile to existing therapies. PMID:23639214

Uings, I J; Needham, D; Matthews, J; Haase, M; Austin, R; Angell, D; Leavens, K; Holt, J; Biggadike, K; Farrow, S N

2013-01-01

396

Chromatin modifications remodel cardiac gene expression.  

PubMed

Signalling and transcriptional control involve precise programmes of gene activation and suppression necessary for cardiovascular physiology. Deep sequencing of DNA-bound transcription factors reveals a remarkable complexity of co-activators or co-repressors that serve to alter chromatin modification and regulate gene expression. The regulated complexes characterized by genome-wide mapping implicate the recruitment and exchange of proteins with specific enzymatic activities that include roles for histone acetylation and methylation in key developmental programmes of the heart. As for transcriptional changes in response to pathological stress, co-regulatory complexes are also differentially utilized to regulate genes in cardiac disease. Members of the histone deacetylase (HDAC) family catalyse the removal of acetyl groups from proteins whose pharmacological inhibition has profound effects preventing heart failure. HDACs interact with a complex co-regulatory network of transcription factors, chromatin-remodelling complexes, and specific histone modifiers to regulate gene expression in the heart. For example, the histone methyltransferase (HMT), enhancer of zeste homolog 2 (Ezh2), is regulated by HDAC inhibition and associated with pathological cardiac hypertrophy. The challenge now is to target the activity of enzymes involved in protein modification to prevent or reverse the expression of genes implicated with cardiac hypertrophy. In this review, we discuss the role of HDACs and HMTs with a focus on chromatin modification and gene function as well as the clinical treatment of heart failure. PMID:24812277

Mathiyalagan, Prabhu; Keating, Samuel T; Du, Xiao-Jun; El-Osta, Assam

2014-07-01

397

Electrostatic Surface Modifications to Improve Gene Delivery  

PubMed Central

Importance of the field Gene therapy has the potential to treat a wide variety of diseases including genetic diseases and cancer. Areas covered in this review This review introduces biomaterials used for gene delivery and then focuses on the use of electrostatic surface modifications to improve gene delivery materials. These modifications have been used to stabilize therapeutics in vivo, add cell-specific targeting ligands, and promote controlled release. Coatings of nanoparticles and microparticles as well as non-particulate surface coatings are covered in this review. Electrostatic principles are crucial for the development of multilayer delivery structures fabricated by the layer-by-layer method. What the reader will gain The reader will gain knowledge about the composition of biomaterials used for surface modifications and how these coatings and multilayers can be utilized to improve spatial control and efficiency of delivery. Examples are shown for the delivery of nucleic acids, including DNA and siRNA, to in vitro and in vivo systems. Take home message The versatile and powerful approach of electrostatic coatings and multilayers will lead to the development of enhanced gene therapies. PMID:20201712

Shmueli, Ron B.; Anderson, Daniel G.

2010-01-01

398

Particle Distribution Modification by Low Amplitude Modes  

SciTech Connect

Modification of a high energy particle distribution by a spectrum of low amplitude modes is investigated using a guiding center code. Only through resonance are modes effective in modifying the distribution. Diagnostics are used to illustrate the mode-particle interaction and to find which effects are relevant in producing significant resonance, including kinetic Poincare plots and plots showing those orbits with time averaged mode-particle energy transfer. Effects of pitch angle scattering and drag are studied, as well as plasma rotation and time dependence of the equilibrium and mode frequencies. A specific example of changes observed in a DIII-D deuterium beam distribution in the presence of low amplitude experimentally validated Toroidal Alfven (TAE) eigenmodes and Reversed Shear Alfven (RSAE) eigenmodes is examined in detail. Comparison with experimental data shows that multiple low amplitude modes can account for significant modification of high energy beam particle distributions. It is found that there is a stochastic threshold for beam profile modification, and that the experimental amplitudes are only slightly above this threshold.

R.B. White, N. Gorelenkov, W.W. Heidbrink, and M.A. Van Zeeland

2009-08-28

399

The MacNeille completion of a uniquely complemented lattice  

E-print Network

regarding the axiomatics of Boolean algebras led Huntington to conjec- ture, in 1904, that every uniquely complemented lattice was distributive. By 1940, Huntington's conjecture had been veri ed for the classes of the results mentioned above and of the history of Huntington's conjecture, see 6] and 1]. Glivenko's theorem

Harding, John

400

Uniqueness results for the Minkowski problem extended to hedgehogs  

E-print Network

Uniqueness results for the Minkowski problem extended to hedgehogs by Yves Martinez-Maure Abstract.- The classical Minkowski problem has a natural extension to hedgehogs, that is to Minkowski differences of closed to hedgehogs, that is to Minkowski differences H = K-L of closed convex hypersurfaces K, L Rn+1 , at least

Paris-Sud XI, Université de

401

Uniqueness results for the Minkowski problem extended to hedgehogs  

E-print Network

Uniqueness results for the Minkowski problem extended to hedgehogs by Yves Martinez-Maure Abstract.- The classical Minkowski problem has a natural extension to hedgehogs, that is to Minkowski differences of closed is of class Cm+1, for every ]0, 1[. This classical Minkowski problem has a natural extension to hedgehogs

402

Uniqueness results for the Minkowski problem extended to hedgehogs  

E-print Network

Uniqueness results for the Minkowski problem extended to hedgehogs by Yves Martinez-Maure Abstract.- The classical Minkowski problem has a natural extension to hedgehogs, that is to Minkowski differences of closed extension to hedgehogs, that is to Minkowski differences H = K-L of closed convex hypersurfaces K, L Rn+1

Paris-Sud XI, Université de

403

PATHWISE UNIQUENESS FOR SINGULAR SDEs DRIVEN BY STABLE PROCESSES  

E-print Network

is a positive constant. The second example is L = (L1 t , . . . , Ld t ), where L1, . . . , Ld are independent-a.s.) and d 1. Currently, there is a great interest in understanding pathwise uniqueness for SDEs when b|) , u Rd , t 0, (1.3) where k is a positive constant. Martingale problems for SDEs driven by (L1

404

The Guatemalan Beaded Lizard: Endangered Inhabitant of a Unique Ecosystem  

Microsoft Academic Search

he semiarid Motagua Valley in Guatemala is one of the most endangered and unique ecosystems in the world. This region receives the lowest average rainfall in Central America (ca. 500 mm) and is characterized by many endemic species. This region once occupied about 200,000 ha, most of which is now a heterogeneous landscape of crops, grasslands, thornscrub, and very dry

Daniel Ariano-Sánchez

405

Utilization of the texture uniqueness cue in Xenophon Zabulis1  

E-print Network

Utilization of the texture uniqueness cue in stereo Xenophon Zabulis1 Informatics and Telematics Institute, Centre for Research and Technology Hellas xenophon@iti.gr 1 Introduction The cue to depth due after #12;2 Xenophon Zabulis backprojecting them onto a hypothetical surface. Space-sweeping methods [17

Zabulis, Xenophon

406

ORIGINAL ARTICLE Co-habiting amphibian species harbor unique skin  

E-print Network

ORIGINAL ARTICLE Co-habiting amphibian species harbor unique skin bacterial communities in wild four pond habitats in Colorado, USA, where multiple amphibian species were present. In total, 32 amphibian individuals were sampled from three different species including northern leopard frogs (Lithobates

McKenzie, Valerie

407

The unique Antarctic atmosphere: implications for adaptive optics  

E-print Network

The unique Antarctic atmosphere: implications for adaptive optics Jon S. Lawrence1 , Michael C, USA Abstract. The turbulence structure of the atmosphere is the primary limitation to adaptive optics. The potential for adaptive optics correction on extremely large telescopes located at Dome C station

Ashley, Michael C. B.

408

Characterization, Similarity Score and Uniqueness Associated with Perspiration Pattern  

Microsoft Academic Search

Vulnerabilities in biometric systems including spoofing has emerged as an important issue. The focus of this work is on characteri- zation of 'perspiration pattern' in a time-series of fingerprint images for liveness detection. By using information in the high pass bands of the im- ages the similarity score for the two images is calculated to determine the uniqueness of the

Aditya Abhyankar; Stephanie A. C. Schuckers

2005-01-01

409

The Differential Impact of Unique Behavioral and Psychological Symptoms  

E-print Network

The Differential Impact of Unique Behavioral and Psychological Symptoms for the Dementia Caregiver individual BPSD, categorized based on how they may affect caregivers, impact depressive symptoms for dementia Symptoms on Dementia Caregivers increasing burden and evoking empathy for the patient. (Am J Geriatr

410

Genome analysis of the platypus reveals unique signatures of evolution  

E-print Network

ARTICLES Genome analysis of the platypus reveals unique signatures of evolution A list of authors and their affiliations appears at the end of the paper We present a draft genome sequence of the platypus. For example, platypuses have a coat of fur adapted to an aquatic lifestyle; platypus females lactate, yet lay

Ray, David

411

Marketing the Uniqueness of Small Towns. Small Town Strategy.  

ERIC Educational Resources Information Center

A small town can strengthen its local economy as a result of business people and concerned citizens collectively identifying that community's uniqueness and then capitalizing on it via advertising, personal selling, sales promotion, or publicity. This publication relates the science of marketing to communities. Seven simple techniques are provided…

Hogg, David H.; Dunn, Douglas

412

1 INTRODUCTION Oil sand has unique properties exhibits performance  

E-print Network

1 INTRODUCTION Oil sand has unique properties exhibits performance akin to sandstone in winter seated on oil sand can sink after a number of cycles with ground softening oc- curring rapidly due true for unconsolidated sands such as oil sand. 2 ASSUMPTIONS Following the work of Sharif-Abadi (2006

Joseph, Tim Grain

413

Mentoring During Residency Education A Unique Challenge for the Surgeon?  

