Inhibition of the carotid sinus reflex by stimulation of the inferior olive   总被引：2，自引：0，他引：2  

O A Smith  M A Nathan 《Science (New York, N.Y.)》1966,154(749):674-675

A projection of nerve fibers from rostral brainstem areas, which produce pressor responses and tachycardia, terminates in the inferior olive. Electrical stimulation of the olive in the cat produces no cardiovascular response but inhibits the depressor cotnponent of the carotid sinusreflex.  相似文献   

Lawsonia intracellularis and Equine Proliferative Enteropathy     

Allen E. Page  Nathan M. Slovis  David W. Horohov 《Veterinary Clinics of North America: Equine Practice》2014

  相似文献   

A live-attenuated and an inactivated chimeric porcine circovirus (PCV)1-2 vaccine are both effective at inducing a humoral immune response and reducing PCV2 viremia and intrauterine infection in female swine of breeding age     

Michelle Hemann  Nathan M. Beach  Xiang-Jin Meng  Chong Wang  Patrick G. Halbur  Tanja Opriessnig 《Canadian journal of veterinary research》2014,78(1):8-16

The objective of this pilot study was to determine the efficacy of inactivated (1 or 2 dose) and live-attenuated chimeric porcine circovirus (PCV)1-2 vaccines in sows using the PCV2-spiked semen model. Thirty-five sows were randomly divided into 6 groups: negative and positive controls, 1 dose inactivated PCV1-2 vaccine challenged (1-VAC-PCV2), 2 dose inactivated PCV1-2 vaccine challenged (2-VAC-PCV2), 1 dose live-attenuated PCV1-2 vaccine unchallenged (1-LIVE-VAC), and 1 dose live-attenuated PCV1-2 vaccine challenged (1-LIVE-VAC-PCV2). The inactivated PCV1-2 vaccine induced higher levels of PCV2-specific antibodies in dams. All vaccination strategies provided good protection against PCV2 viremia in dams, whereas the majority of the unvaccinated sows were viremic. Four of the 35 dams became pregnant: a negative control, a positive control, a 2-VAC-PCV2 sow, and a 1-LIVE-VAC-PCV2 sow. The PCV2 DNA was detected in 100%, 67%, and 29% of the fetuses obtained from the positive control, inactivated vaccinated, or live-attenuated vaccinated dams, respectively. The PCV2 antigen in hearts was only detectable in the positive control litter (23% of the fetuses). The PCV1-2 DNA was detected in 29% of the fetuses in the litter from the 1-LIVE-VAC-PCV2 dam. Under the conditions of this pilot study, both vaccines protected against PCV2 viremia in breeding age animals; however, vertical transmission was not prevented.  相似文献   

Spectral signatures of hydrated proton vibrations in water clusters     

Headrick JM  Diken EG  Walters RS  Hammer NI  Christie RA  Cui J  Myshakin EM  Duncan MA  Johnson MA  Jordan KD 《Science (New York, N.Y.)》2005,308(5729):1765-1769

  相似文献   

Leukocyte oxidase: defective activity in chronic granulomatous disease   总被引：50，自引：0，他引：50  

R L Baehner  D G Nathan 《Science (New York, N.Y.)》1967,155(764):835-836

The intact leukocytes of two children with chronic granulomatous disease fail to reduce nitroblue tetrazolium during phagocytosis. This is due to defective operation of an oxidase of reduced nicotinamide adenine dinucleotide that is insensitive to cyanide and that indirectly stimulates the oxidation of glucose-6-phosphate in leukocytes. Such leukocytes undergo no increase in oxygen consumption or in activity of the hexose monophosphate shunt during phagocytosis, although lactate production is normal. The addition of nitroblue tetrazolium to a leukocyte suspension appears to provide a sensitive diagnostic screening test for this disease.  相似文献   

Saturation of the southern ocean CO2 sink due to recent climate change   总被引：2，自引：0，他引：2  

Le Quéré C  Rödenbeck C  Buitenhuis ET  Conway TJ  Langenfelds R  Gomez A  Labuschagne C  Ramonet M  Nakazawa T  Metzl N  Gillett N  Heimann M 《Science (New York, N.Y.)》2007,316(5832):1735-1738

