Academic literature on the topic 'Initial susceptibility'
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Journal articles on the topic "Initial susceptibility"
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Gonzalez, J. M., G. R. Aranda, J. Gonzalez, O. A. Chubykalo, and Byron Lengsfield. "Transverse biased initial susceptibility:." Journal of Magnetism and Magnetic Materials 226-230 (May 2001): 1203–5. http://dx.doi.org/10.1016/s0304-8853(01)00021-x.
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Klik, I., and Y. D. Yao. "Initial susceptibility of noninteracting particulate media." Journal of Magnetism and Magnetic Materials 186, no. 1-2 (July 1998): 233–38. http://dx.doi.org/10.1016/s0304-8853(97)01143-8.
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Chantrell, R. W., N. S. Walmsley, J. Gore, and M. Maylin. "Initial susceptibility of interacting fine particles." Journal of Magnetism and Magnetic Materials 196-197 (May 1999): 118–19. http://dx.doi.org/10.1016/s0304-8853(98)00683-0.
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Swartzendruber, L. J., L. H. Bennett, and H. Ettedgui. "Initial susceptibility studies of rapidly solidified monel." Journal of Applied Physics 61, no. 8 (April 15, 1987): 3991–93. http://dx.doi.org/10.1063/1.338555.
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Aharoni, Amikam. "Enhanced initial susceptibility in small amorphous disks." Applied Physics Letters 78, no. 4 (January 22, 2001): 504–5. http://dx.doi.org/10.1063/1.1342052.
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Ayoub, N. Y., N. Laham, J. Popplewell, and R. W. Chantrell. "Initial susceptibility of a textured fine particle system." Journal of Applied Physics 61, no. 8 (April 15, 1987): 3305–7. http://dx.doi.org/10.1063/1.338939.
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Akisheva, A. V., and E. S. Pyanzina. "Initial Susceptibility in Systems of Magnetic Ellipsoidal Nanoparticles." Physics of the Solid State 62, no. 9 (September 2020): 1685–90. http://dx.doi.org/10.1134/s1063783420090024.
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Aranda, G. R., O. A. Chubykalo, J. González, J. M. González, and B. Lengsfield. "Micromagnetic simulation of transverse biased initial susceptibility measurements." Physica B: Condensed Matter 299, no. 3-4 (June 2001): 205–14. http://dx.doi.org/10.1016/s0921-4526(01)00467-7.
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Bhosale, D. N., V. M. S. Verenkar, K. S. Rane, P. P. Bakare, and S. R. Sawant. "Initial susceptibility studies on Cu-Mg-Zn ferrites." Materials Chemistry and Physics 59, no. 1 (April 1999): 57–62. http://dx.doi.org/10.1016/s0254-0584(99)00028-0.
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Bouchaud, J. P., and P. G. Zerah. "The initial susceptibility of ferrites: A quantitative theory." Journal of Applied Physics 67, no. 9 (May 1990): 5512–14. http://dx.doi.org/10.1063/1.345868.
Full textDissertations / Theses on the topic "Initial susceptibility"
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Sivathayalan, Sivapathasundaram. "Fabric, initial state and stress path effects on liquefaction susceptibility of sands." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0017/NQ56623.pdf.
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Gibbens, Clem Alexander Molloy. "The Use of the Multi-channel Analysis of Surface Waves (MASW) Method as an Initial Estimator of Liquefaction Susceptibility in Greymouth, New Zealand." Thesis, University of Canterbury. Geological Sciences, 2014. http://hdl.handle.net/10092/10244.
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Combined analysis of the geomorphic evolution of Greymouth with Multi-channel Analysis of Surface Waves (MASW) provides new insight into the geotechnical implications of reclamation work.
The MASW method utilises the frequency dependent velocity (dispersion) of planar Rayleigh waves created by a seismic source as a way of assessing the stiffness of the subsurface material. The surface wave is inverted to calculate a shear wave velocity (Park et al., 1999). Once corrected, these shear-wave (Vs) velocities can be used to obtain a factor of safety for liquefaction susceptibility based on a design earthquake.
The primary study site was the township of Greymouth, on the West Coast of New Zealand’s South Island. Greymouth is built on geologically young (Holocene-age) deposits of beach and river sands and gravels, and estuarine and lagoonal silts (Dowrick et al., 2004). Greymouth is also in a tectonically active region, with the high seismic hazard imposed by the Alpine Fault and other nearby faults, along with the age and type of sediment, mean the probability of liquefaction occurring is high particularly for the low-lying areas around the estuary and coastline. Repeated mapping over 150 years shows that the geomorphology of the Greymouth Township has been heavily modified during that timeframe, with both anthropogenic and natural processes developing the land into its current form. Identification of changes in the landscape was based on historical maps for the area and interpreting them to be either anthropogenic or natural changes, such as reclamation work or removal of material through natural events.
This study focuses on the effect that anthropogenic and natural geomorphic processes have on the stiffness of subsurface material and its liquefaction susceptibility for three different design earthquake events. Areas of natural ground and areas of reclaimed land, with differing ages, were investigated through the use of the MASW method, allowing an initial estimation of the relationship between landscape modification and liquefaction susceptibility. The susceptibility to liquefaction of these different materials is important to critical infrastructure, such as the St. John Ambulance Building and Greymouth Aerodrome, which must remain functional following an earthquake. Areas of early reclamation at the Greymouth Aerodrome site have factors of safety less than 1 and will liquefy in most plausible earthquake scenarios, although the majority of the runway has a high factor of safety and should resist liquefaction. The land west of the St. John’s building has slightly to moderately positive factors of safety. Other areas have factors of safety that reflect the different geology and reclamation history.
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Mehdaoui, Ahmed. "Caractérisation de supraconducteurs haute température critique par susceptibilité initiale dans la limite des champs magnétiques faibles : relation entre champs critiques dynamiques et homogénéité." Mulhouse, 1991. http://www.theses.fr/1991MULH0174.
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Le travail présenté dans cette thèse a pour but de préciser le rôle des processus de fabrication, des traitements thermiques, de la morphologie et de la composition dans l'aspect final d'une transition supraconductrice telle qu'elle apparaît dans une mesure de susceptibilité. Les résultats obtenus, tant pour la partie réelle c que pour la partie imaginaire c de la susceptibilité initiale c=c’+ic’’, complétés par des données bibliographiques, ont permis de proposer un modèle phénoménologique qui autorise une comparaison de la qualité (en termes d'homogénéité) par la détermination du champ critique dynamique hc*. Le champ critique dynamique hc* permet une classification très générale, applicable non seulement aux différentes classes de supraconducteurs haute température (YBaCuO, LaBaCuO, Bi(Pb)SrCaCuO, T*, etc. . . ), mais également aux supraconducteurs classiques basse température tels que les phases de Chevrel. Cette étude met également en évidence les contributions intragranulaires et intergranulaires dans les échantillons polycristallins, et montre une similitude de qualité entre le matériau intragrain et un monocristal : tous deux présentent les champs critiques dynamiques hc* les plus élevés. Par ailleurs, la grande dispersion de qualité des échantillons polycristallins, observée au sein même d'un type donné de composés, reflète l'influence et l'importance du processus de fabrication et du traitement thermique. En particulier, les champs critiques dynamiques les plus faibles et donc les plus grandes inhomogénéités sont toujours le fait d'échantillons obtenus par une technique de frittage. Enfin, l'étude des composés à base de bismuth confirme le comportement très particulier de ce type de céramiques supraconductrices qui présentent un ancrage des vortex (flux-pinning) extrêmement faible, voire inexistant
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Darrigan, Clovis. "Calcul quantique de susceptibilités électriques dans les solides cristallins." Pau, 2001. http://www.theses.fr/2001PAUU3029.
