Transformations structurales d'un acier AU Cr(9%) Mo(2%) (type ZlOCDNbV 09-02) utilisable dans les generateurs de vapeur des reacteurs a neutrons rapides

NASA Astrophysics Data System (ADS)

Vilar, Rui M.; Cizeron, Georges; Pelletier, Michel

1981-12-01

Transformations undergone by a 9 Cr-2 Mo-Nb-V steel on heating depend on the structure previously developped by quenching or tempering and on the heating rate. TTT and CCT diagrams, plotted after austenizing at 1000 and 1100°C, show only one diffusional transformation at high temperature producing equiaxed ferrite which contains a precipitate of M 23C 6 carbide; the activation energy of the process involved is 123.3 kJ/mol. At low temperatures a martensitic transformation is observed; the martensite is lath-type and autotempered.

Dysfonctionnements radio-induits du transport colique chez le rat

NASA Astrophysics Data System (ADS)

François, A.; Lebrun, F.; Ksas, B.; Aigueperse, J.; Gourmelon, P.; MacNaughton, W. K.; Griffiths, N. M.

1998-04-01

The symptom commonly associated with whole body irradiation is diarrhoea, a still quite obscure phenomenon, which leads to decreased chance of cure of irradiated people. The aim of this study was to provide evidence for dysfunction of intestinal water and electrolyte transport regulation by the enteric nervous system after exposure to ionising radiation. This study shows decreased capacity of enteric nervous system to influence colonic transport 3days after irradiation, correlated to a diminished response to a neurotransmitter: serotonin. Radio-induced diarrhea may result from epithelial structural injury but also from impaired regulatory processes of intestinal transport. L'un des symptômes majeurs d'une irradiation corporelle totale ou abdominale est l'apparition de diarrhées, dont les causes sont encore mal connues, et qui mettent en jeu le pronostique vital de l'individu irradié. Cette étude vise à mettre en évidence l'atteinte de la régulation du transport intestinal d'eau et d'électrolytes par les rayonnements ionisants. On observe une diminution de la capacité du système nerveux entérique à influencer le transport colique 3jours après irradiation, corrélée à une diminution de la réponse épithéliale à un neurotransmetteur : la sérotonine. Les diarrhées radio-induites résulteraient d'une atteinte structurelle de l'épithélium mais également des processus de régulation du transport intestinal.

Les carcinomes epidermoïdes du scrotum: à propos de 7 cas avec revue de la litterature

PubMed Central

Halfya, Ayoub; Elmortaji, Khalid; Redouane, Rabii; fethi, Meziane; Rafik, Amine; Mohamed, Ezzoubi; Abdessamad, Chlihi

2015-01-01

Quoique rare le carcinome épidermoïde du scrotum a un mauvais pronostic. Les Carcinomes du scrotum induite et - liées au travail sont moins fréquentes en raison d'une meilleure hygiène, vêtements de protection, et la sensibilisation de la cancérogénicité des huiles industrielles. L’épidémie à l'HPV a induit une augmentation de l'incidence. Le traitement de dépend toujours exérèse locale de la lésion primaire. La radiothérapie a peu de bénéfice thérapeutique dans le traitement d'un carcinome épidermoïde du scrotum. La bléomycine peut être utile comme traitement adjuvant pour les maladies ilio-inguinal généralisée avant la tentative exérèse, même si cela n'a pas encore été prouvé. Entre janvier 2011 au 1er janvier 2013, 7 patients atteints de carcinome épidermoïde ont été pris en charge, Trois patients ont présenté une localisation ganglionnaire. Les sept patients ont eu un traitement chirurgical par exérèse large avec reconstruction, Deux patients ont été adressé pour chimiothérapie.2 patients ont présenté une récidive, dont un est décédé. PMID:26113906

Effets des electrons secondaires sur l'ADN

NASA Astrophysics Data System (ADS)

Boudaiffa, Badia

Les interactions des electrons de basse energie (EBE) representent un element important en sciences des radiations, particulierement, les sequences se produisant immediatement apres l'interaction de la radiation ionisante avec le milieu biologique. Il est bien connu que lorsque ces radiations deposent leur energie dans la cellule, elles produisent un grand nombre d'electrons secondaires (4 x 104/MeV), qui sont crees le long de la trace avec des energies cinetiques initiales bien inferieures a 20 eV. Cependant, il n'y a jamais eu de mesures directes demontrant l'interaction de ces electrons de tres basse energie avec l'ADN, du principalement aux difficultes experimentales imposees par la complexite du milieu biologique. Dans notre laboratoire, les dernieres annees ont ete consacrees a l'etude des phenomenes fondamentaux induits par impact des EBE sur differentes molecules simples (e.g., N2, CO, O2, H2O, NO, C2H 4, C6H6, C2H12) et quelques molecules complexes dans leur phase solide. D'autres travaux effectues recemment sur des bases de l'ADN et des oligonucleotides ont montre que les EBE produisent des bris moleculaires sur les biomolecules. Ces travaux nous ont permis d'elaborer des techniques pour mettre en evidence et comprendre les interactions fondamentales des EBE avec des molecules d'interet biologique, afin d'atteindre notre objectif majeur d'etudier l'effet direct de ces particules sur la molecule d'ADN. Les techniques de sciences des surfaces developpees et utilisees dans les etudes precitees peuvent etre etendues et combinees avec des methodes classiques de biologie pour etudier les dommages de l'ADN induits par l'impact des EBE. Nos experiences ont montre l'efficacite des electrons de 3--20 eV a induire des coupures simple et double brins dans l'ADN. Pour des energies inferieures a 15 eV, ces coupures sont induites par la localisation temporaire d'un electron sur une unite moleculaire de l'ADN, ce qui engendre la formation d'un ion negatif transitoire dans un etat electronique dissociatif, cette localisation est suivie d'une fragmentation. A plus haute energie, la dissociation dipolaire (i.e., la formation simultanee d'un ion positif et negatif) et l'ionisation jouent un role important dans le dommage de l'ADN. L'ensemble de nos resultats permet d'expliquer les mecanismes de degradation de l'ADN par les EBE et d'obtenir des sections efficaces effectives des differents types de dommages.

Modèle de formation du gisement d'argent d'Imiter (Anti-Atlas oriental, Maroc). Nouveaux apports de l'analyse structurale et minéralogique

NASA Astrophysics Data System (ADS)

Tuduri, Johann; Chauvet, Alain; Ennaciri, Aomar; Barbanson, Luc

2006-03-01

Based on a combined geometrical and mineralogical analysis, a three-stage model of formation of the mineralized veins of the giant Imiter silver deposit (Anti-Atlas, Morocco) is herein proposed. A first episode is characterized by the development of quartz, pink dolomite and Ag-rich minerals veins formed during a dextral transpressive event. The second episode is associated with a normal left-lateral motion that re-opens previous structures, filled by pink dolomite gangue. Alteration stages contribute to a local Ag enrichment. To cite this article: J. Tuduri et al., C. R. Geoscience 338 (2005).

Analyse de l'effet des courants induits sur l'impédance d'un système électromagnétique alimenté en tension BF ou HF. Utilisation de la méthode des circuits couplés

NASA Astrophysics Data System (ADS)

Maouche, B.; Feliachi, M.

1997-10-01

In this paper, a study of the interaction between the inductor and the load of an axisymmetrical induction device is proposed. This interaction concerns the effect of the eddy current on both the excitation current and on the system impedance. A half analytical model, based on a numerical discretization of the electromagnetic solution domain, is used. In each cell of the numerical discretization, an analytical calculation using the Moment Method (MM) is considered. In the case of strong skin effect (High Frequency: HF), the formulation makes use of the Impedance Boundary Condition (IBC); in the contrary case (Low Frequency: LF), the interior domain is discretized. Dans cet article nous proposons l'étude de l'influence d'une charge (induit) conductrice sur la répartition du courant inducteur ainsi que sur l'impédance du système. L'inducteur est à géométrie axisymétrique de forme solénoïdale ou pancake destiné au chauffage par induction. Une méthode semi-analytique, basée sur une discrétisation du domaine en mailles élémentaires auxquelles s'applique une formulation intégrale (Méthode des Circuits Couplés : MCC) des grandeurs électromagnétiques, est utilisée. Dans le cas où l'effet de peau est important (Haute Fréquence:HF), la formulation associe la Condition d'Impédance de Surface; dans le cas contraire (Basse Fréquence : BF), un maillage du domaine interne est pratiqué.

Extended Generation Profile - E.B.I.C. Model

NASA Astrophysics Data System (ADS)

Guermazi, S.; Toureille, A.; Grill, C.; El Jani, B.; Lakhoua, N.

1996-04-01

We have developed a model for the calculation of the induced current due to an electron beam with an extended profile. As well as the number of absorbed and diffuse electrons as a function of the depth, the generation profile takes into account the lateral diffusion and the effect of defects, dislocations and recombination surfaces. The expression from the Electron Beam Induced Current (EBIC) is obtained by solving the continuity equation in permanent regime by the Green function method. In the case of a Schottky diode Au/InP, obtained by ionic scattering followed by a quick thermal treatment, the induced current profile is compared to the theoretical profiles whose analytical expressions are given by Van Roosbroeck and Bresse. The experimental current profile, measured by S.E.M provided us with the calculation of the diffusion length of the minority carriers, L_n=1 μm. The theoretical curve obtained from the proposed model is in good agreement with the experimental one for a surface recombination velocity of 104 cm s^{-1}. Our results are found to be consistent with those obtained by other experimental techniques on the same samples. Nous avons développé un modèle de calcul du courant induit par un faisceau d'électrons avec un profil de génération élargi. Le profil de génération tient compte, en plus du nombre d'électrons absorbés et du nombre d'électrons diffusés en fonction de la profondeur, de la diffusion latérale (en prenant en considération la diffusion angulaire), de l'effet des défauts, des dislocations et de la recombinaison à la surface. L'expression analytique du courant induit E.B.I.C est déterminée par résolution de l'équation de continuité en régime permanent par la méthode des fonctions de Green. Le profil de courant induit obtenu dans le cas d'une diode Schottky Au/InP dopé p et fabriqué par implantation suivit d'un recuit, est comparé au profil de courant théorique dont l'expression analytique est explicité par Van Roosbroeck et Bresse. Le profil de courant expérimental, mesuré par un microscope électronique à balayage, nous a permis de calculer la longueur de diffusion des porteurs minoritaires L_n=1 μm. La courbe théorique, tracée à partir du modèle proposé, est en bon accord avec la courbe expérimental pour une vitesse de recombinaison à la surface de 104 cm s^{-1}. Ces résultats sont conformes avec ceux obtenus par d'autres techniques expérimentales sur les mêmes échantillons.

Les effets des interfaces sur les proprietes magnetiques et de transport des multicouches nickel/iron et cobalt/silver

NASA Astrophysics Data System (ADS)

Veres, Teodor

Cette these est consacree a l'etude de l'evolution structurale des proprietes magnetiques et de transport des multicouches Ni/Fe et nanostructures a base de Co et de l'Ag. Dans une premiere partie, essentiellement bibliographique, nous introduisons quelques concepts de base relies aux proprietes magnetiques et de transport des multicouches metalliques. Ensuite, nous presentons une breve description des methodes d'analyse des resultats. La deuxieme partie est consacree a l'etude des proprietes magnetiques et de transport des multicouches ferromagnetiques/ferromagnetiques Ni/Fe. Nous montrerons qu'une interpretation coherente de ces proprietes necessite la prise en consideration des effets des interfaces. Nous nous attacherons a mettre en evidence, a evaluer et a etudier les effets de ces interfaces ainsi que leur evolution, et ce, suite a des traitements thermiques tel que le depot a temperature elevee et l'irradiation ionique. Les analyses correlees de la structure et de la magnetoresistance nous permettront d'emettre des conclusions sur l'influence des couches tampons entre l'interface et le substrat ainsi qu'entre les couches elles-memes sur le comportement magnetique des couches F/F. La troisieme partie est consacree aux systemes a Magneto-Resistance Geante (MRG) a base de Co et Ag. Nous allons etudier l'evolution de la microstructure suite a l'irradiation avec des ions Si+ ayant une energie de 1 MeV, ainsi que les effets de ces changements sur le comportement magnetique. Cette partie debutera par l'analyse des proprietes d'une multicouche hybride, intermediaire entre les multicouches et les materiaux granulaires. Nous analyserons a l'aide des mesures de diffraction, de relaxation superparamagnetique et de magnetoresistance, les evolutions structurales produites par l'irradiation ionique. Nous etablirons des modeles qui nous aideront a interpreter les resultats pour une serie des multicouches qui couvrent un large eventail de differents comportements magnetiques et ceci en fonction de l'epaisseur de la couche magnetique de Co. Nous verrons que dans ces systemes les effets de l'irradiation ionique sont fortement influences par l'energie de surface ainsi que par l'enthalpie de formation, largement positive pour le systeme Co/Ag.

Extended generation profile - E.B.I.C model application in the case of a PN junction

NASA Astrophysics Data System (ADS)

Guermazi, S.; Toureille, A.; Grill, C.; El Jani, B.

2000-01-01

We have developed a model for the calculation of the induced current due to an electron beam with an extended generation profile. Added to the absorbed and diffuse electrons in the depth distribution, the generation profile takes into account the lateral diffusion. The analytical expression of the electron beam induced current (EBIC) is obtained by solving the continuity equation in permanent regime by the Green function method. The induced current profile, obtained in the case of a ternary component (Ga{0.7}Al{0.3}As:N^+/Ga{0.7}Al{0.3}As:P) sulfur doped and prepared by organometallic compounds phase vapor epitaxy method, is compared to the theoretical profiles whose analytical expressions are given by Van Roosbroeck and Bresse. The experimental current profile, measured by S.E.M provided us to calculate the diffusion length of the minority carriers: L_p=1 μm in the N region and L_n=1.80 μm in the P region of the ternaire component. The theoretical curve obtained from the proposed model is in good agreement with the experimental one for a surface recombination velocity of 10^6 cm s^{-1}. Our results are found to be consistent compared to those obtained by other experimental techniques using the same samples. Nous avons développé un modèle de calcul du courant induit par un faisceau d'électrons avec un profil de génération élargi. Le profil de génération prend en compte la répartition spatiale de la diffusion et de l'absorption des électrons. L'expression analytique du courant induit (E.B.I.C) est déterminée par résolution de l'équation de continuité en régime permanent par la méthode des fonctions de Green. Le profil de courant induit obtenu dans le cas d'une jonction PN (Ga{0,7}Al{0,3}As:N^+/Ga{0,7}Al{0,3}As:P) dopée par le soufre et préparée par épitaxie à phase vapeur organo-métallique, est comparé au profil de courant théorique dont l'expression analytique est explicitée par Van Roosbroeck et Bresse. Le profil expérimental de courant E.B.I.C, mesuré par un microscope électronique à balayage, nous a permis de déterminer la longueur de diffusion des porteurs minoritaires L_p=1 μm dans la région N du composant ternaire et L_n=1,8 μm dans la région P de ce composant. La courbe théorique, tracée à partir du modèle proposé, est en bon accord avec la courbe expérimentale pour une vitesse de recombinaison à la surface de 10^6 cm s^{-1}. Ces résultats sont conformes avec ceux obtenus par d'autres techniques expérimentales sur les mêmes échantillons.

Synthesis, structurale elucidation and antioxidant study of Ortho-substituted N,N’-bis(benzamidothiocarbonyl)hydrazine derivatives

NASA Astrophysics Data System (ADS)

Firdausiah, Syadza; Hasbullah, S. A.; Yamin, B. M.

2018-03-01

Some bis(thiourea) compounds have been reported to posses excellent performance in pharmaceutical and environmental fields because of their ability to form chelating complexes with various anions and metal ions. Structurally for carbonyl thiourea derivatives, to become a chelating agent, it must adopt cis-configuration. In the present study, four new bis(thiourea) derivatives namely N,N’-bis(o-fluorobenzamidothiocarbonyl)hydrazine (1), N,N’- bis(o-chloro-benzamidothiocarbonyl)hydrazine (2), N,N’-bis(o-nitrobenzamidothiocarbonyl)-hydrazine (3), and N,N’-bis(o-methylbenzamidothiocarbonyl)hydrazine (4) were successfully synthesized and characterized by CHNS microelemental analysis, FTIR, UV-Vis, and 1H and 13C NMR spectroscopy. However chemical crystallography study showed that both thiourea moieties in compound (2) and (3) adopt trans geometry. Therefore they are potential monodentate ligand with two active moieties. DPPH radical scavenging experiment showed that compound (1), (2), and (4) exhibited higher antioxidant activity than ascorbic acid (Vitamin C).

Contrôle cohérent de la dynamique de fragmentation d'agrégats alcalins

NASA Astrophysics Data System (ADS)

Lindinger, A.; Lupulescu, C.; Le Roux, J.; Bartelt, A.; Vajda, Š.; Wöste, L.

2004-11-01

Les agrégats métalliques présentent des propriétés extraordinaires, en particulier chimiques et catalytiques, qui dépendent fortement de leur taille. Ce comportement en fait des candidats idéaux pour l'analyse en temps réel de processus photo-induits ultrarapides, le but ultime étant la conduite de scénarios de contrôle cohérent. Nous avons réalisé des expériences d'ionisation multiphotonique non stationnaire sur de petits agrégats alcalins de différentes tailles et dans différents états électroniques rovibrationnels, y compris leur état fondamental, sondant ainsi leur dynamique ondulatoire, leur orientation structurelle, leur transfert de charge et leur dissociation. Les processus observés dépendent grandement des paramètres du faisceau laser d'excitation, tels que sa phase, son amplitude et sa durée ; cette sensibilité plaide pour l'emploi d'un système de contrôle rétroactif permettant de générer les formes d'impulsion optimales. Les caractéristiques spectrales et temporelles de ces dernières reflètent les propriétés du système étudié ainsi que les processus photochimiques que l'irradiation y induit. Nous présentons d'abord la dynamique vibrationelle d'états électroniques excités, liés, dissociatifs et prédissociatifs, des dimères et trimères alcalins. Suit une description du principe d'observation par pompage optique par effet Raman stimulé de la dynamique d'un paquet d'onde dans l'état électronique fondamental. Puisque les paramètres de l'impulsion d'excitation influencent de façon significative le poids des différentes trajectoires dans l'espace des phases, nous avons mené des expériences sur les canaux de fragmentation concurrents d'une réaction photo-induite, en étudiant les différents embranchements des voies d'ionisation et de fragmentation de Na{2}K excité électroniquement. L'utilisation d'un algorithme évolutif, pour l'optimisation de la phase et de l'amplitude de l'onde électromagnétique appliquée, permit d'influencer significativement la quantité résultante d'ions parents ou fragments. Des propriétés intéressantes sont déduites de la forme des impulsions laser optimales obtenues, qui révèlent la période de vibration moléculaire et qui, combinées aux courbes de potentiel, permettent de proposer les trajectoires que l'optimisation impose aux paquets d'onde. Pour finir, nous avons étudié comment une variété plus grande d'agrégats, en contribuant au canal de fragmentation NaK, influe sur la forme optimale d'impulsion. Là encore, la structure de cette dernière apporte des éclaircissements sur les canaux de fragmentation empruntés durant le processus de contrôle.

Durcissement superficiel de la fonte grise Ft25 induit par un traitement de surface dans le moule

NASA Astrophysics Data System (ADS)

Bouitna, Mohamed; Boutarek-Zaourar, Naïma; Mansour, Samir; Chentouf, Samir Mourad; Mossang, Eric

2018-02-01

L'objectif de cette étude est la consolidation en surface de la fonte grise lamellaire Ft25 par un dépôt riche en manganèse en développant une méthode combinant en une seule opération l'élaboration et le traitement de surface dans le moule. Les effets de la granulométrie du ferro-manganèse (80 % Mn + 20 % Fe), ainsi que l'épaisseur des pièces en fontes sur les couches formées ont été étudiés. On a retenu trois granulométries du ferro-manganèse de 0,18 mm, 0,25 mm et 0,5 mm pour le traitement des pièces en fontes présentant des épaisseurs de 25 mm, 100 mm et 200 mm. Parmi les résultats obtenus, on distingue une consolidation des propriétés en surface induite par la formation d'une couche riche en manganèse continue et homogène. L'effet de la granulométrie du ferro-manganèse sur l'épaisseur de la couche traitée a été mis en évidence. La variation de l'épaisseur des couches formées diminue avec l'augmentation de la granulométrie du ferro-manganèse. Pour une pièce de 100 mm d'épaisseur, la couche formée est estimée à 350 μm pour une granulométrie de 0,18 alors qu'elle n'est que de 180 μm pour une granulométrie de 0,5. L'effet de l'épaisseur de la pièce n'est en revanche pas assez prononcé sur la taille des couches formées. Une amélioration nette de la résistance, à l'usure de la fonte traitée en relation avec les transformations en surface, a été mise en évidence.

Une surstructure de α-Ge, type diamant, induite par un dopage d’anti­moine

PubMed Central

Herrero, Adrian Gómez; Hammoudi, Lamia; Kars, Mohammed; Roisnel, Thierry; Otero-Diáz, L. Carlos

2017-01-01

Single crystals of anti­mony-doped germanium, Ge1–xSbx+0.01 (x ≃ 0.0625), were grown by chemical transport reaction. The alloy crystallizes as a superstructure of diamond-type α-Ge. All atoms in the asymmetric unit lie on special positions and are characterized by strong covalent bonds. The anti­mony atoms substitute for one germanium atom at full occupancy at Wyckoff position 4a (site symmetry -43m), and are also at an adjacent tetra­hedral inter­stitial site with partially occupation (16%) at position 4c (or 4d) (site symmetry -43m). The structural model does not show close Sb⋯Sb contacts, and suggests that the inter­stitial anti­mony atoms move between the two adjacent tetra­hedral sites. PMID:28529769

Observation de l'interaction entre atome et surface en cellule de vapeur submicrométrique

NASA Astrophysics Data System (ADS)

Dutier, G.; Saltiel, S.; Bloch, D.; Ducloy, M.; Papoyan, A.; Sarkisyan, D.

2002-06-01

Sur une cellule de vapeur d'épaisseur submicrométrique ( 300 nm), les spectres d'absorption linéaire se révèlent très peu sensibles à l'effet Doppler (les effets transitoires favorisent fortement les atomes lents), et font apparaître les effets de l'interaction van der Waals à longue portée entre atome-surface. L'étude, entreprise d'abord sur la raie de résonance D1 de Cs, est poursuivie sur une transition à deux photons vers le niveau Cs 6(D{3/2}) résonnant avec la surface de YAG de la fenêtre. Elle ouvre diverses perspectives, notamment la détection d'états liés par un puits de potentiel induit par la surface.

Diffraction des neutrons : principe, dispositifs expérimentaux et applications

NASA Astrophysics Data System (ADS)

Muller, C.

2003-02-01

La diffraction de neutrons, sur monocristal ou sur échantillon polycristallin (ou poudre), est une technique très largement utilisée, en science des matériaux comme en biologie, lorsque l'on souhaite déterminer la structure cristalline d'un composé ou d'une molécule. Toutefois, le degré de précision de la détermination structurale est très corrélé au choix de l'instrument utilisé. Il s'en suit que la question “comment choisir l'instrument le mieux adapté au composé et à la problématique ?" apparaît comme fondamentale. L'objectif de ce cours est de tenter de répondre à cette question en décrivant brièvement les caractéristiques instrumentales de différents diffractomètres, en exposant les avantages spécifiques des expériences de diffraction de neutrons et en donnant quelques exemples d'application.

Comportement rhéologique des systèmes mixtes biopolymères / protéines

NASA Astrophysics Data System (ADS)

Rebiha, M.; Moulai-Mostefa, N.; Sadok, A. Hadj; Sabri, N.

2005-05-01

Dans ce travail, on s'est intéressé à l'étude des effets du caséinate de sodium et du xanthane sur les propriétés rhéologiques des solutions aqueuses, préparées suivant un plan d'expériences. Les caractéristiques mécaniques obtenues sont traduites par les coefficients du modèle rhéologique de Casson, en l'occurrence la contrainte seuil, τ 0, et la viscosité plastique, η _c. Ainsi, à l'issue de la modélisation en surface de réponses, il apparaît une interaction répulsive à l'échelle structurale entre le caséinate de sodium et le xanthane, traduite par un abaissement considérable de τ 0. Cet baissement de la rigidité peut conduire à une séparation de phases, phénomène conditionné par la viscosité limite de Casson,η _c.

Détermination assistée par ordinateur de la structure des molécules organiques

NASA Astrophysics Data System (ADS)

Nuzillard, J.-M.

1998-02-01

Nuclear Magnetic Resonance spectroscopy offers the unique possibility of accessing proximity relationships between atoms by means of chemical shift correlation experiments. Structure determination of small molecules has become thus much simpler. Computer programs can use directly correlation information for structure analysis. The use and operation mechanism of such a program, LSD (Logic for Structure Determination) are presented. The example compound is gibberellic acid, a natural product. La spectroscopie de Résonance Magnétique Nucléaire offre un moyen unique de déterminer des relations de proximité entre atomes par le biais des expériences de corrélation. L'analyse structurale de petites molécules organiques s'en trouve extrêmement facilitée. Des programmes informatiques peuvent utiliser directement les informations de corrélation pour déduire des structures. Le fonctionnement et l'usage d'un tel programme, LSD (Logic for Structure Determination), sont détaillés sur un exemple, l'acide gibberellique.

Étude par détection de photons des processus électroniques au sein d'une jonction tunnel dans un milieu moléculaire

NASA Astrophysics Data System (ADS)

Perronet, K.

2005-03-01

Analysis of the luminescence induced by a STM (scanning tunneling microscope) permits to get insights into the electronic processes taking place in a single nanoscopic tunnel junction. We studied a Au(111)/Au junction under vacuum (UHV) and immersed in a molecular medium. The study under UHV reveals the influence of spatial variations of surface local density of states (LDOS) on the luminescence. The emission at the solid-liquid interface is characterized and the role played by the dielectric function is shown. Time correlations between the emitted single photons are then studied. Depending on the liquid immersing the junction, a photon bunching can occur. We link this bunching with structural changes of the junction induced by the presence of a diffusing molecule. If the HOMO LUMO gap of the molecule is small enough, resonant tunnelling paths exist and tunnelling-electron bunching occurs. Finally, the influence of a self-assembled monolayer on the substrate is investigated. Boundings between triphenylene derivatives and Au(111) are too weak, but with chemisorbed alcanethiols, molecular resolution is reached both on the STM image and on the photon map. We show that the contrast on photon map comes from the modulation of the LDOS spatial extension into the barrier due to the S Au bond. The elaboration of organic multilayers is considered as a route for observing the electroluminescence of a single molecule, isolated from the substrate by thiols and to study correlations of electronic origin. We have already optically characterised such a layer using C{60}. La luminescence induite par STM (microscopie à effet tunnel) est une source d'informations d'une grande richesse sur les processus électroniques au sein d'un objet nanoscopique individuel. Nous nous sommes intéressés à une jonction Au/Au(111) sous vide puis dans un milieu moléculaire. L'étude sous vide a permis de montrer l'influence des variations spatiales des densités d'états de la surface. L'émission à l'interface liquide-solide a été démontrée et le rôle de la fonction diélectrique du solvant mis en évidence. Nous avons ensuite étudié les corrélations temporelles entre les photons émis. Selon le liquide environnant la jonction, les photons peuvent être émis par paquets. Nous relions ce phénomène à la modification structurelle de la jonction induite par la présence d'une molécule et à la différence d'énergie entre ses orbitales frontières. Si elle est assez faible, des chemins tunnel résonants existent et les électrons traversent la barrière par paquets. L'influence d'une couche auto-assemblée sur le substrat est étudiée. Des dérivés de triphénylènes interagissent trop faiblement avec Au(111), mais avec des alcanethiols chimisorbés, la résolution moléculaire est atteinte simultanément sur l'image STM et la carte de photons. Nous montrons que le contraste sur cette dernière provient de la modulation de l'extension spatiale à l'intérieur de la barrière des densités d'état locales due à la liaison S Au. L'élaboration de multicouches organiques est alors envisagée pour observer l'électroluminescence d'une molécule unique, isolée du substrat par les thiols et étudier des corrélations d'origine électronique. Nous avons déjà caractérisé optiquement une telle couche de C{60}.

Principales lignes structurales du Maroc nord-oriental : apport de la gravimétrie

NASA Astrophysics Data System (ADS)

Chennouf, Touria; Khattach, Driss; Milhi, Abdellah; Andrieux, Pierre; Keating, Pierre

2007-05-01

The present work is based on various filtered maps (horizontal derivative, upward continuation) and Euler deconvolution of the gravity data from northeastern Morocco. These results allow the delineation of many geological structures, such as faults, basins, or diapirs. Some of these structures are hidden totally or partially by the Mesozoic and Cenozoic cover. The results were used to make a structural map of the study area; this map confirms the existence of several faults, localised or inferred, from former geological studies. It complements information on some of them and outlines a great number of deep or near-surface faults that had remained unknown until the present time. The major features show two principal directions: N080°-085° and N055°-065°, with a predominance of the latter, and their depth can reach 4500 m. The N080°-085° directions correspond to the Kebdana, Sidi Bouhouria, Naima, and Guefait faults, and the N055°-065° directions correspond to a fault parallel to the Mediterranean coast and the Moulouya, Madagh, Angad, and Zekkara faults.

Formability Extension of Aerospace Alloys for Tube Hydroforming Applications =

NASA Astrophysics Data System (ADS)

Anderson, Melissa

L'hydroformage de tube est un procede novateur de mise en forme du metal qui utilise la pression d'un fluide, generalement de l'eau, dans une matrice fermee pour deformer plastiquement des pieces d'epaisseur faible et fabriquer ainsi des composants tubulaires de geometries complexes. Ce procede possede de nombreux avantages tels que la reduction du poids des pieces, la diminution des couts lies a l'outillage et l'assemblage, la reduction du nombre d'etapes de fabrication et l'excellent etat de surface des pieces hydroformees. Cependant, malgre tous ces atouts, l'hydroformage reste un procede marginal dans le domaine aerospatial a cause de plusieurs facteurs dont la formabilite limitee des alliages aeronautiques. L'objectif principal de la recherche conduite dans le cadre de cette these est d'etudier une methode pour augmenter la formabilite de deux alliages aeronautiques designes par l'utilisation d'un procede de mise en forme multi-etapes qui inclue des cycles de mise en forme suivis d'etapes de traitement thermique intermediaires. Une revue de litterature exhaustive sur les methodes existantes pour ameliorer la formabilite des materiaux vises ainsi que les traitements thermiques d'adoucissement disponibles a permis d'etablir une procedure experimentale appropriee. Ce procede comprend plusieurs sequences de mise en forme suivie de traitement thermique successives jusqu'a l'obtention de la piece finale. L'insertion d'etapes de traitements thermiques intermediaires ainsi que la combinaison " deformation + traitement thermique " influencent le comportement mecanique et metallurgique des alliages. De ce fait, une caracterisation complete des materiaux a ete conduite a chaque etape du procede. D'un point de vue mecanique, l'effet des traitements thermiques et plus generalement du procede multi-etapes sur les proprietes mecaniques et lois constitutives des alliages a ete etudie en detail. Au niveau metallurgique, l'influence du procede sur les caracteristiques microstructurales des alliages tels la taille de grains, les phases en presence et la texture a ete analysee. Ces deux etudes paralleles ont permis de comprendre de facon complete et detaillee l'impact des modifications metallurgiques induites par le procede multietapes sur le comportement mecanique macroscopique et les proprietes finales de la piece.

Infections fongiques des brûlé : revue

PubMed Central

Arnould, JF.; Le Floch, R.

2015-01-01

Summary Les infections fongiques locales ou générales sont souvent d’une extrême gravité chez les brûlés. Les brûlés combinent de nombreux facteurs de risque à une immunodépression induite par la brûlure. Les infections de plaies sont le fait des genres Candida, Aspergillus et des agents de mucormycoses. Ces deux derniers cas sont à l’origine de lésions particulièrement sévères. Leur diagnostic repose sur la biopsie cutanée avec examens mycologique et anatomopathologique. Le traitement est essentiellement chirurgical, associé à une antibiothérapie adaptée. Les septicémies sont le fait de levures, essentiellement du genre Candida. Le diagnostic en est difficile dans le contexte des brûlés et repose souvent sur une forte suspicion clinique. Leur traitement repose sur les échinocandines et plus secondairement sur le fluconazole. PMID:26668558

Nouveaux supraconducteurs à haute température critique à base de mercure

NASA Astrophysics Data System (ADS)

Michel, C.; Hervieu, M.; Martin, C.; Maignan, A.; Pelloquin, D.; Goutenoire, F.; Huvé, M.; Raveau, B.

1994-11-01

Structural and superconducting properties of new cations substituted mercury based oxides are described. They are mainly characterized by [ Hg{1-x}MxOδ] infty monolayers, however a compound with doubled [ Hg{1-x}MxOδ] infty layer is described for the first time. Critical temperatures vary in a large range 0leqslant T_cleqslant 130 K, but they are lower than those of related to pure mercury oxides. The influence of annealings in various atmospheres upon T_c is discussed. Les caractéristiques structurales et supraconductrices de nouveaux oxydes à base de mercure, dans lesquels le mercure est partiellement remplacé par un autre cation, sont décrites. Dans la majorité des cas, ces oxydes sont caractérisés par une monocouche [ Hg{1-x}MxOδ] infty ; cependant, pour la première fois un composé contenant une double couche majoritaire en mercure est isolé. Les températures critiques varient dans un large domaine (0-130 K) mais restent inférieures à celles des oxydes parents ll tout mercure gg. L'influence des recuits sous des atmosphères diverses est discutée.

Towards high resolution ^1H NMR spectra of tannin colloidal aggregates

NASA Astrophysics Data System (ADS)

Mirabel, M.; Glories, Y.; Pianet, I.; Dufourc, E. J.

1999-10-01

The time dependent colloidal formation of tannins in hydro-alcoholic medium has been studied by 1H-NMR. Line broadening observed with time can be cancelled by making use of magic angle sample spinning (MASS) thus yielding sharp lines that allow structural studies. We used as an example catechin, a constitutive monomer of Bordeaux young red wine tannins. Chemical shift variations of polyphenol protons allow monitoring the time course of aggregation. La formation de tanins colloïdaux au cours du temps, en milieu hydroalcoolique, a été suivie par RMN-^1H. Un élargissement marqué des résonances est observé et peut être supprimé par la rotation de l'échantillon à l'angle magique ce qui ouvre tout un champ d'études structurales sur ces composés colloïdaux. L'exemple proposé est celui de la catéchine, monomère constitutif de tannins présents en grande quantité dans les vins rouges jeunes de Bordeaux. Des variations du déplacement chimique de certains protons polyphénoliques permettent de suivre l'évolution temporelle de l'agrégation.

Les recommandations thérapeutiques relatives aux effets secondaires extrapyramidaux associés à l’utilisation d’antipsychotiques de deuxième génération chez les enfants et les adolescents

PubMed Central

Pringsheim, Tamara; Doja, Asif; Belanger, Stacey; Patten, Scott

2012-01-01

HISTORIQUE ET OBJECTIF : L’utilisation d’antipsychotiques augmente chez les enfants. Le présent article visait à orienter les cliniciens quant à la prise en charge clinique des effets secondaires extrapyramidaux des antipsychotiques de deuxième génération. MÉTHODOLOGIE : Les publications, les entrevues avec des informateurs clés et des échanges avec les membres d’un groupe de discussion et les partenaires ont permis de déterminer les principaux secteurs cliniques d’orientation et les préférences quant à la structure des présentes recommandations. Les membres responsables des lignes directrices ont reçu le projet de recommandations, ont évalué l’information recueillie grâce à une analyse bibliographique systématique et ont utilisé un processus de groupe nominal pour parvenir à un consensus quant aux recommandations thérapeutiques. Les lignes directrices contiennent une description des anomalies neurologiques souvent observées avec l’utilisation d’antipsychotiques ainsi que les recommandations sur le moyen d’examiner et de quantifier ces anomalies. Une démarche séquentielle sur la prise en charge des anomalies neurologiques est présentée. RÉSULTATS : On peut observer plusieurs types de symptômes extrapyramidaux attribuables à l’utilisation d’antipsychotiques chez les enfants, y compris la dystonie aiguë, l’akathisie, le parkinsonisme et la dyskinésie tardive, toutes induites par les neuroleptiques, de même que la dystonie tardive, l’akathisie tardive et les dyskinésies de sevrage. La forte majorité des données probantes sur le traitement des troubles du mouvement induits par les antipsychotiques proviennent de patients adultes atteints de schizophrénie. Étant donné le peu de données pédiatriques, les recommandations découlent de publications portant tant sur des adultes que sur des enfants. Compte tenu des limites de généralisation des données provenant de sujets adultes pour des enfants, il faudrait évaluer ces recommandations d’après les avis d’experts plutôt que d’après les données probantes. CONCLUSION : Les cliniciens doivent savoir que les antipsychotiques de deuxième génération ont le potentiel d’induire des effets secondaires neurologiques et devraient faire preuve d’une extrême vigilance lorsqu’ils en prescrivent. PMID:24082814

Étude par RMN à l'état solide de catalyseurs oxydes du type Mo-P-Al

NASA Astrophysics Data System (ADS)

Quartararo, J.; Rigole, M.; Guelton, M.; Amoureux, J. P.; Grimblot, J.

1999-10-01

Solid state 27Al NMR and especially 27Al MQMAS is used to characterize the oxide Mo-P-Al hydrotreating catalysts. This application shows that NMR is an efficient method to determine the local structure of the elements in the amorphous catalysts. So, this permits to conclude that the association of the Mo and the P leads to the formation of aluminium phosphates and that differences in the structure depend on the method of preparation. La RMN du solide et notamment la méthode “MQMAS" de 27Al est utilisée pour caractériser en détail les catalyseurs d'hydrotraitement du type Mo-P-Al sous forme oxyde. Cette application montre que la RMN est un outil efficace pour déterminer la structure locale des éléments introduits dans les catalyseurs de caractère amorphe. Ainsi, elle permet d'établir que le Mo associé au P induit la formation de phosphates d'aluminium. Des différences de structure en fonction de la méthode de préparation sont également observées.

Aspects technologiques d'un alternateur synchrone entièrement supraconducteur de 18 kVA

NASA Astrophysics Data System (ADS)

Védrine, P.; Brunet, Y.; Tixador, P.; Bonnet, P.; Laumond, Y.; Sabrié, J. L.

1991-02-01

Taking advantage of the recent development of low loss a.c. superconducting conductors, the realization of a fully superconducting generator is now possible. In collaboration with GEC-ALSTHOM we have first, in the CRTBT-LEG lab, defined the main characteristics of the machine and the technological problems induced by the use of superconducting wires both at the armature and the field windings. We have now constructed the first fully superconducting generator with separated cryostats, for the stator and rotor windings. Le faible niveau de pertes en régime alternatif obtenu dans des brins multifilamentaires NbTi produits par GEC-ALSTHOM, a permis à partir de 1984 d'envisager la réalisation d'un alternateur synchrone dont les deux enroulements, inducteur et induit, seraient supraconducteurs. Le travail entrepris au CRTBT-LEG en collaboration avec GEC-ALSTHOM a eu pour objectif de définir les caractéristiques de la machine, d'identifier puis de résoudre les problèmes technologiques liés aux conditions d'utilisation de ces supraconducteurs, afin de réaliser maintenant, le premier alternateur entièrement supraconducteur à axe horizontal avec des cryostats statorique et rotorique séparés.

Interprétation cohérente du coefficient de Poisson négatif rapporté dans des multicouches métalliques : rôle du paramètre libre de contrainte

NASA Astrophysics Data System (ADS)

Badawi, K. F.; Goudeau, Ph.; Durand, N.

1998-04-01

Elastic properties of multilayers with low period thickness show in some cases anomalies which are generally correlated with structural modifications in individual layers. In the recent past, several studies have evidenced using X-ray diffraction in-plane and out-of-plane strains with the same sign. Some authors have then proposed in the case of W/Ni and Nb/Cu metallic superlattices to use a negative Poisson's ratio. This result is surprising because the value of this coefficient in metals is generally positive. In this article, we introduce a novel interpretation mainly based on the experimental determination by sin^2Psi method of the reference parameter (stress-free lattice parameter) used in strain calculations. Then, we show that the introduction of the bulk parameter instead of stress-free parameter for the reference parameter is an unrealistic assumption in the case of thin films and multilayers (W and Ag/Ni) and may thus lead to wrong results which are then in total disagreement with those obtained by other techniques. Therefore, the elastic anomaly concerning Poisson's ratio which has been reported by some authors in scientific literature do not result from real structure of multilayers but from experimental X-ray diffraction data analysis. Les propriétés élastiques dans certains systèmes multicouches de faible période présentent des anomalies qui sont généralement associées à des modifications des propriétés structurales de chacune des couches. Ainsi, plusieurs études ont mis en évidence par diffraction des rayons X des déformations de même signe dans le plan et selon la normale au plan des couches déposées. Certains auteurs ont alors proposé dans le cas de systèmes métalliques W/Ni et Nb/Cu l'utilisation d'un coefficient de Poisson négatif. Ce résultat est surprenant car la valeur de ce coefficient pour les métaux est généralement positive. Dans cet article, nous présentons une nouvelle interprétation reposant sur la détermination expérimentale par la méthode des sin^2Psi de la référence (paramètre libre de contrainte) servant de base au calcul des déformations. Nous montrons alors que l'introduction du paramètre du matériau massif comme référence est une hypothèse irréaliste dans le cas des films minces et multicouches (W et Ag/Ni) qui peut conduire à des résultats erronés et en total désaccord avec ceux obtenus par d'autres techniques. Ainsi, l'anomalie élastique au niveau du coefficient de Poisson soulevée par certains auteurs dans la littérature n'est pas imputable à la structure elle-même mais à l'analyse qui est faite des données expérimentales obtenues par diffraction des rayons X.

Subaqueous volcanism in the Etnean area: evidence for hydromagmatic activity and regional uplift inferred from the Castle Rock of Acicastello

NASA Astrophysics Data System (ADS)

Corsaro, R. A.; Cristofolini, R.

2000-01-01

The subalkaline rocks outcropping at the Acicastello Castle Rock, Catania, Sicily, and on its abrasion platforms, are related to the oldest Etnean volcanism (500-300 ka; [Gillot, P.Y., Kieffer, G., Romano, R., 1994. The evolution of Mount Etna in the light of potassium-argon dating. Acta Vulcanol. 5, 81-87.]). Here, submarine lavas with pillows closely packed onto each other are associated with heterogeneous and poorly sorted volcaniclastic breccia levels with sub-vertical sharp boundaries. The present-day attitude was previously interpreted as due to a local tilt [Di Re, M., 1963. Hyaloclastites and pillow-lavas of Acicastello (Mt. Etna). Bull. Volcanol. 25, 281-284.; Kieffer, G., 1985. Evolution structurale et dynamique d'un grand volcan polygenique: stades d'edification et activitè actuelle de l'Etna (Sicile). Clermont Ferrand IIDoctorat Etat Tesi, Clermont Ferrand II.], or to the seaward sliding of the entire eastern Etnean flank [Borgia, A., Ferrari, L., Pasquarè, G., 1992. Importance of gravitational spreading in the tectonic and volcanic evolution of Mount Etna. Nature 357, 231-235.], on the assumption of originally horizontal boundaries. On the contrary, our observations do not match the hypothesis of a significantly tilted succession and lead us to conclude that, apart from the strong regional uplift, the present Castle Rock exposure did not suffer any substantial change of its attitude.

Étude de la structure des alliages vitreux Ag-As2S3 par diffraction de rayons X

NASA Astrophysics Data System (ADS)

Popescu, M.; Sava, F.; Cornet, A.; Broll, N.

