Unconditional quantum teleportation   总被引：5，自引：0，他引：5  

A Furusawa  JL Sorensen  SL Braunstein  CA Fuchs  HJ Kimble  ES Polzik 《Science (New York, N.Y.)》1998,282(5389):706-709

Quantum teleportation of optical coherent states was demonstrated experimentally using squeezed-state entanglement. The quantum nature of the achieved teleportation was verified by the experimentally determined fidelity Fexp = 0.58 +/- 0.02, which describes the match between input and output states. A fidelity greater than 0.5 is not possible for coherent states without the use of entanglement. This is the first realization of unconditional quantum teleportation where every state entering the device is actually teleported.  相似文献   

Femtosecond activation of reactions and the concept of nonergodic molecules     

EWG Diau  JL Herek  ZH Kim  AH Zewail 《Science (New York, N.Y.)》1998,279(5352):847-851

  相似文献   

Tracking the long-term decline and recovery of an isolated population     

RL Westemeier  JD Brawn  SA Simpson  TL Esker  RW Jansen  JW Walk  EL Kershner  JL Bouzat  KN Paige 《Science (New York, N.Y.)》1998,282(5394):1695-1698

Effects of small population size and reduced genetic variation on the viability of wild animal populations remain controversial. During a 35-year study of a remnant population of greater prairie chickens, population size decreased from 2000 individuals in 1962 to fewer than 50 by 1994. Concurrently, both fitness, as measured by fertility and hatching rates of eggs, and genetic diversity declined significantly. Conservation measures initiated in 1992 with translocations of birds from large, genetically diverse populations restored egg viability. Thus, sufficient genetic resources appear to be critical for maintaining populations of greater prairie chickens.  相似文献   

Coping with change in predation risk across space and time through complementary behavioral responses     

Pierrick Blanchard  Christine Lauzeral  Simon Chamaillé-Jammes  Clément Brunet  Arnaud Lec’hvien  Guillaume Péron  Dominique Pontier 《BMC ecology》2018,18(1):60

  相似文献   

Clonostachys rosea reduces spot blotch in barley by inhibiting prepenetration growth and sporulation of Bipolaris sorokiniana without inducing resistance          下载免费PDF全文

Birgit Jensen  Peter S Lübeck  Hans JL Jørgensen 《Pest management science》2016,72(12):2231-2239

  相似文献   

Factors Affecting Plasma Pregnancy-associated Glycoprotein 1 Concentrations Throughout Gestation in High-producing Dairy Cows     

B Serrano  F López-Gatius  P Santolaria  S Almería  I García-Ispierto  G Bech-Sabat  J Sulon  NM de Sousa  JF Beckers  JL Yániz 《Reproduction in domestic animals》2009,44(4):600-605

This study was designed to establish the factors, if any, which could affect plasma pregnancy-associated glycoprotein-1 (PAG-1) expression in a study population of 87 pregnant, high-producing dairy cows. The factors examined were: semen providing breed (Holstein-Friesian vs Limousin), outcome of gestation (male vs female newborn, and singleton vs twin pregnancies), lactation number, milk production at pregnancy diagnosis, plasma progesterone concentration, season of gestation (warm period, March–November vs cool period, December–February), and day of gestation (40, 90, 120, 150, 180 and 210). Pregnancy was diagnosed by transrectal ultrasound on day 40 post-insemination and by palpation per rectum on days 90, 120, 150, 180 and 210. Blood samples were collected from each animal immediately before each pregnancy diagnosis. The relative contributions of the different factors on PAG-1 concentrations were evaluated by GLM repeated measures analysis of variance. No significant effects of the herd, foetal sex, milk production, lactation number and plasma progesterone concentrations were observed. In contrast, twin pregnancy, the use of Limousin semen and conception during the cool period were correlated with significantly increased plasma PAG-1 concentrations throughout gestation. Our data indicate that both cow well-being during early placental development, determined in our conditions by reduced heat stress when conception occurred in the cool season, and crossbreed pregnancies lead to improved PAG-1 production throughout the gestation period.  相似文献   

The Influence of Oxygen Tension on Cumulus Cell Viability of Canine COCs Matured in High-Glucose Medium     

AEF Silva  P Rodriguez  LF Cavalcante  BA Rodrigues  JL Rodrigues 《Reproduction in domestic animals》2009,44(S2):259-262