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A la frontiere entre la chimie et la physique, ce travail s'inscrit dans l'etude theorique des proprietes electroniques et optiques de solides cristallins et la comprehension des phenomenes induits par une perturbation electrique exterieure. Notre approche theorique de la matiere est celle des chimistes quanticiens : bases atomiques localisees, orbitales cristallines (oc) construites selon la methode self consistent field (scf) par combinaison lineaire d'orbitales atomiques (lcao) en tenant compte de la symetrie translationnelle. La prevision des comportements de la matiere face a un champ electrique statique (frequence nulle) ou dynamique (frequence non-nulle) passe par l'elaboration de modeles theoriques conduisant aux susceptibilites electriques. Si la perturbation appliquee est faible, la reponse du cristal reste lineaire, nous parlons alors de susceptibilite lineaire (polarisabilite) et des proprietes connexes (constante dielectrique, indice de refraction, reflectivite, fonction de perte d'energie). Les termes d'ordres superieurs, appeles susceptibilites non-lineaires (hyperpolarisabilites), nous conduisent aux phenomenes non-lineaires : generation d'harmoniques, rectification optique, effets pockel, kerr. . . Deux methodes differentes ont ete developpees : 1. Methode couplee (cp), qui inclut analytiquement le potentiel electrique au sein meme du hamiltonien, ou les oc sont relaxees durant le processus scf. Le logiciel crystal98 a ete modifie en consequence. Deux systemes (mgo et lif) ont ete etudies, conduisant a de bonnes valeurs theoriques. 2. Methode non-couplee (uc) sum over states (sos), tenant compte de la frequence du champ perturbateur. Les expressions developpees et generales pour differents ordres sont explicitees. Nous l'appliquons au diamant pour le calcul de la constante dielectrique et la simulation de spectres eels. Des resultats tres encourageants sont obtenus sur le calcul d'effets non-lineaires (shg pour sic, thg pour lif).
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Amzallag, Emilie. "Approche quantique des défauts ponctuels dans les systèmes cristallins : identification et influence sur les propriétés d’optique non linéaire." Pau, 2007. http://www.theses.fr/2007PAUU3030.
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Les recherches actuelles sur les matériaux réels nécessitent une analyse approfondie de leurs propriétés à l’échelle atomique du fait de la présence de défauts (ponctuels, linéaires, de surface ou de volume). Pour l’identification et la caractérisation de ces défauts, la difficulté de la modélisation réside dans la taille du système et la rupture de périodicité occasionnée par la présence du défaut. Au cours de ce travail, deux thèmes principaux ont été abordés à partir d’approches monodéterminantales de type DFT. Le premier concerne la modélisation de différents défauts ponctuels dans le disulfure de titane (TiS2) pour aider à l’interprétation d’images obtenues en microscopie à effet tunnel (STM). Le second est relatif à l’étude théorique des propriétés optiques des systèmes cristallins contenant des défauts en réponse à un champ électrique externe. Dans le cas de TiS2, l’identification de différents défauts ponctuels à la surface de ce composé est basée sur la théorie de Tersoff et Hamman. Les défauts que nous avons envisagés, conformément aux études expérimentales, sont associés à la migration d’un atome de titane vers un site vacant du réseau hexagonal compact des atomes de soufre avec en parallèle la formation d’un défaut lacunaire. En complément de ces travaux, nous avons essayé de simuler le champ local crée par la pointe sur la surface. Concernant les propriétés optiques, il s’agit d’évaluer la capacité de nos méthodes à bien reproduire la réponse optique au premier ordre des systèmes périodiques. Nous avons réalisé une étude sur la fonction de perte d'énergie qui nous a permis de confronter les résultats théoriques aux spectres expérimentaux, tout en essayant d’identifier les transitions électroniques détectées. Enfin, nous nous sommes intéressés à l’étude de l’influence de défauts de substitution sur les propriétés d’optique non linéaires de la silice à partir de la -cristobalite considérée comme un système modèleCurrent researches on real material require a thorough analysis of their properties on an atomic scale because of the presence of defects (point defect, linear, of surface or volume). For the identification and the characterization of these defects, the difficulty of modeling lies in the system size and the rupture of periodicity due to the presence of the defect. During this work, two main themes were approached starting from DFT monodéterminantal approaches. The first one deals with the modelling of different point defects in titanium disulphide (TiS2) to help the interpretation of scanning tunneling microscopy images (STM). The second one is relating to the theoretical study of optical properties of crystalline systems with defects in sesponse to an external electric field. In TiS2 case, identification of various surface defects of this compound is based on the Tersoff and Hamman theory. The defects which we considered, according to experimental studies, are associated with the migration of a titanium atom towards a vacant site of the compact hexagonal structure of sulphur atoms with in parallel the formation of a vacancy. In complement of this work, we tried to simulate the local field created by the tip on the surface. Concerning the optical properties, it is a question of assessing the capacity of our methods to reproduce properly the linear optical response of periodic systems. We made a study on the energy loss function which enabled us to confront the theoretical results with experimental spectra, while trying to identify the detected electronic transitions. Finally, we studied the influence of substitutional defects on the nonlinear optic properties of silica starting from the -cristobalite which is considered as a model system
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Negodaev, Igor. "The calculation of the thermal dependency of the magnetic susceptibility in extended systems with ab initio electronic structure parameters." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/31934.
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La tesi estudia l'acoblament magnètic en sistemes de diferent dimensionalitat amb mètodes multireferencials. L’objectiu principal del treball és calcular propietats macroscòpiques, com la dependència de la susceptibilitat magnètica amb la temperatura, a partir de la constant d'intercanvi magnètic calculada, J. Aquest paràmetre microscòpic quantifica la interacció magnètica entre dos centres i es pot extreure per ajust de la corba de susceptibilitat experimental en sistemes finits però això no és possible en sistemes magnètics infinits com cadenes o capes 2D.
L’estratègia del treball és calcular J en petits clusters i simular els sistemes estesos utilitzant aquesta J en l’Hamiltonià de Heisenberg en models de 8 a 16 centres. Amb l’espectre obtingut es construeixen les corbes de dependència tèrmica de la susceptibilitat magnètica que, comparades amb les experimentals, donen la possibilitat de quantificar les interaccions magnètiques dels materials estudiats a nivell microscòpic.
S'han estudiat diferents tipus de sistemes estesos com cadenes i xarxes hexagonals, on els centres magnètics són ions de metalls de transició.The thesis studies the magnetic coupling in systems of different dimensionality, by using multireference methods. The aim of the work is to determine macroscopic properties such as the thermal dependency of magnetic susceptibility, from the calculated magnetic exchange constant J. This microscopic parameter quantifies the magnetic interaction between two magnetic sites and can be extracted from the experimental susceptibility curve in finite systems. However this extraction is not possible in extended magnetic systems such as chains or 2D-layers. The strategy followed consists in calculating J in small clusters and in simulating the extended systems by introducing the calculated J in the Heisenberg Hamiltonian of 8 to 16 site models. From the spectrum, the thermal dependency of the magnetic susceptibility is the calculated. When compared to the experimental one, this curve gives a quantification of the magnetic interactions of the studied materials at the microscopic level. We have studied different types of extended systems such as chains and hexagonal lattices, where the magnetic sites are transition metal ions.
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Berkaïne, Nabil. "Propriétés optiques non-linéaires de composés métastables du système TeO2 - Bi2O3 : apports de la chimie quantique." Limoges, 2009. https://aurore.unilim.fr/theses/nxfile/default/0553a07f-6261-48b5-a299-9696b78cdb0b/blobholder:0/2009LIMO4029.pdf.