2002-07-01

The structure of several silver alloyed arsenic chalocgenide has been determined by X-ray diffraction. For low silver doping the disordered layer structure, characteristic to the glassy AS2S3 is retained as demonstrated by the well developed first sharp diffraction peak in the X-ray diffraction pattern. For high amount of silver introduced in the As2S3 matrix, the disoredered layer configurations disappear, as shown by the diminishing and even disappearance of the first sharp diffraction peak in the X-ray patterns. A three-dimensional structure based on Ag2S -type configuration is formed. La structure de quelques alliages sulfure d'arsenic - argent a été determinée par diffraction de rayons X. Pour de faibles dopages à l'argent on conserve la structure desordonnées caractéristique des couches atomique d'As2S3 vitreux ; ceci est prouvé par la forte intensité du premier pic étroit de diffraction. Pour des plus grandes proportions d'argent la structure de l'alliage vitreux fait apparaître des unités structurales caractéristiques du cristal d'Ag2S et la configuration atomique avec des couches desordonnées disparaît (le premier pic étroit de diffraction s'évanouit) en faisant place à une structure tridimensionelle.

Etudes optiques de nouveaux materiaux laser: Des orthosilicates dopes a l'ytterbium: Le yttrium (lutetium,scandium) pentoxide de silicium

NASA Astrophysics Data System (ADS)

Denoyer, Aurelie

La decouverte et l'elaboration de nouveaux materiaux laser solides suscitent beaucoup d'interet parmi la communaute scientifique. En particulier les lasers dans la gamme de frequence du micron debouchent sur beaucoup d'applications, en telecommunication, en medecine, dans le domaine militaire, pour la, decoupe des metaux (lasers de puissance), en optique non lineaire (doublage de frequence, bistabilite optique). Le plus couramment utilise actuellement est le Nd:YAG dans cette famille de laser, mais des remplacants plus performants sont toujours recherches. Les lasers a base d'Yb3+ possedent beaucoup d'avantages compares aux lasers Nd3+ du fait de leur structure electronique simple et de leur deterioration moins rapide. Parmi les matrices cristallines pouvant accueillir l'ytterbium, les orthosilicates Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5 se positionnent tres bien, du fait de leur bonne conductivite thermique et du fort eclatement de leur champ cristallin necessaire a l'elaboration de lasers quasi-3 niveaux. De plus l'etude fine et systematique des proprietes microscopiques de nouveaux materiaux s'avere toujours tres interessante du point de vue de la recherche fondamentale, c'est ainsi que de nouveaux modeles sont concus (par exemple pour le champ cristallin) ou que de nouvelles proprietes inhabituelles sont decouvertes, menant a de nouvelles applications. Ainsi d'autres materiaux dopes a l'ytterbium sont connus pour leurs proprietes de couplage electron-phonon, de couplage magnetique, d'emission cooperative ou encore de bistabilite optique, mais ces proprietes n'ont encore jamais ete mises en evidence dans Yb:Y 2SiO5, Yb:Lu2SiO5 et Yb:Sc2SiO 5. Ainsi, cette these a pour but l'etude des proprietes optiques et des interactions microscopiques dans Yb:Y2SiO 5, Yb:Lu2SiO5 et Yb:Sc2SiO5. Nous utilisons principalement les techniques d'absorption IR et de spectroscopie Raman pour determiner les excitations du champ cristallin et les modes de vibration dans le materiau. Des mesures optiques sous champ magnetique ont egalement ete effectuees dans le but de caracteriser le comportement de ces excitations lorsqu'elles sont soumises a l'effet Zeeman. La resonance paramagnetique electronique a permis de completer cette etude de l'eclatement Zeeman suivant toutes les orientations du cristal. Enfin la fluorescence par excitation selective et la fluorescence induite par Raman FT, completent la description des niveaux d'energie et revelent l'existence d'emission cooperative de deux ions Yb3+ et de transferts d'energie. Les resultats de cette these apportent une contribution originale dans le domaine des nouveaux materiaux lasers par l'etude et la comprehension des interactions fines et des proprietes microscopiques d'un materiau en particulier. Ils debouchent a la fois sur des applications possibles dans le domaine de l'optique et des lasers, et sur la comprehension d'aspects fondamentaux. Cette these a prouve l'interet de ces matrices pour leur utilisation comme lasers solides: un fort eclatement du champ cristallin favorable a l'elaboration de laser quasi-3 niveaux, et de larges bandes d'absorption (dues a un fort couplage electron-phonon et a des raies satellites causees par une interaction d'echange entre deux ions Yb3+) qui permettent la generation d'impulsions laser ultra-courtes, l'accordabilite du laser, etc. De plus la miniaturisation des lasers est possible pour l'optique integree grace a des couches minces synthetisees par epitaxie en phase liquide dont nous avons demontre la tres bonne qualite structurale et l'ajustement possible de certains parametres. Nous avons reconstruit le tenseur g du niveau fondamental (qui donne des informations precieuses sur les fonctions d'onde), ceci dans le but d'aider les theoriciens a concevoir un modele de champ cristallin valide. Plusieurs mecanismes de transferts d'energie ont ete mis en evidence: un mecanisme de relaxation d'un site vers l'autre, un mecanisme d'emission cooperative, et un mecanisme d'excitation de l'Yb3+ par le Tm3+ (impurete presente dans le materiau). Ces transferts sont plutot nefastes pour la fabrication d'un laser mais sont interessants pour l'optique non lineaire (doublage de frequence, memoires optiques). Enfin, plusieurs elements (le couplage magnetique de paire, le couplage electron-phonon et l'emission cooperative) nous ont permis de conclure sur le caractere covalent de la matrice. Nous avons d'ailleurs demontre ici le role de la covalence dans l'emission cooperative, transition habituellement attribuee aux interactions multipolaires electriques.

Gestion des ressources hydriques adaptee aux changements climatiques pour la production optimale d'hydroelectricite. Etude de cas: Bassin versant de la riviere Manicouagan

NASA Astrophysics Data System (ADS)

Haguma, Didier

Il est dorenavant etabli que les changements climatiques auront des repercussions sur les ressources en eau. La situation est preoccupante pour le secteur de production d'energie hydroelectrique, car l'eau constitue le moteur pour generer cette forme d'energie. Il sera important d'adapter les regles de gestion et/ou les installations des systemes hydriques, afin de minimiser les impacts negatifs et/ou pour capitaliser sur les retombees positives que les changements climatiques pourront apporter. Les travaux de la presente recherche s'interessent au developpement d'une methode de gestion des systemes hydriques qui tient compte des projections climatiques pour mieux anticiper les impacts de l'evolution du climat sur la production d'hydroelectricite et d'etablir des strategies d'adaptation aux changements climatiques. Le domaine d'etude est le bassin versant de la riviere Manicouagan situe dans la partie centrale du Quebec. Une nouvelle approche d'optimisation des ressources hydriques dans le contexte des changements climatiques est proposee. L'approche traite le probleme de la saisonnalite et de la non-stationnarite du climat d'une maniere explicite pour representer l'incertitude rattachee a un ensemble des projections climatiques. Cette approche permet d'integrer les projections climatiques dans le probleme d'optimisation des ressources en eau pour une gestion a long terme des systemes hydriques et de developper des strategies d'adaptation de ces systemes aux changements climatiques. Les resultats montrent que les impacts des changements climatiques sur le regime hydrologique du bassin de la riviere Manicouagan seraient le devancement et l'attenuation de la crue printaniere et l'augmentation du volume annuel d'apports. L'adaptation des regles de gestion du systeme hydrique engendrerait une hausse de la production hydroelectrique. Neanmoins, une perte de la performance des installations existantes du systeme hydrique serait observee a cause de l'augmentation des deversements non productibles dans le climat futur. Des strategies d'adaptation structurale ont ete analysees pour augmenter la capacite de production et la capacite d'ecoulement de certaines centrales hydroelectriques afin d'ameliorer la performance du systeme. Une analyse economique a permis de choisir les meilleures mesures d'adaptation et de determiner le moment opportun pour la mise en oeuvre de ces mesures. Les resultats de la recherche offrent aux gestionnaires des systemes hydriques un outil qui permet de mieux anticiper les consequences des changements climatiques sur la production hydroelectrique, incluant le rendement de centrales, les deversements non productibles et le moment le plus opportun pour inclure des modifications aux systemes hydriques. Mots-cles : systemes hydriques, adaptation aux changements climatiques, riviere Manicouagan

Comparaison des effets des irradiations γ, X et UV dans les fibres optiques

NASA Astrophysics Data System (ADS)

Girard, S.; Ouerdane, Y.; Baggio, J.; Boukenter, A.; Meunier, J.-P.; Leray, J.-L.

2005-06-01

Les fibres optiques présentent de nombreux avantages incitant à les intégrer dans des applications devant résister aux environnements radiatifs associés aux domaines civil, spatial ou militaire. Cependant, leur exposition à un rayonnement entraîne la création de défauts ponctuels dans la silice amorphe pure ou dopée qui constitue les différentes parties de la fibre optique. Ces défauts causent, en particulier, une augmentation transitoire de l'atténuation linéique des fibres optiques responsable de la dégradation voire de la perte du signal propagé dans celles-ci. Dans cet article, nous comparons les effets de deux types d'irradiation: une impulsion X et une dose γ cumulée. Les effets de ces irradiations sont ensuite comparés avec ceux induits par une insolation ultraviolette (244 nm) sur les propriétés d'absorption des fibres optiques. Nous montrons qu'il existe des similitudes entre ces différentes excitations et qu'il est possible, sous certaines conditions, d'utiliser celles-ci afin d'évaluer la capacité de certaines fibres optiques à fonctionner dans un environnement nucléaire donné.

Oscillator strengths of the optical transitions in a semiconductor superlattice under an electric field

NASA Astrophysics Data System (ADS)

Tronc, P.

1992-04-01

The oscillator strengths of the optical transitions in a semiconductor superlattice under an electric field parallel to the growth axis can be calculated using a perturbative model with Bloch envelope functions. The applied electric field and the electron-hole interaction inducing formation of indirect excitons both induce strength asymmetry between the oblique +p and -p transitions of the Wannier-Stark ladder. Features of the photocurrent spectra recorded at low temperature can be accounted for by the present model in a very simple manner. Les forces d'oscillateur des transitions optiques dans un superréseau semiconducteur soumis à un champ électrique parallèle à la direction de croissance, peuvent être calculées à l'aide d'un modèle de perturbation avec des fonctions enveloppes de Bloch. Le champ électrique appliqué ainsi que l'interaction électron-trou, qui induit la formation d'excitons indirects, entraînent une asymétrie entre les forces d'oscillateur des transitions +p et -p dans l'échelle de Wannier-Stark. Certaines caractéristiques des spectres de photocourant enregistrés à basse température peuvent être prévues d'une manière très simple.

La victimisation homophobe et liée à la non-conformité de genre et l’adaptation scolaire et psychosociale chez les 14–22 ans : Résultats d’une enquête québécoise

PubMed Central

Boucher, Kathleen; Blais, Martin; Hébert, Martine; Gervais, Jesse; Banville-Côté, Christine; Bédard, Isabelle; Dragieva, Nataliya

2017-01-01

Résumés Cet article étudie la victimisation homophobe et liée à la non-conformité de genre et ses effets sur l’adaptation scolaire et psychosociale de jeunes Québécois. Un échantillon non probabiliste de 262 jeunes (173 filles, 89 garçons), âgés de 14 à 22 ans (M = 17,9 ans) a été constitué. Des comparaisons bivariées et un modèle d’équations structurales ont été réalisés. Les jeunes LGBTQ affichent un sentiment de sécurité à l’école et une réussite scolaire autoévaluée plus faibles et un niveau de détresse psychologique plus élevé. Les résultats montrent que la victimisation homophobe, le soutien social des amis, la détresse psychologique et le sentiment de sécurité à l’école jouent un rôle médiateur important dans la réussite scolaire autoévaluée des jeunes LGBTQ. Ces constats appuient l’importance de mettre en place des interventions pour réduire l’homophobie dans les écoles et soulignent le rôle central des pairs dans cet effort. PMID:28191287

L'analyse par activation de neutrons de réacteur

NASA Astrophysics Data System (ADS)

Meyer, G.

2003-02-01

Quand les neutrons traversent la matière, certains sont transmis sans interaction, les autres interagissent avec le milieu traversé par diffusion et par absorption. Ce phénomène d'absorption est utilisé pour se protéger des neutrons, mais aussi pour les détecter; il peut également être utilisé pour identifier les noyaux “absorbants" et ainsi analyser le milieu traversé. En effet par différentes réactions nucléaires (n,γ), (n,p), (n,α), (n,fission), on obtient des noyaux résiduels qui sont souvent radioactifs; on dit que l'échantillon est “activé". Si l'on connaît le rendement d'activation et donc le pourcentage de noyaux ainsi “transmutés", les mesures de radioactivité induite vont permettre de déterminer la composition de l'échantillon irradié. Cette méthode dite d'analyse par activation neutronique est pratiquée depuis la découverte du neutron. Elle a permis grâce à sa sélectivité et à sa sensibilité d'avoir accès au domaine des traces et des ultra-traces dans des champs d'application très divers comme la métallurgie, l'archéologie, la biologie, la géochimie etc...

Trapping of edge dislocations by a moving smectic-A smectic-B interface

NASA Astrophysics Data System (ADS)

Oswald, P.; Lejcek, L.

1991-09-01

We analyze how the motion of the edge dislocations of the smectic-A liquid crystal allows the system to relax plastically the stresses that are generated during the growth of the smectic-B plastic crystal. These stresses are both due, to the density difference between the two phases, and to the layer thickness variation at the phase transition. In particular, we calculate under which conditions a dislocation can be trapped by the smectic-B phase. Finally, we suggest that this dynamical trapping is responsible for the very large amount of stacking faults observed by X-ray diffraction. Nous analysons comment le mouvement des dislocations coin du cristal liquide smectique A permet de relaxer plastiquement les contraintes induites par la croissance du cristal plastique smectique B. Ces contraintes sont engendrées à la fois par la différence de densité qui existe entre les deux phases et par la variation d'épaisseur des couches à la transition. Nous calculons en particulier dans quelles conditions une dislocation coin peut être piégée par le smectique B. Enfin, nous suggérons que ce piégeage dynamique est à l'origine de la très forte densité de fautes d'empilement qui est couramment observée aux rayons X dans la phase B.

Proprietes ionochromes et photochromes de derives du polythiophene

NASA Astrophysics Data System (ADS)

Levesque, Isabelle

La synthese et la caracterisation de derives regioreguliers du polythiophene ont ete effectuees en solution et sur des films minces. La spectroscopie UV-visible de ces derives a permis de constater qu'ils peuvent posseder des proprietes chromiques particulieres selon le stimulus auquel ils sont soumis. Par exemple, une augmentation de la temperature permet en effet aux polymeres de passer d'une couleur violette a jaune, et ce, a l'etat solide aussi bien qu'en solution. Ces proprietes chromiques semblent regies par une transition conformationnelle (plane a non-plane) de la chaine principale. Ce travail avait pour but de mieux comprendre l'influence de l'organisation des chaines laterales sur les transitions chromiques. Deux derives synthetises possedant des chaines laterales sensibles aux cations alcalins se sont averes etre ionochromes en plus d'etre thermochromes. Il s'agit d'un polymere comportant des chaines laterales de type oligo(oxyethylene) et d'un autre comportant un groupement ether couronne specifique aux ions lithium. Les effets chromiques observes sont expliques par des interactions non-covalentes des cations avec les atomes d'oxygene des chaines laterales dans le cas du premier polymere, et par l'insertion de l'ion Li + dans la cavite de l'ether couronne dans le cas du second polymere. Ces interactions semblent provoquer une diminution de l'organisation induisant ainsi une torsion de la chaine principale. Les deux polymeres semblent specifiques a certains cations et pourraient donc servir comme detecteurs optiques. La specificite aux ions Li+ du second polymere pourrait aussi permettre la conduction ionique, en plus de la conductivite electronique caracteristique des polythiophenes, ce qui pourrait s'averer utile dans le cas de batteries legeres entierement faites de polymeres et de sels de lithium. D'autres derives comportant des chaines laterales de type azobenzene se sont averes etre photochromes en plus d'etre thermochromes. Le groupement lateral a la possibilite de changer de configuration de la forme trans a la forme cis lorsqu'il est soumis a une irradiation dans le domaine de l'ultraviolet ce qui provoque, selon toute evidence, un effet marque sur l'organisation des chaines laterales. Cela induit alors une torsion de la chaine principale thiophene entrainant une diminution de conjugaison marquee. Ces effets peuvent etre exploites entre autres dans l'ecriture optique. Il s'est avere que le polymere irradie peu conjugue peut etre force a retourner a son etat initial conjugue tres rapidement par un traitement electrochimique simple. En conclusion, on a pu prouver qu'une modification dans l'organisation des chaines laterales par un stimulus exterieur affecte considerablement la conformation de la chaine principale. Cela porte a croire que les chaines laterales stabilisent une conformation particuliere des polythiophenes.

Dynamique moléculaire et canaux ioniques

NASA Astrophysics Data System (ADS)

Crouzy, S.

2005-11-01

Diffusion de neutrons et Dynamique Moléculaire (DM) sont deux techniques intimement liées car elles portent sur les mêmes échelles de temps: la première apporte des informations structurales ou dynamiques sur le système physique ou biologique, la seconde permet de décoder ces informations à travers un modèle facilitant l'interprétation des résultats. Au delà de l'intérêt que la technique de DM peut avoir en relation directe avec les neutrons, il est intéressant de comprendre comment les modèles sont construits et comment les techniques de simulation peuvent aller beaucoup plus loin que de simples modélisations. Nous décrirons brièvement, dans la suite de cet exposé, la technique de DM et les méthodes plus sophistiquées de calculs d'énergie libre et de potentiels de force moyenne à partir des simulations de DM. Puis nous verrons avec deux exemples tirés de nos travaux théoriques sur les canaux ioniques comment ces calculs peuvent nous donner accès à des vitesses de réaction ou des constantes d'affinité ou de liaison. La première étude porte sur un analogue de la gramicidine A qui forme un canal conducteur d'ions interrompus par le basculement d'un cycle dioxolane [1]. La seconde concerne le canal potassique KcsA dont nous avons étudié le blocage du coté extracellulaire par l'ion Tetra Ethyl Ammonium [2].

Utilisation de l'essai comete et du biomarqueur gamma-H2AX pour detecter les dommages induits a l'ADN cellulaire par le 5-bromodeoxyuridine post-irradiation

NASA Astrophysics Data System (ADS)

La Madeleine, Carole

Ce memoire est presente a la Faculte de medecine et des sciences de la sante de l'Universite de Sherbrooke en vue de l'obtention du grade de maitre es sciences (M.Sc.) en radiobiologie (2009). Un jury a revise les informations contenues dans ce memoire. Il etait compose de professeurs de la Faculte de medecine et des sciences de la sante soit : Darel Hunting PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Leon Sanche PhD, directeur de recherche (departement de medecine nucleaire et radiobiologie), Richard Wagner PhD, membre du programme (departement de medecine nucleaire et radiobiologie) et Guylain Boissonneault PhD, membre exterieur au programme (departement de biochimie). Le 5-bromodeoxyuridine (BrdU), un analogue halogene de la thymidine reconnu depuis les annees 60 comme etant un excellent radiosensibilisateur. L'hypothese la plus repandue au sujet de l'effet radio sensibilisant du BrdU est qu'il augmente le nombre de cassures simple et double brin lorsqu'il est incorpore dans l'ADN de la cellule et expose aux radiations ionisantes. Toutefois, de nouvelles recherches semblent remettre en question les observations precedentes. Ces dernieres etudes ont confirme que le BrdU est un bon radiosensibilisateur, car il augmente les dommages radio-induits dans l'ADN. Mais, c'est en etant incorpore dans une region simple brin que le BrdU radiosensibilise l'ADN. Ces recherches ont egalement revele pour la premiere fois un nouveau type de dommages produits lors de l'irradiation de l'ADN contenant du BrdU : les dimeres interbrins. Le but de ces travaux de recherche est de determiner si la presence de bromodeoxyuridine dans l'ADN augmente l'induction de bris simple et / ou double brin chez les cellules irradiees en utilisant de nouvelles techniques plus sensibles et specifiques que celles utilisees auparavant. Pour ce faire, les essais cometes et la detection des foci H2AX phosphorylee pourraient permettre d'etablir les effets engendres par le BrdU au niveau cellulaire. Notre hypothese (basee sur des resultats preliminaires effectues dans notre laboratoire) est que l'irradiation de l'ADN cellulaire en presence de BrdU augmentera le nombre de bris simple brin sans toutefois augmenter le nombre de bris double brin. Les resultats presentes dans ce memoire semblent corroborer cette hypothese. Les nouvelles methodes d'analyse, soient l'essai comete et la detection des foci gamma-H2AX remettent en question ce qui a ete dit sur le BrdU au sujet de l'induction des cassures double brin depuis plusieurs annees. L'ensemble de ces nouveaux resultats effectue a l'aide de cellules ayant incorporees du BrdU sont en correlation avec de precedents resultats obtenus dans notre laboratoire sur des oligonucleotides bromes. Ils reaffirment que l'irradiation combinee au BrdU augmente l'induction de bris simple brin mais pas de bris double brin. L'investigation approfondie des mecanismes d'action non elucides du BrdU au niveau cellulaire et son utilisation a des moments strategiques pendant le traitement de radiotherapie pourraient accroitre son efficacite a des fins d'utilisation clinique. Mots cles : 5-bromodeoxyuridine, dimeres interbrins, dommage a l'ADN, essai comete, H2AX, radiosensibilisateur, radiotherapie

Mesure et retroaction sur un qubit multi-niveaux en electrodynamique quantique en circuit non lineair

NASA Astrophysics Data System (ADS)

Boissonneault, Maxime

L'electrodynamique quantique en circuit est une architecture prometteuse pour le calcul quantique ainsi que pour etudier l'optique quantique. Dans cette architecture, on couple un ou plusieurs qubits supraconducteurs jouant le role d'atomes a un ou plusieurs resonateurs jouant le role de cavites optiques. Dans cette these, j'etudie l'interaction entre un seul qubit supraconducteur et un seul resonateur, en permettant cependant au qubit d'avoir plus de deux niveaux et au resonateur d'avoir une non-linearite Kerr. Je m'interesse particulierement a la lecture de l'etat du qubit et a son amelioration, a la retroaction du processus de mesure sur le qubit de meme qu'a l'etude des proprietes quantiques du resonateur a l'aide du qubit. J'utilise pour ce faire un modele analytique reduit que je developpe a partir de la description complete du systeme en utilisant principalement des transfprmations unitaires et une elimination adiabatique. J'utilise aussi une librairie de calcul numerique maison permettant de simuler efficacement l'evolution du systeme complet. Je compare les predictions du modele analytique reduit et les resultats de simulations numeriques a des resultats experimentaux obtenus par l'equipe de quantronique du CEASaclay. Ces resultats sont ceux d'une spectroscopie d'un qubit supraconducteur couple a un resonateur non lineaire excite. Dans un regime de faible puissance de spectroscopie le modele reduit predit correctement la position et la largeur de la raie. La position de la raie subit les decalages de Lamb et de Stark, et sa largeur est dominee par un dephasage induit par le processus de mesure. Je montre que, pour les parametres typiques de l'electrodynamique quantique en circuit, un accord quantitatif requiert un modele en reponse non lineaire du champ intra-resonateur, tel que celui developpe. Dans un regime de forte puissance de spectroscopie, des bandes laterales apparaissent et sont causees par les fluctuations quantiques du champ electromagnetique intra-resonateur autour de sa valeur d'equilibre. Ces fluctuations sont causees par la compression du champ electromagnetique due a la non-linearite du resonateur, et l'observation de leur effet via la spectroscopie d'un qubit constitue une premiere. Suite aux succes quantitatifs du modele reduit, je montre que deux regimes de parametres ameliorent marginalement la mesure dispersive d'un qubit avec un resonateur lineaire, et significativement une mesure par bifurcation avec un resonateur non lineaire. J'explique le fonctionnement d'une mesure de qubit dans un resonateur lineaire developpee par une equipe experimentale de l'Universite de Yale. Cette mesure, qui utilise les non-linearites induites par le qubit, a une haute fidelite, mais utilise une tres haute puissance et est destructrice. Dans tous ces cas, la structure multi-niveaux du qubit s'avere cruciale pour la mesure. En suggerant des facons d'ameliorer la mesure de qubits supraconducteurs, et en decrivant quantitativement la physique d'un systeme a plusieurs niveaux couple a un resonateur non lineaire excite, les resultats presentes dans cette these sont pertinents autant pour l'utilisation de l'architecture d'electrodynamique quantique en circuit pour l'informatique quantique que pour l'optique quantique. Mots-cles: electrodynamique quantique en circuit, informatique quantique, mesure, qubit supraconducteur, transmon, non-linearite Kerr

Tableau de cécité bilatérale à fond d’œil normal révélant un anévrisme non rompu de l'artère cérébrale communicante antérieure

PubMed Central

Ismaili, Abdellah Alaoui; Abdellaoui, Meriem; Khrifi, Zineb; Eddassi, Noureddine; Nejjari, Ourda; Andaloussi, Idriss Benatiya; Tahri, Hicham

2014-01-01

Les anévrysmes intracrâniens non rompu (AICNR) se manifestent le plus souvent par des tableaux cliniques non spécifiques (céphalées, accidents vasculaires ischémiques cérébraux, paralysies des nerfs crâniens) et sont généralement découverts à l'occasion d'imagerie cérébrale pour d'autres raisons. Une cécité bilatérale révélant AICNR de l'artère communicante antérieure est unique dans la littérature. Il s'agit d'un homme de 48 ans sans antécédents médicaux notables qui consulte aux urgences ophtalmologiques pour baisse de l'acuité visuelle rapidement évolutive en une semaine aboutissant à une cécité bilatérale. L'examen ophtalmologique objective une acuité visuelle réduite à la présence d'une perception lumineuse bilatérale avec un bon réflexe photomoteur et le reste de l'examen ophtalmologique qui est strictement normal. Un examen général réalisé en urgence trouve une tension artérielle à 20/14mmHG. L'imagerie cérébrale notamment une tomodensitométrie cérébrale complétée par une imagerie en résonnance magnétique objective un aspect spectaculaire d'un grand anévrisme de l'artère cérébrale communicante antérieure partiellement thrombosé responsable d'une compression isolée du chiasma optique. Après un équilibre de l'hypertension artérielle le patient a été adressé en neurochirurgie pour une thérapeutique en urgence. Un anévrisme est toujours la conséquence d'une modification structurale de la paroi artérielle. Dans leur forme commune, les anévrismes développés sur les artères intracrâniennes sont sacciformes. Ses étiologies sont nombreuses et variées. L’évolution des anévrysmes intracrâniens se fait vers une augmentation de leur volume sous l'influence de facteurs hémodynamiques qui conduit à une fragilisation de leur paroi. Une rupture de l'anévrisme est le mode de découverte le plus fréquent et aussi le plus dramatique. Toute baisse d'acuité visuelle à fond d'oeil normal doit imposer sans retard une imagerie orbito-cérébrale. PMID:25392724

Etude de la structure électronique et magnétique de CrO_2

NASA Astrophysics Data System (ADS)

Matar, S.; Demazeau, G.; Sticht, J.; Eyert, V.; Kübler, J.

1992-03-01

The electronic and magnetic properties of CrO2 were investigated using the self-consistent A.S.W. method in a new approach to study the evolution of its magnetic properties at deceasing volume and to assess recent photoemission results on thin films. The results show that a magnetic transition of ferro Rightarrow antiferromagnetic type is likely to be induced under pressure. Experimental results could be explained by a compression of the CrO6 octahedron within the cell. Les propriétés électroniques de CrO2 ont été déterminées par la méthode auto-cohérente de l'onde sphérique augmentée : A.S.W. Cette étude est menée dans le cadre d'une nouvelle approche visant à définir lévolution de ses propriétés magnétiques à volume décroissant d'une part et à élucider les résultats expérimentaux récents de photoémission sur couches minces d'autre part. Les résultats des calculs montrent qu'une transition magnétique de type ferro Rightarrow antiferromagnétique est susceptible d'être induite sous l'effet de la pression. Les résultats expérimentaux pourraient être interprétés par une compression de l'octaèdre CrO6 au sein de la maille.

Influence des traitements thermiques et de la microstructure sur les phénomènes de découplage dans les composés au bismuth

NASA Astrophysics Data System (ADS)

Nicolas, M.; Guyen van Huong, C. N.; Burger, J. P.; Dubon, A.; Fitoussi, J. P.; Laval, J. Y.

1991-11-01

a.c. susceptibility measurements and 3D electronic microscopy observation were carried out on three Bi-compounds (2212 and 2223). Depending on the annealing conditions, one observes lamellar-type materials organized either in a more or less dense structure of fine particles or in very large slabs. The a.c. susceptibility signals allow to separate the intergranular from the intragranular effects. The combined results obtained by both techniques lead us to conclude that the intergranular and the intragranular decoupling, induced by magnetic fields are of same nature, i.e. occur at the (BiO)2 slab. Nous avons couplé des mesures de susceptibilité altemative et d'observation au microscope électronique en 3D sur trois échantillons supraconducteurs au bismuth (2212 et 2223). Selon les conditions de recuit, on observe des matériaux de type lamellaire, organisés soit en une structure plus ou moins dense de fines particules, soit en larges plaquettes. L'étude des signaux de susceptibilité alternative χ' et χ'' permet de séparer les effets intergranulaires des effets intragranulaires. les résultats combinés des deux techniques nous ont conduit à conclure que les deux types de découplage (inter et intragranulaires), induits par les champs magnétiques sont de même nature, c'est-à-dire se produisent au niveau des bicouches (BiO)2.

Appareillage automatisé de mesure simultanée du pouvoir thermoélectrique et de la conductivité électrique. Application à l'étude de couches polymères semi-conductrices

NASA Astrophysics Data System (ADS)

Moliton, A.; Ratier, B.; Moreau, C.; Froyer, G.

1991-05-01

In this paper, we present an automatized system for simultaneous measurement of conductivity σ, and thermoelectric power S : measurements are allowed for temperatures ranging from 130 K to 360 K on brittle semiconductor layers. As an example of the application, results obtained in the case of polymer (PPP) layers implanted with Na ions are presented : with high energy implantation (E = 250 keV) we observe only a defect semiconduction of p type while at low energy (30 keV) an electronic n type conduction appears. Nous présentons dans cet article un système de mesure simultanée de la conductivité σ, et du pouvoir thermoélectrique S : il permet des mesures en fonction de la température (entre 130 K et 360 K) dans le cas de couches semi-conductrices relativement fragiles. A titre d'application, nous indiquons les résultats que nous avons obtenus dans le cas de couches polymères (PPP) implantées avec des ions sodium: alors que seule une semi-conduction par défaut est générée par de fortes énergies d'implantation (E = 250 keV ), il apparaît une semiconduction induite par le dopage n lors d'implantations à basse énergie (E = 30 keV ).

Avant-Propos

NASA Astrophysics Data System (ADS)

Ollivier, J.; Farhi, E.; Ferrand, M.; Benoit, M.

2005-11-01

L'École Thématique “Neutrons et Biologie” s'est tenue du 22 au 26 Mai 2004 à Praz/Arly (Haute-Savoie, France), dans le cadre des 12 èmes Journees de la Diffusion Neutronique de la Societe Française de Neutronique. Cette école a ete organisee avec le concours financier du CNRS (formation permanente), du Laboratoire Léon Brillouin (CEA Saclay), de la region Rhône-Alpes, du conseil général de Haute-Savoie et de l'Université Joseph Fourier de Grenoble. Une cinquantaine de participants, dont une vingtaine d'intervenants, ont largement contribué à la réussite de l'École. D'un point de vue scientifique, l'École s'est déclinée en sept sessions thématiques majeures: - une première session introductive a été consacrée à une revue globale des méthodes biophysiques ayant un fort impact pour l'étude de la structure et de la dynamique des macromolécules biologiques (J. Parello). Un accent tout particulier à été apporté pour décrire les neutrons en tant que composante importante de la panoplie des techniques couramment utilisées en biophysique moléculaire (J. Schweitzer). - une session dédiée aux mesures dynamiques par diffusion incohérente de neutrons a été largement developpée. Qu'ils s'agissent de vibrations et de relaxations moléculaires dans les protéines (J.M. Zanotti), de dynamique globale des protéines (G. Zaccaï), ainsi que de dynamique de l'eau d'hydratation (F. Gabel), de nombreux exemples ont permis d'illustrer la pertinence des neutrons pour étudier la dynamique fonctionnelle des protéines sur l'échelle de temps picosecond nanoseconde. L'analyse des données de diffusion inélastique de neutrons ne peut se passer de modélisation théorique analytique des propriétés dynamique des biomolécules (D. Bicout). - une large place avait été réservée aux études structurales en biologie. Cette troisième session a rassemblé des contributions en diffusion aux petits angles de neutrons pour l'étude structurale en solution (D. Lairez), en réflectométrie de neutrons pour l'étude de systèmes des membranes ou de protéines en interaction avec des membranes (G. Fragneto), ainsi qu'en diffraction de fibres appliquée à l'étude de l'ADN (T. Forsyth). - les simulations de dynamique moléculaire constituent une méthode théorique unique pour étudier, au niveau atomique, les mouvements internes des macromolécules biologiques, que ce soit à l'équilibre (G. Kneller, S. Crouzy) ou hors équilibre (B. Gilquin). Les trajectoires de dynamique moléculaire s'étendent aujourd'hui à la centaine de nanosecondes, et peuvent être de ce fait utilisées par certains programmes pour calculer les observables expérimentales fournies par la diffusion de neutrons (G. Kneller, T. Hinsen). - l'ouverture des neutrons à des techniques instrumentales permettant d'approcher, d'une part, des états hors-équilibre par le biais d'études cinétiques couplées à des mélanges rapides pour des études de croissance de phases (I. Grillo) ou de repliement de protéines, d'autre part, des conditions expérimentales extrèmes (hautes-pressions, M. Plazanet), nous ont semblé constituer des émergences prometteuses. À ce titre, une revue sur le repliement des protéines (V. Forge) a précisé l'importance de nombreuses techniques (fluorescence intrinsèque, dichroïsme, infra-rouge, RMN) dans le domaine, tout en permettant d'entrevoir l'intérêt des études par neutrons. - en marge des sessions purement “neutrons”, il nous semblait important de pouvoir présenter des techniques et méthodes souvent reconnues comme très complémentaires des neutrons, en privilégiant un volet “études structurales” et un volet “études dynamiques”. Côté méthodes dynamiques, la RMN (M. Blackledge) a été positionnée comme une technique permettant d'étudier la flexibilité moléculaire sur des echelles de temps plus lentes (ms). Côté méthodes structurales, la bio-cristallographie des RX appliquée à l'études des structures virales (P. Gouet) a permis de mettre en évidence des aspects complémentaires entre RX et neutrons, et de souligner les avantages et inconvenients respectifs de ces techniques. - l'École Thématique s'est achevée par une session commune avec les Journées Rossat-Mignod, au cours de laquelle J. Helliwell a établi une revue comparative RX/neutrons sur les développements récents en bio-cristallographie des protéines, suivi de deux presentations portant sur la dynamique incohérente et cohérente de systèmes membranaires (F. Natali, M. Rheinstadter). Contrairement aux années précédentes, le contenu de cet ouvrage se veut davantage refléter les applications des neutrons en biologie et biophysique moléculaire, en se reportant à des travaux scientifiques précis, plutôt que d'être constitué d'un recueil de cours, certes trés pédagogiques, mais quelquefois trop éloignés de l'expérience. Nous espérons que ce choix saura satisfaire le lecteur et encourager de nouveaux biologistes à utiliser les neutrons dès que possible pour leurs systèmes d'intérêt. Bonne lecture et bonnes manips !!!!

Etudes diélectriques de la transition ferroélectrique induite par application d'un champ électrique dans les céramiques PbMg{1/3}Nb{2/3}O3 (PMN)

NASA Astrophysics Data System (ADS)

Chabin, M.; Malki, M.; Husson, E.; Morell, A.

1994-07-01

The evolution of the dielectric permittivity and loss factor under an external applied electric field has been studied in PbMg{1/3}Nb{2/3}O3 ceramics between 80 and 420 K. For a threshold field of 4 kV.cm^{-1}, it is possible to induce a ferroelectric transition from the average cubic phase to a macroscopically polar phase. The poling and depoling temperatures depend on the various combinations of thermal treatments and on the applied field strength. The transition between the nanopolar state and the macropolar state is discussed L'évolution de la permittivité diélectrique et du facteur de pertes diélectriques sous un champ électrique extérieur a été étudiée dans des céramiques de PbMg{1/3}Nb{2/3}O3 enre 80 et 420 K. Pour un champ de seuil de 4 kV.cm^{-1} il est possible d'induire une transition ferroélectrique de la phase cubique moyenne en une phase macroscopiquement polaire. Les températures de polarisation et de dépolarisation dépendent des différentes combinaisons de traitements thermiques et de la valeur du champ appliqué. La transition entre la phase constituée de nanodomaines polaires et la phase constituée de macrodomaines polaires est discutée.

Approche morphologique de la fragmentation de l'ADN radio-induite par immunomarquage anti-poly (ADP-ribose) polymérase (PARP) : étude de cultures d'oligodendrogliomes

NASA Astrophysics Data System (ADS)

Varlet, P.; Beuvon, F.; Cervera, P.; Averbeck, D.; Daumas-Duport, C.

1998-04-01

Poly (ADP-ribose) polymerase (PARP) is a nuclear enzyme encompassing two zinc finger motifs which specifically binds to radiation induced DNA strand breaks. We develop a new immuno-labelling of poly ADP-ribose which coupled together with the immunodetection of cells in cycle with MIB1, permits to detect and quantify the DNA fragmentation induced by radiations (Cesium137). This method, applied to organotypical cultures of human oligodendroglioma, submitted to radiation, a dose dependant nuclear signal. This one increased significantly in the presence of a radiosensitizer like iododeoxyuridine (IUDR 5 g/ml). This poly ADP-ribose immunodetection can be useful, to detect furtherly the individual radiosensitivity of human glioma. Les protéases “ICE-like" ou caspases, sont les homologues humaines du produit du gène ced-3 du ver Caenorhabditis elegans et sont activées lors des étapes précoces de l'apoptose. L'objectif de ce travail vise à déterminer dans quelle mesure l'inhibition de l'une d'entre elles, la caspase-3 est susceptible de modifier la sensibilité des cellules vis-à-vis de l'apoptose radioinduite. Des lymphocytes spléniques murins irradiés en présence de Ac-DVED-CHO un inhibiteur spécifique de la caspase-3 présentent un taux de particules hypodiploïdes radioinduites bien inférieur à celui des contrôles et une diminution drastique de la fragmentation internucléosomale de l'ADN. Toutefois, ni l'externalisation des phospholipides anioniques, autre marqueur spécifique de l'apoptose, ni la viabilité ne sont affectées.

Magnetoresistance Studies in the Low-Dimensional Organic Metal α-(ET){2}TlHg(SeCN){4} under Pressure: Experiments and Simulation by Tight Binding Band Structure Calculations

NASA Astrophysics Data System (ADS)

Auban-Senzier, P.; Audouard, A.; Laukhin, V. N.; Rousseau, R.; Canadell, E.; Brossard, L.; Jérome, D.; Kushch, N. D.

1995-10-01

Magnetotransport measurements have been carried out in layered organic metal α-(ET){2}TlHg(SeCN){4} at temperatures down to 0.4 K and under hydrostatic pressure. Only one... Des mesures de magnétorésistance ont été effectuées dans le conducteur organique bidimensionnel α-(ET){2}TlHg(SeCN){4} jusqu'à la température de 0.4 K et sous pression hydrostatique. Une seule série d'oscillations Shubnikov-de Haas est observée dans la gamme de pression comprise entre 3.5 et 11 kbar. La masse cyclotron décroit lentement lorsque la pression augmente et la fréquence des oscillations augmente rapidement depuis la valeur de (653± 3)T à pression ambiante jusqu'à (790± 3)T à 11 kbar. Une modélisation basée sur la méthode des liaisons fortes suggère que la dépendance en pression de l'aire de l'orbite fermée de la surface de Fermi est due au glissement, induit par la pression, des molécules des chaines ne contenant qu'un type de donneurs. Au contraire de son composé frère α-(ET){2}NH{4}Hg(SCN){4}, il présente des oscillations lentes, de fréquence (47± 3)T, à pression ambiante. Elles ne sont pas observées entre 3.5 et 11 kbar et pourraient être en relation avec un emboîtement des orbites ouvertes à pression ambiante qui pourraient détruire la supraconductivité dans le composé à base de sélénium.

Photoémission de Csl induite par une impulsion laser intense femtoseconde

NASA Astrophysics Data System (ADS)

Belsky, A.; Vasil'Ev, A.; Yatsenko, B.; Bachau, H.; Martin, P.; Geoffroy, G.; Guizard, S.

2003-06-01

Nous avons mesuré pour la première fois les spectres de photoélectrons émis par un cristal isolant à large bande interdite, Csl, avec une dynamique de 10^6 coups/s, excité par la source laser haute cadence du C.E.L.I.A (800 nm, 40 fs, 1 kHz, 1 TW). L'émission d'électrons jusqu'à des énergies de quelques dizaines d'électrons-volts a été observée pour des impulsions d'éclairement compris entre 0.5 et 3 TW/cm^2, relativement faible donc par comparaison aux éclairements utilisés pour accélérer les électrons d'un atome aux mêmes énergies. Ces spectres contiennent tous, en particulier, deux bandes dans le domaine des basses énergies d'électrons (<5 eV), également observées lors d'études précédentes. Les électrons les plus énergétiques forment un plateau intense légèrement structuré et limité par une coupure exponentielle. Pour des impulsions de 3 TW/cm^2 cette coupure est située à 27 eV. L'insuffisance du mécanisme électron-photon-phonon, considéré jusqu'à présent comme le principal processus d'échauffement des électrons dans les solides en interaction non destructrice avec un champ laser, nous a poussé à proposer un mécanisme alternatif. Ce modèle met en évidence les transitions directes multiphotoniques dans la bande de conduction du solide qui sont incontournables du fait de sa structure électronique multi-branches

Amelioration de l'efficacite energetique du procede d'electrolyse de l'aluminium conception d'un nouveau bloc cathodique

NASA Astrophysics Data System (ADS)

Blais, Mathieu

Au Quebec, les alumineries sont de grandes consommatrices d'energie electrique, soit pres de 14 % de la puissance installee d'Hydro-Quebec. Dans ce contexte, des petits gains en efficacite energetique des cuves d'electrolyse pourraient avoir un impact important sur la reduction globale de la consommation d'electricite. Le projet de maitrise decrit dans cette etude repond a la problematique suivante : comment l'optimisation de la geometrie d'un bloc cathodique en vue d'uniformiser la densite de courant peut augmenter l'efficacite energetique et la duree de vie de la cuve d'aluminium? Le but premier du projet est de modifier la geometrie en vue d'ameliorer le comportement thermoelectrique des blocs cathodiques et d'accroitre par le fait meme l'efficacite energetique du procede de production d'aluminium. La mauvaise distribution de la densite de courant dans la cuve est responsable de certains problemes energetiques ayant des impacts negatifs sur l'economie et l'environnement. Cette non-uniformite de la distribution du courant induit une usure prematuree de la surface de la cathode et contribue a reduire la stabilite magnetohydrodynamique de la nappe de metal liquide. Afin de quantifier les impacts que peut avoir l'uniformisation de la densite de courant a travers le bloc cathodique, un modele d'un bloc cathodique d'une cuve de la technologie AP-30 a ete concu et analyse par elements finis. A partir de son comportement thermoelectrique et de donnees experimentales d'une cuve AP-30 tirees de la litterature, une correlation entre le profil de densite de courant a la surface du bloc et le taux d'erosion local au meme endroit a ete creee. Cette relation correspond au modele predictif de la duree de vie de tout bloc du meme materiau a partir de son profil de densite de courant. Ensuite, une programmation a ete faite incorporant dans une meme fonction cout les impacts economiques de la duree de vie, de la chute de voltage cathodique et de l'utilisation de nouveaux materiaux. Ceci a permis d'evaluer les benefices faits a partir d'un bloc modifie par rapport au bloc de reference. Plusieurs parametres geometriques du bloc sont variables sur un domaine realiste et l'integration d'un composant en materiau plus conducteur y a egalement ete etudiee. Utilisant des outils mathematiques d'optimisation, un design de bloc optimal a pu etre trouve. Les resultats demontrent qu'il est possible de generer des economies a partir de la modification du bloc. Il est egalement prouve que l'uniformisation de la densite de courant a travers le bloc peut apporter de grands avantages economiques et environnementaux dans le procede d'electrolyse de l'aluminium. Les resultats de cette etude serviront d'arguments pour les chercheurs dans l'industrie a savoir s'il vaut la peine d'investir ou non dans la fabrication d'un prototype experimental souvent tres couteux. Mots-cles : Efficacite energetique, electrolyse de l'aluminium, cathode, simulation thermoelectrique, uniformisation de la densite de courant, optimisation.