Microsoft Academic Search

A mentor serves as role model, counselor, and advocate for an understudy or protégé. The art and science of mentoring have been investigated most thoroughly in the educational literature, yet there are unique situational and individual considerations in the surgical arena that may warrant special consideration. The general attributes of successful mentors are not foreign to academic surgeons but may

Vincent D. Pellegrini

414

Elementary Business Statistics Unique Number 04360, 04365, 04370  

E-print Network

STA309 Elementary Business Statistics Unique Number 04360, 04365, 04370 PROFESSOR Dr. Greenberg.306 E-mail: Betsy.Greenberg@utexas.edu TEACHING ASSISTANTS Prana Narayana Xiao Han Email: prana.n88Pal, a credit card, or an Access Code that may have been included with your textbook purchase. In addition

Ghosh, Joydeep

415

IS THE TURING JUMP UNIQUE? MARTIN'S CONJECTURE, AND COUNTABLE BOREL  

E-print Network

MARKS In 1936, Alan Turing wrote a remarkable paper giving a negative answer to HilbertIS THE TURING JUMP UNIQUE? MARTIN'S CONJECTURE, AND COUNTABLE BOREL EQUIVALENCE RELATIONS ANDREW's Entscheidungsproblem [29]. Restated with modern terminology and in its relativized form, Turing showed that given any

Marks, Andrew

416

FRESIP project observations of cataclysmic variables: A unique opportunity  

NASA Technical Reports Server (NTRS)

FRESIP Project observations of cataclysmic variables would provide unique data sets. In the study of known cataclysmic variables they would provide extended, well sampled temporal photometric information and in addition, they would provide a large area deep survey; obtaining a complete magnitude limited sample of the galaxy in the volume cone defined by the FRESIP field of view.

Howell, Steve B.

1994-01-01

417

Signed and Spoken Language: A Unique Underlying System?*  

E-print Network

333 Signed and Spoken Language: A Unique Underlying System?* SHARON PEPERKAM P and JACQUES M EHLER of the LANGUAGE AND SPEECH, 1999, 42 (2­3), 333­ 346 ABSTRACT Sign language has only recently become a topic fields; in particular, we compare spoken and signed language by looking at data concerning either

Mehler, Jacques

418

Non-uniqueness problem in estimating original gas in place  

E-print Network

to illustrate the non-uniqueness performance. In the first model, which is the forward model, we input the rate schedule and we obtain the pressure performance throughout the production history. In the second model, which is the inverse model, we assume a fake...

El-Ahmady, Mohamed Hamed

2000-01-01

419

12 Victorian Supplement 2010 Victoria's unique geothermal option  

E-print Network

12 Victorian Supplement 2010 Victoria's unique geothermal option Prof Mike Sandiford Professor Australia's `hot rocks'make it one of the best prospects for enhanced geothermal energy anywhere's most exciting geothermal prospects. Extracted from the ground, South Australian uranium could easily

Sandiford, Mike

420

New Proofs of the Uniqueness of Extremal Noneven Digraphs  

E-print Network

Digraphs Chjan C. Lim and Gregory K. Van Patten-theoretic proof of the uniqueness of extrem* *al noneven digraphs, a result first obtained by Gibson. The method of proof is based on mathematical ind* *uction on the number N of vertices in the digraphs

Lim, Chjan C.

421

Unique Structural Features Facilitate Lizard Tail Kristian W. Sanggaard1  

E-print Network

Unique Structural Features Facilitate Lizard Tail Autotomy Kristian W. Sanggaard1 , Carl Chr shedding of a body part; a renowned example is tail loss among lizards as a response to attempted predation. Although many aspects of lizard tail autotomy have been studied, the detailed morphology and mechanism

Schierup, Mikkel Heide

422

Laboratory and Human Exposure Evaluation of Unique Sunscreen  

Microsoft Academic Search

Synapsis-A screening test was developed for efficacy of SUNSCREEN FORMULATIONS which was based on ULTRAVIOLET analysis of alcohol extracts taken from skin treated with sunscreen. This type of analysis showed the superior retention of some unique sun- screen formulations in tests where the subject's forearms were subjected to water sprays and also in swimming tests wherein the formulation was applied

A. F. STEINHAUER

423

Unique Sensor Plane Maps Invisible Toxins for First Responders  

ScienceCinema

A unique airborne emergency response tool, ASPECT is a Los Alamos/U.S. Environmental Protection Agency project that can put chemical and radiological mapping tools in the air over an accident scene. The name ASPECT is an acronym for Airborne Spectral Photometric Environmental Collection Technology.

None

2010-01-08

424

LISTUNIQ: Stata module: returns unique words in list  

Microsoft Academic Search

returns unique words in list. There is nothing more to say about it. For those with Stata v6 on an internet-accessible machine, install by typing .net cd http:\\/\\/www.fss.uu.nl\\/soc\\/iscore\\/stata\\/ then .net install listuniq

Jeroen Weesie

1999-01-01

425

Physical layer design issues unique to cognitive radio systems  

Microsoft Academic Search

Cognitive radio systems offer the opportunity to improve spectrum utilization by detecting unoccupied spectrum bands and adapting the transmission to those bands while avoiding the interference to primary users. This novel approach to spectrum access introduces unique functions at the physical layer: reliable detection of primary users and adaptive transmission over a wide bandwidth. In this paper, we address design

Danijela Cabric; R. W. Brodersen

2005-01-01

426

Duplicate bladder exstrophy: a unique approach to initial repair  

Microsoft Academic Search

Objectives. To describe a unique approach to the management of duplicate bladder exstrophy combining initial bladder closure and epispadias repair. Bladder exstrophy has been successfully managed by staged surgical repair with early bladder closure, subsequent epispadias repair, and, finally, bladder neck reconstruction. Duplicate bladder exstrophy is a rare variant of the exstrophy complex with fewer than 20 cases reported.Methods. A

Michael D Fabrizio; Stephen E Strup; R. Bruce Filmer; John Noseworthy; John P Gearhart

1999-01-01

427

Proposing Perceptions?based Unique Marketing Strategies for Gamblers  

Microsoft Academic Search

This study is unique in suggesting lucrative markets based on perception?driven gambling behavior. It examines dynamism in gambling behavior based on three perception?based groups: “agreed” (those who agree with the socioeconomic and environmental benefits), “disagreed” (those who disagree with the same), and “neutral” (those who have a neutral attitude toward them). Gambling behavior is used as a proxy for the

Deepak Chhabra; Kathy Andereck

2009-01-01

428

Countering Identity Theft Through Digital Uniqueness, Location Cross-Checking,  

E-print Network

Countering Identity Theft Through Digital Uniqueness, Location Cross-Checking, and Funneling C. van Stubblebine Research Labs, Madison, NJ, USA Abstract. One of today's fastest growing crimes is identity theft ­ the unauthorized use and exploitation of another individual's identity- corroborating information

Van Oorschot, Paul

429

Riparian Ecosystems: Conservation of Their Unique Characteristics1  

E-print Network

Riparian Ecosystems: Conservation of Their Unique Characteristics1 Katherine Carter Ewe12 Abstract.--Riparian ecosystems have two essential characteristics: laterally flowing water that rises in hydroperiod or amplitude of water level fluc~uation produce the most dramatic changes in riparian communities

430

Across the Nation: Unique Delivery and Inventive Approaches  

ERIC Educational Resources Information Center

In this article, American Association of Community Colleges member institutions provide information on the collaborative efforts in allied health programs between their colleges and the communities they serve. These are but a fraction of the inventive and unique programs community colleges across the U.S. offer to support the health and wellness…

Fick, Jill; McKeown, Patricia; Whiteside, Ann B.; Paneitz, Becky; Flemming, Sondra; Wolf, Toni; West-Sands, Leslie; Gray, Patricia M.; Orre, Deborah J.; Adams, Ann-Marie

2004-01-01

431

TOXICOLOGY TESTING OF THE UNIQUE RADIOLYTIC PRODUCT 2-DODECYLCYCLOBUTANONE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Treatment of foods containing fatty acids, including meat and poultry, with ionizing radiation can lead to the formation of a class of chemicals called 2-alkylcyclobutanones (2-ACBs) that are unique to irradiated foods. The major 2-ACB formed in irradiated meat is 2 dodecylcyclobutanone (2-DCB), wh...

432

Uniqueness of two phaseless inverse acoustics problems in 3-d  

E-print Network

Uniqueness is proven for two 3-d inverse problems of the determination of the spatially distributed sound speed in the frequency dependent acoustic PDE. The main new point is the assumption that only the modulus of the scattered complex valued wave field is measured on a certain set.

Michael V. Klibanov

2013-03-29

433

Gandhi's Nonviolent Rhetorical Perspective: A Unique Strategy for Peace Communication.  