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Ce travail porte sur l’étude des propriétés optiques non-linéaires des phases métastables orthorhombiques dans la partie riche en TeO2 du système TeO2 - Bi2O3. Après une étude structurale de ces phases, nous nous sommes intéressés à leurs propriétés optiques non-linéaires (ONL) du 2nd ordre en effectuant des mesures expérimentales de génération de seconde harmonique (GSH). Une variation surprenante de l’intensité de GSH de ces phases avec la composition a été observée. Afin d’en expliquer l’origine, la susceptibilité ONL de 2nd ordre de ces phases a été calculée en appliquant une méthode, préalablement validée, basée sur la théorie de la fonctionnelle de la densité (DFT). Cette méthode a aussi été appliquée aux polymorphes α et γ de TeO2 et à la cristobalite SiO2 et a permis de mettre en évidence des relations entre les propriétés ONL du 3me ordre des tellurites et leurs arrangements structuraux (les entités, leurs enchaînements, la paire libre de l’atome Te)This work consisted in the study of non-linear optical properties of orthorhombic metastable phases in the TeO2 rich part of the TeO2 - Bi2O phase diagram. After characterizing the structure of these phases, we focused on the study of their 2nd order non-linear optical properties (NLO) by performing second harmonic generation (SHG) experimental measurements. A surprising variation of the SHG efficiency with TeO2 rate was noted. In order to explain it, the 2nd NLO susceptibility for each TeO2 rate was calculated by applying a theoretical method based on the density functional theory (DFT). Such model was first validated. This method was also applied to α and γ TeO2 crystalline phases and cristobalite SiO2. We evidenced some relationships between the 3rd order NLO properties of tellurites and their structural arrangements (entities connection, tellurium lone pair)
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Jacobsen, Ruth L. "Ab initio configuration interaction (CI) calculation of the charge-density susceptibility of molecular hydrogen and higher-order Van der Waals interactions from perturbation theory." Diss., Connect to online resource - MSU authorized users, 2006.
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Švarcová, Monika. "Dvoufázový systém stabilizace podloží vozovek." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392147.
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This diploma thesis is focused on the properties of unsuitable and conditionally unsuitable fine-grained soils after a one-stage or two-stage treatment by using a binder. The theoretical part occupies with problematical properties of the fine grained soils in a subgrade and a possible technology of the change of these properties. The laboratory testing of treated soils is described and a practical technology of the one stage and two-stage stabilization. In the practical part the fine grained soils are treated by one-stage or two-stage stabilization. For the one stage stabilization the cement is used, for the two-stage stabilization the properties of the soil are improved by lime and then the soil is stabilized by cement. The treated soils are laboratory tested, the initial bearing index IBI, California bearing ratio CBR, unconfined compressive strength and frost susceptibility is tested. Based on the results of the laboratory tests the benefit of the two-stage stabilization is measured.
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Scherrer, Arne. "Density functional perturbation theory for modeling of weak interactions and spectroscopy in the condensed phase." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066716/document.
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Cette thèse porte sur l'étude des interactions faibles et de la spectroscopie vibrationnelle en phase condensée à partir d'un développement théorique basé sur la théorie de la perturbation de la fonctionnelle de densité. D'une part des corrections de la fonction d'onde Born-Oppenheimer ont été calculées pour déterminer le moment magnétique induit par les vibrations et ainsi calculer des spectres de dichroïsme circulaire vibrationnel. D'autre part, une modélisation des effets de polarisation est réalisée à l'aide d'une nouvelle représentation de la susceptibilité électronique non-localeThis thesis deals with the development and application of computational methods for the efficient and accurate calculation of spectroscopic parameters and non-covalent inter-molecular interactions in condensed-phase systems from quantum chemical methods. Specifically, electronic current densities and polarizability effects are computed using density functional perturbation theory. The nuclear velocity perturbation theory is rigorously derived from the exact factorization of the electron-nuclear wave function. Its implementation within a large-scale electronic structure program package is reported and the calculation of dynamical vibrational circular dichroism in the condensed phase is demonstrated. A position-dependent mass of nuclei in molecules is derived, addressing the fundamental questions as to how masses move in a molecule. First steps towards a density-based modeling of inter-molecular interactions using a compact representation of the electronic susceptibility are devised
Books on the topic "Initial susceptibility"
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Morton, Lindsay M., Sharon A. Savage, and Smita Bhatia. Multiple Primary Cancers. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190238667.003.0060.
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As prognosis following a cancer diagnosis has improved and survival has increased, so has the occurrence of multiple primary cancers diagnosed in the same individual. In the United States, one in five cancer diagnoses involves an individual with a previous history of cancer. These new primary cancer diagnoses, or “subsequent neoplasms” (SN), are a substantial cause of morbidity and mortality in cancer survivors. The risk of developing SN varies substantially depending on age, the type of initial primary cancer, chemotherapy, radiotherapy, genetic susceptibility, and exposure to other cancer risk factors. Childhood cancer survivors have particularly elevated SN risks associated with radiotherapy and, to a lesser extent, systemic therapy. Genetic susceptibility to cancer is also thought to play an important role in SN development after childhood cancer. Survivors of many adulthood cancers also have elevated SN risks, likely with a multifactorial etiology.
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Niessen, Timothy. Pleural Effusions (Parapneumonic Process and Empyema). Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199976805.003.0024.
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Pleural effusions occur when an influx of fluid into the pleural space exceeds its removal. An exudative effusion, which results from leaky barriers, is often associated with infections. Parapneumonic effusions are exudative pleural effusions adjacent to pulmonary infections. Most parapneumonic effusions are sterile and resolve with treatment of the underlying pneumonia. They may, however, evolve through the exudative, fibrinopurulent, and organizing phases of empyema formation. Empyema occurs when frank pus occupies the pleural space and requires drainage. For parapneumonic process, antibiotic selection is similar to that for pneumonia and should target the underlying infectious organism according to culture and susceptibility results. Initial empiric therapy should take into account local antibiotic policies, resistance patterns, and should include anaerobic coverage. In some cases, after antibiotics and thoracentesis are initiated, surgical intervention may be necessary. Timely drainage of complicated parapneumonic effusions or empyema is critical.
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Alsulaimy, Mohammad, and Seyed Mohammad Kalantar Motamedi. Bariatric Surgery and Perioperative Infections. Edited by Tomasz Rogula, Philip Schauer, and Tammy Fouse. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190608347.003.0011.
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Morbid obesity is associated with an increased risk of infectious complications including surgical site, urinary tract, and pulmonary infections. Surgical site infections (SSI) are the most common, followed by urinary and respiratory infections. Various risk factors in obese patients including impaired immunity, and altered pulmonary and circulatory systems contribute to the increased susceptibility of morbid obese patients to infectious complications. Perioperative infections are defined to occur within 30 days of the initial operative procedure. Surgical site and urinary tract infections usually occur within 7–10 days post-operatively. Therefore, it is recommended that patients should be followed up between 7 to 10 days post-op to examine surgical sites, and to screen for possible urinary tract symptoms. This chapter will discuss the diagnosis, treatment, and possible preventative measures of the aforementioned infectious complications in the bariatric surgery population.
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Macleod, Beth Abelson. On Tour before European Audiences. University of Illinois Press, 2017. http://dx.doi.org/10.5406/illinois/9780252039348.003.0007.
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This chapter describes some of the situations encountered by Fannie Bloomfield-Zeisler during her European tour in 1893–1894, 1899, 1902, and 1912. Bloomfield-Zeisler made her Berlin debut at the Singakademie in a concert featuring Frederic Chopin's F Minor and Anton Rubinstein's D Minor piano concertos with the Berlin Philharmonic Orchestra; the performance was a success with both audience and critics. In 1902, she faced a hostile audience when making her Paris debut with the Lamoureux Orchestra. The chapter recounts Bloomfield-Zeisler's initial reluctance to play before Berlin critics, who were notorious for their harshness and their susceptibility to bribes; her interpretation of Rubinstein's piano concerto with the composer in the audience; and her controversial orchestral debut in Paris at a time when France was experiencing a time of intense musical nationalism, and Parisian audiences viewed a soloist performing with orchestra as synonymous with a shallow display of virtuosity.
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Lucchesi, John C. Epigenetics, Nuclear Organization & Gene Function. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198831204.001.0001.