Investigation de l'anisotropie du gap supraconducteur dans les composes Ba(Fe(1-x)Co(x))2As2, Ba(1-x)K(x)Fe2As2, LiFeAs et Fe1-deltaTe(1-x)Se(x)

NASA Astrophysics Data System (ADS)

Reid, Jean-Philippe

ommaire La structure du gap supraconducteur et sa modulation sont intimement liees au potentiel d'interaction responsable de l'appariement des electrons d'un supraconducteur. Ainsi, l'etude de la structure du gap-SC et de sa modulation permettent de faire la lumiere sur la nature du mecanisme d'appariement des electrons. A cet egard, les resultats experimentaux des supraconducteurs a base de fer ne cadrent pas dans un seul ensemble, ce qui est en opposition au gap-SC universel des cuprates. Dans ce qui suit, nous presenterons une etude systematique du gap-SC pour plusieurs pnictides. En effet, en utilisant la conductivite thermique, une sonde directionnelle du gap-SC, nous avons ete en mesure de reveler la structure du gap-SC pour les composes suivants : Ba1-xKxFe 2As2, Ba(Fe1-xCo x)2As2, LiFeAs et Fe1-deltaTe 1-xSex. L'etude de ces quatre composes, de trois differentes familles structurales, a pu etablir un tableau partiel mais tres exhaustif de la structure du gap-SC de pnictides. En effet, tel qu'illustre dans cette these, ces quatre composes ne possedent aucun noeud dans leur structure du gap-SC a dopage optimal. Toutefois, a une concentration differente de celle optimale pour les composes K-Ba122 et Co-Ba122, des noeuds apparaissent sur la surface de Fermi, aux extremites 'du dome supraconducteur. Ceci suggere fortement que, pour ces composes, la presence de noeuds sur la surface de Fermi est nuisible a la phase supraconductrice. Mots-cles: Supraconducteurs a base de fer, Pnictides, Structure du gap supraconducteur, Conductivite thermique

Competition entre supraconductivite et magnetisme au voisinage de la transition de Mott dans le conducteur organique quasi-bidimensionnel k-(BEDT-TTF)2copper[N(CN)2]bromine

NASA Astrophysics Data System (ADS)

Fournier, David

Les conducteurs organiques quasi-bidimensionnels kappa-ET2X presentent d'importantes similitudes avec les SCHT telles qu'une phase isolant de Mott, un regime de pseudogap et un etat supraconducteur. L'etude de leurs proprietes apparait donc complementaire. Parmi les interrogations persistantes concernant la physique de ces systemes, l'origine du (ou des) processus exotique d'appariement, responsable de la supraconductivite est le sujet suscitant l'interet le plus marque dans la communaute. L'hypothese d'un mecanisme lie a la proximite d'un etat antiferromagnetique est privilegiee. Une etape importante dans la resolution de cette problematique est l'identification de la symetrie du parametre d'ordre. D'apres de nombreux travaux sur les systemes fortement correles, la sonde ultrasonore, de par sa sensibilite aux excitations de quasiparticule a basse temperature, est consideree comme particulierement adaptee a l'etude de cette propriete. Cependant, son emploi necessite l'utilisation d'un compose metallique a basse temperature et completement supraconducteur. Le compose metallique organique kappa-ET 2Cu[N(CN)2]Br presente toutes les caracteristiques necessaires a l'etude de cette propriete. En effet, il est situe loin de la transition du premier ordre de Mott et est completement supraconducteur. De facon surprenante, ce systeme semble se coupler fortement avec le reseau ce qui augmente significativement la sensibilite de cette sonde aux proprietes du gaz electronique. Cependant, des difficultes techniques importantes, liees a la nature intrinseque de ce materiau, doivent etre surmontees pour proceder a des mesures suivant differentes polarisations. La presente etude a profondement modifie notre comprehension de ce systeme. En effet, ces mesures ont permis de constater que le kappa-ET2Cu[N(CN)2]Br est un compose qui est situe en bordure de la zone de coexistence entre la supraconductivite et le magnetisme, ce qui constitue un resultat totalement inattendu. De plus, la variation judicieuse du cycle thermique s'est averee etre equivalente a une modification de la pression chimique. Cette derniere est modifiee par l'intermediaire d'une relaxation structurale autour de 85 K appelee la transition de verre d'ethylenes. Cela nous a permis de suivre l'evolution de cette coexistence en s'approchant de la transition de premier ordre, et ainsi de statuer sur la competition entre la supraconductivite et le magnetisme ainsi que sur l'existence d'une separation de phase d'ordre macroscopique. De plus, nous avons observe une anisotropie similaire sur les mesures de vitesse ultrasonore entre le regime de pseudogap et la supraconductivite. Ce resultat tend a confirmer l'existence d'une physique commune entre le regime de pseudogap et l'etat supraconducteur. Le regime de pseudogap, encore meconnu a ce jour, est probablement relie a des fluctuations antiferromagnetiques, dont l'origine pourrait etre un emboitement de la surface de Fermi quasi-unidimensionnelle de ce compose, ou bien relie a la proximite de la physique de Mott. Enfin, l'analyse de la symetrie du parametre d'ordre supraconducteur, qui est probablement de type s+d, tend a demontrer que les processus de couplage interplan sont d'une importance cruciale. L'approche theorique de Hubbard purement 2D dans le plan conducteur semble donc insuffisante pour la recherche du mecanisme d'appariement.

tRNAmodpred: a computational method for predicting posttranscriptional modifications in tRNAs

PubMed Central

Machnicka, Magdalena A.; Dunin-Horkawicz, Stanislaw; de Crécy-Lagard, Valerie; Bujnicki, Janusz M.

2016-01-01

tRNA molecules contain numerous chemically altered nucleosides, which are formed by enzymatic modification of the primary transcripts during the complex tRNA maturation process. Some of the modifications are introduced by single reactions, while other require complex series of reactions carried out by several different enzymes. The location and distribution of various types of modifications vary greatly between different tRNA molecules, organisms and organelles. We have developed a computational method tRNAmodpred, for predicting modifications in tRNA sequences. Briefly, our method takes as an input one or more unmodified tRNA sequences and a set of protein sequences corresponding to a proteome of a cell. Subsequently it identifies homologs of known tRNA modification enzymes in the proteome, predicts tRNA modification activities and maps them onto known pathways of RNA modification from the MODOMICS database. Thereby, theoretically possible modification pathways are identified, and products of these modification reactions are proposed for query tRNAs. This method allows for predicting modification patterns for newly sequenced genomes as well as for checking tentative modification status of tRNAs from one species treated with enzymes from another source, e.g. to predict the possible modifications of eukaryotic tRNAs expressed in bacteria. tRNAmodpred is freely available as web server at http://genesilico.pl/trnamodpred/. PMID:27016142

Computer-aided design of high-contact-ratio gears for minimum dynamic load and stress

NASA Technical Reports Server (NTRS)

Lin, Hsiang Hsi; Lee, Chinwai; Oswald, Fred B.; Townsend, Dennis P.

1990-01-01

A computer aided design procedure is presented for minimizing dynamic effects on high contact ratio gears by modification of the tooth profile. Both linear and parabolic tooth profile modifications of high contact ratio gears under various loading conditions are examined and compared. The effects of the total amount of modification and the length of the modification zone were systematically studied at various loads and speeds to find the optimum profile design for minimizing the dynamic load and the tooth bending stress. Parabolic profile modification is preferred over linear profile modification for high contact ratio gears because of its lower sensitivity to manufacturing errors. For parabolic modification, a greater amount of modification at the tooth tip and a longer modification zone are required. Design charts are presented for high contact ratio gears with various profile modifications operating under a range of loads. A procedure is illustrated for using the charts to find the optimum profile design.

Realization and characterization of a beam of titanium atoms

NASA Astrophysics Data System (ADS)

Azaroual, E. M.; Luc, P.; Vetter, R.

1992-06-01

A dense thermal beam of titanium atoms has been realized using a tungsten crucible inside a high temperature oven (leqslant 2 300 K). Its flux (≈ 10^{14} atom/cm^2/s) and its long term stability have been measured by means of a quartz balance, its angular divergence has been evaluated from the size of a metallic spot deposited on a glass plate. A spectroscopic investigation performed via the laser-induced fluorescence technique has led to the measurement of the isotope shifts between ^{46}Ti, ^{48}Ti and ^{50}Ti, for six visible 3d^2 4s^2 a ^3FJ''to 3d^2 4s4p z ^5DJ' transitions. This beam offers the characteristics required to apply high resolution laser techniques to reaction dynamics crossed-beam experiments. Un jet intense de titane atomique a été réalisé à partir d'un creuset de tungstène porté à haute température (leqslant 2 300 K). Le flux (≈ 10^{14} atomes/cm^2/s) et la stabilité à long terme du jet ont été mesurés avec une balance à quartz ; la divergence angulaire a été évaluée à partir de la dimension de dépôts métalliques sur des lames-témoin. Le jet a également été caractérisé par spectroscopie : la technique de fluorescence induite par laser a permis de mesurer le déplacement spectral dû aux isotopes 46, 48 et 50 de Ti, pour six transitions visibles du type 3d^2 4s^2 a ^3FJ''to 3d^2 4s4p z ^5DJ'. Le jet réalisé offre les caractéristiques requises pour l'application des techniques laser à haute résolution aux expériences de dynamique réactionnelle en faisceaux croisés.

40 CFR 144.41 - Minor modifications of permits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 23 2011-07-01 2011-07-01 false Minor modifications of permits. 144.41... (CONTINUED) UNDERGROUND INJECTION CONTROL PROGRAM Authorization by Permit § 144.41 Minor modifications of... part 124. Any permit modification not processed as a minor modification under this section must be made...

40 CFR 122.63 - Minor modifications of permits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 22 2011-07-01 2011-07-01 false Minor modifications of permits. 122.63..., Revocation and Reissuance, and Termination of Permits § 122.63 Minor modifications of permits. Upon the.... Any permit modification not processed as a minor modification under this section must be made for...

[Tattoos and piercings: motives for body modification in women suffering from borderline symptomatology].

PubMed

Höhner, Gesche; Teismann, Tobias; Willutzki, Ulrike

2014-02-01

Do women suffering from borderline symptomatology differ from women without these symptoms regarding their motives for body modifications?A sample of 289 women with body modifications were questioned about their tattoos, piercings and motives for body modifications as well as about symptoms of borderline personality disorder. Women with borderline symptomatology were compared to women without borderline symptomatology concerning the extent of and motives for body modification.The 2 groups showed no differences in regard to amount and extent of body modifications. The "borderline"-group considered individuality, coping and management of negative life-events to be more crucial reasons for body modification than the non-borderline females.The degree of a person's body modification is not a feasible indicator for psychopathological strain. Though, for people with borderline tendency body modification may serve as a coping strategy similar to self-injury. © Georg Thieme Verlag KG Stuttgart · New York.

77 FR 30367 - Defense Federal Acquisition Regulation Supplement: Order of Application for Modifications (DFARS...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-22

... sequence of modifications to a contract or order, a method for determining the order of application for... application for modifications. (a) Circumstances may exist in which the numeric order of the modifications to... date and the same signature date, procuring contracting office modifications will be applied in numeric...

48 CFR 1852.232-70 - NASA modification of FAR 52.232-12.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 6 2012-10-01 2012-10-01 false NASA modification of FAR... Provisions and Clauses 1852.232-70 NASA modification of FAR 52.232-12. As prescribed at 1832.412-70, make the following modifications: NASA Modification of FAR 52.232-12, (MAR 1998) (a) Basic Clause. (1) In paragraph...

48 CFR 1852.232-70 - NASA modification of FAR 52.232-12.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false NASA modification of FAR... Provisions and Clauses 1852.232-70 NASA modification of FAR 52.232-12. As prescribed at 1832.412-70, make the following modifications: NASA Modification of FAR 52.232-12, (MAR 1998) (a) Basic Clause. (1) In paragraph...

48 CFR 1852.232-70 - NASA modification of FAR 52.232-12.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 6 2014-10-01 2014-10-01 false NASA modification of FAR... Provisions and Clauses 1852.232-70 NASA modification of FAR 52.232-12. As prescribed at 1832.412-70, make the following modifications: NASA Modification of FAR 52.232-12, (MAR 1998) (a) Basic Clause. (1) In paragraph...

48 CFR 1852.232-70 - NASA modification of FAR 52.232-12.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 6 2013-10-01 2013-10-01 false NASA modification of FAR... Provisions and Clauses 1852.232-70 NASA modification of FAR 52.232-12. As prescribed at 1832.412-70, make the following modifications: NASA Modification of FAR 52.232-12, (MAR 1998) (a) Basic Clause. (1) In paragraph...

47 CFR 90.751 - Minor modifications of Phase I, non-nationwide licenses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Minor modifications of Phase I, non-nationwide... Frequencies in the 220-222 MHz Band § 90.751 Minor modifications of Phase I, non-nationwide licenses. Phase I.... For CMRS licensees, these modifications will be treated as minor modifications in accordance with § 1...

47 CFR 90.751 - Minor modifications of Phase I, non-nationwide licenses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Minor modifications of Phase I, non-nationwide... Frequencies in the 220-222 MHz Band § 90.751 Minor modifications of Phase I, non-nationwide licenses. Phase I.... For CMRS licensees, these modifications will be treated as minor modifications in accordance with § 1...

Using the Modification Index and Standardized Expected Parameter Change for Model Modification

ERIC Educational Resources Information Center

Whittaker, Tiffany A.

2012-01-01

Model modification is oftentimes conducted after discovering a badly fitting structural equation model. During the modification process, the modification index (MI) and the standardized expected parameter change (SEPC) are 2 statistics that may be used to aid in the selection of parameters to add to a model to improve the fit. The purpose of this…

48 CFR 1852.232-70 - NASA modification of FAR 52.232-12.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true NASA modification of FAR 52... Provisions and Clauses 1852.232-70 NASA modification of FAR 52.232-12. As prescribed at 1832.412-70, make the following modifications: NASA Modification of FAR 52.232-12, (MAR 1998) (a) Basic Clause. (1) In paragraph...

Chemical Modification in the Design of Immobilized Enzyme Biocatalysts: Drawbacks and Opportunities.

PubMed

Rueda, Nazzoly; Dos Santos, Jose C S; Ortiz, Claudia; Torres, Rodrigo; Barbosa, Oveimar; Rodrigues, Rafael C; Berenguer-Murcia, Ángel; Fernandez-Lafuente, Roberto

2016-06-01

Chemical modification of enzymes and immobilization used to be considered as separate ways to improve enzyme properties. This review shows how the coupled use of both tools may greatly improve the final biocatalyst performance. Chemical modification of a previously immobilized enzyme is far simpler and easier to control than the modification of the free enzyme. Moreover, if protein modification is performed to improve its immobilization (enriching the enzyme in reactive groups), the final features of the immobilized enzyme may be greatly improved. Chemical modification may be directed to improve enzyme stability, but also to improve selectivity, specificity, activity, and even cell penetrability. Coupling of immobilization and chemical modification with site-directed mutagenesis is a powerful instrument to obtain fully controlled modification. Some new ideas such as photoreceptive enzyme modifiers that change their physical properties under UV exposition are discussed. © 2016 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advances in chemical synthesis of structurally modified bioactive RNAs.

PubMed

Li, Ziyuan; Zhou, Haipin; Wu, Xiaoming; Yao, Hequan

2013-01-01

Methods for the chemical synthesis of RNA have been available for almost half century, and presently, RNA could be chemically synthesized by automated synthesizers, using protected ribonucleosides preactivated as phosphoramidites, which has already been covered by many reviews. In addition to advancement on synthetic methods, a variety of modifications have also been made on the synthesized oligonucleotides, and previous reviews on the general synthesis of RNAs have not covered this area. In this tutorial review, three types of modifications have been summarized standing at the viewpoint of medicinal chemistry: (1) modifications on nucleobase, comprising substituent introduction and replacement with pseudobase; (2) modifications on ribose, consisting of modifications on the 2', 3' or 5'-position, alternation of configuration, and conformational restriction on ribose; (3) modifications on internucleoside linkages, including amide, formacetal, sulfide, sulfone, ether, phosphorothiolate and phosphorothioate linkages. Synthetic methods achieving these modifications along with the functions or values of these modifications have also been discussed and commented on.

Transcript Isoform Variation Associated with Cytosine Modification in Human Lymphoblastoid Cell Lines.

PubMed

Zhang, Xu; Zhang, Wei

2016-06-01

Cytosine modification on DNA is variable among individuals, which could correlate with gene expression variation. The effect of cytosine modification on interindividual transcript isoform variation (TIV), however, remains unclear. In this study, we assessed the extent of cytosine modification-specific TIV in lymphoblastoid cell lines (LCLs) derived from unrelated individuals of European and African descent. Our study detected cytosine modification-specific TIVs for 17% of the analyzed genes at a 5% false discovery rate. Forty-five percent of the TIV-associated cytosine modifications correlated with the overall gene expression levels as well, with the corresponding CpG sites overrepresented in transcript initiation sites, transcription factor binding sites, and distinct histone modification peaks, suggesting that alternative isoform transcription underlies the TIVs. Our analysis also revealed 33% of the TIV-associated cytosine modifications that affected specific exons, with the corresponding CpG sites overrepresented in exon/intron junctions, splicing branching points, and transcript termination sites, implying that the TIVs are attributable to alternative splicing or transcription termination. Genetic and epigenetic regulation of TIV shared target preference but exerted independent effects on 61% of the common exon targets. Cytosine modification-specific TIVs detected from LCLs were differentially enriched in those detected from various tissues in The Cancer Genome Atlas, indicating their developmental dependency. Genes containing cytosine modification-specific TIVs were enriched in pathways of cancers and metabolic disorders. Our study demonstrated a prominent effect of cytosine modification variation on the transcript isoform spectrum over gross transcript abundance and revealed epigenetic contributions to diseases that were mediated through cytosine modification-specific TIV. Copyright © 2016 by the Genetics Society of America.

Mapping of ribosomal 23S ribosomal RNA modifications in Clostridium sporogenes.

PubMed

Kirpekar, Finn; Hansen, Lykke H; Mundus, Julie; Tryggedsson, Stine; Teixeira Dos Santos, Patrícia; Ntokou, Eleni; Vester, Birte

2018-06-27

All organisms contain RNA modifications in their ribosomal RNA (rRNA), but the importance, positions and exact function of these are still not fully elucidated. Various functions such as stabilising structures, controlling ribosome assembly and facilitating interactions have been suggested and in some cases substantiated. Bacterial rRNA contains much fewer modifications than eukaryotic rRNA. The rRNA modification patterns in bacteria differ from each other, but too few organisms have been mapped to draw general conclusions. This study maps 23S ribosomal RNA modifications in Clostridium sporogenes that can be characterised as a non-toxin producing Clostridium botulinum. Clostridia are able to sporulate and thereby survive harsh conditions, and are in general considered to be resilient to antibiotics. Selected regions of the 23S rRNA were investigated by mass spectrometry and by primer extension analysis to pinpoint modified sites and the nature of the modifications. Apparently, C. sporogenes 23S rRNA contains few modifications compared to other investigated bacteria. No modifications were identified in domain II and III of 23S rRNA. Three modifications were identified in domain IV, all of which have also been found in other organisms. Two unusual modifications were identified in domain V, methylated dihydrouridine at position U2449 and dihydrouridine at position U2500 (Escherichia coli numbering), in addition to four previously known modified positions. The enzymes responsible for the modifications were searched for in the C. sporogenes genome using BLAST with characterised enzymes as query. The search identified genes potentially coding for RNA modifying enzymes responsible for most of the found modifications.

Surface Modification of Intraocular Lenses

PubMed Central

Huang, Qi; Cheng, George Pak-Man; Chiu, Kin; Wang, Gui-Qin

2016-01-01

Objective: This paper aimed to review the current literature on the surface modification of intraocular lenses (IOLs). Data Sources: All articles about surface modification of IOLs published up to 2015 were identified through a literature search on both PubMed and ScienceDirect. Study Selection: The articles on the surface modification of IOLs were included, but those on design modification and surface coating were excluded. Results: Technology of surface modification included plasma, ion beam, layer-by-layer self-assembly, ultraviolet radiation, and ozone. The main molecules introduced into IOLs surface were poly (ethylene glycol), polyhedral oligomeric silsesquioxane, 2-methacryloyloxyethyl phosphorylcholine, TiO2, heparin, F-heparin, titanium, titanium nitride, vinyl pyrrolidone, and inhibitors of cytokines. The surface modification either resulted in a more hydrophobic lens, a more hydrophilic lens, or a lens with a hydrophilic anterior and hydrophobic posterior surface. Advances in research regarding surface modification of IOLs had led to a better biocompatibility in both in vitro and animal experiments. Conclusion: The surface modification is an efficient, convenient, economic and promising method to improve the biocompatibility of IOLs. PMID:26830993

Synergistic Modification Induced Specific Recognition between Histone and TRIM24 via Fluctuation Correlation Network Analysis

NASA Astrophysics Data System (ADS)

Zhang, Jinmai; Luo, Huajie; Liu, Hao; Ye, Wei; Luo, Ray; Chen, Hai-Feng

2016-04-01

Histone modification plays a key role in gene regulation and gene expression. TRIM24 as a histone reader can recognize histone modification. However the specific recognition mechanism between TRIM24 and histone modification is unsolved. Here, systems biology method of dynamics correlation network based on molecular dynamics simulation was used to answer the question. Our network analysis shows that the dynamics correlation network of H3K23ac is distinctly different from that of wild type and other modifications. A hypothesis of “synergistic modification induced recognition” is then proposed to link histone modification and TRIM24 binding. These observations were further confirmed from community analysis of networks with mutation and network perturbation. Finally, a possible recognition pathway is also identified based on the shortest path search for H3K23ac. Significant difference of recognition pathway was found among different systems due to methylation and acetylation modifications. The analysis presented here and other studies show that the dynamic network-based analysis might be a useful general strategy to study the biology of protein post-translational modification and associated recognition.

GPS-Lipid: a robust tool for the prediction of multiple lipid modification sites.

PubMed

Xie, Yubin; Zheng, Yueyuan; Li, Hongyu; Luo, Xiaotong; He, Zhihao; Cao, Shuo; Shi, Yi; Zhao, Qi; Xue, Yu; Zuo, Zhixiang; Ren, Jian

2016-06-16

As one of the most common post-translational modifications in eukaryotic cells, lipid modification is an important mechanism for the regulation of variety aspects of protein function. Over the last decades, three classes of lipid modifications have been increasingly studied. The co-regulation of these different lipid modifications is beginning to be noticed. However, due to the lack of integrated bioinformatics resources, the studies of co-regulatory mechanisms are still very limited. In this work, we developed a tool called GPS-Lipid for the prediction of four classes of lipid modifications by integrating the Particle Swarm Optimization with an aging leader and challengers (ALC-PSO) algorithm. GPS-Lipid was proven to be evidently superior to other similar tools. To facilitate the research of lipid modification, we hosted a publicly available web server at http://lipid.biocuckoo.org with not only the implementation of GPS-Lipid, but also an integrative database and visualization tool. We performed a systematic analysis of the co-regulatory mechanism between different lipid modifications with GPS-Lipid. The results demonstrated that the proximal dual-lipid modifications among palmitoylation, myristoylation and prenylation are key mechanism for regulating various protein functions. In conclusion, GPS-lipid is expected to serve as useful resource for the research on lipid modifications, especially on their co-regulation.

Influence of linear profile modification and loading conditions on the dynamic tooth load and stress of high contact ratio gears

NASA Technical Reports Server (NTRS)

Lee, Chinwai; Lin, Hsiang Hsi; Oswald, Fred B.; Townsend, Dennis P.

1990-01-01

A computer simulation for the dynamic response of high-contact-ratio spur gear transmissions is presented. High contact ratio gears have the potential to produce lower dynamic tooth loads and minimum root stress but they can be sensitive to tooth profile errors. The analysis presented examines various profile modifications under realistic loading conditions. The effect of these modifications on the dynamic load (force) between mating gear teeth and the dynamic root stress is presented. Since the contact stress is dependent on the dynamic load, minimizing dynamic loads will also minimize contact stresses. It is shown that the combination of profile modification and the applied load (torque) carried by a gear system has a significant influence on gear dynamics. The ideal modification at one value of applied load will not be the best solution for a different load. High-contact-ratio gears were found to require less modification than standard low-contact-ratio gears. High-contact-ratio gears are more adversely affected by excess modification than by under modification. In addition, the optimal profile modification required to minimize the dynamic load (hence the contact stress) on a gear tooth differs from the optimal modification required to minimize the dynamic root (bending) stress. Computer simulation can help find the design tradeoffs to determine the best profile modification to satisfy the conflicting constraints of minimizing both the load and root stress in gears which must operate over a range of applied loads.

48 CFR 204.7007 - Order of application for modifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... numeric order of the modifications to a contract is not the order in which the changes to the contract... modifications will be applied in numeric order, followed by contract administration office modifications in numeric order. [77 FR 30368, May 22, 2012] ...

48 CFR 204.7007 - Order of application for modifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... numeric order of the modifications to a contract is not the order in which the changes to the contract... modifications will be applied in numeric order, followed by contract administration office modifications in numeric order. [77 FR 30368, May 22, 2012] ...

48 CFR 204.7007 - Order of application for modifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... numeric order of the modifications to a contract is not the order in which the changes to the contract... modifications will be applied in numeric order, followed by contract administration office modifications in numeric order. [77 FR 30368, May 22, 2012] ...

76 FR 27271 - TSCA Inventory Update Reporting Modifications; Submission Period Suspension

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-11

... TSCA Inventory Update Reporting Modifications; Submission Period Suspension AGENCY: Environmental... proposed modifications to the IUR regulations. EPA is suspending the next submission period to allow additional time to finalize the proposed modifications to the IUR regulations, and to avoid finalizing...

48 CFR 43.103 - Types of contract modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... only by the contracting officer. Unilateral modifications are used, for example, to— (1) Make... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Types of contract... CONTRACT MANAGEMENT CONTRACT MODIFICATIONS General 43.103 Types of contract modifications. Contract...

48 CFR 43.103 - Types of contract modifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... only by the contracting officer. Unilateral modifications are used, for example, to— (1) Make... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Types of contract... CONTRACT MANAGEMENT CONTRACT MODIFICATIONS General 43.103 Types of contract modifications. Contract...

36 CFR 62.7 - Natural landmark modifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Natural landmark... INTERIOR NATIONAL NATURAL LANDMARKS PROGRAM § 62.7 Natural landmark modifications. (a) Determination of need for modifications. After designation, the modification of the boundaries of a natural landmark...

36 CFR 62.7 - Natural landmark modifications.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Natural landmark... INTERIOR NATIONAL NATURAL LANDMARKS PROGRAM § 62.7 Natural landmark modifications. (a) Determination of need for modifications. After designation, the modification of the boundaries of a natural landmark...

Personal cooling air filtering device

DOEpatents

Klett, James [Knoxville, TN; Conway, Bret [Denver, NC

2002-08-13

A temperature modification system for modifying the temperature of fluids includes at least one thermally conductive carbon foam element, the carbon foam element having at least one flow channel for the passage of fluids. At least one temperature modification device is provided, the temperature modification device thermally connected to the carbon foam element and adapted to modify the temperature of the carbon foam to modify the temperature of fluids flowing through the flow channels. Thermoelectric and/or thermoionic elements can preferably be used as the temperature modification device. A method for the reversible temperature modification of fluids includes the steps of providing a temperature modification system including at least one thermally conductive carbon foam element having flow channels and at least one temperature modification device, and flowing a fluid through the flow channels.

Immuno-Northern Blotting: Detection of RNA Modifications by Using Antibodies against Modified Nucleosides.

PubMed

Mishima, Eikan; Jinno, Daisuke; Akiyama, Yasutoshi; Itoh, Kunihiko; Nankumo, Shinnosuke; Shima, Hisato; Kikuchi, Koichi; Takeuchi, Yoichi; Elkordy, Alaa; Suzuki, Takehiro; Niizuma, Kuniyasu; Ito, Sadayoshi; Tomioka, Yoshihisa; Abe, Takaaki

2015-01-01

The biological roles of RNA modifications are still largely not understood. Thus, developing a method for detecting RNA modifications is important for further clarification. We developed a method for detecting RNA modifications called immuno-northern blotting (INB) analysis and herein introduce its various capabilities. This method involves the separation of RNAs using either polyacrylamide or agarose gel electrophoresis, followed by transfer onto a nylon membrane and subsequent immunoblotting using antibodies against modified nucleosides for the detection of specific modifications. We confirmed that INB with the antibodies for 1-methyladenosine (m1A), N6-methyladenosine (m6A), pseudouridine, and 5-methylcytidine (m5C) showed different modifications in a variety of RNAs from various species and organelles. INB with the anti-m5C antibody revealed that the antibody cross-reacted with another modification on DNA, suggesting the application of this method for characterization of the antibody for modified nucleosides. Additionally, using INB with the antibody for m1A, which is a highly specific modification in eukaryotic tRNA, we detected tRNA-derived fragments known as tiRNAs under the cellular stress response, suggesting the application for tracking target RNA containing specific modifications. INB with the anti-m6A antibody confirmed the demethylation of m6A by the specific demethylases fat mass and obesity-associated protein (FTO) and ALKBH5, suggesting its application for quantifying target modifications in separated RNAs. Furthermore, INB demonstrated that the knockdown of FTO and ALKBH5 increased the m6A modification in small RNAs as well as in mRNA. The INB method has high specificity, sensitivity, and quantitative capability, and it can be employed with conventional experimental apparatus. Therefore, this method would be useful for research on RNA modifications and metabolism.

Comprehensive Analysis of Protein Modifications by Top-down Mass Spectrometry

PubMed Central

Zhang, Han; Ge, Ying

2012-01-01

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

N7-Methylguanine at position 46 (m7G46) in tRNA from Thermus thermophilus is required for cell viability at high temperatures through a tRNA modification network.

PubMed

Tomikawa, Chie; Yokogawa, Takashi; Kanai, Tamotsu; Hori, Hiroyuki

2010-01-01

N(7)-methylguanine at position 46 (m(7)G46) in tRNA is produced by tRNA (m(7)G46) methyltransferase (TrmB). To clarify the role of this modification, we made a trmB gene disruptant (DeltatrmB) of Thermus thermophilus, an extreme thermophilic eubacterium. The absence of TrmB activity in cell extract from the DeltatrmB strain and the lack of the m(7)G46 modification in tRNA(Phe) were confirmed by enzyme assay, nucleoside analysis and RNA sequencing. When the DeltatrmB strain was cultured at high temperatures, several modified nucleotides in tRNA were hypo-modified in addition to the lack of the m(7)G46 modification. Assays with tRNA modification enzymes revealed hypo-modifications of Gm18 and m(1)G37, suggesting that the m(7)G46 positively affects their formations. Although the lack of the m(7)G46 modification and the hypo-modifications do not affect the Phe charging activity of tRNA(Phe), they cause a decrease in melting temperature of class I tRNA and degradation of tRNA(Phe) and tRNA(Ile). (35)S-Met incorporation into proteins revealed that protein synthesis in DeltatrmB cells is depressed above 70 degrees C. At 80 degrees C, the DeltatrmB strain exhibits a severe growth defect. Thus, the m(7)G46 modification is required for cell viability at high temperatures via a tRNA modification network, in which the m(7)G46 modification supports introduction of other modifications.

Effect of deformation on the structural state of piracetam

NASA Astrophysics Data System (ADS)

Kanunnikova, O. M.; Mikhailova, S. S.; Karban', O. V.; Mukhgalin, V. V.; Aksenova, V. V.; Sen'kovskii, B. V.; Pechina, E. A.; Lad'yanov, V. I.

2016-04-01

The effect of various deformation actions on the structure-phase transformations in piracetam of modifications I and II with a sodium acetate addition is studied. Mechanical activation and pressing are shown to cause the polymorphic transformation of modification I into modification II, and modification III forms predominantly during severe plastic deformation by torsion. The structural difference between the piracetam molecules of modifications I and II is found to be retained in aqueous solutions.

Body modification and substance use in adolescents: is there a link?

PubMed

Brooks, Traci L; Woods, Elizabeth R; Knight, John R; Shrier, Lydia A

2003-01-01

To describe the characteristics of body modification among adolescents and to determine whether adolescents who engage in body modification are more likely to screen positive for alcohol and other drug problems than those who do not. Adolescents aged 14 to 18 years presenting to an urban adolescent clinic for routine health care completed a questionnaire about body modification and a substance use assessment battery that included the 17-item Problem Oriented Screening Instrument for Teenagers Alcohol/Drug Use and Abuse Scale (POSIT-ADS). Body modification was defined as piercings (other than one pair of bilateral earlobe piercings in females), tattoos, scarification, and branding. Problem substance use was defined as a POSIT-ADS score > or =1. Data were analyzed using logistic regression to determine whether the presence of body modification was an independent predictor of problem substance use. The 210 participants had a mean (+/- SD) age of 16.0 (+/- 1.4) years and 63% were female. One hundred adolescents (48%) reported at least one body modification; girls were more likely than boys to have body modification (59% vs. 28%, p < or = .0005). Ninety (42%) reported piercings, 22 (10%) tattoos, 9 (4%) scarification, and 1 (< 1%) branding; 21 (10%) had more than one type of body modification. These were in a variety of locations, most commonly the ear and the nose (piercings) or the extremities (tattoos). One-third of the sample (33%) screened positive for problem substance use on the POSIT-ADS questionnaire. Controlling for age, adolescents with body modification had 3.1 times greater odds of problem substance use than those without body modification (95% CI 1.7, 5.8). Body modification was associated with self-reported problem alcohol and other drug use among middle adolescents presenting for primary care. More research is needed to determine the clinical and sociocultural significance of body modification and its relationship to substance use in this population. Copyright Society for Adolescent Medicine, 2003

3-(3-amino-3-carboxypropyl)-5,6-dihydrouridine is one of two novel post-transcriptional modifications in tRNALys(UUU) from Trypanosoma brucei.

PubMed

Krog, Jesper S; Español, Yaiza; Giessing, Anders M B; Dziergowska, Agnieszka; Malkiewicz, Andrzej; Ribas de Pouplana, Lluís; Kirpekar, Finn

2011-12-01

tRNA is the most heavily modified of all RNA types, with typically 10-20% of the residues being post-transcriptionally altered. Unravelling the modification pattern of a tRNA is a challenging task; there are 92 currently known tRNA modifications, many of which are chemically similar. Furthermore, the tRNA has to be investigated with single-nucleotide resolution in order to ensure complete mapping of all modifications. In the present work, we characterized tRNA(Lys)(UUU) from Trypanosoma brucei, and provide a complete overview of its post-transcriptional modifications. The first step was MALDI-TOF MS of two independent digests of the tRNA, with RNase A and RNase T1, respectively. This revealed digestion products harbouring mass-changing modifications. Next, the modifications were mapped at the nucleotide level in the RNase products by tandem MS. Comparison with the sequence of the unmodified tRNA revealed the modified residues. The modifications were further characterized at the nucleoside level by chromatographic retention time and fragmentation pattern upon higher-order tandem MS. Phylogenetic comparison with modifications in tRNA(Lys) from other organisms was used through the entire analysis. We identified modifications on 12 nucleosides in tRNA(Lys)(UUU), where U47 exhibited a novel modification, 3-(3-amino-3-carboxypropyl)-5,6-dihydrouridine, based on identical chromatographic retention and MS fragmentation as the synthetic nucleoside. A37 was observed in two versions: a minor fraction with the previously described 2-methylthio-N(6)-threonylcarbamoyl-modification, and a major fraction with A37 being modified by a 294.0-Da moiety. The latter product is the largest adenosine modification reported so far, and we discuss its nature and origin. © 2011 The Authors Journal compilation © 2011 FEBS.

Modification of Sr on 4004 Aluminum Alloy

NASA Astrophysics Data System (ADS)

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

2013-05-01

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.

Aircraft modifications: Assessing the current state of Air Force aircraft modifications and the implications for future military capability

NASA Astrophysics Data System (ADS)

Hill, Owen Jacob

How prepared is the U.S. Air Force to modify its aircraft fleet in upcoming years? Aircraft modernization is a complex interaction of new and legacy aircraft, organizational structure, and planning policy. This research will take one component of modernization: aircraft modification, and apply a new method of analysis in order to help formulate policy to promote modernization. Departing from previous small-sample studies dependent upon weight as a chief explanatory variable, this dissertation incorporates a comprehensive dataset that was constructed for this research of all aircraft modifications from 1996 through 2005. With over 700 modification programs, this dataset is used to examine changes to the current modification policy using policy-response regression models. These changes include separating a codependent procurement and installation schedule, reducing the documentation requirements for safety modifications, and budgeting for aging aircraft modifications. The research then concludes with predictive models for the F-15 and F-16 along with their replacements: the F-22 and F-35 Joint Strike Fighter.

Chemical methods for encoding and decoding of posttranslational modifications

PubMed Central

Chuh, Kelly N.; Batt, Anna R.; Pratt, Matthew R.

2016-01-01

A large array of posttranslational modifications can dramatically change the properties of proteins and influence different aspects of their biological function such as enzymatic activity, binding interactions, and proteostasis. Despite the significant knowledge that has been gained about the function of posttranslational modifications using traditional biological techniques, the analysis of the site-specific effects of a particular modification, the identification of the full compliment of modified proteins in the proteome, and the detection of new types of modifications remains challenging. Over the years, chemical methods have contributed significantly in both of these areas of research. This review highlights several posttranslational modifications where chemistry-based approaches have made significant contributions to our ability to both prepare homogeneously modified proteins and identify and characterize particular modifications in complex biological settings. As the number and chemical diversity of documented posttranslational modifications continues to rise, we believe that chemical strategies will be essential to advance the field in years to come. PMID:26933738

Pretreatment and Membrane Hydrophilic Modification to Reduce Membrane Fouling

PubMed Central

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

2013-01-01

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

Modifications of Glycans: Biological Significance and Therapeutic Opportunities

PubMed Central

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

2012-01-01

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

Genetic modification and genetic determinism

PubMed Central

Resnik, David B; Vorhaus, Daniel B

2006-01-01

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

Engineered/designer biochar for contaminant removal/immobilization from soil and water: Potential and implication of biochar modification.

PubMed

Rajapaksha, Anushka Upamali; Chen, Season S; Tsang, Daniel C W; Zhang, Ming; Vithanage, Meththika; Mandal, Sanchita; Gao, Bin; Bolan, Nanthi S; Ok, Yong Sik

2016-04-01

The use of biochar has been suggested as a means of remediating contaminated soil and water. The practical applications of conventional biochar for contaminant immobilization and removal however need further improvements. Hence, recent attention has focused on modification of biochar with novel structures and surface properties in order to improve its remediation efficacy and environmental benefits. Engineered/designer biochars are commonly used terms to indicate application-oriented, outcome-based biochar modification or synthesis. In recent years, biochar modifications involving various methods such as, acid treatment, base treatment, amination, surfactant modification, impregnation of mineral sorbents, steam activation and magnetic modification have been widely studied. This review summarizes and evaluates biochar modification methods, corresponding mechanisms, and their benefits for contaminant management in soil and water. Applicability and performance of modification methods depend on the type of contaminants (i.e., inorganic/organic, anionic/cationic, hydrophilic/hydrophobic, polar/non-polar), environmental conditions, remediation goals, and land use purpose. In general, modification to produce engineered/designer biochar is likely to enhance the sorption capacity of biochar and its potential applications for environmental remediation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Longitudinal changes in everyday life after home modifications for people aging with disabilities.

PubMed

Petersson, Ingela; Kottorp, Anders; Bergström, Jakob; Lilja, Margareta

2009-05-01

To investigate longitudinal impacts of home modifications on the difficulty of performing everyday life tasks for people aging with disabilities, and to investigate whether other factors had any additional impacts on difficulty in everyday life tasks for people receiving home modifications. The sample consisted of 103 persons aging with disabilities and in need of home modifications, divided into an intervention group and a comparison group. The data were first subjected to Rasch analysis and a random coefficient model was used. Participants in the intervention group reported a significantly lower level of difficulty in everyday life tasks compared with those in the comparison group. One confounding factor, number of months waiting for home modification, had an impact on difficulty in everyday life. Home modifications are effective in decreasing difficulty in performing everyday life tasks up to six months after the installation. Furthermore, to be effective home modifications need to be installed in a timely fashion. For each consecutive month the person waited for their home modification the difficulty of performing everyday life tasks increased. Therefore, it is important that home modifications be installed as soon as possible after the need has been identified.

Effects of tooth profile modification on dynamic responses of a high speed gear-rotor-bearing system

NASA Astrophysics Data System (ADS)

Hu, Zehua; Tang, Jinyuan; Zhong, Jue; Chen, Siyu; Yan, Haiyan

2016-08-01

A finite element node dynamic model of a high speed gear-rotor-bearing system considering the time-varying mesh stiffness, backlash, gyroscopic effect and transmission error excitation is developed. Different tooth profile modifications are introduced into the gear pair and corresponding time-varying mesh stiffness curves are obtained. Effects of the tooth profile modification on mesh stiffness are analyzed, and the natural frequencies and mode shapes of the gear-rotor-bearing transmission system are given. The dynamic responses with respect to a wide input speed region including dynamic factor, vibration amplitude near the bearing and dynamic transmission error are obtained by introducing the time-varying mesh stiffness in different tooth profile modification cases into the gear-rotor-bearing dynamic system. Effects of the tooth profile modification on the dynamic responses are studied in detail. The numerical simulation results show that both the short profile modification and the long profile modification can affect the mutation of the mesh stiffness when the number of engaging tooth pairs changes. A short profile modification with an appropriate modification amount can improve the dynamic property of the system in certain work condition.

23 CFR 630.110 - Modification of original agreement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 23 Highways 1 2010-04-01 2010-04-01 false Modification of original agreement. 630.110 Section 630... OPERATIONS PRECONSTRUCTION PROCEDURES Project Authorization and Agreements § 630.110 Modification of original agreement. (a) When changes are needed to the original project agreement, a modification of agreement shall...

Ecological Effects of Weather Modification: A Problem Analysis.

ERIC Educational Resources Information Center

Cooper, Charles F.; Jolly, William C.

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…

48 CFR 243.205-70 - Pricing of contract modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Pricing of contract modifications. 243.205-70 Section 243.205-70 Federal Acquisition Regulations System DEFENSE ACQUISITION... Pricing of contract modifications. Use the clause at 252.243-7001, Pricing of Contract Modifications, in...

49 CFR 22.59 - Loan modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Loan modifications. 22.59 Section 22.59 Transportation Office of the Secretary of Transportation SHORT-TERM LENDING PROGRAM (STLP) Loan Administration § 22.59 Loan modifications. Any modification to the terms of the DOT OSDBU guarantee agreement must...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

40 CFR 72.82 - Fast-track modifications.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Fast-track modifications. 72.82... (CONTINUED) PERMITS REGULATION Permit Revisions § 72.82 Fast-track modifications. The following procedures shall apply to all fast-track modifications. (a) If the Administrator is the permitting authority, the...