ERIC Educational Resources Information Center

Analysis of Mohandas Karamchand Gandhi's philosophy and rhetoric during a particular campaign for social change will show that his strategies for social change, commonly referred to as "Satyagraha," are rooted in a unique rhetorical perspective. Gandhi repeatedly warned against the use of violent speech and acts, and he has prescribed and…

Bode, Robert Allen

434

On the uniqueness of scales derived from canonical representations  

Microsoft Academic Search

In PFANZAGL [1968] a general theory of deriving scales from canonical representations was developed. In this paper we shall solve some mathematical questions connected with the uniqueness of these scales. To illustrate the scaling problem in question, let us consider the example of mental tests. Let A be a set of dichotomous items, B a set of subjects. As usual,

J. Aczel; D. Ž. Djokovi?; J. Pfanzagl

1970-01-01

435

Occupationally Unique Interests in Scales on the Strong Interest Inventory  

Microsoft Academic Search

This study uncovered new occupationally specific dimensions that emerged from exploratory factor analysis of the female and male Business Education Teacher Occupational Scales of the Strong Interest Inventory (Strong; Harmon, Hansen, Borgen, & Hammer, 1994). The occupationally specific factors differed from the General Occupational Theme scales found on the Strong. Two confirmatory factor analyses were conducted to establish the uniqueness

Mark S. Majors; Lisa M. Larson

2001-01-01

436

Uniqueness of static black-holes without analyticity  

E-print Network

We show that the hypothesis of analyticity in the uniqueness theory of vacuum, or electrovacuum, static black holes is not needed. More generally, we show that prehorizons covering a closed set cannot occur in well-behaved domains of outer communications.

Piotr T. Chru?ciel; Gregory J. Galloway

2010-04-04

437

Forestry Commission Concerts Live Music in Unique Locations  

E-print Network

Forestry Commission Concerts Live Music in Unique Locations objectives Woodlands are naturally atmospheric venues for concerts - the perfect setting for people to come and see their favourite bands. The Forestry Commission concerts aim to attract new and more diverse audiences out to the forest, and raise

438

Cancer Cell Dissecting the Unique Role of the Retinoblastoma  

E-print Network

Cancer Cell Article Dissecting the Unique Role of the Retinoblastoma Tumor Suppressor during-cycle control. However, cancer-associated mutations are almost exclusively found in RB, implying that RB has for cancer development; hence, the roles and regulation of RB have been intensively studied (reviewed

439

The Uniqueness of EFL Teachers: Perceptions of Japanese Learners  

ERIC Educational Resources Information Center

Building on the work of Borg (2006), this article reports on a study of Japanese English as a foreign language (EFL) learners' perceptions of some of the unique characteristics of EFL teachers that distinguish them from teachers of other subjects. The data were collected by means of a questionnaire to which 163 college-level EFL students in Japan…

Lee, Joseph J.

2010-01-01

440

INTRODUCTION Dosage compensation is a unique gene regulation problem in  

E-print Network

INTRODUCTION Dosage compensation is a unique gene regulation problem in that it calls for the sex- scribed by different RNA polymerases. In Drosophila, dosage compensation is achieved by transcribing a protein that shows sequence similarity to RNA helicase-like proteins (Kuroda et al., 1991; Lee and Hurwitz

Baker, Bruce S.

441

A Unique Population: Women Who Are Homeless and Mentally Ill  

ERIC Educational Resources Information Center

This article describes a unique population within the homeless community--women who are homeless and mentally ill. Homelessness prevalence and etiology data are presented, followed by a general discussion of how mental illness affects people who are homeless. The article provides an overview of women who are homeless, focusing on those who are…

Markos, Patricia A.; Baron, Heather Lyn; Allen, Daniel N.

2005-01-01

442

"In Canada Even History Divides": Unique Features of Canadian Citizenship.  

ERIC Educational Resources Information Center

Explores the unique features of Canadian history and society that influence the conception of Canadian citizenship. These include the historical development of Canada as a frontier crown territory, the search for an elusive national identity, the decentralized political structure, and the proximity to the United States. (MJP)

Sears, Alan

1997-01-01

443

Unique Sensor Plane Maps Invisible Toxins for First Responders  

SciTech Connect

A unique airborne emergency response tool, ASPECT is a Los Alamos/U.S. Environmental Protection Agency project that can put chemical and radiological mapping tools in the air over an accident scene. The name ASPECT is an acronym for Airborne Spectral Phot

2008-04-30

444

Sequence and comparative analysis of the chicken genome provide unique  

E-print Network

Sequence and comparative analysis of the chicken genome provide unique perspectives on vertebrate evolution International Chicken Genome Sequencing Consortium* *Lists of participants and affiliations appear ........................................................................................................................................................................................................................... We present here a draft genome sequence of the red jungle fowl, Gallus gallus. Because the chicken

Edwards, Scott

445

Moffitt Cancer Center researchers identify unique immune gene signature  

Cancer.gov

Researchers at Moffitt Cancer Center have discovered a unique immune gene signature that can predict the presence of microscopic lymph node-like structures in metastatic melanoma. The presence of these immune structures, the researchers said, appears to be associated with better survival and may indicate the possibility of selecting patients for immunotherapy based solely on the immune-related makeup of their tumors.

446

Unique Factorization in Cyclotomic Integers of Degree Seven  

ERIC Educational Resources Information Center

This article provides a survey of some basic results in algebraic number theory and applies this material to prove that the cyclotomic integers generated by a seventh root of unity are a unique factorization domain. Part of the proof uses the computer algebra system Maple to find and verify factorizations. The proofs use a combination of historic…

Duckworth, W. Ethan

2008-01-01

447

Apparatus for controlling system state based on unique identifiers  

Microsoft Academic Search

An apparatus allows workers to assert and release control over the energization of a system. The apparatus does not require the workers to carry any additional paraphernalia, and is not be easily defeated by other workers. Users asserting and releasing control present tokens uniquely identifying each user to a reader, and the apparatus prevents transition of the system to an

Drotning; William D

2002-01-01

448

Long-term Potentiation Requires Unique Postsynaptic SNARE Fusion Machinery  

E-print Network

Seminar Long-term Potentiation Requires Unique Postsynaptic SNARE Fusion Machinery Debanjan Goswami LTP, but the exact molecular machinery is unclear. This seminar will focus on the results that show features of this particular SNARE- mediated fusion machinery. SNAP-47, a novel Q-SNARE protein in the post

Shyamasundar, R.K.

449

CAR2 Displays Unique Ligand Binding and RXR Heterodimerization Characteristics  

E-print Network

CAR2 Displays Unique Ligand Binding and RXR Heterodimerization Characteristics Scott S. Auerbach ABSTRACT: The constitutive androstane receptor (CAR; NR1I3) regulates the expression of genes involved in xenobiotic metabolism. Alternative splicing of the human CAR gene yields an array of mRNAs that encode

Omiecinski, Curtis

450

qDNAmod: a statistical model-based tool to reveal intercellular heterogeneity of DNA modification from SMRT sequencing data  

PubMed Central

In an isogenic cell population, phenotypic heterogeneity among individual cells is common and critical for survival of the population under different environment conditions. DNA modification is an important epigenetic factor that can regulate phenotypic heterogeneity. The single molecule real-time (SMRT) sequencing technology provides a unique platform for detecting a wide range of DNA modifications, including N6-methyladenine (6-mA), N4-methylcytosine (4-mC) and 5-methylcytosine (5-mC). Here we present qDNAmod, a novel bioinformatic tool for genome-wide quantitative profiling of intercellular heterogeneity of DNA modification from SMRT sequencing data. It is capable of estimating proportion of isogenic haploid cells, in which the same loci of the genome are differentially modified. We tested the reliability of qDNAmod with the SMRT sequencing data of Streptococcus pneumoniae strain ST556. qDNAmod detected extensive intercellular heterogeneity of DNA methylation (6-mA) in a clonal population of ST556. Subsequent biochemical analyses revealed that the recognition sequences of two type I restriction–modification (R-M) systems are responsible for the intercellular heterogeneity of DNA methylation initially identified by qDNAmod. qDNAmod thus represents a valuable tool for studying intercellular phenotypic heterogeneity from genome-wide DNA modification. PMID:25404133

Feng, Zhixing; Li, Jing; Zhang, Jing-Ren; Zhang, Xuegong

2014-01-01

451

Lifestyle Modification Decreases Arterial Stiffness in Overweight and Obese Men: Dietary Modification vs. Exercise Training.  

PubMed

Obesity and increased arterial stiffness are independent risk factors for cardiovascular disease. Arterial stiffness is increased in obese individuals than in age-matched nonobese individuals. We demonstrated that dietary modification and exercise training are effective in reducing arterial stiffness in obese persons. However, the differences in the effect on arterial stiffness between dietary modification and exercise training are unknown. The purpose of the current study was to compare the effect of dietary modification and aerobic exercise training on arterial stiffness and endothelial function in overweight and obese persons. Forty-five overweight and obese men (48 ± 1 year) completed either a dietary modification (well-balanced nutrient, 1680 kcal/day) or an exercise-training program (walking, 40-60 min/day, 3 days/week) for 12 weeks. Before and after the intervention, all participants underwent anthropometric measurements. Arterial stiffness was measured based on carotid arterial compliance, brachial-ankle pulse wave velocity (baPWV), and endothelial function was determined by circulating level of endothelin-1 (ET-1) and nitric oxide metabolite (nitrites/nitrate as metabolite: NOx). Body mass and waist circumference significantly decreased after both intervention programs. Weight loss was greater after dietary modification than after exercise training (-10.1 ± 0.6 kg vs. -3.6 ± 0.5 kg, p < .01). Although arterial stiffness and the plasma levels of ET-1 and NOx were improved after dietary modification or exercise training, there were no differences in those improvements between the 2 types of interventions. Exercise training improves arterial function in obese men without as much weight loss as after dietary modification. PMID:25029200

Maeda, Seiji; Zempo-Miyaki, Asako; Sasai, Hiroyuki; Tsujimoto, Takehiko; So, Rina; Tanaka, Kiyoji

2015-02-01

452

Attitudes, labeling bias, and behavior modification in work organizations  

Microsoft Academic Search

The present study investigated a labeling bias against behavior modification in work organizations. Groups of individuals in favor or opposed to the use of behavior modification in industry were formed. The identical videotape of a performance appraisal interview was shown to these subjects after half of each group had received a humanistic, and the other half a behavior modification, description

JULIAN BARLING; TREVOR WAINSTEIN

1979-01-01

453

75 FR 69864 - Modification of Class B Airspace; Charlotte, NC  

Federal Register 2010, 2011, 2012, 2013, 2014

...08-AWA-1] RIN 2120-AA66 Modification of Class B Airspace; Charlotte...would cause the loss of, or modification to, an approved Aerobatic...at the Charlotte Airport; weather conditions, which determine...departure procedures. The modifications to the Charlotte Class...