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Epigenetics is the study of heritable changes in gene function that do not involve changes in the DNA sequence. Epigenetic changes, consisting principally of DNA methylation, histone modifications and non-coding RNAs, maintain and modulate the initial impact of regulatory factors that recognize and associate with particular genomic sequences. This book’s primary goal is to establish a framework that can be used to understand the basis of epigenetic regulation and to appreciate both its derivation from genetics and its interdependence with genetic mechanisms. A further aim is to highlight the role played by the three-dimensional organization of the genetic material itself (the complex of DNA, histones and non-histone proteins referred to as chromatin) and its distribution within a functionally compartmentalized nucleus. Dysfunctions at any level of genetic regulation have the potential to result in an increased susceptibility to disease or actually give rise to overt pathologies. As illustrated in this book, research is continuously uncovering the role of epigenetics in a variety of human disorders, providing new avenues for therapeutic interventions and advances in regenerative medicine.
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Luyckx, Valerie A. Nephron numbers and hyperfiltration as drivers of progression. Edited by David J. Goldsmith. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0138.
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The relationship between low birth weight (LBW) and subsequent increased risk of hypertension and renal disease in humans is now well established. The initial hypothesis suggested that an adverse intrauterine environment, reflected by LBW, would impact renal development, resulting in a low nephron number and predisposition to hypertension and renal disease. Studies in various populations have shown a direct correlation between birth weight and nephron number, and in infants, nephron numbers are reduced in those of LBW. Among Caucasian and Australian Aboriginal adults, lower nephron numbers are associated with higher blood pressure, whereas higher nephron numbers appear to protect against hypertension. LBW is currently the best clinical surrogate for low nephron number and has been independently associated with higher blood pressure from infancy through to adulthood in many populations, as well as an increased risk of proteinuria, reduced glomerular filtration rate, chronic kidney disease, and end-stage renal disease in later life. The pathophysiology is analogous to that in other chronic kidney diseases where surviving nephrons are subject to hyperfiltration early on, resulting in glomerular hypertrophy, proteinuria, and eventually, especially in the setting of other renal disease risk factors, glomerulosclerosis, and loss of renal function. Mean nephron number varies by up to 13-fold in certain populations, however, therefore nephron number is unlikely the sole developmentally programmed risk factor for renal disease in later life, but may be a first ‘hit’ impacting an individual’s susceptibility to or resistance to superimposed renal injury. Augmentation of nephron number perinatally has only been addressed in experimental settings. In humans, therefore optimization of nephron number is likely best achieved through good perinatal care and adequate postnatal nutrition. Cardiovascular disease and diabetes are also developmentally programmed and therefore likely coexist in subjects with LBW and low nephron numbers. Awareness of an individual’s birth weight should serve to highlight the possibility of low nephron number and potential risk for future hypertension and renal disease, which may be attenuated by optimization of early nutrition, lifestyle choices, and management of other risk factors for renal disease.
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Weaver, Michael F. Pain and Addiction in Adolescents and Young Adults (DRAFT). Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780190265366.003.0030.
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Distinguishing between the needs of adults and those of adolescents, this chapter concentrates on practical operational approaches to both addiction and pain in the ephebiatric population. The susceptibility of this group to substance use disorders, and the profound impact on the developing brain and body of substances of misuse, is complicated further by their high level of physical activity and vulnerability to trauma. Data are provided from the Monitoring the Future project to profile the substance use risk of this population; a summary table is included giving the prevalence of various substances of misuse among youths. Unique requirements in their treatment are addressed, with emphasis placed on a network therapy, enlistment of family cooperation, and neighborhood resources. Noting that this is a population for whom physicians may be reluctant to initially consider medication, safety profiles are examined.
Book chapters on the topic "Initial susceptibility"
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Wesemael, Wim. "Screening plants for resistance/susceptibility to plant-parasitic nematodes." In Techniques for work with plant and soil nematodes, 60–70. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781786391759.0060.
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Abstract This chapter provides information on the methods for initial screening to determine the resistance or susceptibility of plants, cultivars or breeding lines to plant parasitic nematodes. Specific protocols for screening and further resistance breeding on several plant-nematode combinations are described and practical guidelines for screening of Musa germplasm and several screening procedures for cyst nematodes are presented.
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Wesemael, Wim. "Screening plants for resistance/susceptibility to plant-parasitic nematodes." In Techniques for work with plant and soil nematodes, 60–70. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781786391759.0004.
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Abstract This chapter provides information on the methods for initial screening to determine the resistance or susceptibility of plants, cultivars or breeding lines to plant parasitic nematodes. Specific protocols for screening and further resistance breeding on several plant-nematode combinations are described and practical guidelines for screening of Musa germplasm and several screening procedures for cyst nematodes are presented.
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Cunha, Burke, Paul Schoch, Cheston Cunha, Edward Bottone, John Rex, and Rodger Silletti. "Antibiotic Susceptibility Profiles and Initial Therapy of Isolates Pending Susceptibility Results." In Antibiotic Essentials, 195. Jaypee Brothers Medical Publishers (P) Ltd., 2018. http://dx.doi.org/10.5005/jp/books/14129_4.
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Cunha, Burke, Paul Schoch, Edward Bottone, and John Rex. "Antibiotic Susceptibility Profiles and Initial Therapy of Isolates Pending Susceptibility Results." In Antibiotic Essentials, 185. Jaypee Brothers Medical Publishers (P) Ltd., 2015. http://dx.doi.org/10.5005/jp/books/12574_4.
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Cunha, Burke, Paul Schoch, Edward Bottone, and John Rex. "Antibiotic Susceptibility Profiles and Initial Therapy of Isolates Pending Susceptibility Results." In Antibiotic Essentials, 185. Jaypee Brothers Medical Publishers (P) Ltd., 2015. http://dx.doi.org/10.5005/jp/books/12472_4.
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COLLINSON, D. W. "Measurement of Initial Susceptibility with the Astatic Magnetometer." In Methods in Palaeomagnetism, 360–61. Elsevier, 2013. http://dx.doi.org/10.1016/b978-1-4832-2894-5.50063-x.
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Bloemendal, J., L. Tauxe, and J. P. Valet. "High-Resolution, Whole-Core Magnetic Susceptibility Logs from Leg 108." In Proceedings of the Ocean Drilling Program, 108 Initial Reports. Ocean Drilling Program, 1988. http://dx.doi.org/10.2973/odp.proc.ir.108.115.1988.
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Tarduno, J. A., L. A. Mayer, and R. Musgrave. "High-Resolution, Whole-Core Magnetic Susceptibility Data from Leg 130, Ontong Java Plateau ." In Proceedings of the Ocean Drilling Program, 130 Initial Reports. Ocean Drilling Program, 1991. http://dx.doi.org/10.2973/odp.proc.ir.130.111.1991.
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Fowler, William R. "The Ciudad Vieja Archaeological Project." In A Historical Archaeology of Early Spanish Colonial Urbanism in Central America, 74–83. University Press of Florida, 2022. http://dx.doi.org/10.5744/florida/9780813069128.003.0004.
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The initial stages of archaeological field research at the site of Ciudad Vieja consisted of topographic mapping and controlled surface survey, followed by subsurface geophysical remote sensing to document and explore the production, construction, spatial patterning, and structural organization of this remarkable townscape. Because of its exposure, visibility, and preservation, the site is an ideal environment for total-station mapping and subsurface remote sensing. Methods employed in the latter included magnetic gradiometry, electrical conductivity, and magnetic susceptibility. The geophysical targets consisted mainly of stone building foundations buried slightly below the ground surface. These were made of cut basalt stone naturally present on the site. A highly magnetic volcanic rock, basalt possesses high magnetite content and exhibits high magnetic susceptibility, qualities that ensured excellent results for the magnetic susceptibility survey.
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Abdallah, Sarah B., and Thomas V. Fernandez. "Genetic Susceptibility in Tourette Syndrome." In Tourette Syndrome, edited by Sarah B. Abdallah and Thomas V. Fernandez, 125–36. 2nd ed. Oxford University Press, 2022. http://dx.doi.org/10.1093/med/9780197543214.003.0009.