Public perceptions of hurricane modification.

PubMed

Klima, Kelly; Bruine de Bruin, Wändi; Morgan, M Granger; Grossmann, Iris

2012-07-01

If hurricane modification were to become a feasible strategy for potentially reducing hurricane damages, it would likely generate public discourse about whether to support its implementation. To facilitate an informed and constructive discourse, policymakers need to understand how people perceive hurricane modification. Here, we examine Florida residents' perceptions of hurricane modification techniques that aim to alter path and wind speed. Following the mental models approach, we conducted a survey study about public perceptions of hurricane modification that was guided by formative interviews on the topic. We report a set of four primary findings. First, hurricane modification was perceived as a relatively ineffective strategy for damage reduction, compared to other strategies for damage reduction. Second, hurricane modification was expected to lead to changes in projected hurricane path, but not necessarily to the successful reduction of projected hurricane strength. Third, more anger was evoked when a hurricane was described as having changed from the initially forecasted path or strength after an attempted modification. Fourth, unlike what we expected, participants who more strongly agreed with statements that recognized the uncertainty inherent in forecasts reported more rather than less anger at scientists across hurricane modification scenarios. If the efficacy of intensity-reduction techniques can be increased, people may be willing to support hurricane modification. However, such an effort would need to be combined with open and honest communications to members of the general public. © 2011 Society for Risk Analysis.

Understanding RNA modifications: the promises and technological bottlenecks of the ‘epitranscriptome’

PubMed Central

Kapoor, Utkarsh

2017-01-01

The discovery of mechanisms that alter genetic information via RNA editing or introducing covalent RNA modifications points towards a complexity in gene expression that challenges long-standing concepts. Understanding the biology of RNA modifications represents one of the next frontiers in molecular biology. To this date, over 130 different RNA modifications have been identified, and improved mass spectrometry approaches are still adding to this list. However, only recently has it been possible to map selected RNA modifications at single-nucleotide resolution, which has created a number of exciting hypotheses about the biological function of RNA modifications, culminating in the proposition of the ‘epitranscriptome’. Here, we review some of the technological advances in this rapidly developing field, identify the conceptual challenges and discuss approaches that are needed to rigorously test the biological function of specific RNA modifications. PMID:28566301

10 CFR 40.71 - Modification and revocation of licenses.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 1 2010-01-01 2010-01-01 false Modification and revocation of licenses. 40.71 Section 40.71 Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF SOURCE MATERIAL Modification and Revocation of Licenses § 40.71 Modification and revocation of licenses. (a) The terms and conditions of each...

36 CFR 223.112 - Modification of contracts.

Code of Federal Regulations, 2010 CFR

2010-07-01

... SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER Timber Sale Contracts Contract Administration § 223.112 Modification of contracts. (a) Timber sale contracts may be modified only when the modification.... Modifications may be made by the officer approving the sale, by his successor, or by his superior, except as...

75 FR 29359 - Draft Environmental Impact Statement for the Tamiami Trail Modifications: Next Steps Project...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-25

... Tamiami Trail Modifications: Next Steps Project, Everglades National Park Tamiami Trail Modifications... Interior. ACTION: Notice of availability of the Draft Environmental Impact Statement for the Tamiami Trail... Statement (DEIS) for the Tamiami Trail (U.S. Highway 41) Modifications: Next Steps Project for Everglades...

Audience-Contingent Variation in Action Demonstrations for Humans and Computers

ERIC Educational Resources Information Center

Herberg, Jonathan S.; Saylor, Megan M.; Ratanaswasd, Palis; Levin, Daniel T.; Wilkes, D. Mitchell

2008-01-01

People may exhibit two kinds of modifications when demonstrating action for others: modifications to facilitate bottom-up, or sensory-based processing; and modifications to facilitate top-down, or knowledge-based processing. The current study examined actors' production of such modifications in action demonstrations for audiences that differed in…

48 CFR 204.7004 - Supplementary PII numbers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... as follows: Normal modification Provisioned items order (reserved for exclusive use by the Air Force... supplementary number will be ARZ998, and on down as needed. (6) Each office authorized to issue modifications...) Modifications to calls or orders. Use a two position alpha-numeric suffix, known as a call or order modification...

48 CFR 204.7004 - Supplementary PII numbers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... as follows: Normal modification Provisioned items order (reserved for exclusive use by the Air Force... supplementary number will be ARZ998, and on down as needed. (6) Each office authorized to issue modifications...) Modifications to calls or orders. Use a two position alpha-numeric suffix, known as a call or order modification...

77 FR 810 - Petitions for Modification of Application of Existing Mandatory Safety Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-06

... 44 govern the application, processing, and disposition of petitions for modification. This notice is... modification. II. Petitions for Modification Docket Number: M-2011-040-C. Petitioner: D & F Deep Mine, 15... Drive, Pine Grove, Pennsylvania 17963, located in Schuylkill County, Pennsylvania. Regulation Affected...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

14 CFR 21.9 - Replacement and modification articles.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Replacement and modification articles. 21.9... CERTIFICATION PROCEDURES FOR PRODUCTS AND PARTS General § 21.9 Replacement and modification articles. (a) If a person knows, or should know, that a replacement or modification article is reasonably likely to be...

49 CFR 180.413 - Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Repair, modification, stretching, rebarrelling, or... Tanks § 180.413 Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks. (a) General. Any repair, modification, stretching, rebarrelling, or mounting of a cargo tank must be...

49 CFR 180.413 - Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Repair, modification, stretching, rebarrelling, or... Tanks § 180.413 Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks. (a) General. Any repair, modification, stretching, rebarrelling, or mounting of a cargo tank must be...

49 CFR 180.413 - Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Repair, modification, stretching, rebarrelling, or... Tanks § 180.413 Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks. (a) General. Any repair, modification, stretching, rebarrelling, or mounting of a cargo tank must be...

49 CFR 180.413 - Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Repair, modification, stretching, rebarrelling, or... Tanks § 180.413 Repair, modification, stretching, rebarrelling, or mounting of specification cargo tanks. (a) General. Any repair, modification, stretching, rebarrelling, or mounting of a cargo tank must be...

15 CFR 908.5 - Interim reports.

Code of Federal Regulations, 2011 CFR

2011-01-01

... SUBMITTING REPORTS ON WEATHER MODIFICATION ACTIVITIES § 908.5 Interim reports. (a) Any person engaged in a weather modification project or activity in the United States on January 1 in any year shall submit to the... actual modification activities took place; (2) Number of days on which weather modification activities...

47 CFR 78.109 - Major and minor modifications to stations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Major and minor modifications to stations. 78... SERVICES CABLE TELEVISION RELAY SERVICE Technical Regulations § 78.109 Major and minor modifications to stations. (a) Amendments to applications and modifications to stations are classified as major or minor. A...

10 CFR 501.142 - Modification or rescission.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Modification or rescission. 501.142 Section 501.142 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS ADMINISTRATIVE PROCEDURES AND SANCTIONS Rulings § 501.142 Modification or rescission. (a) A ruling may be modified or rescinded by— (1) Publication of the modification...

7 CFR 1726.251 - Prior approved contract modification related to price escalation on transmission equipment...

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 11 2010-01-01 2010-01-01 false Prior approved contract modification related to price... SERVICE, DEPARTMENT OF AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES Modifications to RUS Standard Contract Forms § 1726.251 Prior approved contract modification related to price...

47 CFR 78.109 - Major and minor modifications to stations.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Major and minor modifications to stations. 78... stations. (a) Amendments to applications and modifications to stations are classified as major or minor. A... new application. (b) Major modifications to a station or amendments to an application include, but are...

47 CFR 78.109 - Major and minor modifications to stations.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Major and minor modifications to stations. 78... stations. (a) Amendments to applications and modifications to stations are classified as major or minor. A... new application. (b) Major modifications to a station or amendments to an application include, but are...

47 CFR 78.109 - Major and minor modifications to stations.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Major and minor modifications to stations. 78... stations. (a) Amendments to applications and modifications to stations are classified as major or minor. A... new application. (b) Major modifications to a station or amendments to an application include, but are...

Optimal Control Modification for Robust Adaptation of Singularly Perturbed Systems with Slow Actuators

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.; Ishihara, Abraham; Stepanyan, Vahram; Boskovic, Jovan

2009-01-01

Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. The model matching conditions in the transformed time coordinate results in increase in the feedback gain and modification of the adaptive law.

The Interaction between Epigenetics, Nutrition and the Development of Cancer

PubMed Central

Bishop, Karen S.; Ferguson, Lynnette R.

2015-01-01

Unlike the genome, the epigenome can be modified and hence some epigenetic risk markers have the potential to be reversed. Such modifications take place by means of drugs, diet or environmental exposures. It is widely accepted that epigenetic modifications take place during early embryonic and primordial cell development, but it is also important that we gain an understanding of the potential for such changes later in life. These “later life” epigenetic modifications in response to dietary intervention are the focus of this paper. The epigenetic modifications investigated include DNA methylation, histone modifications and the influence of microRNAs. The epigenotype could be used not only to predict susceptibility to certain cancers but also to assess the effectiveness of dietary modifications to reduce such risk. The influence of diet or dietary components on epigenetic modifications and the impact on cancer initiation or progression has been assessed herein. PMID:25647662

Surface modification effects on defect-related photoluminescence in colloidal CdS quantum dots.

PubMed

Lee, TaeGi; Shimura, Kunio; Kim, DaeGwi

2018-05-03

We investigated the effects of surface modification on the defect-related photoluminescence (PL) band in colloidal CdS quantum dots (QDs). A size-selective photoetching process and a surface modification technique with a Cd(OH)2 layer enabled the preparation of size-controlled CdS QDs with high PL efficiency. The Stokes shift of the defect-related PL band before and after the surface modification was ∼1.0 eV and ∼0.63 eV, respectively. This difference in the Stokes shifts suggests that the origin of the defect-related PL band was changed by the surface modification. Analysis by X-ray photoelectron spectroscopy revealed that the surface of the CdS QDs before and after the surface modification was S rich and Cd rich, respectively. These results suggest that Cd-vacancy acceptors and S-vacancy donors affect PL processes in CdS QDs before and after the surface modification, respectively.

Impact of acid and oxidative modifications, single or dual, of sorghum starch on biodegradable films.

PubMed

Biduski, Bárbara; Silva, Francine Tavares da; Silva, Wyller Max da; Halal, Shanise Lisie de Mello El; Pinto, Vania Zanella; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2017-01-01

The objective of this study was to evaluate the effects of acid and oxidation modifications on sorghum starch, as well as the effect of dual modification of starch on the physical, morphological, mechanical, and barrier properties of biodegradable films. The acid modification was performed with 3% lactic acid and the oxidation was performed with 1.5% active chlorine. For dual modification, the acid modification was performed first, followed by oxidation under the same conditions as above. Both films of the oxidized starches, single and dual, had increased stiffness, providing a higher tensile strength and lower elongation when compared to films based on native and single acid modified starches. However, the dual modification increased the water vapor permeability of the films without changing their solubility. The increase in sorghum starch concentration in the filmogenic solution increased the thickness, water vapor permeability, and elongation of the films. Copyright © 2016. Published by Elsevier Ltd.

Modification of wheat starch with succinic acid/acetanhydride and azelaic acid/acetanhydride mixtures. II. Chemical and physical properties.

PubMed

Ačkar, Durđica; Subarić, Drago; Babić, Jurislav; Miličević, Borislav; Jozinović, Antun

2014-08-01

The aim of this research was to investigate the influence of modification with succinic acid/acetanhydride and azelaic acid/acetanhydride mixtures on chemical and physical properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetanhydride and azelaic acid and acetanhydride in 4, 6 and 8% (w/w). Total starch content, resistant starch content, degree of modification, changes in FT-IR spectra, colour, gel texture and freeze-thaw stability were determined. Results showed that resistant starch content increased by both investigated modifications, and degree of modification increased proportionally to amount of reagents used. FT-IR analysis of modified starches showed peak around 1,740 cm(-1), characteristic for carbonyl group of ester. Total colour difference caused by modifications was detectable by trained people. Adhesiveness significantly increased, while freeze-thaw stability decreased by both investigated modifications.

Experimental modification of interpretation bias about animal fear in young children: effects on cognition, avoidance behavior, anxiety vulnerability, and physiological responding.

PubMed

Lester, Kathryn J; Field, Andy P; Muris, Peter

2011-01-01

This study investigated the effects of experimentally modifying interpretation biases for children's cognitions, avoidance behavior, anxiety vulnerability, and physiological responding. Sixty-seven children (6-11 years) were randomly assigned to receive a positive or negative interpretation bias modification procedure to induce interpretation biases toward or away from threat about ambiguous situations involving Australian marsupials. Children rapidly learned to select outcomes of ambiguous situations, which were congruent with their assigned condition. Furthermore, following positive modification, children's threat biases about novel ambiguous situations significantly decreased, whereas threat biases significantly increased after negative modification. In response to a stress-evoking behavioral avoidance test, positive modification attenuated behavioral avoidance compared to negative modification. However, no significant effects of bias modification on anxiety vulnerability or physiological responses to this stress-evoking Behavioral Avoidance Task were observed.

On the genetic modification of psychology, personality, and behavior.

PubMed

Neitzke, Alex B

2012-12-01

I argue that the use of heritable modifications for psychology, personality, and behavior should be limited to the reversal or prevention of relatively unambiguous instances of pathology or likely harm (e.g. sociopathy). Most of the likely modifications of psychological personality would not be of this nature, however, and parents therefore should not have the freedom to make such modifications to future children. I argue by examining the viewpoints of both the individual and society. For individuals, modifications would interfere with their capacity for self-determination in a way that undermines the very concept of self-determination. I argue that modification of psychology and personality is unlike present parenting in morally significant ways. For society, modification offers a medium for power to manipulate the makeup of persons and populations, possibly causing biological harm to the species and altering our conceptions of social responsibility.

MARCC (Matrix-Assisted Reader Chromatin Capture): an antibody-free method to enrich and analyze combinatorial nucleosome modifications

PubMed Central

Su, Zhangli

2016-01-01

Combinatorial patterns of histone modifications are key indicators of different chromatin states. Most of the current approaches rely on the usage of antibodies to analyze combinatorial histone modifications. Here we detail an antibody-free method named MARCC (Matrix-Assisted Reader Chromatin Capture) to enrich combinatorial histone modifications. The combinatorial patterns are enriched on native nucleosomes extracted from cultured mammalian cells and prepared by micrococcal nuclease digestion. Such enrichment is achieved by recombinant chromatin-interacting protein modules, or so-called reader domains, which can bind in a combinatorial modification-dependent manner. The enriched chromatin can be quantified by western blotting or mass spectrometry for the co-existence of histone modifications, while the associated DNA content can be analyzed by qPCR or next-generation sequencing. Altogether, MARCC provides a reproducible, efficient and customizable solution to enrich and analyze combinatorial histone modifications. PMID:26131849

Mapping Base Modifications in DNA by Transverse-Current Sequencing

NASA Astrophysics Data System (ADS)

Alvarez, Jose R.; Skachkov, Dmitry; Massey, Steven E.; Kalitsov, Alan; Velev, Julian P.

2018-02-01

Sequencing DNA modifications and lesions, such as methylation of cytosine and oxidation of guanine, is even more important and challenging than sequencing the genome itself. The traditional methods for detecting DNA modifications are either insensitive to these modifications or require additional processing steps to identify a particular type of modification. Transverse-current sequencing in nanopores can potentially identify the canonical bases and base modifications in the same run. In this work, we demonstrate that the most common DNA epigenetic modifications and lesions can be detected with any predefined accuracy based on their tunneling current signature. Our results are based on simulations of the nanopore tunneling current through DNA molecules, calculated using nonequilibrium electron-transport methodology within an effective multiorbital model derived from first-principles calculations, followed by a base-calling algorithm accounting for neighbor current-current correlations. This methodology can be integrated with existing experimental techniques to improve base-calling fidelity.

29 CFR 1903.14a - Petitions for modification of abatement date.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 5 2010-07-01 2010-07-01 false Petitions for modification of abatement date. 1903.14a... ADMINISTRATION, DEPARTMENT OF LABOR INSPECTIONS, CITATIONS AND PROPOSED PENALTIES § 1903.14a Petitions for modification of abatement date. (a) An employer may file a petition for modification of abatement date when he...

29 CFR 2200.37 - Petitions for modification of the abatement period.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Petitions for modification of the abatement period. 2200.37... COMMISSION RULES OF PROCEDURE Pleadings and Motions § 2200.37 Petitions for modification of the abatement period. (a) Grounds for modifying abatement date. An employer may file a petition for modification of...

Residential Modifications and Decline in Physical Function among Community-Dwelling Older Adults

ERIC Educational Resources Information Center

Liu, Sze Y.; Lapane, Kate L.

2009-01-01

Purpose: The purpose of this study is to quantify the effect of residential modification on decreasing risk of physical function decline in 2 years. Design: Cohort study using propensity scores method to control for baseline differences between individuals with residential modifications and those without residential modifications. Participants:…

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

Accommodations and Modifications: What Parents Need To Know = Facilidades y modificaciones: Lo que los padres necesitan saber.

ERIC Educational Resources Information Center

Beech, Marty

This English-Spanish language booklet is designed to help parents understand two important features of special education services, accommodations and modifications for students with disabilities. Examples of accommodations and modifications are provided, federal laws requiring schools to provide accommodations and modifications are cited, and…

40 CFR 1037.655 - Post-useful life vehicle modifications.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Post-useful life vehicle modifications... § 1037.655 Post-useful life vehicle modifications. This section specifies vehicle modifications that may occur after a vehicle reaches the end of its regulatory useful life. It does not apply with respect to...

40 CFR 1037.655 - Post-useful life vehicle modifications.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Post-useful life vehicle modifications... § 1037.655 Post-useful life vehicle modifications. This section specifies vehicle modifications that may occur after a vehicle reaches the end of its regulatory useful life. It does not apply with respect to...

40 CFR 1037.655 - Post-useful life vehicle modifications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Post-useful life vehicle modifications... § 1037.655 Post-useful life vehicle modifications. This section specifies vehicle modifications that may occur after a vehicle reaches the end of its regulatory useful life. It does not apply with respect to...

Modification degrees at specific sites on heparan sulphate: an approach to measure chemical modifications on biological molecules with stable isotope labelling

PubMed Central

Wu, Zhengliang L.; Lech, Miroslaw

2005-01-01

Chemical modification of biological molecules is a general mechanism for cellular regulation. A quantitative approach has been developed to measure the extent of modification on HS (heparan sulphates). Sulphation on HS by sulphotransferases leads to variable sulphation levels, which allows cells to tune their affinities to various extracellular proteins, including growth factors. With stable isotope labelling and HPLC-coupled MS, modification degrees at various O-sulphation sites could be determined. A bovine kidney HS sample was first saturated in vitro with 34S by an OST (O-sulphotransferase), then digested with nitrous acid and analysed with HPLC-coupled MS. The 34S-labelled oligosaccharides were identified based on their unique isotope clusters. The modification degrees at the sulphotransferase recognition sites were obtained by calculating the intensities of isotopic peaks in the isotope clusters. The modification degrees at 3-OST-1 and 6-OST-1 sites were examined in detail. This approach can also be used to study other types of chemical modifications on biological molecules. PMID:15743272

Small nucleolar RNAs that guide modification in trypanosomatids: repertoire, targets, genome organisation, and unique functions.

PubMed

Uliel, Shai; Liang, Xue-hai; Unger, Ron; Michaeli, Shulamit

2004-03-29

Small nucleolar RNAs constitute a family of newly discovered non-coding small RNAs, most of which function in guiding RNA modifications. Two prevalent types of modifications are 2'-O-methylation and pseudouridylation. The modification is directed by the formation of a canonical small nucleolar RNA-target duplex. Initially, RNA-guided modification was shown to take place on rRNA, but recent studies suggest that small nuclear RNA, mRNA, tRNA, and the trypanosome spliced leader RNA also undergo guided modifications. Trypanosomes contain more modifications and potentially more small nucleolar RNAs than yeast, and the increased number of modifications may help to preserve ribosome function under adverse environmental conditions during the cycling between the insect and mammalian host. The genome organisation in clusters carrying the two types of small nucleolar RNAs, C/D and H/ACA-like RNAs, resembles that in plants. However, the trypanosomatid H/ACA RNAs are similar to those found in Archaea and are composed of a single hairpin that may represent the primordial H/ACA RNA. In this review we summarise this new field of trypanosome small nucleolar RNAs, emphasising the open questions regarding the number of small nucleolar RNAs, the repertoire, genome organisation, and the unique function of guided modifications in these protozoan parasites.

Post-Translational Modification Biology of Glutamate Receptors and Drug Addiction

PubMed Central

Mao, Li-Min; Guo, Ming-Lei; Jin, Dao-Zhong; Fibuch, Eugene E.; Choe, Eun Sang; Wang, John Q.

2011-01-01

Post-translational covalent modifications of glutamate receptors remain a hot topic. Early studies have established that this family of receptors, including almost all ionotropic and metabotropic glutamate receptor subtypes, undergoes active phosphorylation at serine, threonine, or tyrosine residues in their intracellular domains. Recent evidence identifies several glutamate receptor subtypes to be direct substrates for palmitoylation at cysteine residues. Other modifications such as ubiquitination and sumoylation at lysine residues also occur to certain glutamate receptors. These modifications are dynamic and reversible in nature and are regulatable by changing synaptic inputs. The regulated modifications significantly impact the receptor in many ways, including interrelated changes in biochemistry (synthesis, subunit assembling, and protein–protein interactions), subcellular redistribution (trafficking, endocytosis, synaptic delivery, and clustering), and physiology, usually associated with changes in synaptic plasticity. Glutamate receptors are enriched in the striatum and cooperate closely with dopamine to regulate striatal signaling. Emerging evidence shows that modification processes of striatal glutamate receptors are sensitive to addictive drugs, such as psychostimulants (cocaine and amphetamine). Altered modifications are believed to be directly linked to enduring receptor/synaptic plasticity and drug-seeking. This review summarizes several major types of modifications of glutamate receptors and analyzes the role of these modifications in striatal signaling and in the pathogenesis of psychostimulant addiction. PMID:21441996

Single-Nucleosome Mapping of Histone Modifications in S. cerevisiae

PubMed Central

Kim, Minkyu; Buratowski, Stephen; Schreiber, Stuart L; Friedman, Nir

2005-01-01

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 caused by the averaging of modification levels over multiple nucleosomes. To overcome this problem, we used a high-resolution tiled microarray with single-nucleosome resolution to investigate the occurrence of combinations of 12 histone modifications on thousands of nucleosomes in actively growing S. cerevisiae. We found that histone modifications do not occur independently; there are roughly two groups of co-occurring modifications. One group of lysine acetylations shows a sharply defined domain of two hypo-acetylated nucleosomes, adjacent to the transcriptional start site, whose occurrence does not correlate with transcription levels. The other group consists of modifications occurring in gradients through the coding regions of genes in a pattern associated with transcription. We found no evidence for a deterministic code of many discrete states, but instead we saw blended, continuous patterns that distinguish nucleosomes at one location (e.g., promoter nucleosomes) from those at another location (e.g., over the 3′ ends of coding regions). These results are consistent with the idea of a simple, redundant histone code, in which multiple modifications share the same role. PMID:16122352

Identification of histone modifications in biomedical text for supporting epigenomic research

PubMed Central

Kolářik, Corinna; Klinger, Roman; Hofmann-Apitius, Martin

2009-01-01

Background Posttranslational modifications of histones influence the structure of chromatine and in such a way take part in the regulation of gene expression. Certain histone modification patterns, distributed over the genome, are connected to cell as well as tissue differentiation and to the adaption of organisms to their environment. Abnormal changes instead influence the development of disease states like cancer. The regulation mechanisms for modifying histones and its functionalities are the subject of epigenomics investigation and are still not completely understood. Text provides a rich resource of knowledge on epigenomics and modifications of histones in particular. It contains information about experimental studies, the conditions used, and results. To our knowledge, no approach has been published so far for identifying histone modifications in text. Results We have developed an approach for identifying histone modifications in biomedical literature with Conditional Random Fields (CRF) and for resolving the recognized histone modification term variants by term standardization. For the term identification F1 measures of 0.84 by 10-fold cross-validation on the training corpus and 0.81 on an independent test corpus have been obtained. The standardization enabled the correct transformation of 96% of the terms from training and 98% from test the corpus. Due to the lack of terminologies exhaustively covering specific histone modification types, we developed a histone modification term hierarchy for use in a semantic text retrieval system. Conclusion The developed approach highly improves the retrieval of articles describing histone modifications. Since text contains context information about performed studies and experiments, the identification of histone modifications is the basis for supporting literature-based knowledge discovery and hypothesis generation to accelerate epigenomic research. PMID:19208128

Identification of histone modifications in biomedical text for supporting epigenomic research.

PubMed

Kolárik, Corinna; Klinger, Roman; Hofmann-Apitius, Martin

2009-01-30

Posttranslational modifications of histones influence the structure of chromatine and in such a way take part in the regulation of gene expression. Certain histone modification patterns, distributed over the genome, are connected to cell as well as tissue differentiation and to the adaption of organisms to their environment. Abnormal changes instead influence the development of disease states like cancer. The regulation mechanisms for modifying histones and its functionalities are the subject of epigenomics investigation and are still not completely understood. Text provides a rich resource of knowledge on epigenomics and modifications of histones in particular. It contains information about experimental studies, the conditions used, and results. To our knowledge, no approach has been published so far for identifying histone modifications in text. We have developed an approach for identifying histone modifications in biomedical literature with Conditional Random Fields (CRF) and for resolving the recognized histone modification term variants by term standardization. For the term identification F1 measures of 0.84 by 10-fold cross-validation on the training corpus and 0.81 on an independent test corpus have been obtained. The standardization enabled the correct transformation of 96% of the terms from training and 98% from test the corpus. Due to the lack of terminologies exhaustively covering specific histone modification types, we developed a histone modification term hierarchy for use in a semantic text retrieval system. The developed approach highly improves the retrieval of articles describing histone modifications. Since text contains context information about performed studies and experiments, the identification of histone modifications is the basis for supporting literature-based knowledge discovery and hypothesis generation to accelerate epigenomic research.

Human Rights and Behavior Modification

ERIC Educational Resources Information Center

Roos, Philip

1974-01-01

Criticisms of behavior modification, which charge that it violates ethical and legal principles, are discussed and reasons are presented to explain behavior modification's susceptibility to attack. (GW)

49 CFR 232.307 - Modification of the single car air brake test procedures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake test...

49 CFR 232.307 - Modification of the single car air brake test procedures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Modification of the single car air brake test... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake test...

75 FR 6252 - Notice of Application for Approval of Discontinuance or Modification of a Railroad Signal System...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-08

... Discontinuance or Modification of a Railroad Signal System or Relief From the Requirements of Title 49 Code of... approval for the discontinuance or modification of the signal system or relief from the requirements of 49... Transportation, Inc. seeks approval of the proposed modification of the bridge tender controlled signals to...

78 FR 17282 - Notice of Application for Approval of Discontinuance or Modification of a Railroad Signal System

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-20

... of Application for Approval of Discontinuance or Modification of a Railroad Signal System In... approval from the Federal Railroad Administration (FRA) for the discontinuance or modification of a signal... modifications that it will make to the signal system at the A&R crossing in preparation for the installation of...

42 CFR 412.72 - Modification of base-year costs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 2 2012-10-01 2012-10-01 false Modification of base-year costs. 412.72 Section 412... Modification of base-year costs. (a) Bases for modification of base-year costs. Base-year costs as determined... before November 16, 1983 has until November 15, 1983 to request its intermediary to reestimate its base...

42 CFR 412.72 - Modification of base-year costs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 2 2013-10-01 2013-10-01 false Modification of base-year costs. 412.72 Section 412... Modification of base-year costs. (a) Bases for modification of base-year costs. Base-year costs as determined... before November 16, 1983 has until November 15, 1983 to request its intermediary to reestimate its base...

42 CFR 412.72 - Modification of base-year costs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 2 2011-10-01 2011-10-01 false Modification of base-year costs. 412.72 Section 412... Modification of base-year costs. (a) Bases for modification of base-year costs. Base-year costs as determined... before November 16, 1983 has until November 15, 1983 to request its intermediary to reestimate its base...

42 CFR 412.72 - Modification of base-year costs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 2 2010-10-01 2010-10-01 false Modification of base-year costs. 412.72 Section 412... Modification of base-year costs. (a) Bases for modification of base-year costs. Base-year costs as determined... before November 16, 1983 has until November 15, 1983 to request its intermediary to reestimate its base...

75 FR 30268 - Airworthiness Directives; AeroSpace Technologies of Australia Pty Ltd Models N22B, N22S, and N24A...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-01

... FAA-approved repair scheme/modification and incorporate the repair scheme/ modification. Due to FAA policy, the repair scheme/modification for crack damage must include an immediate repair of the crack. The repair scheme cannot be by repetitive inspection only. The repair scheme/modification may...

75 FR 10694 - Airworthiness Directives; AeroSpace Technologies of Australia Pty Ltd Models N22B, N22S, and N24A...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-09

... FAA-approved repair scheme/modification and incorporate the repair scheme/ modification. Due to FAA policy, the repair scheme/modification for crack damage must include an immediate repair of the crack. The repair scheme cannot be by repetitive inspection only. The repair scheme/modification may...

49 CFR 232.307 - Modification of the single car air brake test procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake test... 49 Transportation 4 2010-10-01 2010-10-01 false Modification of the single car air brake test...

49 CFR 232.307 - Modification of the single car air brake test procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake test... 49 Transportation 4 2011-10-01 2011-10-01 false Modification of the single car air brake test...

49 CFR 232.307 - Modification of the single car air brake test procedures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Requirements § 232.307 Modification of the single car air brake test procedures. (a) Request. The AAR or other authorized representative of the railroad industry may seek modification of the single car air brake test... 49 Transportation 4 2012-10-01 2012-10-01 false Modification of the single car air brake test...

Functional Modification of Thioether Groups in Peptides, Polypeptides, and Proteins.

PubMed

Deming, Timothy J

2017-03-15

Recent developments in the modification of methionine and other thioether-containing residues in peptides, polypeptides, and proteins are reviewed. Properties and potential applications of the resulting functionalized products are also discussed. While much of this work is focused on natural Met residues, modifications at other side-chain residues have also emerged as new thioether-containing amino acids have been incorporated into peptidic materials. Functional modification of thioether-containing amino acids has many advantages and is a complementary methodology to the widely utilized methods for modification at cysteine residues.

A weight modification sequential method for VSC-MTDC power system state estimation

NASA Astrophysics Data System (ADS)

Yang, Xiaonan; Zhang, Hao; Li, Qiang; Guo, Ziming; Zhao, Kun; Li, Xinpeng; Han, Feng

2017-06-01

This paper presents an effective sequential approach based on weight modification for VSC-MTDC power system state estimation, called weight modification sequential method. The proposed approach simplifies the AC/DC system state estimation algorithm through modifying the weight of state quantity to keep the matrix dimension constant. The weight modification sequential method can also make the VSC-MTDC system state estimation calculation results more ccurate and increase the speed of calculation. The effectiveness of the proposed weight modification sequential method is demonstrated and validated in modified IEEE 14 bus system.

Making the Mark: The Role of Adenosine Modifications in the Lifecycle of RNA Viruses

PubMed Central

Gonzales-van Horn, Sarah R.; Sarnow, Peter

2017-01-01

Summary Viral epitranscriptomics is a newly emerging field that has identified unique roles for RNA modifications in modulating lifecycles of RNA viruses. Despite the observation of a handful of modified viral RNAs five decades ago, very little was known about how these modifications regulate viral lifecycles, until recently. Here we review the pro- and anti-viral effects of methyl-6-adenosine in distinct viral life cycles, the role of 2′ O-methyl modifications in RNA stability and innate immune sensing, and functions of adenosine to inosine modifications in retroviral life cycles. With roles for over 100 modifications in RNA still unknown, this is a rapidly emerging field that is destined to suggest novel antiviral therapies. PMID:28618265

Modern and prospective technologies for weather modification activities: A look at integrating unmanned aircraft systems

NASA Astrophysics Data System (ADS)

Axisa, Duncan; DeFelice, Tom P.

2016-09-01

Present-day weather modification technologies are scientifically based and have made controlled technological advances since the late 1990s, early 2000s. The technological advances directly related to weather modification have primarily been in the decision support and evaluation based software and modeling areas. However, there have been some technological advances in other fields that might now be advanced enough to start considering their usefulness for improving weather modification operational efficiency and evaluation accuracy. We consider the programmatic aspects underlying the development of new technologies for use in weather modification activities, identifying their potential benefits and limitations. We provide context and initial guidance for operators that might integrate unmanned aircraft systems technology in future weather modification operations.

Curcumin/turmeric solubilized in sodium hydroxide inhibits HNE protein modification--an in vitro study.

PubMed

Kurien, Biji T; Scofield, R Hal

2007-03-21

Free radical mediated lipid peroxidation has been implicated in multiple diseases. A major oxidation by-product of this deleterious process is 4-hydroxy-2-nonenal (HNE). HNE is cytotoxic, mutagenic and genotoxic and is involved in disease pathogenesis. Curcumin, a non-steroidal anti-inflammatory agent (occurring as the yellow pigment found in the rhizomes of the perennial herb Curcuma longa known as turmeric), has emerged as the newest "nutraceutical" agent that has been shown to be efficacious against colon cancer and other disorders, including correcting cystic fibrosis defects. Since curcumin has been reported to have anti-oxidant properties we hypothesized that it will inhibit HNE-modification of a protein substrate. Using an ELISA that employed HNE-modification of solid phase antigen following immobilization, we found that the curcumin solubilized in dilute alkali (5mM sodium hydroxide, pH 11) inhibited HNE-protein modification by 65%. Turmeric also inhibited HNE-protein modification similarly (65%) but at a much lower alkali level (130muM sodium hydroxide, pH 7.6). Alkali by itself (5mM sodium hydroxide, pH 11) was found to enhance HNE modification by as much as 267%. Curcumin/turmeric has to inhibit this alkali enhanced HNE-modification prior to inhibiting the normal HNE protein modification induced by HNE. Thus, inhibition of HNE-modification could be a mechanism by which curcumin exerts its antioxidant effects. The pH at which the inhibition of HNE modification of substrate was observed was close to the physiological pH, making this formulation of curcumin potentially useful practically.

RNomics and Modomics in the halophilic archaea Haloferax volcanii: identification of RNA modification genes

PubMed Central

Grosjean, Henri; Gaspin, Christine; Marck, Christian; Decatur, Wayne A; de Crécy-Lagard, Valérie

2008-01-01

Background Naturally occurring RNAs contain numerous enzymatically altered nucleosides. Differences in RNA populations (RNomics) and pattern of RNA modifications (Modomics) depends on the organism analyzed and are two of the criteria that distinguish the three kingdoms of life. If the genomic sequences of the RNA molecules can be derived from whole genome sequence information, the modification profile cannot and requires or direct sequencing of the RNAs or predictive methods base on the presence or absence of the modifications genes. Results By employing a comparative genomics approach, we predicted almost all of the genes coding for the t+rRNA modification enzymes in the mesophilic moderate halophile Haloferax volcanii. These encode both guide RNAs and enzymes. Some are orthologous to previously identified genes in Archaea, Bacteria or in Saccharomyces cerevisiae, but several are original predictions. Conclusion The number of modifications in t+rRNAs in the halophilic archaeon is surprisingly low when compared with other Archaea or Bacteria, particularly the hyperthermophilic organisms. This may result from the specific lifestyle of halophiles that require high intracellular salt concentration for survival. This salt content could allow RNA to maintain its functional structural integrity with fewer modifications. We predict that the few modifications present must be particularly important for decoding, accuracy of translation or are modifications that cannot be functionally replaced by the electrostatic interactions provided by the surrounding salt-ions. This analysis also guides future experimental validation work aiming to complete the understanding of the function of RNA modifications in Archaeal translation. PMID:18844986

Proteomic Approaches to Quantify Cysteine Reversible Modifications in Aging and Neurodegenerative Diseases

PubMed Central

Gu, Liqing; Robinson, Renã A. S.

2016-01-01

Cysteine is a highly reactive amino acid and is subject to a variety of reversible post-translational modifications (PTMs), including nitrosylation, glutathionylation, palmitoylation, as well as formation of sulfenic acid and disulfides. These modifications are not only involved in normal biological activities, such as enzymatic catalysis, redox signaling and cellular homeostasis, but can also be the result of oxidative damage. Especially in aging and neurodegenerative diseases, oxidative stress leads to aberrant cysteine oxidations that affect protein structure and function leading to neurodegeneration as well as other detrimental effects. Methods that can identify cysteine modifications by type, including the site of modification, as well as the relative stoichiometry of the modification can be very helpful for understanding the role of the thiol proteome and redox homeostasis in the context of disease. Cysteine reversible modifications however, are challenging to investigate as they are low abundant, diverse, and labile especially under endogenous conditions. Thanks to the development of redox proteomic approaches, large-scale quantification of cysteine reversible modifications is possible. These approaches cover a range of strategies to enrich, identify, and quantify cysteine reversible modifications from biological samples. This review will focus on nongel-based redox proteomics workflows that give quantitative information about cysteine PTMs and highlight how these strategies have been useful for investigating the redox thiol proteome in aging and neurodegenerative diseases. PMID:27666938

Hunting for unexpected post-translational modifications by spectral library searching with tier-wise scoring.

PubMed

Ma, Chun Wai Manson; Lam, Henry

2014-05-02

Discovering novel post-translational modifications (PTMs) to proteins and detecting specific modification sites on proteins is one of the last frontiers of proteomics. At present, hunting for post-translational modifications remains challenging in widely practiced shotgun proteomics workflows due to the typically low abundance of modified peptides and the greatly inflated search space as more potential mass shifts are considered by the search engines. Moreover, most popular search methods require that the user specifies the modification(s) for which to search; therefore, unexpected and novel PTMs will not be detected. Here a new algorithm is proposed to apply spectral library searching to the problem of open modification searches, namely, hunting for PTMs without prior knowledge of what PTMs are in the sample. The proposed tier-wise scoring method intelligently looks for unexpected PTMs by allowing mass-shifted peak matches but only when the number of matches found is deemed statistically significant. This allows the search engine to search for unexpected modifications while maintaining its ability to identify unmodified peptides effectively at the same time. The utility of the method is demonstrated using three different data sets, in which the numbers of spectrum identifications to both unmodified and modified peptides were substantially increased relative to a regular spectral library search as well as to another open modification spectral search method, pMatch.

tRNA modification profiles of the fast-proliferating cancer cells

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

Dong, Chao; Niu, Leilei; Song, Wei

Despite the recent progress in RNA modification study, a comprehensive modification profile is still lacking for mammalian cells. Using a quantitative HPLC/MS/MS assay, we present here a study where RNA modifications are examined in term of the major RNA species. With paired slow- and fast-proliferating cell lines, distinct RNA modification profiles are first revealed for diverse RNA species. Compared to mRNAs, increased ribose and nucleobase modifications are shown for the highly-structured tRNAs and rRNAs, lending support to their contribution to the formation of high-order structures. This study also reveals a dynamic tRNA modification profile in the fast-proliferating cells. In additionmore » to cultured cells, this unique tRNA profile has been further confirmed with endometrial cancers and their adjacent normal tissues. Taken together, the results indicate that tRNA is a actively regulated RNA species in the fast-proliferating cancer cells, and suggest that they may play a more active role in biological process than expected. -- Highlights: •RNA modifications were first examined in term of the major RNA species. •A dynamic tRNA modifications was characterized for the fast-proliferating cells. •The unique tRNA profile was confirmed with endometrial cancers and their adjacent normal tissues. •tRNA was predicted as an actively regulated RNA species in the fast-proliferating cancer cells.« less

Behavior Modification in the Classroom

ERIC Educational Resources Information Center

Whitman, Mryon; Whitman, Joan

1971-01-01

This article presents the theoretical rationale for behavior modification, principally through its comparison with traditional psychotherapies, and suggests some behavior modification techniques for the classroom management of maladaptive behavior. (Author)

75 FR 6251 - Notice of Application for Approval of Discontinuance or Modification of a Railroad Signal System...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-08

... Discontinuance or Modification of a Railroad Signal System or Relief From the Requirements of Title 49 Code of... approval for the discontinuance or modification of the signal system or relief from the requirements of 49... Company (BNSF) seeks approval of the proposed modification to the traffic control signal system over the...

78 FR 45565 - Notice of Lodging of Proposed Modification to Settlement Agreement Under the Clean Water Act

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-29

... DEPARTMENT OF JUSTICE Notice of Lodging of Proposed Modification to Settlement Agreement Under the Clean Water Act On July 23, 2013, the Department of Justice lodged a proposed Third Modification to the Settlement Agreement and Final Order (``Third Modification'') in United States and State of California ex rel. California Regional Water Quality...

An Analysis of Modifications to the Three-Step Guided Compliance Procedure Necessary to Achieve Compliance among Preschool Children

ERIC Educational Resources Information Center

Wilder, David A.; Myers, Kristin; Fischetti, Anthony; Leon, Yanerys; Nicholson, Katie; Allison, Janelle

2012-01-01

After a 3-step guided compliance procedure (vocal prompt, vocal plus model prompt, vocal prompt plus physical guidance) did not increase compliance, we evaluated 2 modifications with 4 preschool children who exhibited noncompliance. The first modification consisted of omission of the model prompt, and the second modification consisted of omitting…

Effect of Carboxymethylation on the Rheological Properties of Hyaluronan

PubMed Central

Wendling, Rian J.; Christensen, Amanda M.; Quast, Arthur D.; Atzet, Sarah K.; Mann, Brenda K.

2016-01-01

Chemical modifications made to hyaluronan to enable covalent crosslinking to form a hydrogel or to attach other molecules may alter the physical properties as well, which have physiological importance. Here we created carboxymethyl hyaluronan (CMHA) with varied degree of modification and investigated the effect on the viscosity of CMHA solutions. Viscosity decreased initially as modification increased, with a minimum viscosity for about 30–40% modification. This was followed by an increase in viscosity around 45–50% modification. The pH of the solution had a variable effect on viscosity, depending on the degree of carboxymethyl modification and buffer. The presence of phosphates in the buffer led to decreased viscosity. We also compared large-scale production lots of CMHA to lab-scale and found that large-scale required extended reaction times to achieve the same degree of modification. Finally, thiolated CMHA was disulfide crosslinked to create hydrogels with increased viscosity and shear-thinning aspects compared to CMHA solutions. PMID:27611817

Alpha-A crystallin: quantitation of C-terminal modification during lens aging

NASA Technical Reports Server (NTRS)

Takemoto, L.; Gopalakrishnan, S.; Spooner, B. S. (Principal Investigator)

1994-01-01

Previous studies have demonstrated that the C-terminal region of alpha-A crystallin is susceptible to age-dependent, posttranslational modification. To quantitate the amount of modification, alpha-A crystallin was purified from total proteins of the aging bovine lens, then digested with lys-C endoproteinase. Reverse phase, high pressure liquid chromatography was used to resolve and quantitate the resulting peptides, to determine the amount of C-terminal peptide relative to peptides from other regions of the protein that have not been reported to undergo modification. The results indicate that relative to alpha-A crystallin from newborn lens, posttranslational modification has occurred in approximately 45-55% of the C-terminal region from mature lens. These results demonstrate extensive modification of the C-terminal region of alpha-A crystallin from the mature lens, indicating that during the aging process, posttranslational modifications in this region may make significant contributions to the aggregated state and/or molecular chaperone properties of the molecule.

Surface Modification of Biomaterials: A Quest for Blood Compatibility

PubMed Central

de Mel, Achala; Cousins, Brian G.; Seifalian, Alexander M.