2010-11-16

454

Ecological Effects of Weather Modification: A Problem Analysis.  

ERIC Educational Resources Information Center

This publication reviews the potential hazards to the environment of weather modification techniques as they eventually become capable of producing large scale weather pattern modifications. Such weather modifications could result in ecological changes which would generally require several years to be fully evident, including the alteration of…

Cooper, Charles F.; Jolly, William C.

455

WEATHER MODIFICATION BY CARBON DUST ABSORPTION OF SOLAR ENERGY  

E-print Network

WEATHER MODIFICATION BY CARBON DUST ABSORPTION OF SOLAR ENERGY by WM. M. GRAY, WM. M. FRANK, M COLLINS, COLORADO Atmospheric Science PAPER NO. 225 #12;WEATHER MODIFICATION BY CARBON DUST ABSORPTION meteorologists and other scientists on the possibility of meso-scale weather modification through carbon dust

Gray, William

456

Single-Nucleosome Mapping of Histone Modifications in S. cerevisiae  

Microsoft Academic Search

Covalent modification of histone proteins plays a role in virtually every process on eukaryotic DNA, from transcription to DNA repair. Many different residues can be covalently modified, and it has been suggested that these modifications occur in a great number of independent, meaningful combinations. Published low-resolution microarray studies on the combinatorial complexity of histone modification patterns suffer from confounding effects

Chih Long Liu; Tommy Kaplan; Minkyu Kim; Stephen Buratowski; Stuart L Schreiber; Nir Friedman; Oliver J Rando

2005-01-01

457

Complexity Classification of Some Edge Modification Problems \\Lambda  

E-print Network

modification problems have important applications in physical mapping of DNA (see [5, 9, 14, 17]). DependingComplexity Classification of Some Edge Modification Problems \\Lambda Assaf Natanzon y Ron Shamir yz Roded Sharan yx October 1999 Abstract In an edge modification problem one has to change the edge set

Shamir, Ron

458

Modifications for numerical stability of black hole evolution  

E-print Network

We experiment with several new modifications for the Baumgarte-Shapiro-Shibata-Nakamura (BSSN) formulation of the Einstein field equations and demonstrate how these modifications affect the stability of numerical black hole evolution calculations. With these modifications, we evolve both single non-rotating excised Kerr-Schild black holes and punctured binary black holes, and obtain accurate and stable simulations.

Hwei-Jang Yo; Chun-Yu Lin; Zhoujian Cao

2012-08-12

459

Reactive modification of polyesters and their blends  

NASA Astrophysics Data System (ADS)

As part of a broader research effort to investigate the chemical modification of polyesters by reactive processing a low molecular weight (MW) unsaturated polyester (UP) and a higher MW saturated polyester, polyethylene terephthalate (PET), alone or blended with polypropylene (PP) were melt processed in a batch mixer and continuous twin screw extruders. Modification was monitored by on-line rheology and the products were characterized primarily by off-line rheology, morphology and thermal analysis. Efforts were made to establish processing/property relationships and provide an insight of the accompanying structural changes. The overall response of the reactively modified systems was found to be strongly dependent on the component characteristics, blend composition, type and concentrations of reactive additives and processing conditions. The work concluded that UP can be effectively modified through reactive melt processing. Its melt viscosity and MW can be increased through chemical reactions between organic peroxides (POX) and chain unsaturation or between MgO and carboxyl/hydroxyl end groups. Reactive blending of PP/UP blends through peroxide modification gave finer and more uniform morphology than unreacted blends and at a given PP/UP weight ratio more thermoplastic elastomers-like rheological behavior. This is due to the continuously decreasing viscosity ratio of PP/UP towards unity by the competing reactions between POX and the blend components and formation of PP-UP copolymers which serve as in-situ compatibilizers to promote better interfacial adhesion. Kinetics of the competing reactions were analyzed through a developed model. In addition to POX concentration and mixing efficiency, rheology and morphology of UP/PP bends were significantly affected by the addition of inorganic and organic coagents. Addition of coagents such as a difunctional maleimide, MgO and/or an anhydride functionalized PP during reactive blending offers effective means for tailoring the desired rheological and structural characteristics of the final products for potential applications such as low density extrusion foaming or compatibilization of immiscible polymer blends. Important modification conditions through coagents are identified and reaction mechanisms are proposed. A high MW saturated polyester, PET, can also be rheologically modified in extruders through low MW multifunctional anhydride and epoxy compounds by chain extension/branching. Several such modifiers were successfully screened in terms of their reactivity towards PET under controlled reactive extrusion conditions. A dianhydride with medium reactivity was then successfully used in a one-step reactive modification/extrusion foaming process to produce low density foams. A similar process was successfully used to produce small cell size foams from a four component system containing PET, PP and lesser amounts of a low molecular weight multifunctional epoxy compound and an acid functionalized polyolefin, the latter acting as compatibilizers.

Wan, Chen

2004-12-01

460

Conservation of an intricate circuit for crucial modifications of the tRNAPhe anticodon loop in eukaryotes.  

PubMed

Post-transcriptional tRNA modifications are critical for efficient and accurate translation, and have multiple different roles. Lack of modifications often leads to different biological consequences in different organisms, and in humans is frequently associated with neurological disorders. We investigate here the conservation of a unique circuitry for anticodon loop modification required for healthy growth in the yeast Saccharomyces cerevisiae. S. cerevisiae Trm7 interacts separately with Trm732 and Trm734 to 2'-O-methylate three substrate tRNAs at anticodon loop residues C?? and N??, and these modifications are required for efficient wybutosine formation at m(1)G?? of tRNA(Phe). Moreover, trm7? and trm732? trm734? mutants grow poorly due to lack of functional tRNA(Phe). It is unknown if this circuitry is conserved and important for tRNA(Phe) modification in other eukaryotes, but a likely human TRM7 ortholog is implicated in nonsyndromic X-linked intellectual disability. We find that the distantly related yeast Schizosaccharomyces pombe has retained this circuitry for anticodon loop modification, that S. pombe trm7? and trm734? mutants have more severe phenotypes than the S. cerevisiae mutants, and that tRNA(Phe) is the major biological target. Furthermore, we provide evidence that Trm7 and Trm732 function is widely conserved throughout eukaryotes, since human FTSJ1 and THADA, respectively, complement growth defects of S. cerevisiae trm7? and trm732? trm734? mutants by modifying C?? of tRNA(Phe), each working with the corresponding S. cerevisiae partner protein. These results suggest widespread importance of 2'-O-methylation of the tRNA anticodon loop, implicate tRNA(Phe) as the crucial substrate, and suggest that this modification circuitry is important for human neuronal development. PMID:25404562

Guy, Michael P; Phizicky, Eric M

2015-01-01

461

Nucleic acid modifications in bacterial pathogens - impact on pathogenesis, diagnosis, and therapy  

E-print Network

Nucleic acids are subject to extensive chemical modification by all organisms. These modifications display incredible structural diversity, and some are essential for survival. Intriguingly, several of these modifications ...

Russell, Brandon S. (Brandon Skylur)

2014-01-01

462

Profiling of integral membrane proteins and their post translational modifications using high-resolution mass spectrometry.  