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Abstract Early twin and family studies point to a significant genetic contribution to Tourette syndrome (TS). Informed by early segregation analyses in TS families pointing to a single-gene autosomal dominant inheritance pattern with partial penetrance, initial efforts at gene discovery in TS utilized parametric linkage analysis in large multigenerational families but failed to identify a single specific genetic locus. Later segregation analyses supported the current characterization of TS as a complex, genetically heterogeneous disorder. Nonparametric linkage analyses have yet to identify common TS risk alleles. Candidate gene association studies in TS have not yielded significant reproducible findings. Genome-wide association studies (GWAS) have proven valuable for identifying and replicating loci for common complex traits and disorders across the medical field. A GWAS meta-analysis of almost 5,000 cases identified a significant locus in FLT3. Polygenic risk scores, calculated from the most recent TS GWAS summary statistics, have shown correlation with tic severity and affected status in independent samples. There has been an increasing effort to evaluate the contribution of rare allele variants toward TS. Recent studies have found a greater burden of rare copy number variants in TS cases; the largest study to date identified NRXN1 and CNTN6 as TS risk genes. Identifying rare de novo single nucleotide variants and indels in more than 800 parent–child trios has so far identified six likely TS risk genes (WWC1, CELSR3, OPA1, NIPBL, FN1, and FBN2), which present an enriched function for cell polarity.
Conference papers on the topic "Initial susceptibility"
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Goev, G., V. Masheva, J. Geshev, and M. Mikhov. "Irreversible Susceptibility of Initial Magnetization Curve." In SIXTH INTERNATIONAL CONFERENCE OF THE BALKAN PHYSICAL UNION. AIP, 2007. http://dx.doi.org/10.1063/1.2733131.
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Harrison, Joseph M., Raymond A. Applegate, Chen Peng, J. Terry Yates, and Charles Ballentine. "Glare Susceptibility as a Function of Age: Initial Results." In Noninvasive Assessment of the Visual System. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/navs.1990.wd2.
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There is a decrease in sensitivity to high spatial frequencies with aging which becomes significant above age 50(1). Repeating this study with a greater number of subjects, we have found a small but significant difference between subjects aged 20-30 and those 31-40(2). One possible explanation of the loss of sensitivity in this relatively young population is a gradual increase in the light scattering properties of the ocular media increasing disability glare(3). The purpose of this ongoing study is to test the hypothesis that the effect of disability glare on contrast sensitivity increases with age.
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Kergoat, R., M. Labrune, J. MiItat, T. Valet, and J. C. Jacquet. "Initial rotational susceptibility of exchange coupled permalloy/copper/cobalt multilayers." In 1993 Digests of International Magnetics Conference. IEEE, 1993. http://dx.doi.org/10.1109/intmag.1993.640566.
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Appirro, C., F. Fiorillo, and A. Maraner. "Initial Susceptibility vs. Applied Stress In Positive And Negative Magnetostriction Amorphous Alloys." In 1993 Digests of International Magnetics Conference. IEEE, 1993. http://dx.doi.org/10.1109/intmag.1993.642071.
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Lahiri, B. B., Surojit Ranoo, T. Muthukumaran, and John Philip. "Magnetic hyperthermia in water based ferrofluids: Effects of initial susceptibility and size polydispersity on heating efficiency." In DAE SOLID STATE PHYSICS SYMPOSIUM 2017. Author(s), 2018. http://dx.doi.org/10.1063/1.5028628.
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Chen, Renzong. "Initial Events Assessment of Auxiliary Building for Internal Flooding PSA." In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29053.
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This documentation summarized initial events assessment of auxiliary building as a result of internal flooding based on Chinese 1000MWe PWR. Detailed screening procedure of plant areas and quantitative frequency of each identified initial event are presented. In order to implement the analysis, the whole auxiliary building is divided into several areas, depending on elevation, isolation and function. Areas that are essential to plant operation and that house safe shutdown equipment are screened through a two-step process to determine the susceptibility to an internal flood. After this process, areas that are not eliminated are where flooding scenarios may occur. All possible flooding scenarios are reviewed to determine if they could result in any of the initiating events identified in the internal initiating events analysis which belongs to Level 1 PSA. For those flooding scenarios that do not result in an existing initiating event, a new initiating event is developed. Eventually, the frequency of each initiating event is achieved by identifying each flooding source and its failure mode, and correlating this to failure data. It must be paid attention to that the identification of internal flood hazards is plant specific since the routing of piping systems varies substantially from plant to plant. Therefore, the conclusion obtained from this issue may be not applicable for other nuclear power plant.
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Smatti, Maria Khalid, Yasser Al-Sarraj, Omar Albagha, and Hadi Yassine. "Genetic Susceptibility to Infectious Diseases in the Qatari Population." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2021. http://dx.doi.org/10.29117/quarfe.2021.0092.
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Background: Infectious diseases (IDs) account for 8% of deaths annually in Qatar, and therefore, represent a significant challenge for public health. Interestingly, the spread and severity of viral infections vary considerably between individuals and populations. The most recent example is SARS-CoV-2, which ranges from mild/asymptomatic to a severe respiratory syndrome. It has been previously reported that polymorphisms in genes linked to immunity can influence individuals’ responses to infections as observed in tuberculosis, influenza, and HIV; however, studies exploring causal host genetic variants in IDs are still limited and dramatically skewed with regard to population inclusion. In fact, the genetic susceptibility to IDs in the Qatari population is largely unknown. Aim: To perform a comprehensive genetic screening to investigate the presence and frequency of variants previously associated with various infections in the Qatari population. Methods: Whole-genome sequencing was previously performed for 18,000 QBB participants using Illumina HiSeq X Ten1 sequencers. The initial data processing and quality assessment of the raw data has also been performed and variant calling files (VCF) were created. We were granted the access to the VCF files of 6,218 sequenced samples. The genetic variant data was then converted to PLINK file format using PLINK-1.9. Standardized quality-assurance and quality control (QA/QC) methods were followed to generate high quality and confidence on both SNPs and sample levels. The final file used for calculating allele frequency contained 6,047 subjects. Additionally, list of infections-related SNPs that were previously reported in the literature and deposited in GWAS catalog was extracted and used to calculate and compare the allelic frequency in the Qatari genomes compared to other populations. Results: The frequency of infections-related SNPs in the Qatari population was significantly lower for most infections. Most variants (78%) showed negative fold change in the Qatari genomes. Only 22% of all variants were more prevalent in Qatari population compared to others. The most significant differences were observed in genes related to TB and HIV (200-940 and 160-710 fold change, respectively). Conclusion: This study reports a lower susceptibility of the Qatari population to IDs in general. Nonetheless, this might also indicate the presence of unknown Qatari-unique variants and hence, highlights the need for further investigation in future GWAS.
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Hoyt, E., E. De Moor, and K. O. Findley. "Hydrogen Embrittlement Resistance of High Strength 9260 Bar Steel Heat Treated by Quenching and Partitioning." In HT2021. ASM International, 2021. http://dx.doi.org/10.31399/asm.cp.ht2021p0162.
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Abstract The influence of microstructure on hydrogen embrittlement of high strength steels for fastener applications is explored in this study. Space limiting applications in areas such as the automotive or agricultural industries provide a need for higher strength fasteners. Albeit, hydrogen embrittlement susceptibility typically increases with strength. Using a 9260 steel alloy, the influence of retained austenite volume fraction in a martensitic matrix was evaluated with microstructures generated via quenching and partitioning. X-ray diffraction and scanning electron microscopy were used to assess the influence of retained austenite in the matrix with different quenching parameters. The quench temperatures varied from 160 °C up to 220 °C, and a constant partitioning temperature of 290 °C was employed for all quench and partitioned conditions. The target hardness for all testing conditions was 52-54 HRC. Slow strain rate tensile testing was conducted with cathodic hydrogen pre-charging that introduced a hydrogen concentration of 1.0-1.5 ppm to evaluate hydrogen embrittlement susceptibility of these various microstructures. The retained austenite volume fraction and carbon content varied with the initial quench temperature. Additionally, the lowest initial quench temperature employed, which had the highest austenite carbon content, had the greatest hydrogen embrittlement resistance for a hydrogen concentration level of 1.0-1.5 ppm.