2012-01-01

Cardiovascular implants must resist thrombosis and intimal hyperplasia to maintain patency. These implants when in contact with blood face a challenge to oppose the natural coagulation process that becomes activated. Surface protein adsorption and their relevant 3D confirmation greatly determine the degree of blood compatibility. A great deal of research efforts are attributed towards realising such a surface, which comprise of a range of methods on surface modification. Surface modification methods can be broadly categorized as physicochemical modifications and biological modifications. These modifications aim to modulate platelet responses directly through modulation of thrombogenic proteins or by inducing antithrombogenic biomolecules that can be biofunctionalised onto surfaces or through inducing an active endothelium. Nanotechnology is recognising a great role in such surface modification of cardiovascular implants through biofunctionalisation of polymers and peptides in nanocomposites and through nanofabrication of polymers which will pave the way for finding a closer blood match through haemostasis when developing cardiovascular implants with a greater degree of patency. PMID:22693509

Mechanisms of behavior modification in clinical behavioral medicine in China.

PubMed

Yang, Zhiyin; Su, Zhonghua; Ji, Feng; Zhu, Min; Bai, Bo

2014-08-01

Behavior modification, as the core of clinical behavioral medicine, is often used in clinical settings. We seek to summarize behavior modification techniques that are commonly used in clinical practice of behavioral medicine in China and discuss possible biobehavioral mechanisms. We reviewed common behavior modification techniques in clinical settings in China, and we reviewed studies that explored possible biobehavioral mechanisms. Commonly used clinical approaches of behavior modification in China include behavior therapy, cognitive therapy, cognitive-behavioral therapy, health education, behavior management, behavioral relaxation training, stress management intervention, desensitization therapy, biofeedback therapy, and music therapy. These techniques have been applied in the clinical treatment of a variety of diseases, such as chronic diseases, psychosomatic diseases, and psychological disorders. The biobehavioral mechanisms of these techniques involve the autonomic nervous system, neuroendocrine system, neurobiochemistry, and neuroplasticity. Behavior modification techniques are commonly used in the treatment of a variety of somatic and psychological disorders in China. Multiple biobehavioral mechanisms are involved in successful behavior modification.

Novel "anchor modification" of polymeric biomaterial surfaces by the utilization of cyclodextrin inclusion complex supramolecules.

PubMed

Zhao, Xiaobin; Courtney, James M

2009-07-01

In this article, a novel approach for the surface modification of polymeric biomaterials by the utilization of supramolecules was studied. The supramolecules selected were cyclodextrin inclusion complexes (CICs). The biomaterial selected for surface modification was plasticized poly (vinyl chloride) (PVC-P). Results indicate that when the CICs were blended into PVC-P, they tend to migrate and "anchor" on the surface to achieve a remarkable protein-resistant surface, with improved blood compatibility. In comparison with a physical mixture of cyclodextrins and a "guest" molecule, such as poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO)-PEO and PPO-PEO-PPO for PVC-P modification, CICs modified PVC-P are more consistent in processing and achieve reproducible surface characteristics. Based on this study, a novel "anchor modification" was proposed regarding CICs modified surface. This "anchor modification" is likely to reduce plasticizer extraction from PVC-P and also can be utilized for the modification of polymers other than PVC-P.

Celebrating wobble decoding: Half a century and still much is new.

PubMed

Agris, Paul F; Eruysal, Emily R; Narendran, Amithi; Väre, Ville Y P; Vangaveti, Sweta; Ranganathan, Srivathsan V

2017-08-16

A simple post-transcriptional modification of tRNA, deamination of adenosine to inosine at the first, or wobble, position of the anticodon, inspired Francis Crick's Wobble Hypothesis 50 years ago. Many more naturally-occurring modifications have been elucidated and continue to be discovered. The post-transcriptional modifications of tRNA's anticodon domain are the most diverse and chemically complex of any RNA modifications. Their contribution with regards to chemistry, structure and dynamics reveal individual and combined effects on tRNA function in recognition of cognate and wobble codons. As forecast by the Modified Wobble Hypothesis 25 years ago, some individual modifications at tRNA's wobble position have evolved to restrict codon recognition whereas others expand the tRNA's ability to read as many as four synonymous codons. Here, we review tRNA wobble codon recognition using specific examples of simple and complex modification chemistries that alter tRNA function. Understanding natural modifications has inspired evolutionary insights and possible innovation in protein synthesis.

Conceptual design study of a Harrier V/STOL research aircraft

NASA Technical Reports Server (NTRS)

Bode, W. E.; Berger, R. L.; Elmore, G. A.; Lacey, T. R.

1978-01-01

MCAIR recently completed a conceptual design study to define modification approaches to, and derive planning prices for the conversion of a two place Harrier to a V/STOL control, display and guidance research aircraft. Control concepts such as rate damping, attitude stabilization, velocity command, and cockpit controllers are to be demonstrated. Display formats will also be investigated, and landing, navigation and guidance systems flight tested. The rear cockpit is modified such that it can be quickly adapted to faithfully simulate the controls, displays and handling qualities of a Type A or Type B V/STOL. The safety pilot always has take command capability. The modifications studied fall into two categories: basic modifications and optional modifications. Technical descriptions of the basic modifications and of the optional modifications are presented. The modification plan and schedule as well as the test plan and schedule are presented. The failure mode and effects analysis, aircraft performance, aircraft weight, and aircraft support are discussed.

Audience-contingent variation in action demonstrations for humans and computers.

PubMed

Herberg, Jonathan S; Saylor, Megan M; Ratanaswasd, Palis; Levin, Daniel T; Wilkes, D Mitchell

2008-09-01

People may exhibit two kinds of modifications when demonstrating action for others: modifications to facilitate bottom-up, or sensory-based processing; and modifications to facilitate top-down, or knowledge-based processing. The current study examined actors' production of such modifications in action demonstrations for audiences that differed in their capacity for intentional reasoning. Actors' demonstrations of complex actions for a non-anthropomorphic computer system and for people (adult and toddler) were compared. Evidence was found for greater highlighting of top-down modifications in the demonstrations for the human audiences versus the computer audience. Conversely, participants highlighted simple perceptual modifications for the computer audience, producing more punctuated and wider ranging motions. This study suggests that people consider differences in their audiences when demonstrating action. 2008 Cognitive Science Society, Inc.

Making the Mark: The Role of Adenosine Modifications in the Life Cycle of RNA Viruses.

PubMed

Gonzales-van Horn, Sarah R; Sarnow, Peter

2017-06-14

Viral epitranscriptomics is a newly emerging field that has identified unique roles for RNA modifications in modulating life cycles of RNA viruses. Despite the observation of a handful of modified viral RNAs five decades ago, very little was known about how these modifications regulate viral life cycles, until recently. Here we review the pro- and anti-viral effects of methyl-6-adenosine in distinct viral life cycles, the role of 2' O-methyl modifications in RNA stability and innate immune sensing, and functions of adenosine to inosine modifications in retroviral life cycles. With roles for over 100 modifications in RNA still unknown, this is a rapidly emerging field that is destined to suggest novel antiviral therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

KSC-05pd2530

NASA Image and Video Library

2005-11-30

KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility Bay 2, the nose cap of space shuttle Endeavour is prepared for installation of thermal protection system blankets. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

Methodological guidelines for developing accident modification functions.

PubMed

Elvik, Rune

2015-07-01

This paper proposes methodological guidelines for developing accident modification functions. An accident modification function is a mathematical function describing systematic variation in the effects of road safety measures. The paper describes ten guidelines. An example is given of how to use the guidelines. The importance of exploratory analysis and an iterative approach in developing accident modification functions is stressed. The example shows that strict compliance with all the guidelines may be difficult, but represents a level of stringency that should be strived for. Currently the main limitations in developing accident modification functions are the small number of good evaluation studies and the often huge variation in estimates of effect. It is therefore still not possible to develop accident modification functions for very many road safety measures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Partners in crime: The role of tandem modules in gene transcription.

PubMed

Sharma, Rajal; Zhou, Ming-Ming

2015-09-01

Histones and their modifications play an important role in the regulation of gene transcription. Numerous modifications, such as acetylation, phosphorylation, methylation, ubiquitination, and SUMOylation, have been described. These modifications almost always co-occur and thereby increase the combinatorial complexity of post-translational modification detection. The domains that recognize these histone modifications often occur in tandem in the context of larger proteins and complexes. The presence of multiple modifications can positively or negatively regulate the binding of these tandem domains, influencing downstream cellular function. Alternatively, these tandem domains can have novel functions from their independent parts. Here we summarize structural and functional information known about major tandem domains and their histone binding properties. An understanding of these interactions is key for the development of epigenetic therapy. © 2015 The Protein Society.

Introduction to the thematic minireview series on redox-active protein modifications and signaling.

PubMed

Banerjee, Ruma

2013-09-13

The dynamics of redox metabolism necessitate cellular strategies for sensing redox changes and for responding to them. A common mechanism for receiving and transmitting redox changes is via reversible modifications of protein cysteine residues. A plethora of cysteine modifications have been described, including sulfenylation, glutathionylation, and disulfide formation. These post-translational modifications have the potential to alter protein structure and/or function and to modulate cellular processes ranging from division to death and from circadian rhythms to secretion. The focus of this thematic minireview series is cysteine modifications in response to reactive oxygen and nitrogen species.

Behavior Modification in Special Education in the Federal Republic of Germany

ERIC Educational Resources Information Center

Barkey, Peter

1977-01-01

West German literature on educational behavior modification is summarized, and empirical studies of behavior modification intervention with special education students at the elementary level are surveyed. (SBH)

Alteration and modulation of protein activity by varying post-translational modification

DOEpatents

Thompson, David N; Reed, David W; Thompson, Vicki S; Lacey, Jeffrey A; Apel, William A

2015-03-03

Embodiments of the invention include methods of altering the enzymatic activity or solubility of an extremophilic enzyme or post-translationally modifying a protein of interest via using isolated or partially purified glycosyltransferases and/or post-translational modification proteins, extracts of cells comprising glycosyltransferases and/or post-translational modification proteins, and/or in cells comprising one or more glycosyltransferases and/or post-translational modification proteins.

Alteration and modulation of protein activity by varying post-translational modification

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

Thompson, David N.; Reed, David W.; Thompson, Vicki S.

Embodiments of the invention include methods of altering the enzymatic activity or solubility of an extremophilic enzyme or post-translationally modifying a protein of interest via using isolated or partially purified glycosyltransferases and/or post-translational modification proteins, extracts of cells comprising glycosyltransferases and/or post-translational modification proteins, and/or in cells comprising one or more glycosyltransferases and/or post-translational modification proteins.

Rates and Factors Associated with Major Modifications to First-Line Combination Antiretroviral Therapy: Results from the Asia-Pacific Region

PubMed Central

Wright, Stephen; Boyd, Mark A.; Yunihastuti, Evy; Law, Matthew; Sirisanthana, Thira; Hoy, Jennifer; Pujari, Sanjay; Lee, Man Po; Petoumenos, Kathy

2013-01-01

Background In the Asia-Pacific region many countries have adopted the WHO’s public health approach to HIV care and treatment. We performed exploratory analyses of the factors associated with first major modification to first-line combination antiretroviral therapy (ART) in resource-rich and resource-limited countries in the region. Methods We selected treatment naive HIV-positive adults from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD). We dichotomised each country’s per capita income into high/upper-middle (T-H) and lower-middle/low (T-L). Survival methods stratified by income were used to explore time to first major modification of first-line ART and associated factors. We defined a treatment modification as either initiation of a new class of antiretroviral (ARV) or a substitution of two or more ARV agents from within the same ARV class. Results A total of 4250 patients had 961 major modifications to first-line ART in the first five years of therapy. The cumulative incidence (95% CI) of treatment modification was 0.48 (0.44–0.52), 0.33 (0.30–0.36) and 0.21 (0.18–0.23) for AHOD, T-H and T-L respectively. We found no strong associations between typical patient characteristic factors and rates of treatment modification. In AHOD, relative to sites that monitor twice-yearly (both CD4 and HIV RNA-VL), quarterly monitoring corresponded with a doubling of the rate of treatment modifications. In T-H, relative to sites that monitor once-yearly (both CD4 and HIV RNA-VL), monitoring twice-yearly corresponded to a 1.8 factor increase in treatment modifications. In T-L, no sites on average monitored both CD4 & HIV RNA-VL concurrently once-yearly. We found no differences in rates of modifications for once- or twice-yearly CD4 count monitoring. Conclusions Low-income countries tended to have lower rates of major modifications made to first-line ART compared to higher-income countries. In higher-income countries, an increased rate of RNA-VL monitoring was associated with increased modifications to first-line ART. PMID:23840312

Rates and factors associated with major modifications to first-line combination antiretroviral therapy: results from the Asia-Pacific region.

PubMed

Wright, Stephen; Boyd, Mark A; Yunihastuti, Evy; Law, Matthew; Sirisanthana, Thira; Hoy, Jennifer; Pujari, Sanjay; Lee, Man Po; Petoumenos, Kathy

2013-01-01

In the Asia-Pacific region many countries have adopted the WHO's public health approach to HIV care and treatment. We performed exploratory analyses of the factors associated with first major modification to first-line combination antiretroviral therapy (ART) in resource-rich and resource-limited countries in the region. We selected treatment naive HIV-positive adults from the Australian HIV Observational Database (AHOD) and the TREAT Asia HIV Observational Database (TAHOD). We dichotomised each country's per capita income into high/upper-middle (T-H) and lower-middle/low (T-L). Survival methods stratified by income were used to explore time to first major modification of first-line ART and associated factors. We defined a treatment modification as either initiation of a new class of antiretroviral (ARV) or a substitution of two or more ARV agents from within the same ARV class. A total of 4250 patients had 961 major modifications to first-line ART in the first five years of therapy. The cumulative incidence (95% CI) of treatment modification was 0.48 (0.44-0.52), 0.33 (0.30-0.36) and 0.21 (0.18-0.23) for AHOD, T-H and T-L respectively. We found no strong associations between typical patient characteristic factors and rates of treatment modification. In AHOD, relative to sites that monitor twice-yearly (both CD4 and HIV RNA-VL), quarterly monitoring corresponded with a doubling of the rate of treatment modifications. In T-H, relative to sites that monitor once-yearly (both CD4 and HIV RNA-VL), monitoring twice-yearly corresponded to a 1.8 factor increase in treatment modifications. In T-L, no sites on average monitored both CD4 & HIV RNA-VL concurrently once-yearly. We found no differences in rates of modifications for once- or twice-yearly CD4 count monitoring. Low-income countries tended to have lower rates of major modifications made to first-line ART compared to higher-income countries. In higher-income countries, an increased rate of RNA-VL monitoring was associated with increased modifications to first-line ART.

Alternative materials for subgrade modification

DOT National Transportation Integrated Search

2001-10-01

This study examines the laboratory and field performance of two alternative materials used for the modification of unstable (CBR<6) subgrade soils. Modification is temporarily enhancing subgrade : stability to improve the constructability of successi...

Histone modifications in the male germ line of Drosophila.

PubMed

Hennig, Wolfgang; Weyrich, Alexandra

2013-02-22

In the male germ line of Drosophila chromatin remains decondensed and highly transcribed during meiotic prophase until it is rapidly compacted. A large proportion of the cell cycle-regulated histone H3.1 is replaced by H3.3, a histone variant encoded outside the histone repeat cluster and not subject to cell cycle controlled expression. We investigated histone modification patterns in testes of D. melanogaster and D. hydei. In somatic cells of the testis envelope and in germ cells these modification patterns differ from those typically seen in eu- and heterochromatin of other somatic cells. During the meiotic prophase some modifications expected in active chromatin are not found or are found at low level. The absence of H4K16ac suggests that dosage compensation does not take place. Certain histone modifications correspond to either the cell cycle-regulated histone H3.1 or to the testis-specific variant H3.3. In spermatogonia we found H3K9 methylation in cytoplasmic histones, most likely corresponding to the H3.3 histone variant. Most histone modifications persist throughout the meiotic divisions. The majority of modifications persist until the early spermatid nuclei, and only a minority further persist until the final chromatin compaction stages before individualization of the spermatozoa. Histone modification patterns in the male germ line differ from expected patterns. They are consistent with an absence of dosage compensation of the X chromosome during the male meiotic prophase. The cell cycle-regulated histone variant H3.1 and H3.3, expressed throughout the cell cycle, also vary in their modification patterns. Postmeiotically, we observed a highly complex pattern of the histone modifications until late spermatid nuclear elongation stages. This may be in part due to postmeiotic transcription and in part to differential histone replacement during chromatin condensation.

A high-throughput and rapid computational method for screening of RNA post-transcriptional modifications that can be recognized by target proteins.

PubMed

Orr, Asuka A; Gonzalez-Rivera, Juan C; Wilson, Mark; Bhikha, P Reena; Wang, Daiqi; Contreras, Lydia M; Tamamis, Phanourios

2018-02-01

There are over 150 currently known, highly diverse chemically modified RNAs, which are dynamic, reversible, and can modulate RNA-protein interactions. Yet, little is known about the wealth of such interactions. This can be attributed to the lack of tools that allow the rapid study of all the potential RNA modifications that might mediate RNA-protein interactions. As a promising step toward this direction, here we present a computational protocol for the characterization of interactions between proteins and RNA containing post-transcriptional modifications. Given an RNA-protein complex structure, potential RNA modified ribonucleoside positions, and molecular mechanics parameters for capturing energetics of RNA modifications, our protocol operates in two stages. In the first stage, a decision-making tool, comprising short simulations and interaction energy calculations, performs a fast and efficient search in a high-throughput fashion, through a list of different types of RNA modifications categorized into trees according to their structural and physicochemical properties, and selects a subset of RNA modifications prone to interact with the target protein. In the second stage, RNA modifications that are selected as recognized by the protein are examined in-detail using all-atom simulations and free energy calculations. We implement and experimentally validate this protocol in a test case involving the study of RNA modifications in complex with Escherichia coli (E. coli) protein Polynucleotide Phosphorylase (PNPase), depicting the favorable interaction between 8-oxo-7,8-dihydroguanosine (8-oxoG) RNA modification and PNPase. Further advancement of the protocol can broaden our understanding of protein interactions with all known RNA modifications in several systems. Copyright © 2018 Elsevier Inc. All rights reserved.

Microscopic mechanism of amino silicone oil modification and modification effect with different amino group contents based on molecular dynamics simulation

NASA Astrophysics Data System (ADS)

He, Liping; Li, Wenjun; Chen, Dachuan; Yuan, Jianmin; Lu, Gang; Zhou, Dianwu

2018-05-01

The microscopic mechanism of amino silicone oil (ASO) modification of natural fiber was investigated for the first time using molecular dynamics (MD) simulation at the atomic and molecular levels. The MD simulation results indicated that the ASO molecular interacted with the cellulose molecular within the natural fiber, mainly by intermolecular forces of Nsbnd Hsbnd O and Osbnd Hsbnd N hydrogen bonds and the molecular chain of ASO absorbed onto the natural fiber in a selective orientation, i.e., the hydrophobic alkyl groups (sbnd CnH2n+1) project outward and the polar amino groups (sbnd NH2) point to the surface of natural fiber. Consequently, the ASO modification changed the surface characteristic of natural fiber from hydrophilic to hydrophobic. Furthermore, the modification effects of the ASO modification layer with different amino group contents (m:n ratio) were also evaluated in this study by calculating the binding energy between the ASO modifier and natural fiber, and the cohesive energy density and free volume of the ASO modification layer. The results showed that the binding energy reached a maximum when the m:n ratio of ASO was of 8:4, suggesting that a good bonding strength was achieved at this m:n ratio. It was also found that the cohesive energy density enhanced with the increase in the amino group content, and the higher the cohesive energy density, the easier the formation of the ASO modification layer. However, the fraction free volume decreased with the increase in the amino group content. This is good for improving the water-proof property of natural fiber. The present work can provide an effective method for predicting the modification effects and designing the optimized m:n ratio of ASO modification.

40 CFR 52.736 - Review of new sources and modifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sources and modifications. (a) [Reserved] (b) The rules submitted by the State on March 24, 1988, to... Sources Construction and Modification as effective March 22, 1991. The moratorium on construction and...

50 CFR 218.240 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Array Sensor System Low Frequency Active (SURTASS LFA) Sonar § 218.240 Modifications to Letters of... sonar system from one ship to another, is not considered a substantial modification. (b) If NMFS...

50 CFR 218.240 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Array Sensor System Low Frequency Active (SURTASS LFA) Sonar § 218.240 Modifications to Letters of... sonar system from one ship to another, is not considered a substantial modification. (b) If NMFS...

50 CFR 218.240 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Array Sensor System Low Frequency Active (SURTASS LFA) Sonar § 218.240 Modifications to Letters of... sonar system from one ship to another, is not considered a substantial modification. (b) If NMFS...

Behavior Modification in Coaching.

ERIC Educational Resources Information Center

Lynch, Annette Rutt; Stillman, Stephen M.

1979-01-01

An example of behavior modification used in athletic coaching is presented. The case study involves a member of a women's basketball team and details the use of behavior modification for both weight reduction and skill improvement. (JMF)

30 CFR 18.81 - Field modification of approved (permissible) equipment; application for approval of modification...

Code of Federal Regulations, 2014 CFR

2014-07-01

... TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES... and Certification Center, 765 Technology Drive, Triadelphia, WV 26059. (b) Proposed modifications...

KSC-05pd2533

NASA Image and Video Library

2005-11-30

KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility Bay 2, United Space Alliance technician Michael Vanwart installs thermal protection system blankets in the nose cap of space shuttle Endeavour. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

KSC-05pd2531

NASA Image and Video Library

2005-11-30

KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility bay 2, United Space Alliance technician Michael Vanwart prepares to install thermal protection system blankets in the nose cap of space shuttle Endeavour. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

KSC-05pd2532

NASA Image and Video Library

2005-11-30

KENNEDY SPACE CENTER, FLA. - In Orbiter Processing Facility Bay 2, United Space Alliance technician Michael Vanwart installs thermal protection system blankets in the nose cap of space shuttle Endeavour. Endeavour recently came out of a nearly two-year Orbiter Major Modification period which began in December 2003. Engineers and technicians spent 900,000 hours performing 124 modifications to the vehicle. These included all recommended return-to-flight safety modifications, bonding more than 1,000 thermal protection system tiles and inspecting more than 150 miles of wiring throughout the orbiter. Shuttle major modification periods are scheduled at regular intervals to enhance safety and performance, infuse new technology, and allow for thorough inspections of the airframe and wiring of the vehicles. This was the second of these modification periods performed entirely at Kennedy Space Center. Endeavour's previous modification was completed in March 1997.

Crystal structure of laser-induced subsurface modifications in Si

NASA Astrophysics Data System (ADS)

Verburg, P. C.; Smillie, L. A.; Römer, G. R. B. E.; Haberl, B.; Bradby, J. E.; Williams, J. S.; Huis in't Veld, A. J.

2015-08-01

Laser-induced subsurface modification of dielectric materials is a well-known technology. Applications include the production of optical components and selective etching. In addition to dielectric materials, the subsurface modification technology can be applied to silicon, by employing near to mid-infrared radiation. An application of subsurface modifications in silicon is laser-induced subsurface separation, which is a method to separate wafers into individual dies. Other applications for which proofs of concept exist are the formation of waveguides and resistivity tuning. However, limited knowledge is available about the crystal structure of subsurface modifications in silicon. In this work, we investigate the geometry and crystal structure of laser-induced subsurface modifications in monocrystalline silicon wafers. In addition to the generation of lattice defects, we found that transformations to amorphous silicon and Si -iii/Si -xii occur as a result of the laser irradiation.

Knowledge, attitudes towards and acceptability of genetic modification in Germany.

PubMed

Christoph, Inken B; Bruhn, Maike; Roosen, Jutta

2008-07-01

Genetic modification remains a controversial issue. The aim of this study is to analyse the attitudes towards genetic modification, the knowledge about it and its acceptability in different application areas among German consumers. Results are based on a survey from spring 2005. An exploratory factor analysis is conducted to identify the attitudes towards genetic modification. The identified factors are used in a cluster analysis that identified a cluster of supporters, of opponents and a group of indifferent consumers. Respondents' knowledge of genetics and biotechnology differs among the found clusters without revealing a clear relationship between knowledge and support of genetic modification. The acceptability of genetic modification varies by application area and cluster, and genetically modified non-food products are more widely accepted than food products. The perception of personal health risks has high explanatory power for attitudes and acceptability.

Effects of preparation relief and flow channels on seating full coverage castings during cementation.

PubMed

Webb, E L; Murray, H V; Holland, G A; Taylor, D F

1983-06-01

Machined steel dies were used to study the effects of three die modifications on seating full coverage castings during cementation. The die modifications consisted of occlusal channels, occlusal surface relief, and axial channels. Fourteen specimens having one or more forms of die modification were compared with two control specimens having no die modifications. Statistical analysis of the data revealed that the addition of four axial channels to the simulated preparation on the steel die produced a significant reduction in the mean marginal discrepancy during cementation. Occlusal modifications alone failed to produce significant reductions in marginal discrepancies when compared with the control specimens. Occlusal modifications in conjunction with axial channels failed to produce further significant reductions in marginal discrepancies when compared with those reductions observed in specimens having only axial channels.

The impact of teachers’ modifications of an evidenced-based HIV prevention intervention on program outcomes

PubMed Central

Wang, Bo; Stanton, Bonita; Lunn, Sonja; Rolle, Glenda; Poitier, Maxwell; Adderley, Richard; Li, Xiaoming; Koci, Veronica; Deveaux, Lynette

2015-01-01

The degree to which evidence-based program outcomes are affected by modifications is a significant concern in the implementation of interventions. The ongoing national implementation of an evidence-based HIV prevention program targeting grade six students in The Bahamas [Focus on Youth in The Caribbean (FOYC)] offers an opportunity to explore factors associated with teachers’ modification of FOYC lessons and to examine the impact of types and degrees of modifications on student outcomes. Data were collected in 2012 from 155 teachers and 3646 students in 77 government elementary schools. Results indicate that teachers taught 16 of 30 core activities, 24.5 of 46 total activities and 4.7 of 8 sessions. Over one-half of the teachers made modifications to FOYC core activities; one-fourth of the teachers modified 25% or more core activities that they taught (heavily modified FOYC). Omitting core activities was the most common content modification, followed by lengthening FOYC lessons with reading, writing assignments or role-play games, shortening core activities or adding educational videos. Mixed-effects modeling revealed that omitting core activities had negative impacts on all four student outcomes. Shortening core activities and adding videos into lessons had negative impacts on HIV/AIDS knowledge and/or intention to use condom protection. Heavy modifications (>1/4 core activities) were associated with diminished program effectiveness. Heavy modifications and omitting or shortening core activities were negatively related to teachers’ level of implementation. We conclude that poorer student outcomes were associated with heavy modifications. PMID:26297497

The Impact of Teachers' Modifications of an Evidenced-Based HIV Prevention Intervention on Program Outcomes.

PubMed

Wang, Bo; Stanton, Bonita; Lunn, Sonja; Rolle, Glenda; Poitier, Maxwell; Adderley, Richard; Li, Xiaoming; Koci, Veronica; Deveaux, Lynette

2016-01-01

The degree to which evidence-based program outcomes are affected by modifications is a significant concern in the implementation of interventions. The ongoing national implementation of an evidence-based HIV prevention program targeting grade 6 students in The Bahamas [Focus on Youth in The Caribbean (FOYC)] offers an opportunity to explore factors associated with teachers' modification of FOYC lessons and to examine the impact of types and degrees of modifications on student outcomes. Data were collected in 2012 from 155 teachers and 3646 students in 77 government elementary schools. Results indicate that teachers taught 16 of 30 core activities, 24.5 of 46 total activities and 4.7 of 8 sessions. Over one-half of the teachers made modifications to FOYC core activities; one-fourth of the teachers modified 25 % or more core activities that they taught (heavily modified FOYC). Omitting core activities was the most common content modification, followed by lengthening FOYC lessons with reading, writing assignments or role-play games, and shortening core activities or adding educational videos. Mixed-effects modeling revealed that omitting core activities had negative impacts on all four student outcomes. Shortening core activities and adding videos into lessons had negative impacts on HIV/AIDS knowledge and/or intention to use condom protection. Heavy modifications (>1/4 core activities) were associated with diminished program effectiveness. Heavy modifications and omitting or shortening core activities were negatively related to teachers' level of implementation. We conclude that poorer student outcomes were associated with heavy modifications.

Study report on modification of the long term circulatory model for the simulation of bed rest

NASA Technical Reports Server (NTRS)

Leonard, J. I.; Grounds, D. J.

1977-01-01

Modifications were made of the circulatory, fluid, and electrolyte control model which was based on the model of Guyton. The modifications included separate leg compartments and the addition of gravity dependency. It was found that these modifications allowed for more accurate bed rest simulation by simulating changes in the orthostatic gradient and simulating the response to the fluid shifts associated with bed rest.

Pnp gene modification for improved xylose utilization in Zymomonas

DOEpatents

Caimi, Perry G G; Qi, Min; Tao, Luan; Viitanen, Paul V; Yang, Jianjun

2014-12-16

The endogenous pnp gene encoding polynucleotide phosphorylase in the Zymomonas genome was identified as a target for modification to provide improved xylose utilizing cells for ethanol production. The cells are in addition genetically modified to have increased expression of ribose-5-phosphate isomerase (RPI) activity, as compared to cells without this genetic modification, and are not limited in xylose isomerase activity in the absence of the pnp modification.

Pseudouridine and N6-methyladenosine modifications weaken PUF protein/RNA interactions

PubMed Central

AlSadhan, Ishraq; Merriman, Dawn K.; Al-Hashimi, Hashim M.; Herschlag, Daniel

2017-01-01

RNA modifications are ubiquitous in biology, with over 100 distinct modifications. While the vast majority were identified and characterized on abundant noncoding RNA such as tRNA and rRNA, the advent of sensitive sequencing-based approaches has led to the discovery of extensive and regulated modification of eukaryotic messenger RNAs as well. The two most abundant mRNA modifications—pseudouridine (Ψ) and N6-methyladenosine (m6A)—affect diverse cellular processes including mRNA splicing, localization, translation, and decay and modulate RNA structure. Here, we test the hypothesis that RNA modifications directly affect interactions between RNA-binding proteins and target RNA. We show that Ψ and m6A weaken the binding of the human single-stranded RNA binding protein Pumilio 2 (hPUM2) to its consensus motif, with individual modifications having effects up to approximately threefold and multiple modifications giving larger effects. While there are likely to be some cases where RNA modifications essentially fully ablate protein binding, here we see modest responses that may be more common. Such modest effects could nevertheless profoundly alter the complex landscape of RNA:protein interactions, and the quantitative rather than qualitative nature of these effects underscores the need for quantitative, systems-level accounting of RNA:protein interactions to understand post-transcriptional regulation. PMID:28138061

Genome-wide analyses of four major histone modifications in Arabidopsis hybrids at the germinating seed stage.

PubMed

Zhu, Anyu; Greaves, Ian K; Dennis, Elizabeth S; Peacock, W James

2017-02-07

Hybrid vigour (heterosis) has been used for decades in cropping agriculture, especially in the production of maize and rice, because hybrid varieties exceed their parents in plant biomass and seed yield. The molecular basis of hybrid vigour is not fully understood. Previous studies have suggested that epigenetic systems could play a role in heterosis. In this project, we investigated genome-wide patterns of four histone modifications in Arabidopsis hybrids in germinating seeds. We found that although hybrids have similar histone modification patterns to the parents in most regions of the genome, they have altered patterns at specific loci. A small subset of genes show changes in histone modifications in the hybrids that correlate with changes in gene expression. Our results also show that genome-wide patterns of histone modifications in geminating seeds parallel those at later developmental stages of seedlings. Ler/C24 hybrids showed similar genome-wide patterns of histone modifications as the parents at an early germination stage. However, a small subset of genes, such as FLC, showed correlated changes in histone modification and in gene expression in the hybrids. The altered patterns of histone modifications for those genes in hybrids could be related to some heterotic traits in Arabidopsis, such as flowering time, and could play a role in hybrid vigour establishment.

Modification of oral dosage forms for the older adult: An Irish prevalence study.

PubMed

Mc Gillicuddy, Aoife; Kelly, Maria; Sweeney, Catherine; Carmichael, Ann; Crean, Abina M; Sahm, Laura J

2016-08-20

Age-related pharmacological changes complicate oral dosage form (ODF) suitability for older adults. The aim of this study was to investigate the appropriateness of ODF for older adults by determining the prevalence of ODF modifications in an aged care facility in Ireland. Drug charts for eligible patients were obtained. Details of all medications administered were recorded. ODF modifications were examined to determine if they were evidence-based: defined as complying with the product license or best practice guidelines (BPG). In total, of 111 patients, 35.1% received at least one modified medicine. Medicines were most commonly modified to facilitate fractional dosing (82.0%). Of the 68 instances of medicine modification, 35.3% complied with the product license. Of the 44 unlicensed modifications, 14 complied with BPG. Therefore, 44.1% of modifications were not evidence-based. This study highlights that clinicians have to routinely tailor commercial ODF to meet older patients' needs despite the lack of an evidence-base for almost half of these modifications. The main factor contributing to these modifications is the lack of appropriate, licensed dosage forms. However, reimbursement policies also play a role. Research is needed to optimise medicine administration and to provide clinicians with much needed evidence to support their daily practice. Copyright © 2016 Elsevier B.V. All rights reserved.

Adaptive Flight Control Design with Optimal Control Modification on an F-18 Aircraft Model

NASA Technical Reports Server (NTRS)

Burken, John J.; Nguyen, Nhan T.; Griffin, Brian J.

2010-01-01

In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to as the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly; however, a large adaptive gain can lead to high-frequency oscillations which can adversely affect the robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient robustness. A damping term (v) is added in the modification to increase damping as needed. Simulations were conducted on a damaged F-18 aircraft (McDonnell Douglas, now The Boeing Company, Chicago, Illinois) with both the standard baseline dynamic inversion controller and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model.

Space Shuttle orbiter modifications to support Space Station Freedom

NASA Technical Reports Server (NTRS)

Segert, Randall; Lichtenfels, Allyson

1992-01-01

The Space Shuttle will be the primary vehicle to support the launch, assembly, and maintenance of the Space Station Freedom (SSF). In order to accommodate this function, the Space Shuttle orbiter will require significant modifications. These modifications are currently in development in the Space Shuttle Program. The requirements for the planned modifications to the Space Shuttle orbiter are dependent on the design of the SSF. Therefore, extensive coordination is required with the Space Station Freedom Program (SSFP) in order to identify requirements and resolve integration issues. This paper describes the modifications to the Space Shuttle orbiter required to support SSF assembly and operations.

Addendum to the Closure Report for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point, Nevada Test Site, Nevada

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

Lynn Kidman

2008-10-01

This document constitutes an addendum to the July 2003, Closure Report for Corrective Action Unit 262: Area 25 Septic Systems and Underground Discharge Point as described in the document Recommendations and Justifications for Modifications for Use Restrictions Established under the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office Federal Facility Agreement and Consent Order (UR Modification document) dated February 2008. The UR Modification document was approved by NDEP on February 26, 2008. The approval of the UR Modification document constituted approval of each of the recommended UR modifications.

Synthetic Proteins and Peptides for the Direct Interrogation of α-Synuclein Posttranslational Modifications

PubMed Central

Pratt, Matthew R.; Abeywardana, Tharindumala; Marotta, Nicholas P.

2015-01-01

α-Synuclein is the aggregation-prone protein associated with Parkinson’s disease (PD) and related neurodegenerative diseases. Complicating both its biological functions and toxic aggregation are a variety of posttranslational modifications. These modifications have the potential to either positively or negatively affect α-synuclein aggregation, raising the possibility that the enzymes that add or remove these modifications could be therapeutic targets in PD. Synthetic protein chemistry is uniquely positioned to generate site-specifically and homogeneously modified proteins for biochemical study. Here, we review the application of synthetic peptides and proteins towards understanding the effects of α-synuclein posttranslational modifications. PMID:26120904

Retrofit and verification test of a 30-cm ion thruster

NASA Technical Reports Server (NTRS)

Dulgeroff, C. R.; Poeschel, R. L.

1980-01-01

Twenty modifications were found to be necessary and were approved by design review. These design modifications were incorporated in the thruster documents (drawings and procedures) to define the J series thruster. Sixteen of the design revisions were implemented in a 900 series thruster by retrofit modification. A standardized set of test procedures was formulated, and the retrofit J series thruster design was verified by test. Some difficulty was observed with the modification to the ion optics assembly, but the overall effect of the design modification satisfies the design objectives. The thruster was tested over a wide range of operating parameters to demonstrate its capabilities.

tRNA wobble modifications and protein homeostasis

PubMed Central

Ranjan, Namit; Rodnina, Marina V.

2016-01-01

Abstract tRNA is a central component of the protein synthesis machinery in the cell. In living cells, tRNAs undergo numerous post-transcriptional modifications. In particular, modifications at the anticodon loop play an important role in ensuring efficient protein synthesis, maintaining protein homeostasis, and helping cell adaptation and survival. Hypo-modification of the wobble position of the tRNA anticodon loop is of particular relevance for translation regulation and is implicated in various human diseases. In this review we summarize recent evidence of how methyl and thiol modifications in eukaryotic tRNA at position 34 affect cellular fitness and modulate regulatory circuits at normal conditions and under stress. PMID:27335723

50 CFR 216.190 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Array Sensor System Low Frequency Active (SURTASS LFA sonar) Sonar § 216.190 Modifications to Letters of... sonar system from one ship to another, is not considered a substantial modification. (b) If the National...

50 CFR 216.190 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Array Sensor System Low Frequency Active (SURTASS LFA sonar) Sonar § 216.190 Modifications to Letters of... sonar system from one ship to another, is not considered a substantial modification. (b) If the National...

Response modification for enhanced operation and safety of bridges.

DOT National Transportation Integrated Search

2011-08-01

This report shows that safe extension of the service life of existing bridge structures is possible through bridge : health monitoring and structural response modification. To understand bridge health monitoring and structural : response modification...

Crash Modification Factors for Chevrons in Iowa

DOT National Transportation Integrated Search

2018-02-02

Although chevron alignment signs have been utilized for some time along horizontal curves, their effectiveness is not well documented. The Crash Modification Factors Clearinghouse includes crash modification factors (CMFs) for chevrons from 0.41 to 1...

Optimisation structurale de dalles de chaussees en beton jointees avec des goujons en materiaux composites en Polymeres Renforces de Fibres de Verre (PRFV)

NASA Astrophysics Data System (ADS)

Bricola, Julien

In Quebec, the majority of the road network was built in the 60's - 70's and show obvious signs of ageing. Moreover, the increase of road traffic and the rigorous weather conditions, render the maintenance and the exploitation of roads in this Northern American part quite difficult. Indeed, these environmental conditions cause severe damages for roads, especially in winter. The degradation factor of the jointed rigid pavement is intensified by the highway salt. So, the phenomena of deteriorations appears mainly by the corrosion of the steel at the joints (structural elements) guaranteeing the durability of roads. The jointed rigid pavements or "short jointed pavements" are still mainly sized with steel dowels placed at the lining of joints. One of the main functions of these structures is to control the formation of cracking due to the thermal and environmental conditions. In order to reduce these , disorders, the Ministry of Transport of Quebec (MTQ) turned towards new techniques and innovative materials to ensure the longevity of roads. With the rapid evolution of specific methods and knowledge in roads design, joined with technologies and new products, the MTQ emphasizes the research and development. That way, advanced techniques and diverse technologies in the Quebecois context are settled. As a matter of fact, one of the axes of these development researches concerns the composite materials which have recently been given good results in the civil engineering area. That is why Glass Fibre-Reinforced Polymer (GFRP) dowels bars appear as a solution to the steel corrosion. In fact, they provide better durability with lower costs: the increase of service life as well as the decrease of maintenance persons and traffics impac. Thus, this project proposes an optimization of structural design of GFRP dowels for transverse jointed highway pavement slabs, also keeping in mind their use in new projects. The GFRP dowels which are given in this essay are made by the Pultrall Inc. Company from Thetford Mines (Quebec, Canada). The resin used for the polymer materials is only vinylester resin and the dowels have diameters going from 28.6 mm to 34.9 mm. Finally, only a stiff base is used for the road, its particularity is the modulus of subgrade reaction. Keywords: concrete pavement, dowelled slab, jointed concrete pavement, GFRP dowels, optimization, structural, design .

Hydrologic conditions in the Chicod Creek basin, North Carolina, before and during channel modifications, 1975-81

USGS Publications Warehouse

Watkins, S.A.; Simmons, C.E.

1984-01-01

Beginning in late 1978, stream channels throughout the 60-square mile Chicod Creek basin underwent extensive modification to increase drainage efficiency and reduce flooding potential. Drainage modifications in this Coastal Plain basin, consisting primarily of channel excavation and clearing of channel blockages, were completed in December 1981. The hydrologic condition of the basin before and during modification was determined from observed data. Observed data indicate hydrologic changes occurred in selected basin characteristics. For example, water levels in the surficial aquifer within 250 feet of Juniper Branch declined as much as 0.4 feet during modifications; at distances greater than 250 feet from the stream, ground-water levels did not change. Base flows increased, and suspended-sediment concentrations for high flows were several times greater than before channel modifications. Increases in selected chemical constituent concentrations in stream water during modifications were as follows: calcium, 12 percent; sodium, 18 percent; bicarbonate, 84 percent; and phosphorous, 80 percent. Significant changes were not found in either pesticide concentrations or coliform bacteria counts.

Lifestyle modification in the management of the metabolic syndrome: achievements and challenges

PubMed Central

Grave, Riccardo Dalle; Calugi, Simona; Centis, Elena; Marzocchi, Rebecca; Ghoch, Marwan El; Marchesini, Giulio

2010-01-01

Lifestyle modification based on behavior therapy is the most important and effective strategy to manage the metabolic syndrome. Modern lifestyle modification therapy combines specific recommendations on diet and exercise with behavioral and cognitive strategies. The intervention may be delivered face-to-face or in groups, or in groups combined with individual sessions. The main challenge of treatment is helping patients maintain healthy behavior changes in the long term. In the last few years, several strategies have been evaluated to improve the long-term effect of lifestyle modification. Promising results have been achieved by combining lifestyle modification with pharmacotherapy, using meals replacement, setting higher physical activity goals, and long-term care. The key role of cognitive processes in the success/failure of weight loss and maintenance suggests that new cognitive procedures and strategies should be included in the traditional lifestyle modification interventions, in order to help patients build a mind-set favoring long-term lifestyle changes. These new strategies raise optimistic expectations for an effective treatment of metabolic syndrome with lifestyle modifications, provided public health programs to change the environment where patients live support them. PMID:21437107

Controlled levels of protein modification through a chromatography-mediated bioconjugation

DOE PAGES

Kwant, Richard L.; Jaffe, Jake; Palmere, Peter J.; ...

2015-02-27

Synthetically modified proteins are increasingly finding applications as well-defined scaffolds for materials. In practice it remains difficult to construct bioconjugates with precise levels of modification because of the limited number of repeated functional groups on proteins. This article describes a method to control the level of protein modification in cases where there exist multiple potential modification sites. A protein is first tagged with a handle using any of a variety of modification chemistries. This handle is used to isolate proteins with a particular number of modifications via affinity chromatography, and then the handle is elaborated with a desired moiety usingmore » an oxidative coupling reaction. This method results in a sample of protein with a well-defined number of modifications, and we find it particularly applicable to systems like protein homomultimers in which there is no way to discern between chemically identical subunits. We demonstrate the use of this method in the construction of a protein-templated light-harvesting mimic, a type of system which has historically been difficult to make in a well-defined manner.« less

mRNA Traffic Control Reviewed: N6-Methyladenosine (m6 A) Takes the Driver's Seat.