PubMed

Integral membrane proteins pose challenges to traditional proteomics approaches due to unique physicochemical properties including hydrophobic transmembrane domains that limit solubility in aqueous solvents. A well resolved intact protein molecular mass profile defines a protein's native covalent state including post-translational modifications, and is thus a vital measurement toward full structure determination. Both soluble loop regions and transmembrane regions potentially contain post-translational modifications that must be characterized if the covalent primary structure of a membrane protein is to be defined. This goal has been achieved using electrospray-ionization mass spectrometry (ESI-MS) with low-resolution mass analyzers for intact protein profiling, and high-resolution instruments for top-down experiments, toward complete covalent primary structure information. In top-down, the intact protein profile is supplemented by gas-phase fragmentation of the intact protein, including its transmembrane regions, using collisionally activated and/or electron-capture dissociation (CAD/ECD) to yield sequence-dependent high-resolution MS information. Dedicated liquid chromatography systems with aqueous/organic solvent mixtures were developed allowing us to demonstrate that polytopic integral membrane proteins are amenable to ESI-MS analysis, including top-down measurements. Covalent post-translational modifications are localized regardless of their position in transmembrane domains. Top-down measurements provide a more detail oriented high-resolution description of post-transcriptional and post-translational diversity for enhanced understanding beyond genomic translation. PMID:21982782

Souda, Puneet; Ryan, Christopher M; Cramer, William A; Whitelegge, Julian

2011-12-01

463

Profiling of integral membrane proteins and their post translational modifications using high-resolution mass spectrometry  

PubMed Central

Integral membrane proteins pose challenges to traditional proteomics approaches due to unique physicochemical properties including hydrophobic transmembrane domains that limit solubility in aqueous solvents. A well resolved intact protein molecular mass profile defines a protein’s native covalent state including post-translational modifications, and is thus a vital measurement toward full structure determination. Both soluble loop regions and transmembrane regions potentially contain post-translational modifications that must be characterized if the covalent primary structure of a membrane protein is to be defined. This goal has been achieved using electrospray-ionization mass spectrometry (ESI-MS) with low-resolution mass analyzers for intact protein profiling, and high-resolution instruments for top-down experiments, toward complete covalent primary structure information. In top-down, the intact protein profile is supplemented by gas-phase fragmentation of the intact protein, including its transmembrane regions, using collisionally activated and/or electroncapture dissociation (CAD/ECD) to yield sequence-dependent high-resolution MS information. Dedicated liquid chromatography systems with aqueous/organic solvent mixtures were developed allowing us to demonstrate that polytopic integral membrane proteins are amenable to ESI-MS analysis, including top-down measurements. Covalent post-translational modifications are localized regardless of their position in transmembrane domains. Top-down measurements provide a more detail oriented high-resolution description of post-transcriptional and post-translational diversity for enhanced understanding beyond genomic translation. PMID:21982782

Souda, Puneet; Ryan, Christopher M.; Cramer, William A.; Whitelegge, Julian

2011-01-01

464

Development and application of FI catalysts for olefin polymerization: unique catalysis and distinctive polymer formation.  

PubMed

Catalysts contribute to the efficient production of chemicals and materials in almost all processes in the chemical industry. The polyolefin industry is one prominent example of the importance of catalysts. The discovery of Ziegler-Natta catalysts in the 1950s resulted in the production of high-density polyethylenes (PEs) and isotactic polypropylenes (iPPs). Since then, further catalyst development has led to the production of a new series of polyolefins, including linear low-density PEs, amorphous ethylene/1-butene copolymers, ethylene/propylene/diene elastomers, and syndiotactic PPs (sPPs). Polyolefins are now the most important and the most produced synthetic polymers. This Account describes a family of next-generation olefin polymerization catalysts (FI catalysts) that are currently being used in the commercial production of value-added olefin-based materials. An FI catalyst is a heteroatom-coordinated early transition metal complex that combines a pair of nonsymmetric phenoxy-imine [O(-), N] chelating ligands with a group 4 transition metal. The catalytically active species derived from FI catalysts is highly electrophilic and can assume up to five isomeric structures based on the coordination of the phenoxy-imine ligand. In addition, the accessibility of the ligands of the FI catalysts and their amenability to modification offers an opportunity for the design of diverse catalytic structures. FI catalysts exhibit many unique chemical characteristics: precise control over chain transfers (including highly controlled living ethylene and propylene polymerizations), extremely high selectivity for ethylene, high functional group tolerance, MAO- and borate-free polymerization catalysis, significant morphology polymer formation, controlled multimodal behavior, high incorporation ability for higher alpha-olefins and norbornene, and highly syndiospecific and isospecific polymerizations of both propylene and styrene. These reactions also occur with very high catalyst efficiency. The reaction products include a wide variety of unique olefin-based materials, many of which were previously unavailable via other means of polymerization. We have produced selective vinyl- and Al-terminated PEs, ultrahigh molecular weight linear PEs, regio- and stereoirregular high molecular weight poly(higher alpha-olefin)s, ethylene- and propylene-based telechelic polymers, a wide array of polyolefinic block copolymers from ethylene, propylene, and higher alpha-olefins, and ultrafine noncoherent PE particles. FI catalysts are important from the organometallic, catalytic, and polymer science points of view, and the chemical industry is now using them for the production of value-added olefin-based materials. We anticipate that future research on FI catalysts will produce additional olefin-based materials with unique architectures and material properties and will offer scientists the chance to further study olefin polymerization catalysis and related reaction mechanisms. PMID:19588950

Makio, Haruyuki; Fujita, Terunori

2009-10-20

465

Transfer of plasmid DNA to clinical coagulase-negative staphylococcal pathogens by using a unique bacteriophage.  

PubMed

Genetic manipulation of emerging bacterial pathogens, such as coagulase-negative staphylococci (CoNS), is a major hurdle in clinical and basic microbiological research. Strong genetic barriers, such as restriction modification systems or clustered regularly interspaced short palindromic repeats (CRISPR), usually interfere with available techniques for DNA transformation and therefore complicate manipulation of CoNS or render it impossible. Thus, current knowledge of pathogenicity and virulence determinants of CoNS is very limited. Here, a rapid, efficient, and highly reliable technique is presented to transfer plasmid DNA essential for genetic engineering to important CoNS pathogens from a unique Staphylococcus aureus strain via a specific S. aureus bacteriophage, ?187. Even strains refractory to electroporation can be transduced by this technique once donor and recipient strains share similar ?187 receptor properties. As a proof of principle, this technique was used to delete the alternative transcription factor sigma B (SigB) via allelic replacement in nasal and clinical Staphylococcus epidermidis isolates at high efficiencies. The described approach will allow the genetic manipulation of a wide range of CoNS pathogens and might inspire research activities to manipulate other important pathogens in a similar fashion. PMID:25616805

Winstel, Volker; Kühner, Petra; Krismer, Bernhard; Peschel, Andreas; Rohde, Holger

2015-04-01

466

Quantitative acoustic contrast tomography reveals unique multiscale physical fluctuations during aflatoxin synthesis in Aspergillus parasiticus.  

PubMed

Fungal pathogens need regulated mechanical and morphological fine-tuning for pushing through substrates to meet their metabolic and functional needs. Currently very little is understood on how coordinated colony level morphomechanical modifications regulate their behavior. This is due to an absence of a method that can simultaneously map, quantify, and correlate global fluctuations in physical properties of the expanding fungal colonies. Here, we show that three-dimensional ultrasonic reflections upon decoding can render acoustic contrast tomographs that contain information on material property and morphology in the same time scale of one important phytopathogen, Aspergillus parasiticus, at multiple length scales. By quantitative analysis of the changes in acoustic signatures collected as the A. parasiticus colony expands with time, we further demonstrate that the pathogen displays unique acoustic signatures during synthesis and release of its hepatocarcinogenic secondary metabolite, aflatoxin, suggesting an involvement of a multiscale morphomechanical reorganization of the colony in this process. Our studies illustrate for the first time, the feasibility of generating in any invading cell population, four-dimensional maps of global physical properties, with minimal physical perturbation of the specimens. Our developed method that we term quantitative acoustic contrast tomography (Q-ACT), provides a novel diagnostic framework for the identification of in-cell molecular factors and discovery of small molecules that may modulate pathogen invasion in a host. PMID:25312859

Banerjee, Sourav; Gummadidala, Phani M; Rima, Rowshan A; Ahmed, Riaz U; Kenne, Gabriel J; Mitra, Chandrani; Gomaa, Ola M; Hill, Jasmine; McFadden, Sandra; Banaszek, Nora; Fayad, Raja; Terejanu, Gabriel; Chanda, Anindya

2014-12-01

467

Modifications of Glycans: Biological Significance and Therapeutic Opportunities  

PubMed Central

Carbohydrates play a central role in a wide range of biological processes. As with nucleic acids and proteins, modifications of specific sites within the glycan chain can modulate a carbohydrate’s overall biological function. For example, acylation, methylation, sulfation, epimerization, and phosphorylation can occur at various positions within a carbohydrate to modulate bioactivity. Therefore, there is significant interest in identifying discrete carbohydrate modifications and understanding their biological effects. Additionally, enzymes that catalyze those modifications and proteins that bind modified glycans provide numerous targets for therapeutic intervention. This review will focus on modifications of glycans that occur after the oligomer/polymer has been assembled, generally referred to as postglycosylational modifications. PMID:22195988

Muthana, Saddam M.; Campbell, Christopher; Gildersleeve, Jeffrey C.

2012-01-01

468

Pretreatment and Membrane Hydrophilic Modification to Reduce Membrane Fouling  

PubMed Central

The application of low pressure membranes (microfiltration/ultrafiltration) has undergone accelerated development for drinking water production. However, the major obstacle encountered in its popularization is membrane fouling caused by natural organic matter (NOM). This paper firstly summarizes the two factors causing the organic membrane fouling, including molecular weight (MW) and hydrophilicity/hydrophobicity of NOM, and then presents a brief introduction of the methods which can prevent membrane fouling such as pretreatment of the feed water (e.g., coagulation, adsorption, and pre-oxidation) and membrane hydrophilic modification (e.g., plasma modification, irradiation grafting modification, surface coating modification, blend modification, etc.). Perspectives of further research are also discussed. PMID:24956947

Sun, Wen; Liu, Junxia; Chu, Huaqiang; Dong, Bingzhi

2013-01-01

469

Salient Region Detection by UFO: Uniqueness, Focusness and Objectness Peng Jiang 1  

E-print Network

Salient Region Detection by UFO: Uniqueness, Focusness and Objectness Peng Jiang 1 Haibin Ling 2 three important visual cues namely uniqueness, focusness and objectness (UFO). In particular, uniqueness, named UFO saliency, which

Ling, Haibin

470

Unique Perspectives on a Transforming Energy Economy: 2014 Annual Report (Brochure)  

SciTech Connect

What makes JISEA unique? Unique perspectives. This brochure highlights the unique perspectives provided by the Joint Institute for Strategic Energy Analysis through JISEA's recent accomplishments and the people behind them.