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Shabarchin, Oleg, Smitha Koduru, and Sherif Hassanien. "Framework for Pipeline Stress Corrosion Cracking Susceptibility Using Inspection & Mitigation Results: A Bayesian Approach." In 2022 14th International Pipeline Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/ipc2022-87372.
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Abstract Stress Corrosion Cracking (SCC) is a form of cracking caused by interaction of a susceptible material, tensile stress, and a suitable environment. Considering recent SCC failures in pipelines coupled with increasingly stringent regulatory requirements, it is imperative for an operator to have an effective SCC integrity management program. To accomplish this, it is essential for the program to not only integrate multiple interacting factors that influence SCC, but also incorporate evidence from program mitigation actions. This paper presents a framework based on Bayesian approach to incorporate multiple lines of evidence while transparently treating associated uncertainty to estimate a more representative SCC occurrence and corresponding SCC failure rate. Knowledge gathered from industry SCC management best practices and SCC susceptibility models are used in conjunction with expert knowledge and ILI findings to develop the proposed framework. The framework consists of two components; first, SCC susceptibility is established to quantify the SCC occurrence rate on a pipeline. Second, field evidence is incorporated into the framework using Bayesian updating to refine the initial estimates of segment specific SCC occurrence and failure rate. The approach provides a significant flexibility to update the proposed model at any maturity level of the program as additional data becomes available.
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Popp, A., L. Ujj, and G. H. Atkinson. "Picosecond Time-Resolved Vibrational Spectrum of Batho-Rhodopsin at Room Temperature: Concentration Effect." In International Conference on Ultrafast Phenomena. Washington, D.C.: Optica Publishing Group, 1994. http://dx.doi.org/10.1364/up.1994.tud.10.
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The first vibrational spectrum of batho-rhodopsin (Batho), an intermediate formed during the initial 50 ps of the visual process of rhodopsin (Rh) at room temperature, has been measured by picosecond time-resolved coherent anti-Stokes scattering (PTR/CARS). The Batho spectrum is obtained through a third-order susceptibility (χ(3)) analysis of the measured PTR/CARS data in which the resonant and non-resonant contributions to the signal are separated. The PTR/CARS spectrum of Batho reveals structural changes during the Rh photo-reaction which have not previously been recognized.
Reports on the topic "Initial susceptibility"
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Watkins, Chris B., Susan Lurie, Amnon Lers, and Patricia L. Conklin. Involvement of Antioxidant Enzymes and Genes in the Resistance Mechanism to Postharvest Superficial Scald Development. United States Department of Agriculture, December 2004. http://dx.doi.org/10.32747/2004.7586539.bard.
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The objective of this research project was to evaluate the involvement of antioxidant enzymes and genes in the resistance mechanism to postharvest superficial scald development using two primary systems: 1. Resistant and susceptible progenies of an apple cross between a scald resistant crab apple, ‘White Angel’ and a scald susceptible cultivar, ‘Rome Beauty’; 2. Heat-treatment of ‘Granny Smith’, which is known to reduce scald development in this cultivar. In 2002 we asked for, and received (October 14), permission to revise our initial objectives. The US side decided to expand their results to include further work using commercial cultivars. Also, both sides wanted to include an emphasis on the interaction between these antioxidant enzymes and the á-farnesene pathway, with the cooperation of a third party, Dr. Bruce Whitaker, USDA-ARS, Beltsville. Background: Superficial scald is a physiological storage disorder that causes damage to the skin of apple and pear fruit. It is currently controlled by use of an antioxidant, diphenylamine (DPA), applied postharvest by drenching or dips, but concern exists about such chemical usage especially as it also involves application of fungicides. As a result, there has been increased emphasis on understanding of the underlying mechanisms involved in disorder development. Our approach was to focus on the oxidative processes that occur during scald development, and specifically on using the two model systems described above to determine if the levels of specific antioxidants and/or antioxidant enzyme activities correlated with the presence/absence of scald. It was hoped that information about the role of antioxidant-defense mechanisms would lead to identification of candidate genes for future transgenic manipulation. Major conclusions, solutions, achievements: Collectively, our results highlight the complexity of superficial scald developmental processes. Studies involving comparisons of antioxidant enzyme activities in different crab apple selection, commercial cultivars, and in response to postharvest heat and 1-methylcyclopropene (1-MCP) treatments, show no simple direct relationships with antioxidant contents and susceptibility of fruit to scald development. However, a correlative relationship was found between POX activity or isoenzyme number and scald resistance in most of the studies. This relationship, if confirmed, could be exploited in breeding for scald resistance. In addition, our investigations with key genes in the á-farnesenebiosynthetic pathway, together with antioxidant processes, are being followed up by analysis of exposed and shaded sides of fruit of cultivars that show different degrees of scald control by 1-MCP. These data may further reveal productive areas for future research that will lead to long term control of the disorder. However, given the complexity of scald development, the greatest research need is the production of transgenic fruit with down-regulated genes involved in á- farnesene biosynthesis in order to test the currently popular hypothesis for scald development.
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Bourrier, Mathilde, Michael Deml, and Farnaz Mahdavian. Comparative report of the COVID-19 Pandemic Responses in Norway, Sweden, Germany, Switzerland and the United Kingdom. University of Stavanger, November 2022. http://dx.doi.org/10.31265/usps.254.
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The purpose of this report is to compare the risk communication strategies and public health mitigation measures implemented by Germany, Norway, Sweden, Switzerland, and the United Kingdom (UK) in 2020 in response to the COVID-19 pandemic based on publicly available documents. The report compares the country responses both in relation to one another and to the recommendations and guidance of the World Health Organization where available. The comparative report is an output of Work Package 1 from the research project PAN-FIGHT (Fighting pandemics with enhanced risk communication: Messages, compliance and vulnerability during the COVID-19 outbreak), which is financially supported by the Norwegian Research Council's extraordinary programme for corona research. PAN-FIGHT adopts a comparative approach which follows a “most different systems” variation as a logic of comparison guiding the research (Przeworski & Teune, 1970). The countries in this study include two EU member States (Sweden, Germany), one which was engaged in an exit process from the EU membership (the UK), and two non-European Union states, but both members of the European Free Trade Association (EFTA): Norway and Switzerland. Furthermore, Germany and Switzerland govern by the Continental European Federal administrative model, with a relatively weak central bureaucracy and strong subnational, decentralised institutions. Norway and Sweden adhere to the Scandinavian model—a unitary but fairly decentralised system with power bestowed to the local authorities. The United Kingdom applies the Anglo-Saxon model, characterized by New Public Management (NPM) and decentralised managerial practices (Einhorn & Logue, 2003; Kuhlmann & Wollmann, 2014; Petridou et al., 2019). In total, PAN-FIGHT is comprised of 5 Work Packages (WPs), which are research-, recommendation-, and practice-oriented. The WPs seek to respond to the following research questions and accomplish the following: WP1: What are the characteristics of governmental and public health authorities’ risk communication strategies in five European countries, both in comparison to each other and in relation to the official strategies proposed by WHO? WP2: To what extent and how does the general public’s understanding, induced by national risk communication, vary across five countries, in relation to factors such as social capital, age, gender, socio-economic status and household composition? WP3: Based on data generated in WP1 and WP2, what is the significance of being male or female in terms of individual susceptibility to risk communication and subsequent vulnerability during the COVID-19 outbreak? WP4: Based on insight and knowledge generated in WPs 1 and 2, what recommendations can we offer national and local governments and health institutions on enhancing their risk communication strategies to curb pandemic outbreaks? WP5: Enhance health risk communication strategies across five European countries based upon the knowledge and recommendations generated by WPs 1-4. Pre-pandemic preparedness characteristics All five countries had pandemic plans developed prior to 2020, which generally were specific to influenza pandemics but not to coronaviruses. All plans had been updated following the H1N1 pandemic (2009-2010). During the SARS (2003) and MERS (2012) outbreaks, both of which are coronaviruses, all five countries experienced few cases, with notably smaller impacts than the H1N1 epidemic (2009-2010). The UK had conducted several exercises (Exercise Cygnet in 2016, Exercise Cygnus in 2016, and Exercise Iris in 2018) to check their preparedness plans; the reports from these exercises concluded that there were gaps in preparedness for epidemic outbreaks. Germany also simulated an influenza pandemic exercise in 2007 called LÜKEX 07, to train cross-state and cross-department crisis management (Bundesanstalt Technisches Hilfswerk, 2007). In 2017 within the context of the G20, Germany ran a health emergency simulation exercise with WHO and World Bank representatives to prepare for potential future pandemics (Federal Ministry of Health et al., 2017). Prior to COVID-19, only the UK had expert groups, notably the Scientific Advisory Group for Emergencies (SAGE), that was tasked with providing advice during emergencies. It had been used in previous emergency events (not exclusively limited to health). In contrast, none of the other countries had a similar expert advisory group in place prior to the pandemic. COVID-19 waves in 2020 All five countries experienced two waves of infection in 2020. The first wave occurred during the first half of the year and peaked after March 2020. The second wave arrived during the final quarter. Norway consistently had the lowest number of SARS-CoV-2 infections per million. Germany’s counts were neither the lowest nor the highest. Sweden, Switzerland and the UK alternated in having the highest numbers per million throughout 2020. Implementation of measures to control the spread of infection In Germany, Switzerland and the UK, health policy is the responsibility of regional states, (Länders, cantons and nations, respectively). However, there was a strong initial centralized response in all five countries to mitigate the spread of infection. Later on, country responses varied in the degree to which they were centralized or decentralized. Risk communication In all countries, a large variety of communication channels were used (press briefings, websites, social media, interviews). Digital communication channels were used extensively. Artificial intelligence was used, for example chatbots and decision support systems. Dashboards were used to provide access to and communicate data.