PubMed

Visvanathan, Abhirami; Somasundaram, Kumaravel

2018-01-01

Messenger RNA is a flexible tool box that plays a key role in the dynamic regulation of gene expression. RNA modifications variegate the message conveyed by the mRNA. Similar to DNA and histone modifications, mRNA modifications are reversible and play a key role in the regulation of molecular events. Our understanding about the landscape of RNA modifications is still rudimentary in contrast to DNA and histone modifications. The major obstacle has been the lack of sensitive detection methods since they are non-editing events. However, with the advent of next-generation sequencing techniques, RNA modifications are being identified precisely at single nucleotide resolution. In recent years, methylation at the N6 position of adenine (m 6 A) has gained the attention of RNA biologists. The m 6 A modification has a set of writers (methylases), erasers (demethylases), and readers. Here, we provide a summary of interesting facts, conflicting findings, and recent advances in the technical and functional aspects of the m 6 A epitranscriptome. © 2017 WILEY Periodicals, Inc.

Probing medium-induced jet splitting and energy loss in heavy-ion collisions

NASA Astrophysics Data System (ADS)

Chang, Ning-Bo; Cao, Shanshan; Qin, Guang-You

2018-06-01

The nuclear modification of jet splitting in relativistic heavy-ion collisions at RHIC and the LHC energies is studied based on the higher twist formalism. Assuming coherent energy loss for the two splitted subjets, a non-monotonic jet energy dependence is found for the nuclear modification of jet splitting function: strongest modification at intermediate jet energies whereas weaker modification for larger or smaller jet energies. Combined with the smaller size and lower density of the QGP medium at RHIC than at the LHC, this helps to understand the groomed jet measurements from CMS and STAR Collaborations: strong modification of the momentum sharing zg distribution at the LHC and no obvious modification of zg distribution at RHIC. In addition, the observed nuclear modification pattern of the groomed jet zg distribution cannot be explained solely by independent energy loss of the two subjets. Our result may be tested in future measurements of groomed jets with lower jet energies at the LHC and larger jet energies at RHIC, for different angular separations between the two subjets.

Detection of histone modifications in plant leaves.

PubMed

Jaskiewicz, Michal; Peterhansel, Christoph; Conrath, Uwe

2011-09-23

Chromatin structure is important for the regulation of gene expression in eukaryotes. In this process, chromatin remodeling, DNA methylation, and covalent modifications on the amino-terminal tails of histones H3 and H4 play essential roles(1-2). H3 and H4 histone modifications include methylation of lysine and arginine, acetylation of lysine, and phosphorylation of serine residues(1-2). These modifications are associated either with gene activation, repression, or a primed state of gene that supports more rapid and robust activation of expression after perception of appropriate signals (microbe-associated molecular patterns, light, hormones, etc.)(3-7). Here, we present a method for the reliable and sensitive detection of specific chromatin modifications on selected plant genes. The technique is based on the crosslinking of (modified) histones and DNA with formaldehyde(8,9), extraction and sonication of chromatin, chromatin immunoprecipitation (ChIP) with modification-specific antibodies(9,10), de-crosslinking of histone-DNA complexes, and gene-specific real-time quantitative PCR. The approach has proven useful for detecting specific histone modifications associated with C(4;) photosynthesis in maize(5,11) and systemic immunity in Arabidopsis(3).

30 CFR 18.81 - Field modification of approved (permissible) equipment; application for approval of modification...

Code of Federal Regulations, 2010 CFR

2010-07-01

..., and Permits To Use Experimental Equipment § 18.81 Field modification of approved (permissible... alter the basic functional design that was originally approved for the equipment. (c) Upon receipt of...

30 CFR 18.81 - Field modification of approved (permissible) equipment; application for approval of modification...

Code of Federal Regulations, 2013 CFR

2013-07-01

..., and Permits To Use Experimental Equipment § 18.81 Field modification of approved (permissible... alter the basic functional design that was originally approved for the equipment. (c) Upon receipt of...

30 CFR 18.81 - Field modification of approved (permissible) equipment; application for approval of modification...

Code of Federal Regulations, 2011 CFR

2011-07-01

..., and Permits To Use Experimental Equipment § 18.81 Field modification of approved (permissible... alter the basic functional design that was originally approved for the equipment. (c) Upon receipt of...

30 CFR 18.81 - Field modification of approved (permissible) equipment; application for approval of modification...

Code of Federal Regulations, 2012 CFR

2012-07-01

..., and Permits To Use Experimental Equipment § 18.81 Field modification of approved (permissible... alter the basic functional design that was originally approved for the equipment. (c) Upon receipt of...

Air Conditioning Modifications to AMG Buses

DOT National Transportation Integrated Search

1983-12-01

This report presents the documentation and evaluation of air conditioning system modifications devised by Miami (Florida) Metrobus and Los Angeles SCRTD for the AM General Model B bus. The objective of these modifications was to reduce the frequency ...

47 CFR 25.117 - Modification of station license.

Code of Federal Regulations, 2010 CFR

2010-10-01

... application by the Commission. (b) [Reserved] (c) Applications for modification of earth station... station and space station modification applications must be filed electronically through the International... 25.117 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

47 CFR 25.117 - Modification of station license.

Code of Federal Regulations, 2012 CFR

2012-10-01

... application by the Commission. (b) [Reserved] (c) Applications for modification of earth station... station and space station modification applications must be filed electronically through the International... 25.117 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

47 CFR 25.117 - Modification of station license.

Code of Federal Regulations, 2011 CFR

2011-10-01

... application by the Commission. (b) [Reserved] (c) Applications for modification of earth station... station and space station modification applications must be filed electronically through the International... 25.117 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES...

PmrD is Required for Modifications to Escherichia Coli Endotoxin that Promote Antimicrobial Resistance

DTIC Science & Technology

2015-01-20

is unlimited. PmrD Is Required for Modifications to Escherichia coli Endotoxin That Promote Antimicrobial Resistance The views, opinions and/or...East 27th Street Suite 5.300 Austin, TX 78712 -1532 ABSTRACT PmrD Is Required for Modifications to Escherichia coli Endotoxin That Promote...PhoPQ and PmrAB in E. coli than previously understood. PmrD Is Required for Modifications to Escherichia coli Endotoxin That Promote Antimicrobial

Effects of ionospheric modification on system performance

NASA Astrophysics Data System (ADS)

Ganguly, Suman

1989-12-01

Controlled ionospheric modification can be used for disrupting as well as facilitating communication and radar systems. After briefly describing the results achieved with the present day ionospheric modification facilities, a scenario is presented for the generation of strong and significant ionospheric modification. A few schemes are presented for the development of modern high power facilities using the state of the art technology and then the impact of such facilities on the system performance is described.

Chitosan-edible oil based materials as upgraded adsorbents for textile dyes.

PubMed

Dos Santos, Clayane Carvalho; Mouta, Rodolpho; Junior, Manoel Carvalho Castro; Santana, Sirlane Aparecida Abreu; Silva, Hildo Antonio Dos Santos; Bezerra, Cícero Wellington Brito

2018-01-15

Biopolymer chitosan is a low cost, abundant, environmentally friendly, very selective and efficient anionic dyes adsorbent, being a promising material for large-scale removal of dyes from wastewater. However, raw chitosan (CS) is an ineffective cationic dyes adsorbent and its performance is pH sensitive, thus, CS modifications that address these issues need to be developed. Here, we report the preparation and characterization of two new CS modifications using edible oils (soybean oil or babassu oil), and their adsorption performance for two dyes, one anionic (remazol red, RR) and one cationic (methylene blue, MB). Both modifications extended the pH range of RR adsorption. The babassu oil modification increased adsorption capacity of the cationic dye MB, whereas the soybean oil modification increased that of RR. Such improvements demonstrate the potential of these two new CS modifications as adsorbent candidates for controlling dyes pollution in effluents. Copyright © 2017 Elsevier Ltd. All rights reserved.

Proposed modifications to the RCRA post-closure permit for the Upper East Fork Poplar Creek Hydrogeologic Regime at the U.S. Department of Energy Y-12 Plant, Oak Ridge, Tennessee

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

NONE

1997-05-01

This report presents proposed modifications to the Resource Conservation and Recovery Act (RCRA) Post-Closure Permit (PCP) for the Upper East Fork Poplar Creek Hydrogeologic Regime (permit number TNHW-088, EPA ID No. TN3 89 009 0001). The modifications are proposed to: (1) revise the current text for two of the Permit Conditions included in Permit Section II - General Facility Conditions, and (2) update the PCP with revised versions of the Y-12 Plant Groundwater Protection Program (GWPP) technical field procedures included in several of the Permit Attachments. The updated field procedures and editorial revisions are Class 1 permit modifications, as specifiedmore » in Title 40, Code of Federal Regulations (CFR) {section}270.42; Appendix I - Classification of Permit Modifications. These modifications are summarized below.« less

Update: Mechanisms underlying N6-methyladenosine modification of eukaryotic mRNA

PubMed Central

Wang, Yang; Zhao, Jing Crystal

2016-01-01

Summary Eukaryotic messenger RNA (mRNA) undergoes chemical modification both at the 5′cap [1, 2] and internally [3–14]. Among internal modifications, m6A, by far the most abundant, is present in all eukaryotes examined, including mammals [3–6], flies [15], plants [16, 17] and yeast [18, 19]. m6A modification plays an essential role in diverse biological processes. Over the past few years, our knowledge relevant to establishment and function of this modification has grown rapidly. This review focuses on technologies that have facilitated m6A detection in mRNAs, identification of m6A methylation enzymes and binding proteins, and potential functions of the modification at the molecular level. Regarding m6A function at cellular or organismal levels or in disease, please refer to other recent reviews [20–23]. PMID:27793360

Preparation of highly hydrophobic cotton fabrics by modification with bifunctional silsesquioxanes in the sol-gel process

NASA Astrophysics Data System (ADS)

Przybylak, Marcin; Maciejewski, Hieronim; Dutkiewicz, Agnieszka

2016-11-01

The surface modification of cotton fabrics was carried out using two types of bifunctional fluorinated silsesquioxanes with different ratios of functional groups. The modification was performed either by one- or two-step process. Two methods, the sol-gel and the dip coating method were used in different configurations. The heat treatment and the washing process were applied after modification. The wettability of cotton fabric was evaluated by measuring water contact angles (WCA). Changes in the surface morphology were examined by scanning electron microscopy (SEM, SEM-LFD) and atomic force microscopy (AFM). Moreover, the modified fabrics were subjected to analysis of elemental composition of the applied coatings using SEM-EDS techniques. Highly hydrophobic textiles were obtained in all cases studied and one of the modifications resulted in imparting superhydrophobic properties. Most of impregnated textiles remained hydrophobic even after multiple washing process which shows that the studied modification is durable.

Optimal Control Modification Adaptive Law for Time-Scale Separated Systems

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.

2010-01-01

Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. A model matching conditions in the transformed time coordinate results in an increase in the actuator command that effectively compensate for the slow actuator dynamics. Simulations demonstrate effectiveness of the method.

Optimal Control Modification for Time-Scale Separated Systems

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T.

2012-01-01

Recently a new optimal control modification has been introduced that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. This modification is based on an optimal control formulation to minimize the L2 norm of the tracking error. The optimal control modification adaptive law results in a stable adaptation in the presence of a large adaptive gain. This study examines the optimal control modification adaptive law in the context of a system with a time scale separation resulting from a fast plant with a slow actuator. A singular perturbation analysis is performed to derive a modification to the adaptive law by transforming the original system into a reduced-order system in slow time. A model matching conditions in the transformed time coordinate results in an increase in the actuator command that effectively compensate for the slow actuator dynamics. Simulations demonstrate effectiveness of the method.

A Designed Peptide Targets Two Types of Modifications of p53 with Anti-cancer Activity.

PubMed

Liang, Lunxi; Wang, Huanbin; Shi, Hubing; Li, Zhaoli; Yao, Han; Bu, Zhigao; Song, Ningning; Li, Chushu; Xiang, Dabin; Zhang, Yao; Wang, Jilin; Hu, Ye; Xu, Qi; Ma, Yanlei; Cheng, Zhongyi; Wang, Yingchao; Zhao, Shuliang; Qian, Jin; Chen, Yingxuan; Fang, Jing-Yuan; Xu, Jie

2018-06-21

Many cancer-related proteins are controlled by composite post-translational modifications (PTMs), but prevalent strategies only target one type of modification. Here we describe a designed peptide that controls two types of modifications of the p53 tumor suppressor, based on the discovery of a protein complex that suppresses p53 (suppresome). We found that Morn3, a cancer-testis antigen, recruits different PTM enzymes, such as sirtuin deacetylase and ubiquitin ligase, to confer composite modifications on p53. The molecular functions of Morn3 were validated through in vivo assays and chemico-biological intervention. A rationally designed Morn3-targeting peptide (Morncide) successfully activated p53 and suppressed tumor growth. These findings shed light on the regulation of protein PTMs and present a strategy for targeting two modifications with one molecule. Copyright © 2018 Elsevier Ltd. All rights reserved.

Histone modification: cause or cog?

PubMed

Henikoff, Steven; Shilatifard, Ali

2011-10-01

Histone modifications are key components of chromatin packaging but whether they constitute a 'code' has been contested. We believe that the central issue is causality: are histone modifications responsible for differences between chromatin states, or are differences in modifications mostly consequences of dynamic processes, such as transcription and nucleosome remodeling? We find that inferences of causality are often based on correlation and that patterns of some key histone modifications are more easily explained as consequences of nucleosome disruption in the presence of histone modifying enzymes. We suggest that the 35-year-old DNA accessibility paradigm provides a mechanistically sound basis for understanding the role of nucleosomes in gene regulation and epigenetic inheritance. Based on this view, histone modifications and variants contribute to diversification of a chromatin landscape shaped by dynamic processes that are driven primarily by transcription and nucleosome remodeling. Copyright © 2011 Elsevier Ltd. All rights reserved.

Protein mass analysis of histones.

PubMed

Galasinski, Scott C; Resing, Katheryn A; Ahn, Natalie G

2003-09-01

Posttranslational modification of chromatin-associated proteins, including histones and high-mobility-group (HMG) proteins, provides an important mechanism to control gene expression, genome integrity, and epigenetic inheritance. Protein mass analysis provides a rapid and unbiased approach to monitor multiple chemical modifications on individual molecules. This review describes methods for acid extraction of histones and HMG proteins, followed by separation by reverse-phase chromatography coupled to electrospray ionization mass spectrometry (LC/ESI-MS). Posttranslational modifications are detected by analysis of full-length protein masses. Confirmation of protein identity and modification state is obtained through enzymatic digestion and peptide sequencing by MS/MS. For differentially modified forms of each protein, the measured intensities are semiquantitative and allow determination of relative abundance and stoichiometry. The method simultaneously detects covalent modifications on multiple proteins and provides a facile assay for comparing chromatin modification states between different cell types and/or cellular responses.

Crystal structure of laser-induced subsurface modifications in Si

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

Verburg, P. C.; Smillie, L. A.; Römer, G. R. B. E.

2015-06-04

Laser-induced subsurface modification of dielectric materials is a well-known technology. Applications include the production of optical components and selective etching. In addition to dielectric materials, the subsurface modification technology can be applied to silicon, by employing near to mid-infrared radiation. An application of subsurface modifications in silicon is laser-induced subsurface separation, which is a method to separate wafers into individual dies. Other applications for which proofs of concept exist are the formation of waveguides and resistivity tuning. However, limited knowledge is available about the crystal structure of subsurface modifications in silicon. In this paper, we investigate the geometry and crystalmore » structure of laser-induced subsurface modifications in monocrystalline silicon wafers. Finally, in addition to the generation of lattice defects, we found that transformations to amorphous silicon and Si-iii/Si-xii occur as a result of the laser irradiation.« less

General Characteristics of the Changes in the Thermal Stability of Proteins and Enzymes After the Chemical Modification of Their Functional Groups

NASA Astrophysics Data System (ADS)

Kutuzova, G. D.; Ugarova, N. N.; Berezin, Ilya V.

1984-11-01

The principal structural and physicochemical factors determining the stability of protein macromolecules in solution and the characteristics of the structure of the proteins from thermophilic microorganisms are examined. The mechanism of the changes in the thermal stability of proteins and enzymes after the chemical modification of their functional side groups and the experimental data concerning the influence of chemical modification on the thermal stability of proteins are analysed. The dependence of the stabilisation effect and of the changes in the structure of protein macromolecules on the degree of modification and on the nature of the modified groups and the groups introduced into proteins in the course of modification (their charge and hydrophobic properties) is demonstrated. The great practical value of the method of chemical modification for the preparation of stabilised forms of biocatalysts is shown in relation to specific examples. The bibliography includes 178 references.

The Expanding Landscape of the Thiol Redox Proteome*

PubMed Central

Yang, Jing; Carroll, Kate S.; Liebler, Daniel C.

2016-01-01

Cysteine occupies a unique place in protein chemistry. The nucleophilic thiol group allows cysteine to undergo a broad range of redox modifications beyond classical thiol-disulfide redox equilibria, including S-sulfenylation (-SOH), S-sulfinylation (-SO2H), S-sulfonylation (-SO3H), S-nitrosylation (-SNO), S-sulfhydration (-SSH), S-glutathionylation (-SSG), and others. Emerging evidence suggests that these post-translational modifications (PTM) are important in cellular redox regulation and protection against oxidative damage. Identification of protein targets of thiol redox modifications is crucial to understanding their roles in biology and disease. However, analysis of these highly labile and dynamic modifications poses challenges. Recent advances in the design of probes for thiol redox forms, together with innovative mass spectrometry based chemoproteomics methods make it possible to perform global, site-specific, and quantitative analyses of thiol redox modifications in complex proteomes. Here, we review chemical proteomic strategies used to expand the landscape of thiol redox modifications. PMID:26518762

Study of the Electric Field-Induced Low Temperature Phase in Pb(Mg_{1/3}Nb_{2/3})O_3: Titanium Influence

NASA Astrophysics Data System (ADS)

Bidault, O.; Husson, E.; Gaucher, P.

1997-06-01

The temperature dependence of the dielectric permittivity under a dc electric field is studied in (1 - x)Pb(Mg{1/3}Nb{2/3})O3-xPbTiO3 ceramics (0 leq x leq 0.1). The size of the ordered regions, which is the key parameter to understand the dielectric response of such materials, is suggested to be reduced by T_i doping. A ferroelectric transition can be induced by a field E from the average cubic phase. Whereas PMN is a relaxor undergoing a macroscopic phase transition only if E > 4 kV cm^{-1}, materials with x = 0.1 exhibit a spontaneous cubic to rhombohedral transition at 280 K on cooling. Moreover, in all the studied samples, the T_f temperature deduced from the Vogel-Fulcher relation is found to be very close to the poling temperature under high field. La variation en température de la constante diélectrique de céramiques de composition (1 - x)Pb(Mg{1/3}Nb{2/3})O{3}-xPbTiO3 (0 leq x leq 0,1) est étudiée alors qu'un champ dc est appliqué à l'échantillon. La taille des régions ordonnées, paramètre-clé pour comprendre la réponse du matériau, est réduite par l'introduction de titane. Une transition de phase ferroélectrique peut être induite sous champ à partir de la phase cubique en moyenne. Si PMN est un relaxeur, ne transitant qu'à condition d'avoir E > 4 kV cm^{-1}, la transition cubique to rhomboèdrique devient spontanée pour PMN: 10% T_i (à 280 K au refroidissement). De plus, pour tous les échantillons, la température T_f, déduite de la relation de Vogel-Fulcher est systématiquement trouvée voisine de celle d'apparition de la phase polaire sous champ.

The histone modifications governing TFF1 transcription mediated by estrogen receptor.

PubMed

Li, Yanyan; Sun, Luyang; Zhang, Yu; Wang, Dandan; Wang, Feng; Liang, Jing; Gui, Bin; Shang, Yongfeng

2011-04-22

Transcription regulation by histone modifications is a major contributing factor to the structural and functional diversity in biology. These modifications are encrypted as histone codes or histone languages and function to establish and maintain heritable epigenetic codes that define the identity and the fate of the cell. Despite recent advances revealing numerous histone modifications associated with transcription regulation, how such modifications dictate the process of transcription is not fully understood. Here we describe spatial and temporal analyses of the histone modifications that are introduced during estrogen receptor α (ERα)-activated transcription. We demonstrated that aborting RNA polymerase II caused a disruption of the histone modifications that are associated with transcription elongation but had a minimal effect on modifications deposited during transcription initiation. We also found that the histone H3S10 phosphorylation mark is catalyzed by mitogen- and stress-activated protein kinase 1 (MSK1) and is recognized by a 14-3-3ζ/14-3-3ε heterodimer through its interaction with H3K4 trimethyltransferase SMYD3 and the p52 subunit of TFIIH. We showed that H3S10 phosphorylation is a prerequisite for H3K4 trimethylation. In addition, we demonstrated that SET8/PR-Set7/KMT5A is required for ERα-regulated transcription and its catalyzed H4K20 monomethylation is implicated in both transcription initiation and elongation. Our experiments provide a relatively comprehensive analysis of histone modifications associated with ERα-regulated transcription and define the biological meaning of several key components of the histone code that governs ERα-regulated transcription.

Traditional and New Enhancing Human Cybernetic and Nanotechnological Body Modification Technologies: A Comparative Study of Roman Catholic and Transhumanist Ethical Approaches

NASA Astrophysics Data System (ADS)

Caligiuri, Michael J.

Advances in cybernetic and nanotechnological body modifications currently allow for enhancements to human physical and mental function which exceed human species-based norms. This thesis examines body modification and human enhancement from two perspectives---Roman Catholicism and Transhumanism--- in order to contribute to bioethical deliberations regarding enhancement technologies. Roman Catholicism has a longstanding tradition of bioethical discourse, informing the healthcare directives of Roman Catholic institutions. Transhumanism is more recent movement that endorses body modifications and human enhancements as a means of individual betterment and social evolution. The thesis first considers definitions of human enhancement and levels of normalcy in connection to cybernetic and nanotechnological bionic implants, and outlines a series of criteria to assess a technology's potential bioethical acceptability: implantability, permanency, power, and public interaction. The thesis then describes Roman Catholicism's response to non-enhancing decorative body modifications (cosmetic surgeries, common decorative modifications such as tattoos and piercings, and uncommon modifications such as scarifications and brandings) in order to establish a basis for possible Roman Catholic responses to enhancing cybernetic and nanotechnological modifications. This is followed by an analysis from a Roman Catholic perspective of the major social issues brought forward by enhancement technologies: commodification, eugenics, vulnerability, and distributive justice. Turning to Transhumanism, the thesis describes the origins and philosophy of the movement, and then discusses the bioethical principles it advances with regard to human enhancement. The thesis concludes by locating points of convergence between Transhumanism and Roman Catholicism that could be the basis of more widely accepted ethical guidelines regarding modification technologies.

48 CFR 342.7102 - Contract modifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 4 2013-10-01 2013-10-01 false Contract modifications. 342.7102 Section 342.7102 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACT MANAGEMENT CONTRACT ADMINISTRATION Administrative Actions for Cost Overruns 342.7102 Contract modifications...

Documents related to Proposed Class II injection well permit modification MI-147-2D-0014

EPA Pesticide Factsheets

Public notice for proposed modification of permit number MI-147-2D-0014 (St. Clair County, MI). The proposed modification would change the injection zone, the construction, and reduce the injection pressure.

Alternative materials for the modification and stabilization of unstable subgrade soils

DOT National Transportation Integrated Search

1997-05-01

This study examines two lime by-products and two fly ashes for treatment of unstable (CBR<6) subgrade soils. The treatment methods include both modification and stabilization. Modification is temporily enhancing subgrade stability to improve construc...

48 CFR 342.7102 - Contract modifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Contract modifications. 342.7102 Section 342.7102 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES CONTRACT MANAGEMENT CONTRACT ADMINISTRATION Administrative Actions for Cost Overruns 342.7102 Contract modifications...

Incidence and predictors of regimen-modification from first-line antiretroviral therapy in Thailand: a cohort study.

PubMed

Tsuchiya, Naho; Pathipvanich, Panita; Wichukchinda, Nuanjun; Rojanawiwat, Archawin; Auwanit, Wattana; Ariyoshi, Koya; Sawanpanyalert, Pathom

2014-10-30

Antiretroviral therapy markedly reduced mortality in HIV-infected individuals. However, in the previous studies, up to 50% of patients are compelled to modify their regimen in middle and low-income countries where salvage drug is still limited. This cohort study aimed to investigate the incidence and predictors of regimen modification from the first-line antiretroviral regimen in northern Thailand. All HIV-infected patients starting antiretroviral therapy (ART) with generic drug (GPOvir®; stavudine, lamivudine and nevirapine) at a governmental hospital in northern Thailand from 2002 to 2007 were recruited. Baseline characteristics and detailed information of regimen modification until the end of 2010 were ascertained from cohort database and medical charts. As a potential genetic predictor of regimen modification, HLA B allele was determined by bead-based array hybridization (WAKFlow® HLA typing kit). We investigated predictors of the regimen modification using Cox's proportional hazard models. Of 979 patients, 914 were eligible for the analysis. The observed events of regimen modification was 377, corresponding to an incidence 13.8/100 person-year-observation (95% CI:12.5-15.3) over 2,728 person years (PY) follow up. The main reasons for regimen modification were adverse effects (73.5%), especially lipodystrophy (63.2%) followed by rash (17.7%). Sixty three patients (17.1%) changed the regimen due to treatment failure. 2% and 19% of patients had HLA-B*35:05 and B*4001, respectively. HLA-B*35:05 was independently associated with rash-related regimen modification (aHR 7.73, 95% CI:3.16-18.9) while female gender was associated with lipodystrophy (aHR 2.11, 95% CI:1.51-2.95). Female gender (aHR 0.54, 95% CI: 0.30-0.96), elder age (aHR 0.56, 95% CI: 0.32-0.99) and having HLA-B*40:01 (aHR 0.29, 95% CI: 0.10-0.82) were protective for treatment failure related modification. HLA-B*35:05 and female gender were strong predictors of regimen modification due to rash and lipodystrophy, respectively. Female gender, elder age, and having HLA-B*40:01 had protective effects on treatment failure-related regimen modification. This study provides further information of regimen modification for future tailored ART in Asia.

Trafficking and function of the cystic fibrosis transmembrane conductance regulator: a complex network of posttranslational modifications

PubMed Central

McClure, Michelle L.; Barnes, Stephen; Brodsky, Jeffrey L.

2016-01-01

Posttranslational modifications add diversity to protein function. Throughout its life cycle, the cystic fibrosis transmembrane conductance regulator (CFTR) undergoes numerous covalent posttranslational modifications (PTMs), including glycosylation, ubiquitination, sumoylation, phosphorylation, and palmitoylation. These modifications regulate key steps during protein biogenesis, such as protein folding, trafficking, stability, function, and association with protein partners and therefore may serve as targets for therapeutic manipulation. More generally, an improved understanding of molecular mechanisms that underlie CFTR PTMs may suggest novel treatment strategies for CF and perhaps other protein conformational diseases. This review provides a comprehensive summary of co- and posttranslational CFTR modifications and their significance with regard to protein biogenesis. PMID:27474090

Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics.

PubMed

Dong, Yimeng; Gupta, Nirupam; Chopra, Nikhil

2016-11-01

In this paper, vulnerability of a distributed consensus seeking multi-agent system (MAS) with double-integrator dynamics against edge-bound content modification cyber attacks is studied. In particular, we define a specific edge-bound content modification cyber attack called malignant content modification attack (MCoMA), which results in unbounded growth of an appropriately defined group disagreement vector. Properties of MCoMA are utilized to design detection and mitigation algorithms so as to impart resilience in the considered MAS against MCoMA. Additionally, the proposed detection mechanism is extended to detect the general edge-bound content modification attacks (not just MCoMA). Finally, the efficacies of the proposed results are illustrated through numerical simulations.

Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics

NASA Astrophysics Data System (ADS)

Dong, Yimeng; Gupta, Nirupam; Chopra, Nikhil

2016-11-01

In this paper, vulnerability of a distributed consensus seeking multi-agent system (MAS) with double-integrator dynamics against edge-bound content modification cyber attacks is studied. In particular, we define a specific edge-bound content modification cyber attack called malignant content modification attack (MCoMA), which results in unbounded growth of an appropriately defined group disagreement vector. Properties of MCoMA are utilized to design detection and mitigation algorithms so as to impart resilience in the considered MAS against MCoMA. Additionally, the proposed detection mechanism is extended to detect the general edge-bound content modification attacks (not just MCoMA). Finally, the efficacies of the proposed results are illustrated through numerical simulations.

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

PubMed Central

McClelland, M; Nelson, M; Raschke, E

1994-01-01

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

Chromatin Proteomics Reveals Variable Histone Modifications during the Life Cycle of Trypanosoma cruzi.

PubMed

de Jesus, Teresa Cristina Leandro; Nunes, Vinícius Santana; Lopes, Mariana de Camargo; Martil, Daiana Evelin; Iwai, Leo Kei; Moretti, Nilmar Silvio; Machado, Fabrício Castro; de Lima-Stein, Mariana L; Thiemann, Otavio Henrique; Elias, Maria Carolina; Janzen, Christian; Schenkman, Sergio; da Cunha, Julia Pinheiro Chagas

2016-06-03

Histones are well-conserved proteins that form the basic structure of chromatin in eukaryotes and undergo several post-translational modifications, which are important for the control of transcription, replication, DNA damage repair, and chromosome condensation. In early branched organisms, histones are less conserved and appear to contain alternative sites for modifications, which could reveal evolutionary unique functions of histone modifications in gene expression and other chromatin-based processes. Here, by using high-resolution mass spectrometry, we identified and quantified histone post-translational modifications in two life cycle stages of Trypanosoma cruzi, the protozoan parasite that causes Chagas disease. We detected 44 new modifications, namely: 18 acetylations, seven monomethylations, seven dimethylations, seven trimethylations, and four phosphorylations. We found that replicative (epimastigote stage) contains more histone modifications than nonreplicative and infective parasites (trypomastigote stage). Acetylations of lysines at the C-terminus of histone H2A and methylations of lysine 23 of histone H3 were found to be enriched in trypomastigotes. In contrast, phosphorylation in serine 23 of H2B and methylations of lysine 76 of histone H3 predominates in proliferative states. The presence of one or two methylations in the lysine 76 was found in cells undergoing mitosis and cytokinesis, typical of proliferating parasites. Our findings provide new insights into the role of histone modifications related to the control of gene expression and cell-cycle regulation in an early divergent organism.

The increase of apatite layer formation by the poly(3-hydroxybutyrate) surface modification of hydroxyapatite and β-tricalcium phosphate.

PubMed

Szubert, M; Adamska, K; Szybowicz, M; Jesionowski, T; Buchwald, T; Voelkel, A

2014-01-01

The aim of this study was the surface modification of hydroxyapatite and β-tricalcium phosphate by poly(3-hydroxybutyrate) grafting and characterization of modificates. The bioactivity examination was carried out by the determination to grow an apatite layer on modified materials during incubation in simulated body fluid at 37°C. The additional issue taken up in this paper was to investigate the influence of fluid replacement. The process of the surface modification of biomaterials was evaluated by means of infrared and Raman spectroscopy. Formation of the apatite layer was assessed by means of scanning electron microscopy and confirmed by energy dispersive, Raman and Fourier transformed infrared spectroscopy. During exposure in simulated body fluid, the variation of the zeta potential, pH measurement and relative weight was monitored. Examination of scanning electron microscopy micrographs suggests that modification of hydroxyapatite and β-tricalcium phosphate by poly(3-hydroxybutyrate) significantly increases apatite layer formation. Raman spectroscopy evaluation revealed that the formation of the apatite layer was more significant in the case of hydroxyapatite modificate, when compared to the β-tricalcium phosphate modificate. Both modificates were characterized by stable pH, close to the natural pH of human body fluids. Furthermore, we have shown that a weekly changed, simulated body fluid solution increases apatite layer formation. © 2013.

The modification of hybrid method of ant colony optimization, particle swarm optimization and 3-OPT algorithm in traveling salesman problem

NASA Astrophysics Data System (ADS)

Hertono, G. F.; Ubadah; Handari, B. D.

2018-03-01

The traveling salesman problem (TSP) is a famous problem in finding the shortest tour to visit every vertex exactly once, except the first vertex, given a set of vertices. This paper discusses three modification methods to solve TSP by combining Ant Colony Optimization (ACO), Particle Swarm Optimization (PSO) and 3-Opt Algorithm. The ACO is used to find the solution of TSP, in which the PSO is implemented to find the best value of parameters α and β that are used in ACO.In order to reduce the total of tour length from the feasible solution obtained by ACO, then the 3-Opt will be used. In the first modification, the 3-Opt is used to reduce the total tour length from the feasible solutions obtained at each iteration, meanwhile, as the second modification, 3-Opt is used to reduce the total tour length from the entire solution obtained at every iteration. In the third modification, 3-Opt is used to reduce the total tour length from different solutions obtained at each iteration. Results are tested using 6 benchmark problems taken from TSPLIB by calculating the relative error to the best known solution as well as the running time. Among those modifications, only the second and third modification give satisfactory results except the second one needs more execution time compare to the third modifications.

Modifications in small nuclear RNAs and their roles in spliceosome assembly and function.

PubMed

Bohnsack, Markus T; Sloan, Katherine E

2018-06-01

Modifications in cellular RNAs have emerged as key regulators of all aspects of gene expression, including pre-mRNA splicing. During spliceosome assembly and function, the small nuclear RNAs (snRNAs) form numerous dynamic RNA-RNA and RNA-protein interactions, which are required for spliceosome assembly, correct positioning of the spliceosome on substrate pre-mRNAs and catalysis. The human snRNAs contain several base methylations as well as a myriad of pseudouridines and 2'-O-methylated nucleotides, which are largely introduced by small Cajal body-specific-RNPs. Modified nucleotides typically cluster in functionally important regions of the snRNAs, suggesting that their presence could optimise the interactions of snRNAs with each other or with pre-mRNAs, or may affect the binding of spliceosomal proteins. snRNA modifications appear to play important roles in snRNP biogenesis and spliceosome assembly, and have also been proposed to influence the efficiency and fidelity of pre-mRNAs splicing. Interestingly, alterations in the modification status of snRNAs have recently been observed in different cellular conditions, implying that some snRNA modifications are dynamic and raising the possibility that these modifications may fine-tune the spliceosome for particular functions. Here, we review the current knowledge on the snRNA modification machinery and discuss the timing, functions and dynamics of modifications in snRNAs.

Effects of tRNA modification on translational accuracy depend on intrinsic codon-anticodon strength.

PubMed

Manickam, Nandini; Joshi, Kartikeya; Bhatt, Monika J; Farabaugh, Philip J

2016-02-29

Cellular health and growth requires protein synthesis to be both efficient to ensure sufficient production, and accurate to avoid producing defective or unstable proteins. The background of misreading error frequency by individual tRNAs is as low as 2 × 10(-6) per codon but is codon-specific with some error frequencies above 10(-3) per codon. Here we test the effect on error frequency of blocking post-transcriptional modifications of the anticodon loops of four tRNAs in Escherichia coli. We find two types of responses to removing modification. Blocking modification of tRNA(UUC)(Glu) and tRNA(QUC)(Asp) increases errors, suggesting that the modifications act at least in part to maintain accuracy. Blocking even identical modifications of tRNA(UUU)(Lys) and tRNA(QUA)(Tyr) has the opposite effect of decreasing errors. One explanation could be that the modifications play opposite roles in modulating misreading by the two classes of tRNAs. Given available evidence that modifications help preorder the anticodon to allow it to recognize the codons, however, the simpler explanation is that unmodified 'weak' tRNAs decode too inefficiently to compete against cognate tRNAs that normally decode target codons, which would reduce the frequency of misreading. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Comparisons of geoid models over Alaska computed with different Stokes' kernel modifications

NASA Astrophysics Data System (ADS)

Li, X.; Wang, Y.

2011-01-01

Various Stokes kernel modification methods have been developed over the years. The goal of this paper is to test the most commonly used Stokes kernel modifications numerically by using Alaska as a test area and EGM08 as a reference model. The tests show that some methods are more sensitive than others to the integration cap sizes. For instance, using the methods of Vaníček and Kleusberg or Featherstone et al. with kernel modification at degree 60, the geoid decreases by 30 cm (on average) when the cap size increases from 1° to 25°. The corresponding changes in the methods of Wong and Gore and Heck and Grüninger are only at the 1 cm level. At high modification degrees, above 360, the methods of Vaníček and Kleusberg and Featherstone et al become unstable because of numerical problems in the modification coefficients; similar conclusions have been reported by Featherstone (2003). In contrast, the methods of Wong and Gore, Heck and Grüninger and the least-squares spectral combination are stable at any modification degree, though they do not provide as good fit as the best case of the Molodenskii-type methods at the GPS/Leveling benchmarks. However, certain tests for choosing the cap size and modification degree have to be performed in advance to avoid abrupt mean geoid changes if the latter methods are applied.

WIPP Hazardous Waste Facility Permit Update

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

Kehrman, B.; Most, W.

2006-07-01

The Waste Isolation Pilot Plant (WIPP) Hazardous Waste Facility Permit (HWFP) was issued on October 27, 1999 [1]. Since that time, the WIPP has sought modifications to clarify the permit language, provide alternative methods for meeting permit requirements and to update permit conditions. Significant advancements have been made in transuranic (TRU) waste management as the result of modifications to the HWFP. Among these advancements is a modification to obtain a drum age criteria (DAC) value to perform headspace gas sampling on drums to be super-compacted and placed in a 100-gallon overpack drum. In addition, the Section 311 permit modification requestmore » that would allow for more efficient waste characterization, and the modification to authorize the shipment and disposal of Remote-Handled (RH) TRU waste were merged together and submitted to the regulator as the Consolidated Permit Modification Request (PMR). The submittal of the Consolidated PMR came at the request of the regulator as part of responses to Notices of Deficiency (NODs) for the separate PMRs which had been submitted in previous years. Section 311 of the fiscal year 2004 Energy and Water Developments Appropriations Act (Public Law 108-137) [2] directs the Department of Energy to submit a permit modification that limits waste confirmation to radiography or visual examination of a statistical subpopulation of containers. Section 311 also specifically directs that disposal room performance standards be to be met by monitoring for volatile organic compounds in the underground disposal rooms. This statute translates into the elimination of other waste confirmation methods such as headspace gas sampling and analysis and solids sampling and analysis. These methods, as appropriate, will continue to be used by the generator sites during hazardous waste determinations or characterization activities. This modification is expected to reduce the overall cost of waste analysis by hundreds of millions of dollars [3]. Combining both the chap. 311 and RH TRU waste permit modification requests allows for both the regulator and DOE to expedite action on the modification requests. The Combined PMR reduces costs by having only one administrative process for both modification requests. (authors)« less

Harnessing epigenome modifications for better crops

USDA-ARS?s Scientific Manuscript database

Chemical DNA modifications such as methylation influence translation of the DNA code to specific genetic outcomes. While such modifications can be heritable, others are transient, and their overall contribution to plant genetic diversity remains intriguing but uncertain. The focus of this article is...

7 CFR 636.10 - Modifications.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 6 2013-01-01 2013-01-01 false Modifications. 636.10 Section 636.10 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE LONG TERM CONTRACTING WILDLIFE HABITAT INCENTIVE PROGRAM § 636.10 Modifications. (a) The...

7 CFR 636.10 - Modifications.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Modifications. 636.10 Section 636.10 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE LONG TERM CONTRACTING WILDLIFE HABITAT INCENTIVES PROGRAM § 636.10 Modifications. (a) The...

7 CFR 636.10 - Modifications.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 6 2014-01-01 2014-01-01 false Modifications. 636.10 Section 636.10 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE LONG TERM CONTRACTING WILDLIFE HABITAT INCENTIVE PROGRAM § 636.10 Modifications. (a) The...

7 CFR 636.10 - Modifications.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 6 2012-01-01 2012-01-01 false Modifications. 636.10 Section 636.10 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE LONG TERM CONTRACTING WILDLIFE HABITAT INCENTIVE PROGRAM § 636.10 Modifications. (a) The...

7 CFR 636.10 - Modifications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 6 2011-01-01 2011-01-01 false Modifications. 636.10 Section 636.10 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE LONG TERM CONTRACTING WILDLIFE HABITAT INCENTIVE PROGRAM § 636.10 Modifications. (a) The...

49 CFR 605.20 - Modification of prior agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Modification of prior agreements. 605.20 Section 605.20 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL TRANSIT ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SCHOOL BUS OPERATIONS Modification of Prior Agreements and Amendment...

AI-MSG modification work plan. [LMFBR

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

Page, J.P.

1973-08-20

This document contains the Work Plan for the modification of the AI Steam Generator for tests in Large Leak Test Rig. This Work Plan describes the objectives, scope of work, schedule and manpower, end items, and meetings and reports required for the modification.

75 FR 29784 - Petitions for Modification

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-27

... training plans will apply. The petitioner asserts that the proposed alternative method will at all times... DEPARTMENT OF LABOR Mine Safety and Health Administration Petitions for Modification AGENCY: Mine Safety and Health Administration (MSHA), Labor. ACTION: Notice of petitions for modification of existing...

Characterization of Surface Modification of Polyethersulfone Membrane

USDA-ARS?s Scientific Manuscript database

Surface modification of polyethersulfone (PES) membrane surface using UV/ozone-treated grafting and interfacial polymerization on membrane surface was investigated in order to improve the resistance of membrane surface to protein adsorption. These methods of surface modification were compared in te...

50 CFR 660.409 - Inseason actions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... resource, any adjudicated Indian fishing rights, and the ocean allocation scheme in the fishery management..., the following: (i) Modification of quotas and/or fishing seasons. (ii) Modification of the species... retention regulations. (iii) Modification of recreational bag limits and recreational fishing days per...

50 CFR 660.409 - Inseason actions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... resource, any adjudicated Indian fishing rights, and the ocean allocation scheme in the fishery management..., the following: (i) Modification of quotas and/or fishing seasons. (ii) Modification of the species... retention regulations. (iii) Modification of recreational bag limits and recreational fishing days per...

77 FR 71033 - Notice of Applications for Modification of Special Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-28

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration Notice of Applications for Modification of Special Permit AGENCY: Office of Hazardous Materials Safety, Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications for modification of...

Quantitative PCR measurement of tRNA 2-methylthio modification for assessing type 2 diabetes risk.

PubMed

Xie, Peiyu; Wei, Fan-Yan; Hirata, Shoji; Kaitsuka, Taku; Suzuki, Tsutomu; Suzuki, Takeo; Tomizawa, Kazuhito

2013-11-01

Genetic variants in the human CDKAL1 (CDK5 regulatory subunit associated protein 1-like 1) gene have been associated with reduced insulin secretion and type 2 diabetes (T2D). CDKAL1 is a methylthiotransferase that catalyzes 2-methylthio (ms(2)) modification of the adenine at position 37 (A37) of cytoplasmic tRNA(Lys)(UUU). We investigated the ms(2)-modification level of tRNA(Lys)(UUU) as a direct readout of CDKAL1 enzyme activity in human samples. We developed a quantitative PCR (qPCR)-based method to measure ms(2) modification. tRNA(Lys)(UUU) was reverse-transcribed with 2 unique primers: Reverse primer r1 was designed to anneal to the middle of this tRNA, including the nucleotide at A37, and reverse primer r2 was designed to anneal to the region downstream (3') of A37. Subsequent qPCR was performed to detect the corresponding transcribed cDNAs. The efficiency of reverse transcription of tRNA(Lys)(UUU) was ms(2)-modification dependent. The relative difference in threshold cycle number obtained with the r1 or r2 primer yielded the ms(2)-modification level in tRNA(Lys)(UUU) precisely as predicted by an original mathematical model. The method was capable of measuring ms(2)-modification levels in tRNA(Lys)(UUU) in total RNA isolated from human peripheral blood samples, revealing that the ms(2)-modification rate in tRNA(Lys)(UUU) was decreased in individuals carrying the CDKAL1 genotype associated with T2D. In addition, the ms(2)-modification level was correlated with insulin secretion. The results point to the critical role of ms(2) modification in T2D and to a potential clinical use of a simple and high-throughput method for assessing T2D risk.

