352 research outputs found

    An in vivo culture system for human embryos using an encapsulation technology: a pilot study

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    BACKGROUND Animal studies have demonstrated better embryo development in vivo than in vitro. This pilot study tested the feasibility of using a novel in utero culture system (IUCS) to obtain normal human fertilization and embryo development. METHODS The IUCS device comprised a perforated silicone hollow tube. The study included 13 patients (<36 years) undergoing a first intracytoplasmic sperm injection (ICSI) treatment and 167 metaphase II oocytes in three groups. In Group 1, 1-2 h after ICSI, sibling oocytes were assigned to IUCS or conventional in vitro culture. The device was retrieved on Day 1, and all zygotes were cultured in vitro till Day 5. In Group 2, fertilized oocytes were assigned on Day 1, embryos retrieved on Day 3 and all embryos cultured till Day 5. In Group 3, after Day 0 assignment, embryos were retrieved on Day 3 for blastomere biopsy and fluorescence in situ hybridization (FISH) and cultured until Day 5. The highest quality blastocysts were transferred on Day 5. RESULTS Fertilization and embryo development were comparable in the in vitro and IUCS arms, with a tendency towards better embryo quality in the IUCS. FISH analysis in Group 3 revealed more normal embryos using the IUCS (P = 0.049). Three clinical pregnancies and live births were obtained: two from the IUCS arm and one from the in vitro arm. CONCLUSIONS Our pilot study shows that this new IUCS appears to be feasible and safe, supporting normal fertilization, embryo development and normal chromosomal segregation. Furthermore, live births are possible after the transient presence of a silicone device in the uterus.Clinicaltrials.gov: NCT0048010

    An in vivo culture system for human embryos using an encapsulation technology: a pilot study

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    ACKGROUND: Animal studies have demonstrated better embryo development in vivo than in vitro. This pilot study tested the feasibility of using a novel in utero culture system (IUCS) to obtain normal human fertilization and embryo development. METHODS: The IUCS device comprised a perforated silicone hollow tube. The study included 13 patients (<36 years) undergoing a first intracytoplasmic sperm injection (ICSI) treatment and 167 metaphase II oocytes in three groups. In Group 1, 1-2 h after ICSI, sibling oocytes were assigned to IUCS or conventional in vitro culture. The device was retrieved on Day 1, and all zygotes were cultured in vitro till Day 5. In Group 2, fertilized oocytes were assigned on Day 1, embryos retrieved on Day 3 and all embryos cultured till Day 5. In Group 3, after Day 0 assignment, embryos were retrieved on Day 3 for blastomere biopsy and fluorescence in situ hybridization (FISH) and cultured until Day 5. The highest quality blastocysts were transferred on Day 5. RESULTS: Fertilization and embryo development were comparable in the in vitro and IUCS arms, with a tendency towards better embryo quality in the IUCS. FISH analysis in Group 3 revealed more normal embryos using the IUCS (P = 0.049). Three clinical pregnancies and live births were obtained: two from the IUCS arm and one from the in vitro arm. CONCLUSIONS: Our pilot study shows that this new IUCS appears to be feasible and safe, supporting normal fertilization, embryo development and normal chromosomal segregation. Furthermore, live births are possible after the transient presence of a silicone device in the uterus. Clinicaltrials.gov: NCT00480103

    Effect of yeast culture on milk production and metabolic and reproductive performance of early lactation dairy cows

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    <p>Abstract</p> <p>Background</p> <p>The main objective of this study was to estimate the effect of supplementation with <it>Saccaromyces cerevisiae (SC</it>) (Yea-Sacc<sup>® </sup>1026) on milk production, metabolic parameters and the resumption of ovarian activity in early lactation dairy cows.</p> <p>Methods</p> <p>The experiment was conducted during 2005/2006 in a commercial tied-house farm with an average of 200 milking Estonian Holstein Friesian cows. The late pregnant multiparous cows (n = 46) were randomly divided into two groups; one group received 10 g yeast culture from two weeks before to 14 weeks after calving. The groups were fed a total mixed ration with silages and concentrates. Milk recording data and blood samples for plasma metabolites were taken. Resumption of luteal activity was determined using milk progesterone (P<sub>4</sub>) measurements. Uterine bacteriology and ovarian ultrasonography (US) were performed and body condition scores (BCS) and clinical disease occurrences were recorded. For analysis, the statistical software Stata 9.2 and R were used to compute Cox proportional hazard and linear mixed models.</p> <p>Results</p> <p>The average milk production per cow did not differ between the groups (32.7 ± 6.4 vs 30.7 ± 5.3 kg/day in the SC and control groups respectively), but the production of milk fat (<it>P </it>< 0.001) and milk protein (<it>P </it>< 0.001) were higher in the SC group. There was no effect of treatment on BCS. The analysis of energy-related metabolites in early lactation showed no significant differences between the groups. In both groups higher levels of β-hydroxybutyrate (BHB) appeared from days 14 to 28 after parturition and the concentration of non-esterfied fatty acid (NEFA) was higher from days 1–7 post partum (PP). According to US and P<sub>4 </sub>results, all cows in both groups ovulated during the experimental period. The resumption of ovarian activity (first ovulations) and time required for elimination of bacteria from the uterus did not differ between the groups.</p> <p>Conclusion</p> <p>Supplementation with SC had an effect on milk protein and fat production, but did not influence the milk yield. No effects on PP metabolic status, bacterial elimination from the uterus nor the resumption of ovarian activity were found.</p