Gossett, S.

2014-03-01

471

A proposal on quantum histone modification in gene expression  

NASA Astrophysics Data System (ADS)

A quantum mechanical model on histone modification is proposed. Along with the methyl / acetate or other groups bound to the modified residues the torsion angles of the nearby histone chain are supposed to participate in the quantum transition cooperatively. The transition rate W is calculated based on the non-radiative quantum transition theory in adiabatic approximation. By using W's the reaction equations can be written for histone modification and the histone modification level can be calculable from the equations. The rate is decided by not only the atomic group bound to the modified residue, but also the nearby histone chain. The theory can explain the mechanism for the correlation between a pair of chromatin markers observed in histone modification. The temperature dependence and the coherencelength dependence of histone modification are deduced. Several points for checking the proposed theory and the quantum nature of histone modification are suggested as follows: 1, The relationship between lnW and 1/T is same as usual protein folding. The non-Arhenius temperature dependence of the histone modification level is predicted. 2, The variation of histone modification level through point mutation of some residues on the chain is predicted since the mutation may change the coherence-length of the system. 3, Multi-site modification obeys the quantum superposition law and the comparison between multi-site transition and single modification transition gives an additional clue to the testing of the quantum nature of histone modification.

Luo, Liaofu

2012-09-01

472

Surface Modifications in Adhesion and Wetting  

NASA Astrophysics Data System (ADS)

Advances in surface modification are changing the world. Changing surface properties of bulk materials with nanometer scale coatings enables inventions ranging from the familiar non-stick frying pan to advanced composite aircraft. Nanometer or monolayer coatings used to modify a surface affect the macro-scale properties of a system; for example, composite adhesive joints between the fuselage and internal frame of Boeing's 787 Dreamliner play a vital role in the structural stability of the aircraft. This dissertation focuses on a collection of surface modification techniques that are used in the areas of adhesion and wetting. Adhesive joints are rapidly replacing the familiar bolt and rivet assemblies used by the aerospace and automotive industries. This transition is fueled by the incorporation of composite materials into aircraft and high performance road vehicles. Adhesive joints have several advantages over the traditional rivet, including, significant weight reduction and efficient stress transfer between bonded materials. As fuel costs continue to rise, the weight reduction is accelerating this transition. Traditional surface pretreatments designed to improve the adhesion of polymeric materials to metallic surfaces are extremely toxic. Replacement adhesive technologies must be compatible with the environment without sacrificing adhesive performance. Silane-coupling agents have emerged as ideal surface modifications for improving composite joint strength. As these coatings are generally applied as very thin layers (<50 nm), it is challenging to characterize their material properties for correlation to adhesive performance. We circumvent this problem by estimating the elastic modulus of the silane-based coatings using the buckling instability formed between two materials of a large elastic mismatch. The elastic modulus is found to effectively predict the joint strength of an epoxy/aluminum joint that has been reinforced with silane coupling agents. This buckling technique is extended to investigate the effects of chemical composition on the elastic modulus. Finally, the effect of macro-scale roughness on silane-reinforced joints is investigated within the framework of the unresolved problem of how to best characterize rough surfaces. Initially, the fractal dimension is used to characterize grit-blasted and sanded surfaces. It is found that, contrary to what has been suggested in the literature, the fractal dimension is independent of the roughening mechanism. Instead, the use of an anomalous diffusion coefficient is proposed as a more effective way to characterize a rough surface. Surface modification by preparation of surface energy gradients is then investigated. Materials with gradients in surface energy are useful in the areas of microfluidics, heat transfer and protein adsorption, to name a few. Gradients are prepared by vapor deposition of a reactive silane from a filter paper source. The technique gives control over the size and shape of the gradient. This surface modification is then used to induce droplet motion through repeated stretching and compression of a water drop between two gradient surfaces. This inchworm type motion is studied in detail and offers an alternative method to surface vibration for moving drops in microfluidic devices. The final surface modification considered is the application of a thin layer of rubber to a rigid surface. While this technique has many practical uses, such as easy release coatings in marine environments, it is applied herein to enable spontaneous healing between a rubber surface and a glass cover slip. Study of the diffusion controlled healing of a blister can be made by trapping an air filled blister between a glass cover slip and a rubber film. Through this study we find evidence for an interfacial diffusion process. This mechanism of diffusion is likely to be important in many biological systems.

Longley, Jonathan

473

A Giant Chelonioid Turtle from the Late Cretaceous of Morocco with a Suction Feeding Apparatus Unique among Tetrapods  

PubMed Central

Background Secondary adaptation to aquatic life occurred independently in several amniote lineages, including reptiles during the Mesozoic and mammals during the Cenozoic. These evolutionary shifts to aquatic environments imply major morphological modifications, especially of the feeding apparatus. Mesozoic (250–65 Myr) marine reptiles, such as ichthyosaurs, plesiosaurs, mosasaurid squamates, crocodiles, and turtles, exhibit a wide range of adaptations to aquatic feeding and a broad overlap of their tooth morphospaces with those of Cenozoic marine mammals. However, despite these multiple feeding behavior convergences, suction feeding, though being a common feeding strategy in aquatic vertebrates and in marine mammals in particular, has been extremely rarely reported for Mesozoic marine reptiles. Principal Findings A relative of fossil protostegid and dermochelyoid sea turtles, Ocepechelon bouyai gen. et sp. nov. is a new giant chelonioid from the Late Maastrichtian (67 Myr) of Morocco exhibiting remarkable adaptations to marine life (among others, very dorsally and posteriorly located nostrils). The 70-cm-long skull of Ocepechelon not only makes it one of the largest marine turtles ever described, but also deviates significantly from typical turtle cranial morphology. It shares unique convergences with both syngnathid fishes (unique long tubular bony snout ending in a rounded and anteriorly directed mouth) and beaked whales (large size and elongated edentulous jaws). This striking anatomy suggests extreme adaptation for suction feeding unmatched among known turtles. Conclusion/Significance The feeding apparatus of Ocepechelon, a bony pipette-like snout, is unique among tetrapods. This new taxon exemplifies the successful systematic and ecological diversification of chelonioid turtles during the Late Cretaceous. This new evidence for a unique trophic specialization in turtles, along with the abundant marine vertebrate faunas associated to Ocepechelon in the Late Maastrichtian phosphatic beds of Morocco, further supports the hypothesis that marine life was, at least locally, very diversified just prior to the Cretaceous/Palaeogene (K/Pg) biotic crisis. PMID:23874378

Bardet, Nathalie; Jalil, Nour-Eddine; de Lapparent de Broin, France; Germain, Damien; Lambert, Olivier; Amaghzaz, Mbarek

2013-01-01

474

Unique, icy gathering system will serve Norman Wells  

SciTech Connect

One of the more unique communities on the Mackenzie River is Norman Wells, ca 90 miles south of the Arctic Circle and 450 air miles south of the Beaufort Sea. For over 50 yr, Norman Wells has been a major supplier of petroleum products to the Mackenzie Valley. The most unique aspect of Norman Wells is that it is underlain by a large reservoir of oil. Fifty wells in the area produce over 3000 bbl of light crude daily, which is refined locally. Esso Resources Canada Ltd. now is developing the field and expanding production. New facilities will include 151 new wells for producing oil and injecting water, 6 artificial islands in the 3-mile wide river to accommodate gathering points, and a new central processing facility. The crude oil to be produced will be transported by Interprovincial Pipeline (NW) Ltd. from Norman Wells to Zama, Alta.

Hale, D.

1983-09-01

475

Unique-hue stimulus selection using Munsell color chips.  

PubMed

Presented are intra- and inter-observer variability data comparing the unique-hue (UH) selections of sets of males and females, using two different visual experimental procedures incorporating Munsell color chips of varying hue but identical chroma and value. Although 34 of the 40 Munsell hue chips were selected by at least one observer as a UH, selections were generally repeatable. In addition, intra-observer variability represented approximately 15% of inter-observer variability. Also, when only three consecutive Munsell chips were viewed at a time, females showed significantly larger intra-observer variability than males, especially when making unique green selections. However, variability in UH selections was statistically insignificant between males and females when all Munsell chips were viewed simultaneously. No correlation was found between UH selections or intra-observer variability and hue ordering ability. PMID:17912334

Hinks, David; Cárdenas, Lina M; Kuehni, Rolf G; Shamey, Renzo

2007-10-01

476

Mechanism behind Unique Properties of Local Heating in Nanoscale Junctions  

NASA Astrophysics Data System (ADS)

We investigate the unique properties of current-induced heat generation in nanojunctions, such as failed Q ? I relation (where Q is the heat generation and I the current), threshold voltage required to generate heat, etc. By employing the lead-quantum dot (QD)-lead system, we find these unique properties stem from (i) the discontinuity of Fermi distribution at chemical potentials of the leads and (ii) the satellite peaks in spectral function of the QD electron, which are induced by the electron-phonon interaction. Supported by the National Natural Science Foundation of China under Grant No. 11164011 and the Provincial Nature Science Foundation of Jiangxi under Grant Nos. 20122BAB212006 and 20132BAB212003

Zhou, Li-Ling; Li, Yong-Jun; Yu, Li-Sheng

2015-03-01

477

Classical and Bayesian Linear Data Estimators for Unique Word OFDM  

E-print Network

Unique word - orthogonal frequency division multiplexing (UW-OFDM) is a novel OFDM signaling concept, where the guard interval is built of a deterministic sequence - the so-called unique word - instead of the conventional random cyclic prefix. In contrast to previous attempts with deterministic sequences in the guard interval the addressed UW-OFDM signaling approach introduces correlations between the subcarrier symbols, which can be exploited by the receiver in order to improve the bit error ratio performance. In this paper we develop several linear data estimators specifically designed for UW-OFDM, some based on classical and some based on Bayesian estimation theory. Furthermore, we derive complexity optimized versions of these estimators, and we study their individual complex multiplication count in detail. Finally, we evaluate the estimators' performance for the additive white Gaussian noise channel as well as for selected indoor multipath channel scenarios.