The effects of size and surface modification of amorphous silica particles on biodistribution and liver metabolism in mice

NASA Astrophysics Data System (ADS)

Lu, Xiaoyan; Ji, Cai; Jin, Tingting; Fan, Xiaohui

2015-05-01

Engineered nanoparticles, with unconventional properties, are promising platforms for biomedical applications. Since they may interact with a wide variety of biomolecules, it is critical to understand the impact of the physicochemical properties of engineered nanoparticles on biological systems. In this study, the effects of particle size and surface modification alone or in combination of amorphous silica particles (SPs) on biological responses were determined using a suite of general toxicological assessments and metabonomics analysis in mice model. Our results suggested that amino or carboxyl surface modification mitigated the liver toxicity of plain-surface SPs. 30 nm SPs with amino surface modification were found to be the most toxic SPs among all the surface-modified SP treatments at the same dosage. When treatment dose was increased, submicro-sized SPs with amino or carboxyl surface modification also induced liver toxicity. Biodistribution studies suggested that 70 nm SPs were mainly accumulated in liver and spleen regardless of surface modifications. Interestingly, these two organs exhibited different uptake trends. Furthermore, metabonomics studies indicated that surface modification plays a more dominant role to affect the liver metabolism than particle size.

An assessment of lifestyle modification versus medical treatment with clomiphene citrate, metformin, and clomiphene citrate-metformin in patients with polycystic ovary syndrome.

PubMed

Karimzadeh, Mohammad Ali; Javedani, Mojgan

2010-06-01

To compare the effect of clomiphene citrate, metformin, and lifestyle modification on treatment of patients with polycystic ovary syndrome (PCOS). Prospective randomized double-blind study. University-based infertility clinic and research center. Three hundred forty-three overweight infertile women with PCOS. The participating women were assigned to four groups: clomiphene (n = 90), metformin (n = 90), clomiphene + metformin (n = 88), and lifestyle modification (n = 75). The patients in each group received standardized dietary and exercise advice from a dietitian. The primary outcome variables were change in menstrual cycle, waist circumference measurements, endocrine parameters, and lipid profile. The main secondary outcome variable was clinical pregnancy rate. The clinical pregnancy rate was 12.2% in clomiphene group, 14.4% in metformin group, 14.8% in clomiphene + metformin group, and 20% in lifestyle modification group. Lifestyle modification group achieved a significant reduction in waist circumference, total androgen, and lipid profile. Lifestyle modification improves the lipid profile in PCOS patients. Therefore, lifestyle modification may be used as the first line of ovulation induction in PCOS patients. Copyright (c) 2010 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Fall determinants and home modifications by occupational therapists to prevent falls: Facteurs déterminants des chutes et modifications du domicile effectuées par les ergothérapeutes pour prévenir les chutes.

PubMed

Maggi, Patrick; de Almeida Mello, Johanna; Delye, Sam; Cès, Sophie; Macq, Jean; Gosset, Christiane; Declercq, Anja

2018-02-01

Approximately one third of older people over 65 years fall each year. Home modifications may decrease occurrence of falls. This study aims to determine the risk factors of falls for frail older persons and to evaluate the impact of home modifications by an occupational therapist on the occurrence of falls. We conducted a longitudinal study using a quasiexperimental design to examine occurrence of falls. All participants 65 years of age and older and were assessed at baseline and 6 months after the intervention. Bivariate analysis and logistic regression models were used to study the risk factors of falls and the effect of home modifications on the incidence of falls. The main predictors of falls were vision problems, distress of informal caregiver, and insufficient informal support. Home modifications provided by an occupational therapist showed a significant reduction of falls. Informal caregivers and their health status had an impact on the fall risk of frail older persons. Home modifications by an occupational therapist reduced the fall risk of frail older persons at 6-months follow-up.

Functional O-GlcNAc modifications: Implications in molecular regulation and pathophysiology

PubMed Central

Wells, Lance

2016-01-01

O-linked β-N-acetylglucosamine (O-GlcNAc) is a regulatory post-translational modification of intracellular proteins. The dynamic and inducible cycling of the modification is governed by O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) in response to UDP-GlcNAc levels in the hexosamine biosynthetic pathway (HBP). Due to its reliance on glucose flux and substrate availability, a major focus in the field has been on how O-GlcNAc contributes to metabolic disease. For years this post-translational modification has been known to modify thousands of proteins implicated in various disorders, but direct functional connections have until recently remained elusive. New research is beginning to reveal the specific mechanisms through which O-GlcNAc influences cell dynamics and disease pathology including clear examples of O-GlcNAc modification at a specific site on a given protein altering its biological functions. The following review intends to focus primarily on studies in the last half decade linking O-GlcNAc modification of proteins with chromatin-directed gene regulation, developmental processes, and several metabolically related disorders including Alzheimer’s, heart disease and cancer. These studies illustrate the emerging importance of this post-translational modification in biological processes and multiple pathophysiologies. PMID:24524620

A study of dietary modification: Perceptions and attitudes of patients with multiple sclerosis.

PubMed

Brenton, J Nicholas; Goldman, Myla D

2016-07-01

Modifiable risk factors for multiple sclerosis (MS), including obesity and the gut microbiome, have been studied and have been found to be potentially relevant. Given this, there is a growing interest in diet modification as a means of impacting MS risk and disease course. The aim of this study was to determine the current behaviors, level of interest, and relevant factors surrounding modification of diet in MS patients. A total of 601 MS patients were mailed a dietary modification survey containing questions regarding subject demographics, disease course, and diet-related questions. Of the 199 survey responders, 17% admitted to currently attempting a diet for their MS and 91.5% were interested in diet modification as a means of benefiting their disease. Willingness to attempt diet therapy was not affected by demographic features or an individual's disease course. Over 85% of these patients were willing to attempt diet therapy for 3 months or longer. The majority of survey responders expressed interest in diet modification in attempts to improve or treat their MS. Our data demonstrate the feasibility of patient recruitment for future studies assessing therapeutic intervention by way of diet modification for MS disease. Copyright © 2016 Elsevier B.V. All rights reserved.

m1A Post-Transcriptional Modification in tRNAs.

PubMed

Oerum, Stephanie; Dégut, Clément; Barraud, Pierre; Tisné, Carine

2017-02-21

To date, about 90 post-transcriptional modifications have been reported in tRNA expanding their chemical and functional diversity. Methylation is the most frequent post-transcriptional tRNA modification that can occur on almost all nitrogen sites of the nucleobases, on the C5 atom of pyrimidines, on the C2 and C8 atoms of adenosine and, additionally, on the oxygen of the ribose 2'-OH. The methylation on the N1 atom of adenosine to form 1-methyladenosine (m1A) has been identified at nucleotide position 9, 14, 22, 57, and 58 in different tRNAs. In some cases, these modifications have been shown to increase tRNA structural stability and induce correct tRNA folding. This review provides an overview of the currently known m1A modifications, the different m1A modification sites, the biological role of each modification, and the enzyme responsible for each methylation in different species. The review further describes, in detail, two enzyme families responsible for formation of m1A at nucleotide position 9 and 58 in tRNA with a focus on the tRNA binding, m1A mechanism, protein domain organisation and overall structures.

40 CFR 58.14 - System modification.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false System modification. 58.14 Section 58.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) AMBIENT AIR QUALITY SURVEILLANCE Monitoring Network § 58.14 System modification. (a) The State, or where...

40 CFR 58.14 - System modification.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false System modification. 58.14 Section 58.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) AMBIENT AIR QUALITY SURVEILLANCE Monitoring Network § 58.14 System modification. (a) The State, or where...

47 CFR 1.947 - Modification of licenses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 1 2011-10-01 2011-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947 Modification of licenses. (a) All...

47 CFR 1.947 - Modification of licenses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 1 2010-10-01 2010-10-01 false Modification of licenses. 1.947 Section 1.947 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL PRACTICE AND PROCEDURE Wireless Radio Services Applications and Proceedings Application Requirements and Procedures § 1.947 Modification of licenses. (a) All...

76 FR 18723 - Proposed Information Collection; Comment Request; Weather Modification Activities Reports

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-05

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Proposed Information Collection; Comment Request; Weather Modification Activities Reports AGENCY: National Oceanic and Atmospheric...) of Public Law 92-205 requires that persons who engage in weather modification activities (e.g., cloud...

7 CFR 1467.13 - Modifications.

Code of Federal Regulations, 2011 CFR

2011-01-01

... must meet WRP regulations and program objectives, comply with the definition of wetland restoration as... AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS WETLANDS RESERVE PROGRAM § 1467.13 Modifications. (a... the program so long as the modification will not adversely affect the wetland functions and values for...

76 FR 51878 - Modifications of Certain Derivative Contracts; Correction

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-19

... Modifications of Certain Derivative Contracts; Correction AGENCY: Internal Revenue Service (IRS), Treasury... temporary regulations (TD 9538) that address when a transfer or assignment of certain derivative contracts... read as follows: Sec. 1.1001-4T Modifications of certain derivative contracts (temporary). * * * * * (a...

Chemically Derivatized Semiconductor Photoelectrodes.

ERIC Educational Resources Information Center

Wrighton, Mark S.

1983-01-01

Deliberate modification of semiconductor photoelectrodes to improve durability and enhance rate of desirable interfacial redox processes is discussed for a variety of systems. Modification with molecular-based systems or with metals/metal oxides yields results indicating an important role for surface modification in devices for fundamental study…

47 CFR 76.59 - Modification of television markets.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Modification of television markets. 76.59 Section 76.59 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.59 Modification...

47 CFR 76.59 - Modification of television markets.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Modification of television markets. 76.59 Section 76.59 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.59 Modification...

47 CFR 76.59 - Modification of television markets.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Modification of television markets. 76.59 Section 76.59 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.59 Modification...

47 CFR 76.59 - Modification of television markets.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Modification of television markets. 76.59 Section 76.59 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) BROADCAST RADIO SERVICES MULTICHANNEL VIDEO AND CABLE TELEVISION SERVICE Carriage of Television Broadcast Signals § 76.59 Modification...

Aircraft Modifications: Assessing the Current State of Air Force Aircraft Modifications and the Implications for Future Military Capability

DTIC Science & Technology

2007-01-25

Air, Space , and Cyberspace." Introduction 3 group production lots together into ’spirals’ or ’increments’. These groupings, as well as an increased...important reference point for this work. The analysis of the modification process presented in this reserach , however, does help shed light on the...planning efforts. Chapter 7- The Future of Aircraft Modifications "Strategy is the art of making use of time and space . I am less concerned about the

Study on the Modifications Required to Re-Engine the Lockheed D-21 Drone

NASA Technical Reports Server (NTRS)

1999-01-01

This report was prepared by Lockheed Martin (LM). The purpose of this 45 day study contract was to investigate the feasibility of using the D-21 as a Rocket Based Combined Cycle engine test-bed. The new NASA engine is entitled "Demonstration of Rocket Combined Cycle Operations (DRACO)". Four objectives were defined and modification study provide an estimation of the: (1) mudified vehicle performance; (2) required engine performance; (3) required vehicle modification; and (4) modification cost and schedule.

Distal vein patch as a form of autologus modification for infragenicular prosthetic bypass.

PubMed

Totic, Dragan; Rustempasic, Nedzad; Djedovic, Muhamed; Solakovic, Sid; Vukas, Haris; Aslani, Ilijas; Krvavac, Alma; Rudalija, Dzejra; Ahmetasevic, Alen

2013-01-01

Preferred graft for infragenicular bypass is autologus vein. The problem is when there is not available autologus vein. Literature suggest that in these situations, prosthetic graft with some form of modification of distal anastomosis with autogenic tissue is valuable adjunctive. Frequently used modifications are Miller's cuff, Taylor's patch and St. Mary's boot. Recently, there are reports on "Distal vein patch" as a form of autologus modification which, due to its simplicity and patency rate, attracted attention. The aim of this study was to evaluate benefits of this novel modification by comparing its patencies with other autologus modification of distal anastomosis. Study was performed on 60 patients, diabetics, with critical limb ischemia (CLI). Patients were divided in two groups: Group with distal vein patch modification; and group with some other form modification - control group. Patients were followed at least 22 months. We examined patency of grafts by physical examination or using Color Doppler. For statistical purposes we used KIaplan Meier analysis and curve. Significance was determined by Mann-Whitney, Fisher's exact, Pearsons chi square or Student T test as appropriate. P value less than 0,05 was considered significant. Groups were fairly matched relative to demographics, risk factors, operative intervention and distal anastomosis site. There was not statistical difference in two year primary patency between distal vein patch and control group--50% vs 53% respectivly (X2 = 0,08; p = 0,773). Also, there was not statistically significant difference in extremity survival (77% vs 77%) and patient survival between groups (89% vs 93%; X2 = 2,458; p = 0,117). This study proved equivalent patencies of infragenicular prosthetic bypasses performed using distal vein patch technique as with any other modification of distal anastomosis.

Maximum type 1 error rate inflation in multiarmed clinical trials with adaptive interim sample size modifications.

PubMed

Graf, Alexandra C; Bauer, Peter; Glimm, Ekkehard; Koenig, Franz

2014-07-01

Sample size modifications in the interim analyses of an adaptive design can inflate the type 1 error rate, if test statistics and critical boundaries are used in the final analysis as if no modification had been made. While this is already true for designs with an overall change of the sample size in a balanced treatment-control comparison, the inflation can be much larger if in addition a modification of allocation ratios is allowed as well. In this paper, we investigate adaptive designs with several treatment arms compared to a single common control group. Regarding modifications, we consider treatment arm selection as well as modifications of overall sample size and allocation ratios. The inflation is quantified for two approaches: a naive procedure that ignores not only all modifications, but also the multiplicity issue arising from the many-to-one comparison, and a Dunnett procedure that ignores modifications, but adjusts for the initially started multiple treatments. The maximum inflation of the type 1 error rate for such types of design can be calculated by searching for the "worst case" scenarios, that are sample size adaptation rules in the interim analysis that lead to the largest conditional type 1 error rate in any point of the sample space. To show the most extreme inflation, we initially assume unconstrained second stage sample size modifications leading to a large inflation of the type 1 error rate. Furthermore, we investigate the inflation when putting constraints on the second stage sample sizes. It turns out that, for example fixing the sample size of the control group, leads to designs controlling the type 1 error rate. © 2014 The Author. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The relationship between gene transcription and combinations of histone modifications

NASA Astrophysics Data System (ADS)

Cui, Xiangjun; Li, Hong; Luo, Liaofu

2012-09-01

Histone modification is an important subject of epigenetics which plays an intrinsic role in transcriptional regulation. It is known that multiple histone modifications act in a combinatorial fashion. In this study, we demonstrated that the pathways within constructed Bayesian networks can give an indication for the combinations among 12 histone modifications which have been studied in the TSS+1kb region in S. cerevisiae. After Bayesian networks for the genes with high transcript levels (H-network) and low transcript levels (L-network) were constructed, the combinations of modifications within the two networks were analyzed from the view of transcript level. The results showed that different combinations played dissimilar roles in the regulation of gene transcription when there exist differences for gene expression at transcription level.

MODFLOW-CDSS, a version of MODFLOW-2005 with modifications for Colorado Decision Support Systems

USGS Publications Warehouse

Banta, Edward R.

2011-01-01

MODFLOW-CDSS is a three-dimensional, finite-difference groundwater-flow model based on MODFLOW-2005, with two modifications. The first modification is the introduction of a Partition Stress Boundaries capability, which enables the user to partition a selected subset of MODFLOW's stress-boundary packages, with each partition defined by a separate input file. Volumetric water-budget components of each partition are tracked and listed separately in the volumetric water-budget tables. The second modification enables the user to specify that execution of a simulation should continue despite failure of the solver to satisfy convergence criteria. This modification is particularly intended to be used in conjunction with automated model-analysis software; its use is not recommended for other purposes.

Role of epigenetic modifications in luminal breast cancer

PubMed Central

Abdel-Hafiz, Hany A; Horwitz, Kathryn B

2015-01-01

Luminal breast cancers represent approximately 75% of cases. Explanations into the causes of endocrine resistance are complex and are generally ascribed to genomic mechanisms. Recently, attention has been drawn to the role of epigenetic modifications in hormone resistance. We review these here. Epigenetic modifications are reversible, heritable and include changes in DNA methylation patterns, modification of histones and altered microRNA expression levels that target the receptors or their signaling pathways. Large-scale analyses indicate distinct epigenomic profiles that distinguish breast cancers from normal and benign tissues. Taking advantage of the reversibility of epigenetic modifications, drugs that target epigenetic modifiers, given in combination with chemotherapies or endocrine therapies, may represent promising approaches to restoration of therapy responsiveness in these cases. PMID:25689414

Polymerization reactivity of sulfomethylated alkali lignin modified with horseradish peroxidase.

PubMed

Yang, Dongjie; Wu, Xiaolei; Qiu, Xueqing; Chang, Yaqi; Lou, Hongming

2014-03-01

Alkali lignin (AL) was employed as raw materials in the present study. Sulfomethylation was conducted to improve the solubility of AL, while sulfomethylated alkali lignin (SAL) was further polymerized by horseradish peroxidase (HRP). HRP modification caused a significant increase in molecular weight of SAL which was over 20 times. It was also found to increase the amount of sulfonic and carboxyl groups while decrease the amount of phenolic and methoxyl groups in SAL. The adsorption quantity of self-assembled SAL film was improved after HRP modification. Sulfonation and HRP modification were mutually promoted. The polymerization reactivity of SAL in HRP modification was increased with its sulfonation degree. Meanwhile, HRP modification facilitated SAL's radical-sulfonation reaction. Copyright © 2014. Published by Elsevier Ltd.

78 FR 51818 - Notice of Applications for Modification of Special Permits

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-21

... Applications for Modification of Special Permits AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications for modification of special permits SUMMARY: In accordance with the procedures governing the application for, and the processing of, special permits from the...

45 CFR 160.104 - Modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... paragraph (b) of this section, the Secretary may adopt a modification to a standard or implementation specification adopted under this subchapter no more frequently than once every 12 months. (b) The Secretary may adopt a modification at any time during the first year after the standard or implementation...

21 CFR 352.77 - Test modifications.

Code of Federal Regulations, 2010 CFR

2010-04-01

... modification of the testing procedures in this subpart. In addition, alternative methods (including automated or in vitro procedures) employing the same basic procedures as those described in this subpart may be used. Any proposed modification or alternative procedure shall be submitted as a petition in accord...

21 CFR 352.77 - Test modifications.

Code of Federal Regulations, 2011 CFR

2011-04-01

... modification of the testing procedures in this subpart. In addition, alternative methods (including automated or in vitro procedures) employing the same basic procedures as those described in this subpart may be used. Any proposed modification or alternative procedure shall be submitted as a petition in accord...

49 CFR 180.513 - Repairs, alterations, conversions, and modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Repairs, alterations, conversions, and modifications. 180.513 Section 180.513 Transportation Other Regulations Relating to Transportation PIPELINE AND... Repairs, alterations, conversions, and modifications. (a) In order to repair tank cars, the tank car...

49 CFR 180.513 - Repairs, alterations, conversions, and modifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Repairs, alterations, conversions, and modifications. 180.513 Section 180.513 Transportation Other Regulations Relating to Transportation (Continued..., alterations, conversions, and modifications. (a) In order to repair tank cars, the tank car facility must...

77 FR 74631 - General Services Administration Acquisition Regulation: Modifications (Multiple Award Schedules...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-17

...-0001; Sequence 21] General Services Administration Acquisition Regulation: Modifications (Multiple... Modifications (Multiple Award Schedule). DATES: Submit comments on or before: February 15, 2013. FOR FURTHER INFORMATION CONTACT: Ms. Dana Munson, General Services Acquisition Policy Division, GSA, (202) 357-9652 or...

14 CFR 151.99 - Modifications of programming standards.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Modifications of programming standards. 151... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.99 Modifications of programming standards. The Director, Airports, Service, or the Regional Director concerned may, on individual...

14 CFR 151.99 - Modifications of programming standards.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Modifications of programming standards. 151... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.99 Modifications of programming standards. The Director, Airports, Service, or the Regional Director concerned may, on individual...

14 CFR 151.99 - Modifications of programming standards.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Modifications of programming standards. 151... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.99 Modifications of programming standards. The Director, Airports, Service, or the Regional Director concerned may, on individual...

Defining Reinforcers--A Problem in Communication For Consultation in Behavior Modification

ERIC Educational Resources Information Center

Schmits, Donald W.

1973-01-01

This paper reviews the respondent (Hull-Spence) and operant (Skinnerian) conditioning definitions of reinforcers and reinforcement and demonstrates the need to keep the systems separate when consulting about behavior modification. The two systems are shown to lead to different modification procedures. (Author)

78 FR 33864 - Negotiated Service Agreement

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... POSTAL REGULATORY COMMISSION [Docket No. CP2013-23; Order No. 1736] Negotiated Service Agreement... Service filing concerning an amendment to the 2013 China Post Agreement. This notice informs the public of... modification (Modification) of the 2013 China Post Agreement (Agreement).\\1\\ The Modification pertains to rates...

39 CFR 501.10 - Postage Evidencing System modifications.

Code of Federal Regulations, 2010 CFR

2010-07-01

... AND DISTRIBUTE POSTAGE EVIDENCING SYSTEMS § 501.10 Postage Evidencing System modifications. (a) An... 39 Postal Service 1 2010-07-01 2010-07-01 false Postage Evidencing System modifications. 501.10... a previously approved Postage Evidencing System. The notification must include a summary of all...

45 CFR 670.15 - Modification, suspension, and revocation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 3 2012-10-01 2012-10-01 false Modification, suspension, and revocation. 670.15 Section 670.15 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CONSERVATION OF ANTARCTIC ANIMALS AND PLANTS Permits § 670.15 Modification, suspension, and...

45 CFR 670.15 - Modification, suspension, and revocation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Modification, suspension, and revocation. 670.15 Section 670.15 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CONSERVATION OF ANTARCTIC ANIMALS AND PLANTS Permits § 670.15 Modification, suspension, and...

45 CFR 670.15 - Modification, suspension, and revocation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Modification, suspension, and revocation. 670.15 Section 670.15 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CONSERVATION OF ANTARCTIC ANIMALS AND PLANTS Permits § 670.15 Modification, suspension, and...

45 CFR 670.15 - Modification, suspension, and revocation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Modification, suspension, and revocation. 670.15 Section 670.15 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CONSERVATION OF ANTARCTIC ANIMALS AND PLANTS Permits § 670.15 Modification, suspension, and...

12 CFR 1710.30 - Modification of certain provisions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 7 2010-01-01 2010-01-01 false Modification of certain provisions. 1710.30 Section 1710.30 Banks and Banking OFFICE OF FEDERAL HOUSING ENTERPRISE OVERSIGHT, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT SAFETY AND SOUNDNESS CORPORATE GOVERNANCE Modification of Certain Provisions...

Treating Retentive Encopresis: Dietary Modification and Behavioral Techniques.

ERIC Educational Resources Information Center

Nabors, Laura; Morgan, Sam B.

1995-01-01

A home-based contingency management program, consisting of diet modification, laxatives, correction for soiling accidents, stimulus control training, and positive reinforcement, was implemented for treatment of a 4-year-old encopretic male. The findings provide evidence supporting the effectiveness of dietary modification combined with behavior…

12 CFR 725.21 - Modification of agreements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Modification of agreements. 725.21 Section 725.21 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS NATIONAL CREDIT UNION ADMINISTRATION CENTRAL LIQUIDITY FACILITY § 725.21 Modification of agreements. The...

14 CFR 151.99 - Modifications of programming standards.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Modifications of programming standards. 151... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.99 Modifications of programming standards. The Director, Airports, Service, or the Regional Director concerned may, on individual...

Taking Another Look at Behavior Modification and Assertive Discipline.

ERIC Educational Resources Information Center

Palardy, J. Michael

1996-01-01

Behavior modification and assertive discipline approaches use rewards and negative consequences (extinction procedures) to deal with students' maladaptive behavior. Behavior modification has significant limitations, as it treats symptoms, not causes; yields only short-term benefits; has limited transfer value for other environments; and values…

45 CFR 671.10 - Review, modification, suspension, and revocation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Review, modification, suspension, and revocation. 671.10 Section 671.10 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION WASTE REGULATION Permits § 671.10 Review, modification, suspension, and revocation. (a...

14 CFR 151.99 - Modifications of programming standards.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Modifications of programming standards. 151... (CONTINUED) AIRPORTS FEDERAL AID TO AIRPORTS Project Programming Standards § 151.99 Modifications of programming standards. The Director, Airports, Service, or the Regional Director concerned may, on individual...

48 CFR 243.205-70 - Pricing of contract modifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Pricing of contract modifications. 243.205-70 Section 243.205-70 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CONTRACT MANAGEMENT CONTRACT MODIFICATIONS Change Orders 243.205-70...

Oligo/Polynucleotide-Based Gene Modification: Strategies and Therapeutic Potential

PubMed Central

Sargent, R. Geoffrey; Kim, Soya

2011-01-01

Oligonucleotide- and polynucleotide-based gene modification strategies were developed as an alternative to transgene-based and classical gene targeting-based gene therapy approaches for treatment of genetic disorders. Unlike the transgene-based strategies, oligo/polynucleotide gene targeting approaches maintain gene integrity and the relationship between the protein coding and gene-specific regulatory sequences. Oligo/polynucleotide-based gene modification also has several advantages over classical vector-based homologous recombination approaches. These include essentially complete homology to the target sequence and the potential to rapidly engineer patient-specific oligo/polynucleotide gene modification reagents. Several oligo/polynucleotide-based approaches have been shown to successfully mediate sequence-specific modification of genomic DNA in mammalian cells. The strategies involve the use of polynucleotide small DNA fragments, triplex-forming oligonucleotides, and single-stranded oligodeoxynucleotides to mediate homologous exchange. The primary focus of this review will be on the mechanistic aspects of the small fragment homologous replacement, triplex-forming oligonucleotide-mediated, and single-stranded oligodeoxynucleotide-mediated gene modification strategies as it relates to their therapeutic potential. PMID:21417933

Role of novel histone modifications in cancer

PubMed Central

Shanmugam, Muthu K.; Arfuso, Frank; Arumugam, Surendar; Chinnathambi, Arunachalam; Jinsong, Bian; Warrier, Sudha; Wang, Ling Zhi; Kumar, Alan Prem; Ahn, Kwang Seok; Sethi, Gautam; Lakshmanan, Manikandan

2018-01-01

Oncogenesis is a multistep process mediated by a variety of factors including epigenetic modifications. Global epigenetic post-translational modifications have been detected in almost all cancers types. Epigenetic changes appear briefly and do not involve permanent changes to the primary DNA sequence. These epigenetic modifications occur in key oncogenes, tumor suppressor genes, and transcription factors, leading to cancer initiation and progression. The most commonly observed epigenetic changes include DNA methylation, histone lysine methylation and demethylation, histone lysine acetylation and deacetylation. However, there are several other novel post-translational modifications that have been observed in recent times such as neddylation, sumoylation, glycosylation, phosphorylation, poly-ADP ribosylation, ubiquitination as well as transcriptional regulation and these have been briefly discussed in this article. We have also highlighted the diverse epigenetic changes that occur during the process of tumorigenesis and described the role of histone modifications that can occur on tumor suppressor genes as well as oncogenes, which regulate tumorigenesis and can thus form the basis of novel strategies for cancer therapy. PMID:29541423

Influence of major-groove chemical modifications of DNA on transcription by bacterial RNA polymerases

PubMed Central

Raindlová, Veronika; Janoušková, Martina; Slavíčková, Michaela; Perlíková, Pavla; Boháčová, Soňa; Milisavljevič, Nemanja; Šanderová, Hana; Benda, Martin; Barvík, Ivan; Krásný, Libor; Hocek, Michal

2016-01-01

DNA templates containing a set of base modifications in the major groove (5-substituted pyrimidines or 7-substituted 7-deazapurines bearing H, methyl, vinyl, ethynyl or phenyl groups) were prepared by PCR using the corresponding base-modified 2′-deoxyribonucleoside triphosphates (dNTPs). The modified templates were used in an in vitro transcription assay using RNA polymerase from Bacillus subtilis and Escherichia coli. Some modified nucleobases bearing smaller modifications (H, Me in 7-deazapurines) were perfectly tolerated by both enzymes, whereas bulky modifications (Ph at any nucleobase) and, surprisingly, uracil blocked transcription. Some middle-sized modifications (vinyl or ethynyl) were partly tolerated mostly by the E. coli enzyme. In all cases where the transcription proceeded, full length RNA product with correct sequence was obtained indicating that the modifications of the template are not mutagenic and the inhibition is probably at the stage of initiation. The results are promising for the development of bioorthogonal reactions for artificial chemical switching of the transcription. PMID:27001521

S-Nitrosylation: Specificity, Occupancy, and Interaction with Other Post-Translational Modifications

PubMed Central

Kohr, Mark J.; Murphy, Elizabeth

2013-01-01

Abstract Significance: S-nitrosylation (SNO) has been identified throughout the body as an important signaling modification both in physiology and a variety of diseases. SNO is a multifaceted post-translational modification, in that it can either act as a signaling molecule itself or as an intermediate to other modifications. Recent Advances and Critical Issues: Through extensive SNO research, we have made progress toward understanding the importance of single cysteine-SNO sites; however, we are just beginning to explore the importance of specific SNO within the context of other SNO sites and post-translational modifications. Additionally, compartmentalization and SNO occupancy may play an important role in the consequences of the SNO modification. Future Directions: In this review, we will consider the context of SNO signaling and discuss how the transient nature of SNO, its role as an oxidative intermediate, and the pattern of SNO, should be considered when determining the impact of SNO signaling. Antioxid. Redox Signal. 19, 1209–1219. PMID:23157187

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part V - Wing-Alone Tests and Effect of Modifications to the Vertical Fins, Speed Brakes, and Fuselage TED No. NACA DE308. Part V; Wing-Alone Tests and Effect of Modifications to the Vertical Fins, Speed Brakes, and Fuselage, TED No. NACA DE308

NASA Technical Reports Server (NTRS)

Kuhri, Richard E.; Myers, Boyd C., II

1947-01-01

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The wing-alone tests and the effect of the various vertical-fin modifications, speed-brake modifications, and fuselage modifications on the aerodynamic characteristics in pitch and yaw are presented in the present paper with a limited analysis of the results. Also included are tuft studies of the flow for some of the modifications tested.

Effects of channel modifications on the hydrology of Chicod Creek basin, North Carolina, 1975-87

USGS Publications Warehouse

Mason, R.R.; Simmons, C.E.; Watkins, S.A.

1990-01-01

Drainage modifications in this Coastal Plain basin from 1978 to 1981 consisted of channel excavation and clearing of blockages. A study was begun in 1975 to define hydrologic conditions of the basin before, during, and after modifications and to determine what changes were attributed to modifications. Surface-water conditions were altered during and following modifications. Minimum flow at Juniper Branch was increased from less than 0.1 cu ft/sec to 0.4 cu ft/second;streamflow variability was reduced from an index of 0.87 to 0.49. In-channel velocity at Chicod Creek was increased from a mean of 0.4 ft/sec to 1.5 ft/sec. Substantial groundwater level declines were observed in wells 180 and 250 ft from Juniper Branch during the modifications phase;these were 0.4 and 0.2 ft, respectively. However, most surface-water and groundwater conditions returned nearly to premodification levels by 1987. Water-quality characteristics monitored during the investigation included physical, chemical, and bacteriological characteristics. Physical characteristics monitored were suspended sediment, temperature, dissolved oxygen, and pH. Of these physical characteristics, only sediment concentrations increased substantially during channel modifications. Chemical characteristics studied were major dissolved constituents, nutrients, trace metals, and pesticides. Substantial changes ranged from a decline in total iron concentrations of 77% to an increase in total nitrite concentrations of 130%. Changes in many chemical characteristics persisted following channel modifications. Bacterial counts did not change substantially.

Landscape changes as a factor affecting the course and consequences of extreme floods in the Otava river basin, Czech Republic.

PubMed

Langhammer, Jakub; Vilímek, Vít

2008-09-01

The paper presents the analysis of anthropogenical modifications of the landscape in relation to the course and consequences of floods. The research was conducted in the Otava river basin which represents the core zone of the extreme flood in August 2002 in Central Europe. The analysis was focused on the key indicators of landscape modification potentially affecting the runoff process - the long-term changes of land-use, changes of land cover structure, land drainage, historical shortening of the river network and the modifications of streams and floodplains. The information on intensity and spatial distribution of modifications was derived from different data sources--historical maps, available GIS data, remote sensing and field mapping. The results revealed a high level of spatial diversity of anthropogenical modifications in different parts of the river basin. The intensive modifications in most of indicators were concentrated in the lowland region of the river basin due to its agricultural use; however important changes were also recorded in the headwater region of the basin. The high spatial diversity of the modifications may result in their varying effect on the course and consequences of floods in different parts of the river basin. This effect is demonstrated by the cluster analysis based on the matrix of indicators of stream and floodplain modification, physiogeographical characteristics and geomorphological evidences of the flood in August 2002, derived from the individual thematic layers using GIS.

Ball with hair: modular functionalization of highly stable G-quadruplex DNA nano-scaffolds through N2-guanine modification

PubMed Central

Lech, Christopher Jacques

2017-01-01

Abstract Functionalized nanoparticles have seen valuable applications, particularly in the delivery of therapeutic and diagnostic agents in biological systems. However, the manufacturing of such nano-scale systems with the consistency required for biological application can be challenging, as variation in size and shape have large influences in nanoparticle behavior in vivo. We report on the development of a versatile nano-scaffold based on the modular functionalization of a DNA G-quadruplex. DNA sequences are functionalized in a modular fashion using well-established phosphoramidite chemical synthesis with nucleotides containing modification of the amino (N2) position of the guanine base. In physiological conditions, these sequences fold into well-defined G-quadruplex structures. The resulting DNA nano-scaffolds are thermally stable, consistent in size, and functionalized in a manner that allows for control over the density and relative orientation of functional chemistries on the nano-scaffold surface. Various chemistries including small modifications (N2-methyl-guanine), bulky aromatic modifications (N2-benzyl-guanine), and long chain-like modifications (N2-6-amino-hexyl-guanine) are tested and are found to be generally compatible with G-quadruplex formation. Furthermore, these modifications stabilize the G-quadruplex scaffold by 2.0–13.3 °C per modification in the melting temperature, with concurrent modifications producing extremely stable nano-scaffolds. We demonstrate the potential of this approach by functionalizing nano-scaffolds for use within the biotin–avidin conjugation approach. PMID:28499037

14 CFR 60.23 - Modifications to FSTDs.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Modifications to FSTDs. 60.23 Section 60.23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.23 Modifications to FSTDs. (a...

14 CFR 60.23 - Modifications to FSTDs.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Modifications to FSTDs. 60.23 Section 60.23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.23 Modifications to FSTDs. (a...

14 CFR 60.23 - Modifications to FSTDs.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Modifications to FSTDs. 60.23 Section 60.23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.23 Modifications to FSTDs. (a...

14 CFR 60.23 - Modifications to FSTDs.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Modifications to FSTDs. 60.23 Section 60.23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.23 Modifications to FSTDs. (a...

14 CFR 60.23 - Modifications to FSTDs.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Modifications to FSTDs. 60.23 Section 60.23 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN FLIGHT SIMULATION TRAINING DEVICE INITIAL AND CONTINUING QUALIFICATION AND USE § 60.23 Modifications to FSTDs. (a...

30 CFR 582.25 - Plan modification.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false Plan modification. 582.25 Section 582.25 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OPERATIONS IN THE... of Lessees § 582.25 Plan modification. Approved Delineation, Testing, and Mining Plans may be...

30 CFR 582.25 - Plan modification.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 2 2014-07-01 2014-07-01 false Plan modification. 582.25 Section 582.25 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OPERATIONS IN THE... of Lessees § 582.25 Plan modification. Approved Delineation, Testing, and Mining Plans may be...

30 CFR 582.25 - Plan modification.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false Plan modification. 582.25 Section 582.25 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OPERATIONS IN THE... of Lessees § 582.25 Plan modification. Approved Delineation, Testing, and Mining Plans may be...

78 FR 21230 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-10

... Failed Post-Modification Operational Test After accomplishment of the modification specified in paragraph... of the GFI or deactivation of the associated fuel pump following failure of any post-modification operational test of the GFI. We are issuing this AD to prevent the potential of ignition sources inside fuel...

40 CFR 52.2223 - Compliance schedules.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., 1974: Submit to the Administrator a projection of the amount of fuel, by types, that will be... projected above. (iii) April 30, 1974: Submit a statement as to whether boiler modifications will be required. If modifications will be required, submit plans for such modifications. (iv) May 31, 1974: Let...

48 CFR 252.236-7000 - Modification proposals-price breakdown.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-price breakdown. 252.236-7000 Section 252.236-7000 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.236-7000 Modification proposals—price breakdown. As prescribed in 236.570(a), use the following clause: Modification Proposals—Price Breakdown (DEC 1991) (a) The...

40 CFR 403.18 - Modification of POTW pretreatment programs.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 30 2013-07-01 2012-07-01 true Modification of POTW pretreatment programs. 403.18 Section 403.18 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... POLLUTION § 403.18 Modification of POTW pretreatment programs. (a) General. Either the Approval Authority or...

46 CFR 309.7 - Modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 8 2010-10-01 2010-10-01 false Modifications. 309.7 Section 309.7 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS VALUES FOR WAR RISK INSURANCE § 309.7 Modifications. The Maritime Administration reserves the right to exempt any vessel from the scope of this part...

76 FR 78732 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-19

... or modification of a signal system. FRA has assigned the petition Docket Number FRA-2011-0092. CSX seeks approval of the proposed modification of the bridge tender controlled signals to automatic signals..., Jacksonville Division. The modification consists of the conversion of bridge tender controlled signals to...

47 CFR 73.152 - Modification of directional antenna data.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Modification of directional antenna data. 73... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.152 Modification of directional antenna data. (a) If, after construction and final adjustment of a directional antenna, a measured inverse distance...

47 CFR 73.152 - Modification of directional antenna data.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Modification of directional antenna data. 73... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.152 Modification of directional antenna data. (a) If, after construction and final adjustment of a directional antenna, a measured inverse distance...

47 CFR 73.152 - Modification of directional antenna data.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Modification of directional antenna data. 73... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.152 Modification of directional antenna data. (a) If, after construction and final adjustment of a directional antenna, a measured inverse distance...

47 CFR 73.152 - Modification of directional antenna data.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Modification of directional antenna data. 73... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.152 Modification of directional antenna data. (a) If, after construction and final adjustment of a directional antenna, a measured inverse distance...

47 CFR 73.152 - Modification of directional antenna data.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Modification of directional antenna data. 73... SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.152 Modification of directional antenna data. (a) If, after construction and final adjustment of a directional antenna, a measured inverse distance...

78 FR 18285 - General Services Administration Acquisition Regulation; Submission for OMB Review; Modifications...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

...; Modifications 552.243-72 (Multiple Award Schedules) AGENCY: Office of Acquisition Policy, General Services... information collection requirement regarding the Modifications (Multiple Award Schedule) clause. DATES: Submit comments on or before: April 25, 2013. FOR FURTHER INFORMATION CONTACT: Ms. Dana Munson, General Services...

31 CFR 501.803 - Amendment, modification, or revocation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance:Treasury 3 2014-07-01 2014-07-01 false Amendment, modification, or revocation. 501.803 Section 501.803 Money and Finance: Treasury Regulations Relating to Money and Finance... REGULATIONS Procedures § 501.803 Amendment, modification, or revocation. Except as otherwise provided by law...

31 CFR 501.803 - Amendment, modification, or revocation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Amendment, modification, or revocation. 501.803 Section 501.803 Money and Finance: Treasury Regulations Relating to Money and Finance... REGULATIONS Procedures § 501.803 Amendment, modification, or revocation. Except as otherwise provided by law...

31 CFR 501.803 - Amendment, modification, or revocation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance:Treasury 3 2013-07-01 2013-07-01 false Amendment, modification, or revocation. 501.803 Section 501.803 Money and Finance: Treasury Regulations Relating to Money and Finance... REGULATIONS Procedures § 501.803 Amendment, modification, or revocation. Except as otherwise provided by law...

31 CFR 501.803 - Amendment, modification, or revocation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Amendment, modification, or revocation. 501.803 Section 501.803 Money and Finance: Treasury Regulations Relating to Money and Finance... REGULATIONS Procedures § 501.803 Amendment, modification, or revocation. Except as otherwise provided by law...

40 CFR 147.2927 - Permit modification.

Code of Federal Regulations, 2012 CFR

2012-07-01

... standards on which the permit was based have changed. (4) The Regional Administrator has received notice of a proposed permit transfer. (5) An interested person requests in writing that a permit be modified... appropriate. (b) Minor modifications. (1) Minor modifications do not require that the procedures listed in...

24 CFR 401.460 - Modification or refinancing of first mortgage.

Code of Federal Regulations, 2013 CFR

2013-04-01

... modification under the Restructuring Plan. The debt service coverage used by the PAE must be adequate for... RESTRUCTURING, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT MULTIFAMILY HOUSING MORTGAGE AND HOUSING ASSISTANCE RESTRUCTURING PROGRAM (MARK-TO-MARKET) Restructuring Plan § 401.460 Modification or refinancing of first...

78 FR 57156 - General Services Administration Acquisition Regulation; Submission for OMB Review; Modifications...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-17

... Supply Schedules) AGENCY: Office of Acquisition Policy, General Services Administration (GSA). ACTION... collection requirement regarding the Modifications (Federal Supply Schedule) clause. DATES: Submit comments... (GSAR) to add clause 552.243-81 Modifications (Federal Supply Schedule) and an Alternate I version of...

49 CFR 595.7 - Requirements for vehicle modifications to accommodate people with disabilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... accommodate people with disabilities. 595.7 Section 595.7 Transportation Other Regulations Relating to... (CONTINUED) MAKE INOPERATIVE EXEMPTIONS Vehicle Modifications To Accommodate People With Disabilities § 595.7 Requirements for vehicle modifications to accommodate people with disabilities. (a) Any motor vehicle repair...

76 FR 15046 - Office of Hazardous Materials Safety; Notice of Applications for Modification of Special Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration Office of Hazardous Materials Safety; Notice of Applications for Modification of Special Permit AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications for modification of...

48 CFR 422.404-6 - Modifications of wage determinations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Modifications of wage determinations. 422.404-6 Section 422.404-6 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE... Involving Construction 422.404-6 Modifications of wage determinations. HCA's are authorized to request...

48 CFR 622.404-6 - Modifications of wage determinations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Modifications of wage determinations. 622.404-6 Section 622.404-6 Federal Acquisition Regulations System DEPARTMENT OF STATE... Involving Construction 622.404-6 Modifications of wage determinations. The cognizant contracting activity is...

In silico prediction of post-translational modifications.

PubMed

Liu, Chunmei; Li, Hui

2011-01-01

Methods for predicting protein post-translational modifications have been developed extensively. In this chapter, we review major post-translational modification prediction strategies, with a particular focus on statistical and machine learning approaches. We present the workflow of the methods and summarize the advantages and disadvantages of the methods.

33 CFR 167.15 - Modification of schemes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Modification of schemes. 167.15...) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES General § 167.15 Modification of schemes. (a) A traffic separation scheme or precautionary area described in this part may be permanently...

33 CFR 167.15 - Modification of schemes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Modification of schemes. 167.15...) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES General § 167.15 Modification of schemes. (a) A traffic separation scheme or precautionary area described in this Part may be permanently...