Based on observed atmospheric carbon dioxide (CO2) concentration and an inverse method, we estimate that the Southern Ocean sink of CO2 has weakened between 1981 and 2004 by 0.08 petagrams of carbon per year per decade relative to the trend expected from the large increase in atmospheric CO2. We attribute this weakening to the observed increase in Southern Ocean winds resulting from human activities, which is projected to continue in the future. Consequences include a reduction of the efficiency of the Southern Ocean sink of CO2 in the short term (about 25 years) and possibly a higher level of stabilization of atmospheric CO2 on a multicentury time scale.  相似文献   

Polarization of PAR proteins by advective triggering of a pattern-forming system     

Goehring NW  Trong PK  Bois JS  Chowdhury D  Nicola EM  Hyman AA  Grill SW 《Science (New York, N.Y.)》2011,334(6059):1137-1141

In the Caenorhabditis elegans zygote, a conserved network of partitioning-defective (PAR) polarity proteins segregates into an anterior and a posterior domain, facilitated by flows of the cortical actomyosin meshwork. The physical mechanisms by which stable asymmetric PAR distributions arise from transient cortical flows remain unclear. We present evidence that PAR polarity arises from coupling of advective transport by the flowing cell cortex to a multistable PAR reaction-diffusion system. By inducing transient PAR segregation, advection serves as a mechanical trigger for the formation of a PAR pattern within an otherwise stably unpolarized system. We suggest that passive advective transport in an active and flowing material may be a general mechanism for mechanochemical pattern formation in developmental systems.  相似文献   

The role of endosymbiotic Wolbachia bacteria in the pathogenesis of river blindness     

Saint André Av  Blackwell NM  Hall LR  Hoerauf A  Brattig NW  Volkmann L  Taylor MJ  Ford L  Hise AG  Lass JH  Diaconu E  Pearlman E 《Science (New York, N.Y.)》2002,295(5561):1892-1895

Parasitic filarial nematodes infect more than 200 million individuals worldwide, causing debilitating inflammatory diseases such as river blindness and lymphatic filariasis. Using a murine model for river blindness in which soluble extracts of filarial nematodes were injected into the corneal stroma, we demonstrated that the predominant inflammatory response in the cornea was due to species of endosymbiotic Wolbachia bacteria. In addition, the inflammatory response induced by these bacteria was dependent on expression of functional Toll-like receptor 4 (TLR4) on host cells.  相似文献   

Genome-wide insertional mutagenesis of Arabidopsis thaliana   总被引：2，自引：0，他引：2  

Alonso JM  Stepanova AN  Leisse TJ  Kim CJ  Chen H  Shinn P  Stevenson DK  Zimmerman J  Barajas P  Cheuk R  Gadrinab C  Heller C  Jeske A  Koesema E  Meyers CC  Parker H  Prednis L  Ansari Y  Choy N  Deen H  Geralt M  Hazari N  Hom E  Karnes M  Mulholland C  Ndubaku R  Schmidt I  Guzman P  Aguilar-Henonin L  Schmid M  Weigel D  Carter DE  Marchand T  Risseeuw E  Brogden D  Zeko A  Crosby WL  Berry CC  Ecker JR 《Science (New York, N.Y.)》2003,301(5633):653-657

Over 225,000 independent Agrobacterium transferred DNA (T-DNA) insertion events in the genome of the reference plant Arabidopsis thaliana have been created that represent near saturation of the gene space. The precise locations were determined for more than 88,000 T-DNA insertions, which resulted in the identification of mutations in more than 21,700 of the approximately 29,454 predicted Arabidopsis genes. Genome-wide analysis of the distribution of integration events revealed the existence of a large integration site bias at both the chromosome and gene levels. Insertion mutations were identified in genes that are regulated in response to the plant hormone ethylene.  相似文献   

Cognitive recovery in socially deprived young children: the Bucharest Early Intervention Project     

Nelson CA  Zeanah CH  Fox NA  Marshall PJ  Smyke AT  Guthrie D 《Science (New York, N.Y.)》2007,318(5858):1937-1940

In a randomized controlled trial, we compared abandoned children reared in institutions to abandoned children placed in institutions but then moved to foster care. Young children living in institutions were randomly assigned to continued institutional care or to placement in foster care, and their cognitive development was tracked through 54 months of age. The cognitive outcome of children who remained in the institution was markedly below that of never-institutionalized children and children taken out of the institution and placed into foster care. The improved cognitive outcomes we observed at 42 and 54 months were most marked for the youngest children placed in foster care. These results point to the negative sequelae of early institutionalization, suggest a possible sensitive period in cognitive development, and underscore the advantages of family placements for young abandoned children.  相似文献