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111.
A study is made of the linear and nonlinear stages of the low-frequency instability of an ensemble of ions that execute radial oscillations in the electric field of the space charge of an unneutralized high-current relativistic electron beam. Nonlinear mechanisms for stabilizing the low-frequency ion instability are considered. It is shown, in particular, that, under certain conditions, the development of the low-frequency instability can lead to the ejection of ions onto the walls of the drift chamber. 相似文献
112.
A. E. Balakirev A. V. Abramov A. N. Tikhonov V. V. Rozhnov 《Doklady biological sciences》2012,445(1):251-254
113.
The excitation of a wake wave by a relativistic electron beam in an unbounded magnetized plasma and a plasma waveguide is studied theoretically. It is shown that, in a waveguide partially filled with a plasma, the energy that the electrons of the accelerated beam can gain is 37 times higher than the energy of the electrons of the beam generating wakefield. 相似文献
114.
Prameladevi Chinnasamy Sarah E Lutz Dario F Riascos-Bernal Venkatesh Jeganathan Isabel Casimiro Celia F Brosnan Nicholas ES Sibinga 《Molecular medicine (Cambridge, Mass.)》2015,21(1):233-241
Experimental autoimmune encephalomyelitis (EAE), an animal model of human multiple sclerosis (MS), is mediated by myelin-specific autoreactive T cells that cause inflammation and demyelination in the central nervous system (CNS), with significant contributions from activated microglia and macrophages. The molecular bases for expansion and activation of these cells, plus trafficking to the CNS for peripheral cells, are not fully understood. Allograft inflammatory factor-1 (Aif-1) (also known as ionized Ca2+ binding adapter-1 [Iba-1]) is induced in leukocytes in MS and EAE; here we provide the first assessment of Aif-1 function in this setting. After myelin oligodendrocyte glycoprotein peptide (MOG35–55) immunization, Aif-1–deficient mice were less likely than controls to develop EAE and had less CNS leukocyte infiltration and demyelination; their spinal cords contained fewer CD4 T cells and microglia and more CD8 T cells. These mice also showed significantly less splenic CD4 T-cell expansion and activation, plus decreased proinflammatory cytokine expression. These findings identify Aif-1 as a potent molecule that promotes expansion and activation of CD4 T cells, plus elaboration of a proinflammatory cytokine milieu, in MOG35–55-induced EAE and as a potential therapeutic target in MS. 相似文献
115.
A study was made of the nonlinear low-frequency interaction of a longitudinal ion beam with a virtual cathode of a relativistic high-current electron beam injected into a cylindrical drift chamber. Cases are considered in which the electron and ion beams have the same radii and in which the radius an ion beam is greaterthan that of an electron beam. 相似文献
116.
ADRIAN A. BARNETT SARAH A. BOYLE MARILYN M. NORCONK SUZANNE PALMINTERI RICARDO R. SANTOS LIZA M. VEIGA THIAGO H.G. ALVIM MARK BOWLER JANICE CHISM ANTHONY DI FIORE EDUARDO FERNANDEZ‐DUQUE ANA C. P. GUIMARÃES AMY HARRISON‐LEVINE TORBJØRN HAUGAASEN SHAWN LEHMAN KATHERINE C. MACKINNON FABIANO R. DE MELO LEANDRO S. MOREIRA VIVIANE S. MOURA CARSON R. PHILLIPS LILIAM P. PINTO MARCIO PORT‐CARVALHO ELEONORE Z. F. SETZ CHRISTOPHER SHAFFER LÍVIA RODRIGUES DA SILVA SULEIMA DO S. B. DA SILVA RAFAELA F. SOARES CYNTHIA L. THOMPSON TATIANA M. VIEIRA ARIOENE VREEDZAAM SUZANNE E. WALKER‐PACHECO WILSON R. SPIRONELLO ANN MACLARNON STEPHEN F. FERRARI 《American journal of primatology》2012,74(12):1106-1127