33 CFR 167.15 - Modification of schemes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Modification of schemes. 167.15...) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES General § 167.15 Modification of schemes. (a) A traffic separation scheme or precautionary area described in this part may be permanently...

33 CFR 167.15 - Modification of schemes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Modification of schemes. 167.15...) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES General § 167.15 Modification of schemes. (a) A traffic separation scheme or precautionary area described in this part may be permanently...

33 CFR 167.15 - Modification of schemes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Modification of schemes. 167.15...) PORTS AND WATERWAYS SAFETY OFFSHORE TRAFFIC SEPARATION SCHEMES General § 167.15 Modification of schemes. (a) A traffic separation scheme or precautionary area described in this part may be permanently...

14 CFR 45.15 - Replacement and modification parts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Replacement and modification parts. 45.15 Section 45.15 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT IDENTIFICATION AND REGISTRATION MARKING Marking of Products and Articles § 45.15 Replacement and modification...

76 FR 9611 - Notice of Permit Modification Request Received Under the Antarctic Conservation Act of 1978

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-18

... NATIONAL SCIENCE FOUNDATION Notice of Permit Modification Request Received Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of permit modification request... that the National Science Foundation (NSF) has received a request to modify a permit issued to conduct...

Physical Education: The Behavior Modification Approach. The Curriculum Series.

ERIC Educational Resources Information Center

Presbie, Robert J.; Brown, Paul L.

Behavior modification is discussed as a new approach to teaching and curriculum implementation in physical education. It is suggested that behavior modification offers physical education several advantages: (1) extensive research findings of various kinds directly applicable to the work of the physical education teacher; (2) a set of behavioral…

20 CFR 410.515 - Modification of benefit amounts; general.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 20 Employees' Benefits 2 2011-04-01 2011-04-01 false Modification of benefit amounts; general. 410.515 Section 410.515 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL COAL MINE HEALTH AND SAFETY ACT OF 1969, TITLE IV-BLACK LUNG BENEFITS (1969- ) Payment of Benefits § 410.515 Modification of...

Modifications Of Hydrostatic-Bearing Computer Program

NASA Technical Reports Server (NTRS)

Hibbs, Robert I., Jr.; Beatty, Robert F.

1991-01-01

Several modifications made to enhance utility of HBEAR, computer program for analysis and design of hydrostatic bearings. Modifications make program applicable to more realistic cases and reduce time and effort necessary to arrive at a suitable design. Uses search technique to iterate on size of orifice to obtain required pressure ratio.

Mechanical methods of chaparral modification

Treesearch

George Roby; Lisle Green

1976-01-01

Chaparral modification is undertaken for a variety of land-management purposes. To help land managers in selecting equipment and methods for such work, practitioners in county, State, and Federal modification projects were asked for evaluations of equipment and techniques they had used. This handbook describes the alternative techniques and equipment, provides...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

48 CFR 217.7103-6 - Modification of master agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Modification of master... Master Agreement for Repair and Alteration of Vessels 217.7103-6 Modification of master agreements. (a) Review each master agreement at least annually before the anniversary of its effective date and revise it...

14 CFR 302.419 - Modification or dissolution of enforcement actions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Modification or dissolution of enforcement actions. 302.419 Section 302.419 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... Enforcement Proceedings § 302.419 Modification or dissolution of enforcement actions. Whenever any party to a...

14 CFR 302.419 - Modification or dissolution of enforcement actions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Modification or dissolution of enforcement actions. 302.419 Section 302.419 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... Enforcement Proceedings § 302.419 Modification or dissolution of enforcement actions. Whenever any party to a...

14 CFR 302.419 - Modification or dissolution of enforcement actions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Modification or dissolution of enforcement actions. 302.419 Section 302.419 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF... Enforcement Proceedings § 302.419 Modification or dissolution of enforcement actions. Whenever any party to a...

76 FR 66089 - Notice of Permit Modification Issued Under the Antarctic Conservation Act of 1978

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-25

... NATIONAL SCIENCE FOUNDATION Notice of Permit Modification Issued Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of permit modification issued under the Antarctic Conservation of 1978, Public Law 95-541. SUMMARY: The National Science Foundation (NSF...

76 FR 47611 - Notice of Permit Modification Issued Under the Antarctic Conservation Act of 1978

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-05

... NATIONAL SCIENCE FOUNDATION Notice of Permit Modification Issued Under the Antarctic Conservation Act of 1978 AGENCY: National Science Foundation. ACTION: Notice of permit modification issued under the Antarctic Conservation Act of 1978, Public Law 95-541. SUMMARY: The National Science Foundation...

50 CFR 218.188 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Modifications to Letters of Authorization. 218.188 Section 218.188 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND... Surface Warfare Center Panama City Division § 218.188 Modifications to Letters of Authorization. (a...

50 CFR 218.188 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 7 2010-10-01 2010-10-01 false Modifications to Letters of Authorization. 218.188 Section 218.188 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND... Surface Warfare Center Panama City Division § 218.188 Modifications to Letters of Authorization. (a...

50 CFR 218.188 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Modifications to Letters of Authorization. 218.188 Section 218.188 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND... Surface Warfare Center Panama City Division § 218.188 Modifications to Letters of Authorization. (a...

50 CFR 218.188 - Modifications to Letters of Authorization.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Modifications to Letters of Authorization. 218.188 Section 218.188 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND... Surface Warfare Center Panama City Division § 218.188 Modifications to Letters of Authorization. (a...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

14 CFR 437.85 - Allowable design changes; modification of an experimental permit.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Conditions of an Experimental Permit § 437.85 Allowable design changes; modification of an experimental... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Allowable design changes; modification of an experimental permit. 437.85 Section 437.85 Aeronautics and Space COMMERCIAL SPACE TRANSPORTATION...

48 CFR 52.215-13 - Subcontractor Certified Cost or Pricing Data-Modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Cost or Pricing Data-Modifications. 52.215-13 Section 52.215-13 Federal Acquisition Regulations System... Text of Provisions and Clauses 52.215-13 Subcontractor Certified Cost or Pricing Data—Modifications. As prescribed in 15.408(e), insert the following clause: Subcontractor Certified Cost or Pricing Data...

48 CFR 252.243-7001 - Pricing of contract modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Pricing of contract... of Provisions And Clauses 252.243-7001 Pricing of contract modifications. As prescribed in 243.205-70, use the following clause: Pricing of Contract Modifications (DEC 1991) When costs are a factor in any...

Beliefs about Child Support Modification Following Remarriage and Subsequent Childbirth

ERIC Educational Resources Information Center

Hans, Jason D.

2009-01-01

Framed by equity theory, fairness beliefs regarding child support modification to account for the financial impact of remarriage and subsequent childbirth were assessed. Based on a random sample of 407 Kentucky residents using a multiple segment factorial vignette approach, modification was supported by 57% of respondents following remarriage, but…

41 CFR 101-39.304 - Modification or installation of accessory equipment.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., TRANSPORTATION, AND MOTOR VEHICLES 39-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.3-Use and Care of GSA Interagency Fleet Management System Vehicles § 101-39.304 Modification or installation of accessory equipment. The modification of a GSA Interagency Fleet Management System (IFMS) vehicle or the permanent installation of...

47 CFR 15.204 - External radio frequency power amplifiers and antenna modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... antenna modifications. 15.204 Section 15.204 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... antenna modifications. (a) Except as otherwise described in paragraphs (b) and (d) of this section, no... antenna, may be authorized, marketed and used under this part. Except as described otherwise in this...

47 CFR 15.204 - External radio frequency power amplifiers and antenna modifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... antenna modifications. 15.204 Section 15.204 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... antenna modifications. (a) Except as otherwise described in paragraphs (b) and (d) of this section, no... antenna, may be authorized, marketed and used under this part. Except as described otherwise in this...

47 CFR 15.204 - External radio frequency power amplifiers and antenna modifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... antenna modifications. 15.204 Section 15.204 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... antenna modifications. (a) Except as otherwise described in paragraphs (b) and (d) of this section, no... antenna, may be authorized, marketed and used under this part. Except as described otherwise in this...

47 CFR 15.204 - External radio frequency power amplifiers and antenna modifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... antenna modifications. 15.204 Section 15.204 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... antenna modifications. (a) Except as otherwise described in paragraphs (b) and (d) of this section, no... antenna, may be authorized, marketed and used under this part. Except as described otherwise in this...

47 CFR 15.204 - External radio frequency power amplifiers and antenna modifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... antenna modifications. 15.204 Section 15.204 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL... antenna modifications. (a) Except as otherwise described in paragraphs (b) and (d) of this section, no... antenna, may be authorized, marketed and used under this part. Except as described otherwise in this...

77 FR 59454 - Proposed Collection; Comment Request for Regulation Project

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-27

... 1995, Public Law 104-13(44 U.S.C. 3506(c)(2)(A)). Currently, the IRS is soliciting comments concerning modifications of commercial mortgage loans held by a real estate mortgage investment conduit. DATES: Written... would expand the list of permitted loan modifications to include certain modifications of commercial...

The Modification of Compounds by Attributive Adjectives

ERIC Educational Resources Information Center

Berg, Thomas

2011-01-01

This paper examines the modification of nominal compounds by attributive adjectives in English. It draws on a distinction between compound-external (i.e. syntactic) and compound-internal (i.e. morphological) modification. An analysis is presented of more than 1000 pertinent cases, which are roughly equally divided into two-, three- and four-noun…

Cognitive Modification and Systematic Desensitization with Test Anxious High School Students.

ERIC Educational Resources Information Center

Leal, Lois L.; And Others

1981-01-01

Compares the relative effectiveness of cognitive modification and systematic desensitization with test anxious high school students (N=30). The systematic desensitization treatment appeared to be significantly more effective on the performance measure while cognitive modification was more effective on one of the self-report measures. (Author/JAC)

24 CFR 100.203 - Reasonable modifications of existing premises.

Code of Federal Regulations, 2010 CFR

2010-04-01

... before the modification, reasonable wear and tear excepted. The landlord may not increase for handicapped... before the modification, reasonable wear and tear excepted. It would be reasonable for the landlord to... condition, reasonable wear and tear excepted. However, it would be unreasonable for the landlord to require...

15 CFR 908.4 - Initial report.

Code of Federal Regulations, 2011 CFR

2011-01-01

... SUBMITTING REPORTS ON WEATHER MODIFICATION ACTIVITIES § 908.4 Initial report. (a) Any person intending to engage in any weather modification project or activity in the United States shall provide a report of his... operator for the project or activity; (2) The following dates for weather modification activities: (i) The...

15 CFR 908.8 - Maintenance of records.

Code of Federal Regulations, 2011 CFR

2011-01-01

... RECORDS AND SUBMITTING REPORTS ON WEATHER MODIFICATION ACTIVITIES § 908.8 Maintenance of records. (a) Any person engaging in a weather modification activity in the United States shall maintain a record of such... assigned to the project, the designation of each unit of weather modification apparatus, and at least the...

47 CFR 90.135 - Modification of license.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MOBILE RADIO SERVICES Applications and Authorizations § 90.135 Modification of license. (a) In addition... below 470 or above 800 MHz meeting the requirements of § 90.119(b). (2) Change in the number of mobile..., licensees must submit a Form 601 application for modification to the applicable frequency coordinator for...

7 CFR 625.13 - Modification of the HFRP restoration plan.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Modification of the HFRP restoration plan. 625.13... CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES HEALTHY FORESTS RESERVE PROGRAM § 625.13 Modification of the HFRP restoration plan. Consistent with the easement and applicable law, the State...

22 CFR 126.2 - Temporary suspension or modification of this subchapter.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

22 CFR 126.2 - Temporary suspension or modification of this subchapter.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

22 CFR 126.2 - Temporary suspension or modification of this subchapter.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

22 CFR 126.2 - Temporary suspension or modification of this subchapter.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Temporary suspension or modification of this subchapter. 126.2 Section 126.2 Foreign Relations DEPARTMENT OF STATE INTERNATIONAL TRAFFIC IN ARMS REGULATIONS GENERAL POLICIES AND PROVISIONS § 126.2 Temporary suspension or modification of this subchapter...

78 FR 3367 - Modification of Regulation Regarding the Extension of Time Limits

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-16

...-2747-01] RIN 0625-AA94 Modification of Regulation Regarding the Extension of Time Limits AGENCY: Import... the extension of time limits for submissions in antidumping (AD) and countervailing duty (CVD) proceedings. The modification, if adopted, will clarify that parties may request an extension of time limits...

The effect of polymer surface modification on polymer-protein interaction via interfacial polymerization and hydrophilic polymer grafting

USDA-ARS?s Scientific Manuscript database

Protein membrane separation is prone to fouling on the membrane surface resulting from protein adsorption onto the surface. Surface modification of synthetic membranes is one way to reduce fouling. We investigated surface modification of polyethersulfone (PES) as a way of improving hydrophilicity ...

30 CFR 282.25 - Plan modification.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Plan modification. 282.25 Section 282.25... § 282.25 Plan modification. Approved Delineation, Testing, and Mining Plans may be modified upon the... to modify an approved plan to adjust to changed conditions. If the lessee requests the change, the...

24 CFR 100.203 - Reasonable modifications of existing premises.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Discrimination Because of Handicap § 100.203 Reasonable modifications of existing premises. (a) It shall be unlawful for any person to refuse to permit, at the expense of a handicapped person, reasonable modifications of existing premises, occupied or to be occupied by a handicapped person, if the proposed...

24 CFR 100.203 - Reasonable modifications of existing premises.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Discrimination Because of Handicap § 100.203 Reasonable modifications of existing premises. (a) It shall be unlawful for any person to refuse to permit, at the expense of a handicapped person, reasonable modifications of existing premises, occupied or to be occupied by a handicapped person, if the proposed...

24 CFR 100.203 - Reasonable modifications of existing premises.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Discrimination Because of Handicap § 100.203 Reasonable modifications of existing premises. (a) It shall be unlawful for any person to refuse to permit, at the expense of a handicapped person, reasonable modifications of existing premises, occupied or to be occupied by a handicapped person, if the proposed...

24 CFR 100.203 - Reasonable modifications of existing premises.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Discrimination Because of Handicap § 100.203 Reasonable modifications of existing premises. (a) It shall be unlawful for any person to refuse to permit, at the expense of a handicapped person, reasonable modifications of existing premises, occupied or to be occupied by a handicapped person, if the proposed...

Behavior Modification Revisited: Practical Application for the Reading Teacher.

ERIC Educational Resources Information Center

Lang, Deborah Odom; Lang, William Steve

An informal study examined the impact of a simple behavior modification procedure on the reading habits of second and fifth grade students. Behavior modification theory was pared down to two rules ("reinforce proper behavior" and "reinforce anything close to proper behavior") so that no additional burdens would be placed on…

48 CFR 22.404-6 - Modifications of wage determinations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Modifications of wage... Involving Construction 22.404-6 Modifications of wage determinations. (a) General. (1) The Department of Labor may modify a wage determination to make it current by specifying only the items being changed or...

48 CFR 1422.404-6 - Modifications of wage determinations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Modifications of wage determinations. 1422.404-6 Section 1422.404-6 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Involving Construction 1422.404-6 Modifications of wage determinations. The HCA is authorized to request an...

48 CFR 1322.404-6 - Modification of wage determination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Modification of wage... Involving Construction 1322.404-6 Modification of wage determination. The designee authorized to request an extension beyond 90 days after bid opening from the Department of Labor Administrator, Wage and Hour...

Housing Modifications for Persons Who Are Blind or Visually Impaired.

ERIC Educational Resources Information Center

Cocke, Elizabeth A.

1992-01-01

This paper outlines housing modification issues for both the housing consumer with visual impairments and the builder/remodeler, with emphasis on single-family housing. Suggested modifications are listed for the exterior, entrance, elevator, doors, floors, lighting and the electrical system, windows, room layout and shape, kitchen, and stairs and…

29 CFR 4211.13 - Modifications to the direct attribution method.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Modifications to the direct attribution method. 4211.13... Changes Not Subject to PBGC Approval § 4211.13 Modifications to the direct attribution method. (a) Error in direct attribution method. The unfunded vested benefits allocated to a withdrawing employer under...

Recent Advances in Attention Bias Modification for Substance Addictions

PubMed Central

Zhang, Melvyn Weibin; Ying, Jiang Bo; Song, Guo; Fung, Daniel S. S.; Smith, Helen E.

2018-01-01

Research on attentional bias modification has increased since 2014. A recent meta-analysis demonstrates evidence for bias modification for substance disorders, including alcohol and tobacco use disorders. Several pharmacological trials have shown that pharmacological agents can attenuate and modify such attentional bias. The pharmacological trials that have appeared to date have produced mixed results, which has clinical implications. Developments in Internet and mobile technologies have transformed how attention bias modification is currently being achieved. There remains great potential for further research that examines the efficacy of technology-aided attention bias interventions. PMID:29617325

Alteration of human serum albumin binding properties induced by modifications: A review

NASA Astrophysics Data System (ADS)

Maciążek-Jurczyk, Małgorzata; Szkudlarek, Agnieszka; Chudzik, Mariola; Pożycka, Jadwiga; Sułkowska, Anna

2018-01-01

Albumin, a major transporting protein in the blood, is the main target of modification that affects the binding of drugs to Sudlow's site I and II. These modification of serum protein moderates its physiological function, and works as a biomarker of some diseases. The main goal of the paper was to explain the possible alteration of human serum albumin binding properties induced by modifications such as glycation, oxidation and ageing, their origin, methods of evaluation and positive and negative meaning described by significant researchers.

ChIP-Seq Analysis for Identifying Genome-Wide Histone Modifications Associated with Stress-Responsive Genes in Plants.

PubMed

Li, Guosheng; Jagadeeswaran, Guru; Mort, Andrew; Sunkar, Ramanjulu

2017-01-01

Histone modifications represent the crux of epigenetic gene regulation essential for most biological processes including abiotic stress responses in plants. Thus, identification of histone modifications at the genome-scale can provide clues for how some genes are 'turned-on' while some others are "turned-off" in response to stress. This chapter details a step-by-step protocol for identifying genome-wide histone modifications associated with stress-responsive gene regulation using chromatin immunoprecipitation (ChIP) followed by sequencing of the DNA (ChIP-seq).

Detecting Chemically Modified DNA Bases Using Surface Enhanced Raman Spectroscopy

PubMed Central

Barhoumi, Aoune; Halas, Naomi J.

2013-01-01

Post-translational modifications of DNA- changes in the chemical structure of individual bases that occur without changes in the DNA sequence- are known to alter gene expression. They are believed to result in frequently deleterious phenotypic changes, such as cancer. Methylation of adenine, methylation and hydroxymethylation of cytosine, and guanine oxidation are the primary DNA base modifications identified to date. Here we show it is possible to use surface enhanced Raman spectroscopy (SERS) to detect these primary DNA base modifications. SERS detection of modified DNA bases is label-free and requires minimal additional sample preparation, reducing the possibility of additional chemical modifications induced prior to measurement. This approach shows the feasibility of DNA base modification assessment as a potentially routine analysis that may be further developed for clinical diagnostics. PMID:24427449

Detecting Chemically Modified DNA Bases Using Surface Enhanced Raman Spectroscopy.

PubMed

Barhoumi, Aoune; Halas, Naomi J

2011-12-15

Post-translational modifications of DNA- changes in the chemical structure of individual bases that occur without changes in the DNA sequence- are known to alter gene expression. They are believed to result in frequently deleterious phenotypic changes, such as cancer. Methylation of adenine, methylation and hydroxymethylation of cytosine, and guanine oxidation are the primary DNA base modifications identified to date. Here we show it is possible to use surface enhanced Raman spectroscopy (SERS) to detect these primary DNA base modifications. SERS detection of modified DNA bases is label-free and requires minimal additional sample preparation, reducing the possibility of additional chemical modifications induced prior to measurement. This approach shows the feasibility of DNA base modification assessment as a potentially routine analysis that may be further developed for clinical diagnostics.

Effects of wing modification on an aircraft's aerodynamic parameters as determined from flight data

NASA Technical Reports Server (NTRS)

Hess, R. A.

1986-01-01

A study of the effects of four wing-leading-edge modifications on a general aviation aircraft's stability and control parameters is presented. Flight data from the basic aircraft configuration and configurations with wing modifications are analyzed to determine each wing geometry's stability and control parameters. The parameter estimates and aerodynamic model forms are obtained using the stepwise regression and maximum likelihood techniques. The resulting parameter estimates and aerodynamic models are verified using vortex-lattice theory and by analysis of each model's ability to predict aircraft behavior. Comparisons of the stability and control derivative estimates from the basic wing and the four leading-edge modifications are accomplished so that the effects of each modification on aircraft stability and control derivatives can be determined.

Efficient reanalysis of structures by a direct modification method. [local stiffness modifications of large structures

NASA Technical Reports Server (NTRS)

Raibstein, A. I.; Kalev, I.; Pipano, A.

1976-01-01

A procedure for the local stiffness modifications of large structures is described. It enables structural modifications without an a priori definition of the changes in the original structure and without loss of efficiency due to multiple loading conditions. The solution procedure, implemented in NASTRAN, involved the decomposed stiffness matrix and the displacement vectors of the original structure. It solves the modified structure exactly, irrespective of the magnitude of the stiffness changes. In order to investigate the efficiency of the present procedure and to test its applicability within a design environment, several real and large structures were solved. The results of the efficiency studies indicate that the break-even point of the procedure varies between 8% and 60% stiffness modifications, depending upon the structure's characteristics and the options employed.

Clients' experiences of a community based lifestyle modification program: a qualitative study.

PubMed

Chan, Ruth S M; Lok, Kris Y W; Sea, Mandy M M; Woo, Jean

2009-10-01

There is little information about how clients attending lifestyle modification programs view the outcomes. This qualitative study examined the clients' experience of a community based lifestyle modification program in Hong Kong. Semi-structured interviews were conducted with 25 clients attending the program. Clients perceived the program had positive impacts on their health and nutrition knowledge. They experienced frustration, negative emotion, lack of motivation, and pressure from others during the program. Working environment and lack of healthy food choices in restaurants were the major perceived environmental barriers for lifestyle modification. Clients valued nutritionists' capability of providing professional information and psychological support in the program. Our results suggest that nutritionist's capability of providing quality consultations and patient-centered care are important for empowering clients achieve lifestyle modification.

Simultaneous Sterilization With Surface Modification Of Plastic Bottle By Plasma-Based Ion Implantation

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

Sakudo, N.; Ikenaga, N.; Ikeda, F.

2011-01-07

Dry sterilization of polymeric material is developed. The technique utilizes the plasma-based ion implantation which is same as for surface modification of polymers. Experimental data for sterilization are obtained by using spores of Bacillus subtilis as samples. On the other hand we previously showed that the surface modification enhanced the gas barrier characteristics of plastic bottles. Comparing the implantation conditions for the sterilization experiment with those for the surface modification, we find that both sterilization and surface modification are simultaneously performed in a certain range of implantation conditions. This implies that the present bottling system for plastic vessels will bemore » simplified and streamlined by excluding the toxic peroxide water that has been used in the traditional sterilization processes.« less

Factors affecting caregivers' ability to make environmental modifications.

PubMed

Messecar, D C

2000-12-01

This study explored factors that family caregivers described as affecting their ability to use environmental modifications. Intensive interviews and participant observation were used to collect detailed data from 24 primary family caregivers. Several factors that affect the caregivers' ability to implement modification strategies were identified in the analysis. These factors included attributes of the elderly individual, attributes of the modification, quality of the caregiver-elderly relationship, caregivers' skills, personal resources of the caregiver, and the informal and formal supports available. Of these factors, the most important were the salient skills that caregivers need to implement environmental modifications. These findings point to the importance of caregivers receiving skills training in this important dimension of caregiving. Intervention should be based on a collaborative approach that ensures the caregiver and care receiver's needs and preferences are respected.

Influence of shifting positions of Ser, Thr, and Cys residues in prenisin on the efficiency of modification reactions and on the antimicrobial activities of the modified prepeptides.

PubMed

Lubelski, Jacek; Overkamp, Wout; Kluskens, Leon D; Moll, Gert N; Kuipers, Oscar P

2008-08-01

Since the recent discovery that the nisin modification and transport machinery can be used to produce and modify peptides unrelated to nisin, specific questions arose concerning the specificity of the modification enzymes involved and the limits of their promiscuity with respect to the dehydration and cyclization processes. The nisin leader peptide has been postulated to fulfill a recognition and binding function required for these modifications. Here, we investigated whether the relative positions of the modifiable residues in the nisin prepeptide, with respect to the leader peptide, could influence the efficiency of their modification. We conducted a systematic study on the insertion of one to four alanines in front of either ring A or ring D to change the "reading frame" of modifiable residues, resulting in altered distance and topology of the modifiable residues relative to the leader. The insertion of N-terminal and hinge-located Ala residues had only a modest influence on the modification efficiency, demonstrating that the "phasing" of these residues relative to the leader peptide is not a critical factor in determining modification. However, in all cases, but especially with the N-terminal insertions, the antimicrobial activities of the fully modified nisin species were decreased.

Long-term drug modification to the surface of mesenchymal stem cells by the avidin-biotin complex method.

PubMed

Takayama, Yukiya; Kusamori, Kosuke; Hayashi, Mika; Tanabe, Noriko; Matsuura, Satoru; Tsujimura, Mari; Katsumi, Hidemasa; Sakane, Toshiyasu; Nishikawa, Makiya; Yamamoto, Akira

2017-12-05

Mesenchymal stem cells (MSCs) have various functions, making a significant contribution to tissue repair. On the other hand, the viability and function of MSCs are not lasting after an in vivo transplant, and the therapeutic effects of MSCs are limited. Although various chemical modification methods have been applied to MSCs to improve their viability and function, most of conventional drug modification methods are short-term and unstable and cause cytotoxicity. In this study, we developed a method for long-term drug modification to C3H10T1/2 cells, murine mesenchymal stem cells, without any damage, using the avidin-biotin complex method (ABC method). The modification of NanoLuc luciferase (Nluc), a reporter protein, to C3H10T1/2 cells by the ABC method lasted for at least 14 days in vitro without major effects on the cellular characteristics (cell viability, cell proliferation, migration ability, and differentiation ability). Moreover, in vivo, the surface Nluc modification to C3H10T1/2 cells by the ABC method lasted for at least 7 days. Therefore, these results indicate that the ABC method may be useful for long-term surface modification of drugs and for effective MSC-based therapy.

New concepts in ionospheric modification. Final report, 15 April 1986-30 September 1987

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

Banks, P.M.; Fraser-Smith, A.C.; Gilchrist, B.E.

1987-04-01

This report considers the ionospheric modification that can be produced by energetic charged-particle and photon beams, which are emitted from a platform or vehicle (spacecraft or rockets) located in the ionosphere. The various beams considered include (1) charged-particle beams composed of low-, moderate-, and high-energy electrons, (2) beams of ions and plasma, and (3) photon beams of soft x rays and extreme-ultraviolet radiation. Briefly considered, in addition to the beam topics, is the ionospheric modification produced by the release of neutral gas of high molecular weight from a rapidly moving vehicle such as the Space Shuttle Orbiter. When a rankingmore » is made in terms of the new information that may be obtained, the scale of the modification that may be produced, and the availability of beam sources, ionospheric modification by means of relativistic electron beams appears particularly promising. However, all the methods have their own distinctive features that could make their use desirable under particular circumstances. The modification produced by means of beams of soft x rays, for example, is not strongly dependent on the beam's direction relative to the earth's magnetic field, and thus modification can be produced in regions inaccessible to a charged-particle beam from the same vehicle.« less

Hypoxia-induced oxidative base modifications in the VEGF hypoxia-response element are associated with transcriptionally active nucleosomes.

PubMed

Ruchko, Mykhaylo V; Gorodnya, Olena M; Pastukh, Viktor M; Swiger, Brad M; Middleton, Natavia S; Wilson, Glenn L; Gillespie, Mark N

2009-02-01

Reactive oxygen species (ROS) generated in hypoxic pulmonary artery endothelial cells cause transient oxidative base modifications in the hypoxia-response element (HRE) of the VEGF gene that bear a conspicuous relationship to induction of VEGF mRNA expression (K.A. Ziel et al., FASEB J. 19, 387-394, 2005). If such base modifications are indeed linked to transcriptional regulation, then they should be detected in HRE sequences associated with transcriptionally active nucleosomes. Southern blot analysis of the VEGF HRE associated with nucleosome fractions prepared by micrococcal nuclease digestion indicated that hypoxia redistributed some HRE sequences from multinucleosomes to transcriptionally active mono- and dinucleosome fractions. A simple PCR method revealed that VEGF HRE sequences harboring oxidative base modifications were found exclusively in mononucleosomes. Inhibition of hypoxia-induced ROS generation with myxathiozol prevented formation of oxidative base modifications but not the redistribution of HRE sequences into mono- and dinucleosome fractions. The histone deacetylase inhibitor trichostatin A caused retention of HRE sequences in compacted nucleosome fractions and prevented formation of oxidative base modifications. These findings suggest that the hypoxia-induced oxidant stress directed at the VEGF HRE requires the sequence to be repositioned into mononucleosomes and support the prospect that oxidative modifications in this sequence are an important step in transcriptional activation.

Trophic interaction modifications: an empirical and theoretical framework.

PubMed

Terry, J Christopher D; Morris, Rebecca J; Bonsall, Michael B

2017-10-01

Consumer-resource interactions are often influenced by other species in the community. At present these 'trophic interaction modifications' are rarely included in ecological models despite demonstrations that they can drive system dynamics. Here, we advocate and extend an approach that has the potential to unite and represent this key group of non-trophic interactions by emphasising the change to trophic interactions induced by modifying species. We highlight the opportunities this approach brings in comparison to frameworks that coerce trophic interaction modifications into pairwise relationships. To establish common frames of reference and explore the value of the approach, we set out a range of metrics for the 'strength' of an interaction modification which incorporate increasing levels of contextual information about the system. Through demonstrations in three-species model systems, we establish that these metrics capture complimentary aspects of interaction modifications. We show how the approach can be used in a range of empirical contexts; we identify as specific gaps in current understanding experiments with multiple levels of modifier species and the distributions of modifications in networks. The trophic interaction modification approach we propose can motivate and unite empirical and theoretical studies of system dynamics, providing a route to confront ecological complexity. © 2017 The Authors. Ecology Letters published by CNRS and John Wiley & Sons Ltd.

A Kantian argument against comparatively advantageous genetic modification.

PubMed

Jensen, David

2011-08-01

The genetic modification of children is becoming a more likely possibility given our rapid progress in medical technologies. I argue, from a broadly Kantian point of view, that at least one kind of such modification-modification by a parent for the sake of a child's comparative advantage-is not rationally justified. To argue this, I first characterize a necessary condition on reasons and rational justification: what is a reason for an agent to do an action in one set of circumstances must be a reason for any in those circumstances to do the action. I then show that comparatively advantageous genetic modification violates this principle since a child's "getting ahead" through genetic modification cannot be rationally justified unless other children also could receive the modification, thus rendering the advantage useless. Finally, I consider the major objection to this it seems to disallow all cases of a parent's helping a child get ahead, something that parents normally engage in with their children. I argue that typical practices of developing a comparative advantage in a child, as well as practices of societal competition in general, do not conflict because they involve circumstances that mitigate the universal character of reasons. Many ordinary cases of competitive advantage that we think of as unjust, in fact, can be explained by my argument.

Regulation of alternative splicing by local histone modifications: potential roles for RNA-guided mechanisms

PubMed Central

Zhou, Hua-Lin; Luo, Guangbin; Wise, Jo Ann; Lou, Hua

2014-01-01

The molecular mechanisms through which alternative splicing and histone modifications regulate gene expression are now understood in considerable detail. Here, we discuss recent studies that connect these two previously separate avenues of investigation, beginning with the unexpected discoveries that nucleosomes are preferentially positioned over exons and DNA methylation and certain histone modifications also show exonic enrichment. These findings have profound implications linking chromatin structure, histone modification and splicing regulation. Complementary single gene studies provided insight into the mechanisms through which DNA methylation and histones modifications modulate alternative splicing patterns. Here, we review an emerging theme resulting from these studies: RNA-guided mechanisms integrating chromatin modification and splicing. Several groundbreaking papers reported that small noncoding RNAs affect alternative exon usage by targeting histone methyltransferase complexes to form localized facultative heterochromatin. More recent studies provided evidence that pre-messenger RNA itself can serve as a guide to enable precise alternative splicing regulation via local recruitment of histone-modifying enzymes, and emerging evidence points to a similar role for long noncoding RNAs. An exciting challenge for the future is to understand the impact of local modulation of transcription elongation rates on the dynamic interplay between histone modifications, alternative splicing and other processes occurring on chromatin. PMID:24081581

Performance of activities of daily living in a sample of applicants for home modification services.

PubMed

Johansson, Karin; Lilja, Margareta; Petersson, Ingela; Borell, Lena

2007-01-01

Home modification services are provided to support persons with functional limitations to live independently at home. It is not well known what causes individuals to apply for home modifications, or in what kind of life situation this need appears. The aim of this study was to examine the relationship between performance of activities of daily living, housing and living situation, and the home modification applied for in a sample of home modification applicants. Further, the aim was to examine differences in performance of activities of daily living between subgroups with different social support. A total of 102 participants were included in the study. Data on performance of activities of daily living was collected through interviews in the participants' homes, using structured instruments. The participants reported high levels of independence in activities of daily living, and were using assistive devices to a large extent. However, the applicants clearly experienced difficulties in performing activities related to the applied home modification. The study indicates that the main reason for applying for Home Modification Grants was perceived difficulties in performance of activities of daily living. This stresses the importance of including other aspects besides independence when trying to understand persons' activity performance and planning for occupational therapy interventions.

Ubiquitin modifications

PubMed Central

Swatek, Kirby N; Komander, David

2016-01-01

Protein ubiquitination is a dynamic multifaceted post-translational modification involved in nearly all aspects of eukaryotic biology. Once attached to a substrate, the 76-amino acid protein ubiquitin is subjected to further modifications, creating a multitude of distinct signals with distinct cellular outcomes, referred to as the 'ubiquitin code'. Ubiquitin can be ubiquitinated on seven lysine (Lys) residues or on the N-terminus, leading to polyubiquitin chains that can encompass complex topologies. Alternatively or in addition, ubiquitin Lys residues can be modified by ubiquitin-like molecules (such as SUMO or NEDD8). Finally, ubiquitin can also be acetylated on Lys, or phosphorylated on Ser, Thr or Tyr residues, and each modification has the potential to dramatically alter the signaling outcome. While the number of distinctly modified ubiquitin species in cells is mind-boggling, much progress has been made to characterize the roles of distinct ubiquitin modifications, and many enzymes and receptors have been identified that create, recognize or remove these ubiquitin modifications. We here provide an overview of the various ubiquitin modifications present in cells, and highlight recent progress on ubiquitin chain biology. We then discuss the recent findings in the field of ubiquitin acetylation and phosphorylation, with a focus on Ser65-phosphorylation and its role in mitophagy and Parkin activation. PMID:27012465

Analysis by oxygen atom number density measurement of high-speed hydrophilic treatment of polyimide using atmospheric pressure microwave plasma

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

Ono, S.

2015-03-30

This paper describes the fundamental experimental data of the plasma surface modification of the polyimide using atmospheric pressure microwave plasma source. The experimental results were discussed from the point of view of the radical’s behavior, which significantly affects the modification mechanism. The purpose of the study is to examine how the value of the oxygen atom density will affect the hydrophilic treatment in the upstream region of the plasma where gas temperature is very high. The surface modification experiments were performed by setting the polyimide film sample in the downstream region of the plasma. The degree of the modification wasmore » measured by a water contact angle measurement. The water contact angle decreased less than 30 degrees within 1 second treatment time in the upstream region. Very high speed modification was observed. The reason of this high speed modification seems that the high density radical which contributes the surface modification exist in the upstream region of the plasma. This tendency is supposed to the measured relatively high electron density (~10{sup 15}cm{sup −3}) at the center of the plasma. We used the electric heating catalytic probe method for oxygen radical measurement. An absolute value of oxygen radical density was determined by catalytic probe measurement and the results show that ~10{sup 15}cm{sup −3} of the oxygen radical density in the upstream region and decreases toward downstream region. The experimental results of the relation of the oxygen radical density and hydrophilic modification of polyimide was discussed.« less

Loss of a Conserved tRNA Anticodon Modification Perturbs Plant Immunity

PubMed Central

López, Ana; Castelló, María José; Gil, María José; Zheng, Bo; Chen, Peng; Vera, Pablo

2015-01-01

tRNA is the most highly modified class of RNA species, and modifications are found in tRNAs from all organisms that have been examined. Despite their vastly different chemical structures and their presence in different tRNAs, occurring in different locations in tRNA, the biosynthetic pathways of the majority of tRNA modifications include a methylation step(s). Recent discoveries have revealed unprecedented complexity in the modification patterns of tRNA, their regulation and function, suggesting that each modified nucleoside in tRNA may have its own specific function. However, in plants, our knowledge on the role of individual tRNA modifications and how they are regulated is very limited. In a genetic screen designed to identify factors regulating disease resistance and activation of defenses in Arabidopsis, we identified SUPPRESSOR OF CSB3 9 (SCS9). Our results reveal SCS9 encodes a tRNA methyltransferase that mediates the 2´-O-ribose methylation of selected tRNA species in the anticodon loop. These SCS9-mediated tRNA modifications enhance during the course of infection with the bacterial pathogen Pseudomonas syringae DC3000, and lack of such tRNA modification, as observed in scs9 mutants, severely compromise plant immunity against the same pathogen without affecting the salicylic acid (SA) signaling pathway which regulates plant immune responses. Our results support a model that gives importance to the control of certain tRNA modifications for mounting an effective immune response in Arabidopsis, and therefore expands the repertoire of molecular components essential for an efficient disease resistance response. PMID:26492405

The impact of metformin, oral contraceptives, and lifestyle modification on polycystic ovary syndrome in obese adolescent women in two randomized, placebo-controlled clinical trials.

PubMed

Hoeger, Kathleen; Davidson, Kristen; Kochman, Lynda; Cherry, Tracy; Kopin, Laurie; Guzick, David S

2008-11-01

Polycystic ovary syndrome (PCOS) presents in adolescence, and obesity is a common finding. The benefits and risks of alternate approaches to the management of PCOS in obese adolescent women are not clear. We investigated the effects of metformin, oral contraceptives (OCs), and/or lifestyle modification in obese adolescent women with PCOS. Two small, randomized, placebo-controlled clinical trials were performed. A total of 79 obese adolescent women with PCOS participated. In the single treatment trial, subjects were randomized to metformin, placebo, a lifestyle modification program, or OC. In the combined treatment trial, all subjects received lifestyle modification and OC and were randomized to metformin or placebo. Serum concentrations of androgens and lipids were measured. Lifestyle modification alone resulted in a 59% reduction in free androgen index with a 122% increase in SHBG. OC resulted in a significant decrease in total testosterone (44%) and free androgen index (86%) but also resulted in an increase in C-reactive protein (39.7%) and cholesterol (14%). The combination of lifestyle modification, OC, and metformin resulted in a 55% decrease in total testosterone, as compared to 33% with combined treatment and placebo, a 4% reduction in waist circumference, and a significant increase in HDL (46%). In these preliminary trials, both lifestyle modification and OCs significantly reduce androgens and increase SHBG in obese adolescents with PCOS. Metformin, in combination with lifestyle modification and OC, reduces central adiposity, reduces total testosterone, and increases HDL, but does not enhance overall weight reduction.

Immediate effects of a distal gait modification during stair descent in individuals with patellofemoral pain.

PubMed

Aliberti, Sandra; Mezêncio, Bruno; Amadio, Alberto Carlos; Serrão, Julio Cerca; Mochizuki, Luis

2018-05-23

Knee pain during stair managing is a common complaint among individuals with PFP and can negatively affect their activities of daily living. Gait modification programs can be used to decrease patellofemoral pain. Immediate effects of a stair descent distal gait modification session that intended to emphasize forefoot landing during stair descent are described in this study. To analyze the immediate effects of a distal gait modification session on lower extremity movements and intensity of pain in women with patellofemoral pain during stair descent. Nonrandomized controlled trial. Sixteen women with patellofemoral pain were allocated into two groups: (1) Gait Modification Group (n = 8); and 2) Control Group (n = 8). The intensity of pain (visual analog scale) and kinematics of knee, ankle, and forefoot (multi-segmental foot model) during stair descent were assessed before and after the intervention. After the gait modification session, there was an increase of forefoot eversion and ankle plantarflexion as well as a decrease of knee flexion. An immediate decrease in patellofemoral pain intensity during stair descent was also observed. The distal gait modification session changed the lower extremity kinetic chain strategy of movement, increasing foot and ankle movement contribution and decreasing knee contribution to the task. An immediate decrease in patellofemoral pain intensity during stair descent was also observed. To emphasize forefoot landing may be a useful intervention to immediately relieve pain in patients with patellofemoral pain during stair descent. Clinical studies are needed to verify the gait modification session effects in medium and long terms.

Muscle force modification strategies are not consistent for gait retraining to reduce the knee adduction moment in individuals with knee osteoarthritis.

PubMed

Shull, Peter B; Huang, Yangjian; Schlotman, Taylor; Reinbolt, Jeffrey A

2015-09-18

While gait retraining paradigms that alter knee loads typically focus on modifying kinematics, the underlying muscle force modifications responsible for these kinematic changes remain largely unknown. As humans are generally thought to select uniform gait muscle patterns such as strategies based on fatigue cost functions or energy minimization, we hypothesized that a kinematic gait change known to reduce the knee adduction moment (i.e. toe-in gait) would be accompanied by a uniform muscle force modification strategy for individuals with symptomatic knee osteoarthritis. Ten subjects with self-reported knee pain and radiographic evidence of medial compartment knee osteoarthritis performed normal gait and toe-in gait modification walking trials. Two hundred muscle-actuated dynamic simulations (10 steps for normal gait and 10 steps from toe-in gait for each subject) were performed to determine muscle forces for each gait. Results showed that subjects internally rotated their feet during toe-in gait, which decreased the foot progression angle by 7° (p<0.01) and reduced the first peak knee adduction moment by 20% (p<0.01). While significant muscle force modifications were evidenced within individuals, there were no consistent muscle force modifications across all subjects. It may be that self-selected muscle pattern changes are not uniform for gait modification particularly for individuals with knee pain. Future studies focused on altering knee loads should not assume consistent muscle force modifications for a given kinematic gait change across subjects and should consider muscle forces in addition to kinematics in gait retraining paradigms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ball with hair: modular functionalization of highly stable G-quadruplex DNA nano-scaffolds through N2-guanine modification.

PubMed

Lech, Christopher Jacques; Phan, Anh Tuân

2017-06-20

Functionalized nanoparticles have seen valuable applications, particularly in the delivery of therapeutic and diagnostic agents in biological systems. However, the manufacturing of such nano-scale systems with the consistency required for biological application can be challenging, as variation in size and shape have large influences in nanoparticle behavior in vivo. We report on the development of a versatile nano-scaffold based on the modular functionalization of a DNA G-quadruplex. DNA sequences are functionalized in a modular fashion using well-established phosphoramidite chemical synthesis with nucleotides containing modification of the amino (N2) position of the guanine base. In physiological conditions, these sequences fold into well-defined G-quadruplex structures. The resulting DNA nano-scaffolds are thermally stable, consistent in size, and functionalized in a manner that allows for control over the density and relative orientation of functional chemistries on the nano-scaffold surface. Various chemistries including small modifications (N2-methyl-guanine), bulky aromatic modifications (N2-benzyl-guanine), and long chain-like modifications (N2-6-amino-hexyl-guanine) are tested and are found to be generally compatible with G-quadruplex formation. Furthermore, these modifications stabilize the G-quadruplex scaffold by 2.0-13.3 °C per modification in the melting temperature, with concurrent modifications producing extremely stable nano-scaffolds. We demonstrate the potential of this approach by functionalizing nano-scaffolds for use within the biotin-avidin conjugation approach. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.