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The vascular cell adhesion molecule 1 (VCAM1) has a strong influence on embryonic development and on the formation of the umbilical cord and placenta. These developmental processes are crucial to ensure the success of pregnancy. In this work, we have identified two T306A and C558T single nucleotide polymorphisms (SNP) at exons 2 and 3 of the pig VCAM1 locus, respectively. The T306A substitution involves a non conservative Asn to Lys replacement at amino acid position 102, whereas the C558T polymorphism is synonymous. An in silico prediction of the consequences of the Asn102→Lys102 mutation with the PolyPhen software revealed that it is not deleterious. The T306A SNP segregated in the Iberian, Piétrain, Duroc, Large White and Landrace breeds as well as in European wild boars. The C558T SNP also segregated and most of commercial standard breeds. The genotyping of the C558T SNP in an Iberian × Meishan intercross allowed to find a suggestive association (Bonferroni threshold, p < 0.004) between C558T genotype and time the newborn piglet needs to reach the udder (p = 0.013) as well as a significant one with time to make the first ingestion of colostrum (p = 0.003). The biological basis of these associations remains unclear and they should be interpreted with caution.  相似文献   
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Loss of pigs during or after transport is a welfare concern, but also an economic concern for producers. Transport losses include animals that are dead on arrival (DOA) at the plant, pigs that are injured, and pigs which are not obviously injured but unwilling or unable to walk (non-ambulatory, non-injured or NANI). The objective of this research was to assess the health of non-ambulatory, non-injured (NANI) pigs relative to control pigs at the processing plant by looking at a range of measures, including complete blood chemistry, anatomy, and pathology to determine potential factors associated with pigs going down. Data were collected from NANI and control pigs at five plants in the midwest USA. Feet and legs and internal organs were inspected and the severity of the pathology scored. Alveolar macrophages were collected and counted. Blood was collected for analysis of hematology, blood chemistry and cortisol concentrations. Titers to common porcine respiratory viruses were measured in pigs from one plant. Hoof and pad problems did not differ overall between control and NANI pigs, however the percentage of severe foot problems was greater (P < 0.05) in NANI compared with control pigs at plants A and E. The percentage of total ulcers, rhinitis, and empty stomachs differed (P < 0.05) between control and NANI pigs at individual plants, but not overall. Blood hematology and chemistry differed (P < 0.05) between NANI and control pigs. Cortisol concentrations did not differ between NANI and control pigs. Titers to swine influenza virus (SIV) H1N1 and H3N2 and porcine circovirus (PCV) were lower (P < 0.01) among NANI compared with control pigs. However, more (P < 0.01) NANI pigs were positive for SIV H1N1 and H3N2 compared with control pigs. Blood hematology, chemistry, and pathology indicate a large difference between NANI and controls pigs. No single health problem was higher among NANI pigs compared to plant-matched control pigs. Rather, several problems appear to contribute to pigs becoming NANI which may differ from one plant too another.  相似文献   
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Two depth profiles of the osmium concentration and the 187Os/186Os isotopic ratio in the Indian Ocean showed that the osmium concentration seems to be unaltered by chemical or biological processes occuring in seawater; accordingly, osmium is conservative. These data were obtained from an experimental method that eliminated the problems related to osmium preconcentration. This method led to a new evaluation of the concentration of osmium in seawater; the mean concentration of osmium and the 187Os/186Os ratio are equal to 10.86 +/- 0.07 picograms per kilogram and 8.80 +/- 0.07, respectively. The results suggest the existence of an organocomplex that dominates the speciation of osmium in seawater.  相似文献   
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Unconditional quantum teleportation   总被引:5,自引:0,他引:5  
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   
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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   
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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   
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