Huemer, Mario; Hofbauer, Christian; 10.1109/TSP.2011.2164912

2012-01-01

478

The unique enzymatic and mechanistic properties of plant myosins.  

PubMed

Myosins are molecular motors that move along actin-filament tracks. Plants express two main classes of myosins, myosin VIII and myosin XI. Along with their relatively conserved sequence and functions, plant myosins have acquired some unique features. Myosin VIII has the enzymatic characteristics of a tension sensor and/or a tension generator, similar to functions found in other eukaryotes. Interestingly, class XI plant myosins have gained a novel function that consists of propelling the exceptionally rapid cytoplasmic streaming. This specific class includes the fastest known translocating molecular motors, which can reach an extremely high velocity of about 60?ms(-1). However, the enzymatic properties and mechanistic basis for these remarkable manifestations are not yet fully understood. Here we review recent progress in understanding the uniqueness of plant myosins, while emphasizing the unanswered questions. PMID:25435181

Henn, Arnon; Sadot, Einat

2014-12-01

479

Solitary intraosseous neurofibroma: Report of a unique case  

PubMed Central

Neural tumors located centrally in jaw bones are relatively rare compared with soft tissue neurofibromas. Less than 50 cases have been reported in the literature with a predilection for mandible. This article aims to elucidate a unique case of intraosseous neurofibroma of mandible in a 62-year-old edentulous female patient associated with facial asymmetry due to the swelling extending from the right body of mandible to left body of mandible. The uniqueness of this case is related to the age and extensiveness of this lesion. A review of clinical, radiographic, histological, and immunohistochemical features, and the surgical management pertaining to this case are discussed along with a review of the literature. PMID:25395781

Jangam, Sagar Satish; Ingole, Snehal Nilesh; Deshpande, Mohan Devidas; Ranadive, Pallavi Adinath

2014-01-01

480

Uniqueness of black holes with bubbles in minimal supergravity  

NASA Astrophysics Data System (ADS)

We generalize uniqueness theorems for non-extremal black holes with three mutually independent Killing vector fields in five-dimensional minimal supergravity in order to account for the existence of non-trivial two-cycles in the domain of outer communication. The black hole space-times we consider may contain multiple disconnected horizons and be asymptotically flat or asymptotically Kaluza–Klein. We show that in order to uniquely specify the black hole space-time, besides providing its domain structure and a set of asymptotic and local charges, it is necessary to measure the magnetic fluxes that support the two-cycles as well as fluxes in the two semi-infinite rotation planes of the domain diagram.

Armas, Jay

2015-02-01

481

Unique and conserved features of floral evocation in legumes.  

PubMed

Legumes, with their unique ability to fix atmospheric nitrogen, play a vital role in ensuring future food security and mitigating the effects of climate change because they use less fossil energy and produce less greenhouse gases compared with N-fertilized systems. Grain legumes are second only to cereal crops as a source of human and animal food, and they contribute approximately one third of the protein consumed by the human population. The productivity of seed crops, such as grain legumes, is dependent on flowering. Despite the genetic variation and importance of flowering in legume production, studies of the molecular pathways that control flowering in legumes are limited. Recent advances in genomics have revealed that legume flowering pathways are divergent from those of such model species as Arabidopsis thaliana. Here, we discuss the current understanding of flowering time regulation in legumes and highlight the unique and conserved features of floral evocation in legumes. PMID:24930396

Liew, Lim Chee; Singh, Mohan B; Bhalla, Prem L

2014-08-01

482

Unique aspects of caring for young breast cancer patients.  

PubMed

Breast cancer is the most commonly diagnosed malignancy in young women in the USA. Although breast cancer mortality has decreased overall, survival rates in young women remain lower than those in older women. Young women with breast cancer comprise a special population due to the aggressive biology of their tumors as well as their unique psychosocial concerns. Although general treatment principles are similar regardless of age, recent developments from research focused on younger women have provided new insights to guide treatment of this special population. This article will focus on these new developments in areas including endocrine therapy and fertility preservation as well as the unique treatment-related sequelae and psychosocial concerns among young women with breast cancer face. PMID:25645111

Ferzoco, Raina M; Ruddy, Kathryn J

2015-02-01

483

WURCS: the Web3 unique representation of carbohydrate structures.  

PubMed

In recent years, the Semantic Web has become the focus of life science database development as a means to link life science data in an effective and efficient manner. In order for carbohydrate data to be applied to this new technology, there are two requirements for carbohydrate data representations: (1) a linear notation which can be used as a URI (Uniform Resource Identifier) if needed and (2) a unique notation such that any published glycan structure can be represented distinctively. This latter requirement includes the possible representation of nonstandard monosaccharide units as a part of the glycan structure, as well as compositions, repeating units, and ambiguous structures where linkages/linkage positions are unidentified. Therefore, we have developed the Web3 Unique Representation of Carbohydrate Structures (WURCS) as a new linear notation for representing carbohydrates for the Semantic Web. PMID:24897372

Tanaka, Kenichi; Aoki-Kinoshita, Kiyoko F; Kotera, Masaaki; Sawaki, Hiromichi; Tsuchiya, Shinichiro; Fujita, Noriaki; Shikanai, Toshihide; Kato, Masaki; Kawano, Shin; Yamada, Issaku; Narimatsu, Hisashi

2014-06-23

484

Transfer RNA modifications: Nature’s combinatorial chemistry playground  

PubMed Central

Following synthesis, tRNAs are peppered by numerous chemical modifications which may differentially affect a tRNA’s structure and function. Although modifications affecting the business ends of a tRNA are predictably important for cell viability, a majority of modifications play more subtle structural roles that can affect tRNA stability and folding. The current trend is that modifications act in concert and it is in the context of the specific sequence of a given tRNA that they impart their differing effects. Recent developments in the modification field have highlighted the diversity of modifications in tRNA. From these the combinatorial nature of modifications in explaining previously described phenotypes derived from their absence has emerged as a growing theme. PMID:23139145

Jackman, Jane E.; Alfonzo, Juan D.

2012-01-01

485

Unique mitochondrial DNA in highly inbred feral cattle  

PubMed Central

The Chillingham herd of wild Northumbrian cattle remains viable despite over 300 years of in-breeding and a near-homozygous nuclear genome. Here we report the complete mitochondrial DNA sequence using ultra-deep next generation sequencing. Random population sampling of ~ 10% of the extant herd identified a single mtDNA haplotype harbouring a unique bovine variant present in all other higher mammals (m.11789C/Y421H) which may contribute to their survival. PMID:22609322

Hudson, Gavin; Wilson, Ian; Payne, Brendan I.A.; Elson, Joanna; Samuels, David C.; Santibanez-Korev, Mauro; Hall, Stephen J.G.; Chinnery, Patrick F.

2012-01-01

486

A unique case of thyroid dysgenesis in a neonate.  

PubMed

Neonates with congenital hypothyroidism often demonstrate ectopic thyroid tissue. However, 2 sites of abnormally located thyroid tissue are exceptionally rare with only one other published case on a neonate. The authors present a unique case of a neonate who was found to have congenital hypothyroidism on laboratory screening; Tc-99m pertechnetate scintigraphy demonstrated 2 sites of abnormal uptake: one at the base of the tongue and the other in the midline at the expected location of the thyroid bed. PMID:21637059

Bryant, Adam; Reid, Marion C; Oates, M Elizabeth

2011-07-01

487

Development of unique ISI equipment for an RPV  

Microsoft Academic Search

A cooperative effort involving the Japan Atomic Power Company (JAPC) and Hitachi Ltd. has provided unique automated ultrasonic testing equipment for the reactor pressure vessel (RPV) of JAPC's Tsuruga unit 1, which is a 357-MW (electric) non-jet-pumped boiling water reactor. Using this equipment package at the 20th scheduled outage of Tsuruga unit 1, the in-service inspection (ISI) performed in accordance

Katsumi Tokunaga; Takayuki Aoki; Tsukasa Sasaki

1992-01-01

488

Guide to good practices for operations aspects of unique processes  

SciTech Connect

This Guide to Good Practices is written to enhance understanding of, and provide direction for, Operations Aspects of Facility Chemistry and Unique Process, Chapter 13 of Department of Energy (DOE) Order 5480.19, ``Conduct of Operations Requirements for DOE Facilities.`` The practices in this guide should be considered when planning or reviewing employee training and facility management programs. Contractors are advised to adopt procedures that meet the intent of DOE Order 5480.19.