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Sessa, Guido, and Gregory Martin. role of FLS3 and BSK830 in pattern-triggered immunity in tomato. United States Department of Agriculture, January 2016. http://dx.doi.org/10.32747/2016.7604270.bard.
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Pattern-recognition receptors (PRRs) located on the plant cell surface initiate immune responses by perceiving conserved pathogen molecules known as pathogen-associated molecular patterns (PAMPs). PRRs typically function in multiprotein complexes that include transmembrane and cytoplasmickinases and contribute to the initiation and signaling of pattern-triggered immunity (PTI). An important challenge is to identify molecular components of PRR complexes and downstream signaling pathways, and to understand the molecular mechanisms that mediate their function. In research activities supported by BARD-4931, we studied the role of the FLAGELLIN SENSING 3 (FLS3) PRR in the response of tomato leaves to flagellin-derivedPAMPs and PTI. In addition, we investigated molecular properties of the tomato brassinosteroid signaling kinase 830 (BSK830) that physically interacts with FLS3 and is a candidate for acting in the FLS3 signaling pathway. Our investigation refers to the proposal original objectives that were to: 1) Investigate the role of FLS3 and its interacting proteins in PTI; 2) Investigate the role of BSK830 in PTI; 3) Examine molecular and phosphorylation dynamics of the FLS3-BSK830 interaction; 4) Examine the possible interaction of FLS3 and BSK830 with Pstand Xcveffectors. We used CRISPR/Cas9 techniques to develop plants carrying single or combined mutations in the FLS3 gene and in the paralogsFLS2.1 and FLS2.2 genes, which encode the receptor FLAGELLIN SENSING2 (FLS2), and analyzed their function in PTI. Domain swapping analysis of the FLS2 and FLS3 receptors revealed domains of the proteins responsible for PAMP detection and for the different ROS response initiated by flgII-28/FLS3 as compared to flg22/FLS2. In addition, in vitro kinase assays and point mutations analysis identified FLS2 and FLS3 domains required for kinase activity and ATP binding. In research activities on tomato BSK830, we found that it interacts with PRRs and with the co-receptor SERK3A and PAMP treatment affects part of these interactions. CRISPR/Cas9 bsk830 mutant plants displayed enhanced pathogen susceptibility and reduced ROS production upon PAMP treatment. In addition, BSK830 interacted with 8 Xanthomonastype III secreted effectors. Follow up analysis revealed that among these effectors XopAE is part of an operon, is translocated into plant cells, and displays E3 ubiquitinligase activity. Our investigation was also extended to other Arabidopsis and tomato BSK family members. Arabidopsis BSK5 localized to the plant cell periphery, interacted with receptor-like kinases, and it was phosphorylatedin vitro by the PEPR1 and EFRPRRs. bsk5 mutant plants displayed enhanced susceptibility to pathogens and were impaired in several, but not all, PAMP-induced responses. Conversely, BSK5 overexpression conferred enhanced disease resistance and caused stronger PTI responses. Genetic complementation suggested that proper localization, kinase activity, and phosphorylation by PRRs are critical for BSK5 function. BSK7 and BSK8 specifically interacted with the FLS2 PRR, their respective mutant plants were more susceptible to B. cinereaand displayed reduced flg22-induced responses. The tomato BSK Mai1 was found to interact with the M3KMAPKKK, which is involved in activation of cell death associated with effector-triggered immunity. Silencing of Mai1 in N. benthamianaplants compromised cell death induced by a specific class of immune receptors. In addition, co-expression of Mai1 and M3Kin leaves enhanced MAPKphosphorylation and cell death, suggesting that Mai1 acts as a molecular link between pathogen recognition and MAPK signaling. Finally, We identified the PP2C phosphatase Pic1 that acts as a negative regulator of PTI by interacting with and dephosphorylating the receptor-like cytoplasmickinase Pti1, which is a positive regulator of plant immunity. The results of this investigation shed new light on the molecular characteristics and interactions of components of the immune system of crop plants providing new knowledge and tools for development of novel strategies for disease control.
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Dolja, Valerian V., Amit Gal-On, and Victor Gaba. Suppression of Potyvirus Infection by a Closterovirus Protein. United States Department of Agriculture, March 2002. http://dx.doi.org/10.32747/2002.7580682.bard.