High in vitro oxygen (O₂) tensions are associated with enhanced levels of reactive oxygen species and cumulus oocyte complex (COC) apoptosis. The objective of this study was to determine the influence of O₂ tension on cumulus cell (CC) viability from canine oocytes. Cumulus oocyte complexes were distributed into three groups (CG, T20 and T5) and two O₂ tension levels (20% and 5%). The control group (CG) was matured in vitro in a humidified atmosphere with 5% CO₂ in air in TCM199 with 26.19 m m sodium bicarbonate, 10% (v/v) foetal calf serum (FCS), 0.10 m m gentamicin, 0.20 m m pyruvic acid, 20 μg/ml oestradiol, 0.5 μg/ml follicle-stimulating hormone, 0.03 IU/ml human chorionic gonadotropin, and 1.0 μg/ml human somatotropin. Groups T20 and T5 were matured under 20% or 5% O₂ tensions respectively in a high-glucose medium, without FCS. T20 and T5 were as CG, and supplemented with 0.1% Polyvinyl Alcohol, and 5.5 m m glucose. After 48 h of IVM, CCs from COCs were stained with propidium iodide (1.50 m m ). The results showed that viability of CCs (cytoplasmic features and nuclear morphological integrity) was different for the three groups. Rates of apoptosis were at 57.9% (521/900) for CG, 54.4% (490/900) for T20 and 38.9% (350/900) for T5 (p < 0.001). Predominant features in apoptotic cells (n = 1361) were DNA nuclear fragments (94.0%). It was concluded that CCs of canine COCs cultured in high-glucose medium showed significantly less apoptosis than those cultured in medium with FCS. Low O₂ tension was efficient in reducing apoptosis in canine CCs.  相似文献   

Changing trends in mastitis     

RN Zadoks  JL Fitzpatrick 《Irish veterinary journal》2009,62(Z4):S59

The global dairy industry, the predominant pathogens causing mastitis, our understanding of mastitis pathogens and the host response to intramammary infection are changing rapidly. This paper aims to discuss changes in each of these aspects. Globalisation, energy demands, human population growth and climate change all affect the dairy industry. In many western countries, control programs for contagious mastitis have been in place for decades, resulting in a decrease in occurrence of Streptococcus agalactiae and Staphylococcus aureus mastitis and an increase in the relative impact of Streptococcus uberis and Escherichia coli mastitis. In some countries, Klebsiella spp. or Streptococcus dysgalactiae are appearing as important causes of mastitis. Differences between countries in legislation, veterinary and laboratory services and farmers' management practices affect the distribution and impact of mastitis pathogens. For pathogens that have traditionally been categorised as contagious, strain adaptation to human and bovine hosts has been recognised. For pathogens that are often categorised as environmental, strains causing transient and chronic infections are distinguished. The genetic basis underlying host adaptation and mechanisms of infection is being unravelled. Genomic information on pathogens and their hosts and improved knowledge of the host's innate and acquired immune responses to intramammary infections provide opportunities to expand our understanding of bovine mastitis. These developments will undoubtedly contribute to novel approaches to mastitis diagnostics and control.  相似文献   

Response of Thawed Epidi dymal Red Deer Spermatozoa to Increasing Concentrations of Hydrogen Peroxide,and Importance of Individual Male Variability     

AE Domínguez‐Rebolledo  F Martínez‐Pastor  AF Bisbal  JL Ros‐Santaella  O García‐Álvarez  A Maroto‐Morales  AJ Soler  JJ Garde  MR Fernández‐Santos 《Reproduction in domestic animals》2011,46(3):393-403

Oxidative stress represents a challenge during sperm manipulation. We have tested the effect of increasing hydrogen peroxide (H₂O₂) levels on red deer spermatozoa after cryopreservation, and the role of male‐to‐male variation in that response. In a first experiment, eight thawed samples were submitted to 0, 25, 50, 100 and 200 μm H₂O₂ for 2 h at 37°C. Intracellular reactive oxygen species (H₂DCFDA‐CM) increased with H₂O₂ concentration, but we only detected a decrease in sperm function (motility by CASA and chromatin damage by sperm chromatin structure assay) with 200 μm . Lipoperoxidation assessed by the thiobarbituric acid reactive substance (TBARS) method increased slightly with 50 μm H₂O₂ and above. In a second experiment, samples from seven males were submitted to 0 and 200 μm H₂O₂ for 2 h, triplicating the experiment within each male. Males differed at thawing and regarding their response to incubation and H₂O₂ presence. We found that the kinematic parameters reflected male‐to‐male variability, whereas the response of the different males was similar for lipid peroxidation and viability. A multiparametric analysis showed that males grouped differently if samples were assessed after thawing, after incubation without H₂O₂ or after incubation with H₂O₂. Red deer spermatozoa are relatively resilient to H₂O₂ after thawing, but it seems to be a great male‐to‐male variability regarding the response to oxidative stress. The acknowledgement of this individual variability might improve the development of optimized sperm work protocols.  相似文献   

Computed tomographic findings,surgical management and postoperative outcomes of large intermuscular lipomas in the hindlimb of 11 dogs     

JD Crowley  G Hosgood  NV Crawford  JL Richardson 《Australian veterinary journal》2020,98(4):135-139

  相似文献