Not Available

1993-06-01

489

The Mysteries of Diamonds: Bizarre History, Amazing Properties, Unique Applications  

SciTech Connect

Diamonds have been a prized material throughout history. They are scarce and beautiful, wars have been fought over them, and they remain today a symbol of wealth and power. Diamonds also have exceptional physical properties which can lead to unique applications in science. There are now techniques to artificially synthesize diamonds of extraordinarily high quality. In this talk, Professor Kagan will discuss the history of diamonds, their bizarre properties, and their manufacture and use for 21st century science.

Kagan, Harris (Ohio State University) [Ohio State University

2008-06-24

490

Uniqueness of Kerr space-time near null infinity  

SciTech Connect

We reexpress the Kerr metric in standard Bondi-Sachs coordinates near null infinity I{sup +}. Using the uniqueness result of the characteristic initial value problem, we prove the Kerr metric is the only asymptotically flat, stationary, axially symmetric, type-D solution of the vacuum Einstein equation. The Taylor series of Kerr space-time is expressed in terms of Bondi-Sachs coordinates, and the Newman-Penrose constants have been calculated.

Wu Xiaoning [Institute of Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, P.O. Box 2734, Beijing, 100080 (China); Bai Shan [Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, Beijing, 100080 (China)

2008-12-15

491

Diophantine and minimal but not uniquely ergodic (almost)  

NASA Astrophysics Data System (ADS)

We demonstrate that minimal non-uniquely ergodic behaviour can be generated by slowing down a simple harmonic oscillator with diophantine frequency, in contrast with the known examples where the frequency is well approximable by the rationals. The slowing is effected by a singular time change that brings one phase point to rest. The time one-map of the flow has uncountably many invariant measures yet every orbit is dense, with the minor exception of the rest point.

Kwapisz, Jaroslaw; Mathison, Mark

2012-07-01

492

On Uniqueness of Kerr Space-time near null infinity  

E-print Network

We re-express the Kerr metric in standard Bondi-Saches' coordinate near null infinity ${\\cal I}^+$. Using the uniqueness result of characteristic initial value problem, we prove the Kerr metric is the only asymptotic flat, stationary, axial symmetric, Type-D solution of vacuum Einstein equation. The Taylor series of Kerr space-time is expressed in terms of B-S coordinates and the N-P constants have been calculated.

Xiaoning Wu; Shan Bai

2008-11-24

493

Unique Large-Scale Wave Basins for NEES Collaborative Research  

Microsoft Academic Search

Abstract Under the Network for Earthquake Engineering Simulation (NEES) program ,at the National Science Foundation, the multidirectional (3-D) wave basin at Oregon State University is expanded,to create a unique,large-scale experimental testing facility for tsunami hazard mitigation research. When completed in 2004, this 3-D basin, together with the other existing directional (2-D) and circular wave basins, will support high resolution, unprecedented-scale

Solomon C. s. Yim; Charles K. Sollitt; Harry H. Yeh

494

Black hole uniqueness theorems in higher dimensional spacetimes  

E-print Network

We review uniqueness theorems as well as other general results about higher dimensional black hole spacetimes. This includes in particular theorems about the topology of higher dimensional spacetimes, theorems about their symmetries (rigidity theorem), and the classification of supersymmetric black holes. We outline the basic ideas underlying the proofs of these statements, and we also indicate ways to generalize some of these results to more general contexts, such as more complicated theories.

Stefan Hollands; Akihiro Ishibashi

2012-08-30

495

Unique monetary equilibria with interest rate rules: An extension  

Microsoft Academic Search

In a recent paper, Adão et al. (2011), using a cash-in-advance framework, derive an interest rate rule that results in a unique monetary equilibrium. The resulting interest rate rule is forward looking and the interest rate responds positively to forecasts of future real activity and to forecasts of the future price level. This paper extends their approach to a transactions

Kent P. Kimbrough

2012-01-01

496

Post-Translational Modifications of Exosomal Proteins  

PubMed Central

Exosomes mediate intercellular communication and participate in many cell processes such as cancer progression, immune activation or evasion, and the spread of infection. Exosomes are small vesicles secreted to the extracellular environment through the release of intraluminal vesicles contained in multivesicular bodies (MVBs) upon the fusion of these MVBs with the plasma membrane. The composition of exosomes is not random, suggesting that the incorporation of cargo into them is a regulated process. However, the mechanisms that control the sorting of protein cargo into exosomes are currently elusive. Here, we review the post-translational modifications detected in exosomal proteins, and discuss their possible role in their specific sorting into exosomes. PMID:25157254

Moreno-Gonzalo, Olga; Villarroya-Beltri, Carolina; Sánchez-Madrid, Francisco

2014-01-01

497

Covalent modification of proteins by cocaine  

NASA Astrophysics Data System (ADS)

Cocaine covalently modifies proteins through a reaction in which the methyl ester of cocaine acylates the -amino group of lysine residues. This reaction is highly specific in vitro, because no other amino acid reacts with cocaine, and only cocaine's methyl ester reacts with the lysine side chain. Covalently modified proteins were present in the plasma of rats and human subjects chronically exposed to cocaine. Modified endogenous proteins are immunogenic, and specific antibodies were elicited in mouse and detected in the plasma of human subjects. Covalent modification of proteins could explain cocaine's autoimmune effects and provide a new biochemical approach to cocaine's long-term actions.

Deng, Shi-Xian; Bharat, Narine; Fischman, Marian C.; Landry, Donald W.

2002-03-01

498

Parent-Body Modification of Chondritic Meteorites  

NASA Technical Reports Server (NTRS)

This proposal focused on the parent-body modification of chondritic materials and substantial progress was made in the last year. A summary of the work accomplished during this period is discussed. The topics include: 1) Chromite-Plagioclase Assemblages in Ordinary Chondrites; 2) The Gujba Bencubbin-like meteorite fall; 3) NWA428: A rock that Experienced Impact-induced Annealing; 4) Spade: An Annealed H-chondrite Impact-melt Breccia; and 5) Post-shock Annealing in Ordinary Chondrites. A list of the papers submitted or published during the period is also presented.

Rubin, Alan

2003-01-01

499

Histone modifications and traditional Chinese medicinals  

PubMed Central

Background Chromatin, residing in the nuclei of eukaryotic cells, comprises DNA and histones to make up chromosomes. Chromatin condenses to compact the chromosomes and loosens to facilitate gene transcription and DNA replication/repair. Chemical modifications to the histones mediate changes in chromatin structure. Histone-modifying enzymes are potential drug targets. How herbs affect phenotypes through histone modifications is interesting. Methods Two public traditional Chinese medicine (TCM) databases were accessed to retrieve the chemical constituents and TCM natures of 3,294 TCM medicinals. NCBI taxonomy database was accessed to build the phylogenetic tree of the TCM medicinals. Statistical test was used to test if TCM natures of the medicinals cluster in the phylogenetic tree. A public chemical-protein interaction database was accessed to identify TCM medicinals whose constituent chemicals interact with human histone-modifying enzymes. For each histone modification, a correlation coefficient was calculated between the medicinals’ TCM natures and modification modulabilities. Information of the ingredient medicinals of 200 classical TCM formulas was accessed from a public database. Results It was found that 1,170 or 36% of the 3,294 TCM medicinals interact with human histone-modifying enzymes. Among the histone-modifying medicinals, 56% of them promote chromatin condensation. The cold-hot natures of TCM medicinals were found to be phylogenetically correlated. Furthermore, cold (hot) TCM medicinals were found to be associated with heterochromatinization (euchromatinization) through mainly H3K9 methylation and H3K4 demethylation. The associations were weak yet statistically significant. On the other hand, analysis of TCM formulas, the major form of TCM prescriptions in clinical practice, found that 99% of 200 government approved TCM formulas are histone-modifying. Furthermore, in formula formation, heterochromatic medicinals were found to team up with other heterochromatic medicinals to enhance the heterochromatinization of the formula. The synergy was mainly through concurrent DNMT and HDAC inhibition, co-inhibition of histone acetylation and H3S10 phosphorylation, or co-inhibition of H3K4 demethylation and H3K36 demethylation. Conclusions TCM prescriptions’ modulation of the human epigenome helps elucidation of phyto-pharmacology and discovery of epigenetic drugs. Furthermore, as TCM medicinals’ properties are closely tied to patient TCM syndromes, results of this materia-medica-wide, bioinformatic analysis of TCM medicinals may have implications for molecular differentiation of TCM syndromes. PMID:23711355

2013-01-01

500

STS-114: Discovery Propulsion System Modification Briefing  

NASA Technical Reports Server (NTRS)

A briefing on the propulsion system modification of the STS-114 Discovery is presented. June Malone, NASA Public Affairs, introduces the panel who consists of: Sandy Coleman, External Tank Project Manager, Neil Otte, External Tank Chief Engineer, and Tom Williams, Solid Rocket Booster, Deputy Project Manager. Neil Otte presents charts on new requirements for foam debris reduction on the external tank. He also presents charts describing the Forward Bipod Redesign, LO2 Feedline Bellows Location, LH2 Intertank Flange Location, and In-Flight Imagery. Tom Williams presents charts describing Solid Rocket Booster Activities and Return to Flight efforts.

2005-01-01