Neotropical monkeys of the genera Cacajao, Chiropotes, and Pithecia (Pitheciidae) are considered to be highly arboreal, spending most of their time feeding and traveling in the upper canopy. Until now, the use of terrestrial substrates has not been analyzed in detail in this group. Here, we review the frequency of terrestrial use among pitheciin taxa to determine the ecological and social conditions that might lead to such behavior. We collated published and unpublished data from 14 taxa in the three genera. Data were gleaned from 53 published studies (including five on multiple pitheciin genera) and personal communications of unpublished data distributed across 31 localities. Terrestrial activity was reported in 61% of Pithecia field studies (11 of 18), in 34% of Chiropotes studies (10 of 29), and 36% of Cacajao studies (4 of 11). Within Pithecia, terrestrial behavior was more frequently reported in smaller species (e.g. P. pithecia) that are vertical clingers and leapers and make extensive use of the understory than in in the larger bodied canopy dwellers of the western Amazon (e.g. P. irrorata). Terrestrial behavior in Pithecia also occurred more frequently and lasted longer than in Cacajao or Chiropotes. An apparent association was found between flooded habitats and terrestrial activity and there is evidence of the development of a “local pattern” of terrestrial use in some populations. Seasonal fruit availability also may stimulate terrestrial behavior. Individuals also descended to the ground when visiting mineral licks, escaping predators, and responding to accidents such as a dropped infant. Overall, the results of this review emphasize that terrestrial use is rare among the pitheciins in general and is usually associated with the exploitation of specific resources or habitat types. Am. J. Primatol. 74:1106‐1127, 2012. © 2012 Wiley Periodicals, Inc. 相似文献
117.
118.
The age dependence of haemoglobin denaturation temperature in the composition of erythrocytes is established. Children have a much more expressed correlation of this temperature depending on the type and stage of disease than the adult. It is found that children ill with leukemia have haemoglobin, the value of heat denaturation of which is decreased about 15-25% in relation to the norm. Tests are created. They allow to reveal leukemia by heat parameters of haemoglobin denaturation of the whole blood. 相似文献
119.
The fourth component of rat complement was purified to homogeneity by sequential chromatography of rat plasma in benzamidine on QAE-A50, SP-C50, hydroxyapatite, and gel filtration on Bio-Gel A 1.5. The final material was homogeneous on SDS-PAGE analysis and had a calculated m.w. of 198,000. A monospecific antibody against rat C4 was obtained from immunized rabbits. The concentration of rat C4 in the plasma of normal 4-month-old Wistar rats was 190 +/- 34 microgram/ml (mean +/- 1 S.D.). 相似文献
120.
Mitochondrial DNA analysis of Rhipicephalus sanguineus s.l. from the western Iberian peninsula 下载免费PDF全文
C. ALMEIDA R. SIMÕES M. J. COIMBRA‐DORES F. ROSA D. DIAS 《Medical and veterinary entomology》2017,31(2):167-177
Rhipicephalus sanguineus Latreille (1806) (Ixodida: Ixodidae) is considered to be the most widely distributed tick and to have a vast range of habitats and hosts, including livestock, pets and wildlife. In addition to morphological differences, recent investigations using approaches based on molecular genetic markers have revealed the existence of different R. sanguineus lineages in different geographic regions. In this study, 475 ticks collected from dogs in the western Iberian peninsula were studied both morphologically and genetically, using 12S and 16S rDNA and COI gene markers in order to clarify the controversy over the systematic status of R. sanguineus sensu lato in Western Europe, and to compare the present data with those sourced from studies conducted in other regions of the world. Despite the high morphometric variability, particularly on spiracles in both genders and in female genitalia, data obtained with different genetic molecular markers show very low variability, suggesting the existence of a unique species. In addition, the phylogenetic analysis showed genetic uniformity, supporting the existence of a well‐defined clade consisting of R. sanguineus s.l. specimens from Western Europe that are distinct from R. sanguineus s.l. from Africa. Furthermore, these data corroborate the existence of a polymorphic species in Western Europe, which requires to be consensually redescribed in view of its medical and veterinary importance in pathogen transmission. 相似文献