    Measurement of the Spectroscopy of Orbitally Excited B Mesons at LEP

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    We measure the masses, decay widths and relative production rate of orbitally excited B mesons using 1.25 million hadronic Z decays recorded by the L3 detector. B-meson candidates are inclusively reconstructed and combined with charged pions produced at the primary event vertex. An excess of events above the expected background in the B\pi mass spectrum in the region 5.6-5.8 GeV is interpreted as resulting from the decay B_u,d^** -> B^(*)\pi, where B_u,d^** denotes a mixture of l=1 B-meson states containing a u or a d quark. A fit to the mass spectrum yields the masses and decay widths of the B_1^* and B_2^* spin states, as well as the branching fraction for the combination of l=1 states. In addition, evidence is presented for the existence of an excited B-meson state or mixture of states in the region 5.9-6.0 GeV

    Search for Charged Higgs Bosons in e+e- Collisions at \sqrt{s} = 189 GeV

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    A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a charm and a strange quark or into a tau lepton and its associated neutrino are considered. The observed events are consistent with the expectations from Standard Model background processes. A lower limit of 65.5 GeV on the charged Higgs mass is derived at 95 % confidence level, independent of the decay branching ratio Br(H^{+/-} -> tau nu)

    Search for the standard model Higgs boson at LEP

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    Variation in Size and Growth of the Great Scallop Pecten maximus along a Latitudinal Gradient

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    Understanding the relationship between growth and temperature will aid in the evaluation of thermal stress and threats to ectotherms in the context of anticipated climate changes. Most Pecten maximus scallops living at high latitudes in the northern hemisphere have a larger maximum body size than individuals further south, a common pattern among many ectotherms. We investigated differences in daily shell growth among scallop populations along the Northeast Atlantic coast from Spain to Norway. This study design allowed us to address precisely whether the asymptotic size observed along a latitudinal gradient, mainly defined by a temperature gradient, results from differences in annual or daily growth rates, or a difference in the length of the growing season. We found that low annual growth rates in northern populations are not due to low daily growth values, but to the smaller number of days available each year to achieve growth compared to the south. We documented a decrease in the annual number of growth days with age regardless of latitude. However, despite initially lower annual growth performances in terms of growing season length and growth rate, differences in asymptotic size as a function of latitude resulted from persistent annual growth performances in the north and sharp declines in the south. Our measurements of daily growth rates throughout life in a long-lived ectothermic species provide new insight into spatio-temporal variations in growth dynamics and growing season length that cannot be accounted for by classical growth models that only address asymptotic size and annual growth rate

    Production of Single W Bosons at LEP

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    We report on the observation of single W boson production in a data sample collected by the L3 detector at LEP2. The signal consists of large missing energy final states with a single energetic lepton or two hadronic jets. The cross-section is measured to be 0.610.33+0.43±0.05  pb0.61^{+0.43}_{-0.33} \pm 0.05 \; \rm{pb} at the centre of mass energy \sqrt{s}=172 \GeV{}, consistent with the Standard Model expectation. From this measurement the following limits on the anomalous γ\gammaWW gauge couplings are derived at 95\% CL: 3.6Δκγ1.5\rm -3.6 \Delta \kappa_\gamma 1.5 and 3.6λγ3.6\rm -3.6 \lambda_\gamma 3.6

    Measurement of the Average Lifetime of b-Hadrons in Z Decays

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    We present a measurement of the average b-hadron lifetime τb{\rm \tau_b} at the e+e\mathrm{e^+e^-} \, collider LEP. Using hadronic Z decays collected in the period from 1991 to 1994, two independent analyses have been performed. In the first one, the b-decay position is reconstructed as a secondary vertex of hadronic b-decay particles. The second analysis is an updated measurement of τb{\rm \tau_b} using the impact parameter of leptons with high momentum and high transverse momentum. The combined result is \begin{center} τb=[1549±9(stat)±15(syst)]  fs{\rm \tau_b= [ 1549 \pm 9 \, (stat) \, \pm 15 \, (syst) ] \; fs \,} . \end{center} In addition, we measure the average charged b-decay multiplicity nb{\rm \langle n_{\rm b}} \rangle and the normalized average b-energy xEb{\rm \langle x_E \rangle_{\rm b}} at LEP to be \begin{center} nb=4.90±0.04 (stat)±0.11(syst){\rm \langle n_{\rm b} \rangle = 4.90 \pm 0.04 \ (stat) \pm 0.11 \, (syst)} , \end{center} \begin{center} xEb=0.709±0.004(stat+syst).{\rm \langle x_E \rangle_{\rm b} = 0.709 \pm 0.004 \, (stat + syst).} \end{center
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