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The plant virus family Polyviridae is the largest and most destructive of all plant viruses. Despite the continuous effort to develop resistant plant varieties, there is a desperate need for novel approaches conferring wide-range potyvirus resistance. Based on experiments with the tobacco etch potyvirus (TEV)-derived gene expression vector, we suggested approach for screening of the candidate resistance genes. This approach relies on insertion of the genes into a virus vector and evaluation of the phenotypes of the resulting recombinant viruses. The genes which suppress infection by the recombinant virus are selected as candidates for engineering transgenic resistance. Our analysis of the TEV variants expressing proteins of the beet yellows closterovirus (BYV) revealed that one of those, the leader proteinase (L-Pro), strongly and specifically interfered with the hybrid TEV infection. Since closterovirus L-Pro is evolutionary related to potyviral helper component-proteinase (HC-Pro), we suggested that the L-Pro interfered with HC-Pro function via a trans-dominant inhibitory effect. Based on these findings, we proposed to test two major hypotheses. First, we suggested that L-Pro-mediated suppression of potyvirus infection is a general phenomenon effective against a range of potyviruses. The second hypothesis stated that the suppression effect can be reproduced in transgenic plants expressing L-Pro, and can be utilized for generation of resistance to potyviruses. In accord with these hypotheses, we developed two original objectives of our proposal: A) to determine the range of the closterovirus-derived suppression of potyviral infection, and B) to try and utilize the L-Pro-mediated suppression for the development of transgenic resistance to potyviruses. In the first phase of the project, we have developed all major tools and technologies required for successful completion of the proposed research. These included TEV and ZYMV vectors engineered to express several closteroviral L-Pro variants, and generation of the large collection of transgenic plants. To our satisfaction, characterization of the infection phenotypes exhibited by chimeric TEV and ZYMV variants confirmed our first hypothesis. For instance, similar to TEV-L- Pro(BYV) chimera, ZYMV-L-Pro(LIYV) chimera was debilitated in its systemic spread. In contrast, ZYMV-GUS chimera (positive control) was competent in establishing vigorous systemic infection. These and other results with chimeric viruses indicated that several closteroviral proteinases inhibit long-distance movement of the potyviruses upon co-expression in infected plants. In order to complete the second objective, we have generated ~90 tobacco lines transformed with closteroviral L-Pro variants, as well as ~100 lines transformed with BYV Hsp70-homolog (Hsp70h; a negative control). The presence and expression of the trans gene in each line was initially confirmed using RT-PCR and RNA preparations isolated from plants. However, since detection of the trans gene-specific RNA can not guarantee production of the corresponding protein, we have also generated L-Pro- and Hsp70h-specific antisera using corresponding synthetic peptides. These antisera allowed us to confirm that the transgenic plant lines produced detectable, although highly variable levels of the closterovirus antigens. In a final phase of the project, we tested susceptibility of the transgenic lines to TEV infection. To this end, we determined that the minimal dilution of the TEV inoculum that is still capable of infecting 100% of nontransgenic plants was 1:20, and used 10 plants per line (in total, ~2,000 plants). Unfortunately, none of the lines exhibited statistically significant reduction in susceptibility. Although discouraging, this outcome prompted us to expand our experimental plan and conduct additional experiments. Our aim was to test if closteroviral proteinases are capable of functioning in trans. We have developed agroinfection protocol for BYV, and tested if co- expression of the L-Pro is capable of rescuing corresponding null-mutant. The clear-cut, negative results of these experiments demonstrated that L-Pro acts only in cis, thus explaining the lack of resistance in our transgenic plants. We have also characterized a collection of the L-Pro alanine- scanning mutants and found direct genetic evidence of the requirement for L-Pro in virus systemic spread. To conclude, our research supported by BARD confirmed one but not another of our original hypotheses. Moreover, it provided an important insight into functional specialization of the viral proteinases and generated set of tools and data with which we will be able to address the molecular mechanisms by which these proteins provide a variety of critical functions during virus life cycle.
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Jorgensen, Frieda, Andre Charlett, Craig Swift, Anais Painset, and Nicolae Corcionivoschi. A survey of the levels of Campylobacter spp. contamination and prevalence of selected antimicrobial resistance determinants in fresh whole UK-produced chilled chickens at retail sale (non-major retailers). Food Standards Agency, June 2021. http://dx.doi.org/10.46756/sci.fsa.xls618.
Full textAbstract:
Campylobacter spp. are the most common bacterial cause of foodborne illness in the UK, with chicken considered to be the most important vehicle for this organism. The UK Food Standards Agency (FSA) agreed with industry to reduce Campylobacter spp. contamination in raw chicken and issued a target to reduce the prevalence of the most contaminated chickens (those with more than 1000 cfu per g chicken neck skin) to below 10 % at the end of the slaughter process, initially by 2016. To help monitor progress, a series of UK-wide surveys were undertaken to determine the levels of Campylobacter spp. on whole UK-produced, fresh chicken at retail sale in the UK. The data obtained for the first four years was reported in FSA projects FS241044 (2014/15) and FS102121 (2015 to 2018). The FSA has indicated that the retail proxy target for the percentage of highly contaminated raw whole retail chickens should be less than 7% and while continued monitoring has demonstrated a sustained decline for chickens from major retailer stores, chicken on sale in other stores have yet to meet this target. This report presents results from testing chickens from non-major retailer stores (only) in a fifth survey year from 2018 to 2019. In line with previous practise, samples were collected from stores distributed throughout the UK (in proportion to the population size of each country). Testing was performed by two laboratories - a Public Health England (PHE) laboratory or the Agri-Food & Biosciences Institute (AFBI), Belfast. Enumeration of Campylobacter spp. was performed using the ISO 10272-2 standard enumeration method applied with a detection limit of 10 colony forming units (cfu) per gram (g) of neck skin. Antimicrobial resistance (AMR) to selected antimicrobials in accordance with those advised in the EU harmonised monitoring protocol was predicted from genome sequence data in Campylobacter jejuni and Campylobacter coli isolates The percentage (10.8%) of fresh, whole chicken at retail sale in stores of smaller chains (for example, Iceland, McColl’s, Budgens, Nisa, Costcutter, One Stop), independents and butchers (collectively referred to as non-major retailer stores in this report) in the UK that are highly contaminated (at more than 1000 cfu per g) with Campylobacter spp. has decreased since the previous survey year but is still higher than that found in samples from major retailers. 8 whole fresh raw chickens from non-major retailer stores were collected from August 2018 to July 2019 (n = 1009). Campylobacter spp. were detected in 55.8% of the chicken skin samples obtained from non-major retailer shops, and 10.8% of the samples had counts above 1000 cfu per g chicken skin. Comparison among production plant approval codes showed significant differences of the percentages of chicken samples with more than 1000 cfu per g, ranging from 0% to 28.1%. The percentage of samples with more than 1000 cfu of Campylobacter spp. per g was significantly higher in the period May, June and July than in the period November to April. The percentage of highly contaminated samples was significantly higher for samples taken from larger compared to smaller chickens. There was no statistical difference in the percentage of highly contaminated samples between those obtained from chicken reared with access to range (for example, free-range and organic birds) and those reared under standard regime (for example, no access to range) but the small sample size for organic and to a lesser extent free-range chickens, may have limited the ability to detect important differences should they exist. Campylobacter species was determined for isolates from 93.4% of the positive samples. C. jejuni was isolated from the majority (72.6%) of samples while C. coli was identified in 22.1% of samples. A combination of both species was found in 5.3% of samples. C. coli was more frequently isolated from samples obtained from chicken reared with access to range in comparison to those reared as standard birds. C. jejuni was less prevalent during the summer months of June, July and August compared to the remaining months of the year. Resistance to ciprofloxacin (fluoroquinolone), erythromycin (macrolide), tetracycline, (tetracyclines), gentamicin and streptomycin (aminoglycosides) was predicted from WGS data by the detection of known antimicrobial resistance determinants. Resistance to ciprofloxacin was detected in 185 (51.7%) isolates of C. jejuni and 49 (42.1%) isolates of C. coli; while 220 (61.1%) isolates of C. jejuni and 73 (62.9%) isolates of C. coli isolates were resistant to tetracycline. Three C. coli (2.6%) but none of the C. jejuni isolates harboured 23S mutations predicting reduced susceptibility to erythromycin. Multidrug resistance (MDR), defined as harbouring genetic determinants for resistance to at least three unrelated antimicrobial classes, was found in 10 (8.6%) C. coli isolates but not in any C. jejuni isolates. Co-resistance to ciprofloxacin and erythromycin was predicted in 1.7% of C. coli isolates. 9 Overall, the percentages of isolates with genetic AMR determinants found in this study were similar to those reported in the previous survey year (August 2016 to July 2017) where testing was based on phenotypic break-point testing. Multi-drug resistance was similar to that found in the previous survey years. It is recommended that trends in AMR in Campylobacter spp. isolates from retail chickens continue to be monitored to realise any increasing resistance of concern, particulary to erythromycin (macrolide). Considering that the percentage of fresh, whole chicken from non-major retailer stores in the UK that are highly contaminated (at more than 1000 cfu per g) with Campylobacter spp. continues to be above that in samples from major retailers more action including consideration of interventions such as improved biosecurity and slaughterhouse measures is needed to achieve better control of Campylobacter spp. for this section of the industry. The FSA has indicated that the retail proxy target for the percentage of highly contaminated retail chickens should be less than 7% and while continued monitoring has demonstrated a sustained decline for chickens from major retailer stores, chicken on sale in other stores have yet to meet this target.