High-fidelity laser-free universal control of trapped ion qubits.

Universal control of multiple qubits-the ability to entangle qubits and to perform arbitrary individual qubit operations1-is a fundamental resource for quantum computing2, simulation3 and networking4. Qubits realized in trapped atomic ions have shown the highest-fidelity two-qubit entangling operations5-7 and single-qubit rotations8 so far. Universal control of trapped ion qubits has been separately demonstrated using tightly focused laser beams9-12 or by moving ions with respect to laser beams13-15, but at lower fidelities. Laser-free entangling methods16-20 may offer improved scalability by harnessing microwave technology developed for wireless communications, but so far their performance has lagged the best reported laser-based approaches. Here we demonstrate high-fidelity laser-free universal control of two trapped-ion qubits by creating both symmetric and antisymmetric maximally entangled states with fidelities of [Formula: see text] and [Formula: see text], respectively (68 per cent confidence level), corrected for initialization error. We use a scheme based on radiofrequency magnetic field gradients combined with microwave magnetic fields that is robust against multiple sources of decoherence and usable with essentially any trapped ion species. The scheme has the potential to perform simultaneous entangling operations on multiple pairs of ions in a large-scale trapped-ion quantum processor without increasing control signal power or complexity. Combining this technology with low-power laser light delivered via trap-integrated photonics21,22 and trap-integrated photon detectors for qubit readout23,24 provides an opportunity for scalable, high-fidelity, fully chip-integrated trapped-ion quantum computing.

Pregnancy-Induced ISG-15 and MX-1 Gene Expression is Detected in the Liver of Holstein-Friesian Heifers During Late Peri-Implantation Period.

The bovine embryonic signal interferon-τ (IFN-τ) produced by the trophoblast is known to pass through the uterine fluid towards the endometrium and further into the maternal blood, where IFN-τ induces specific expression of interferon-stimulated gene expression (ISG), for example in peripheral leucocytes. In sheep, it was shown experimentally by administration of IFN-τ that ISG is also detectable in the liver. The objective was to test whether ISG can be detected in liver biopsy specimens from Holstein-Friesian heifers during early pregnancy. Liver biopsies were taken on day 18 from pregnant and non-pregnant heifers (n = 19), and the interferon-stimulated protein 15 kDa (ISG-15) and myxovirus-resistance protein-1 (MX-1) gene expression was detected. The expression of both MX-1 (p: 24.33 ± 7.40 vs np: 9.00 ± 4.02) and ISG-15 (p: 43.73 ± 23.22 vs 7.83 ± 3.63) was higher in pregnant compared to non-pregnant heifers (p < 0.05). In conclusion, pregnancy induced ISG-15 and MX-1 gene expression in the liver already at day 18 in cattle.

The somatotropic axis during the physiological estrus cycle in dairy heifers--Effect on hepatic expression of GHR and SOCS2.

Pituitary growth hormone (GH) release and hepatic insulin-like growth factor-I (IGF-I) production increase after an injection of 17ß-estradiol (E2) in ovariectomized dairy cattle. However, whether endogenous sexual steroid hormones also influence the hepatic GH receptor (GHR) signaling pathway during a physiological estrus cycle remains unclear. The aim of this study was to analyze the hepatic GHR signaling pathway during the luteal phase and after a period of increased E2 concentrations (after ovulation) as well as in 7 heifers before ovulation. Ovarian ultrasounds were performed daily during repeated physiological cycles (n = 56) of 30 Holstein Friesian heifers to determine ovulation [before ovulation (n = 7, bOv) and after ovulation 24-60 h after the appearance of estrus signs (n = 49, aOv)] and luteal phase (CLP; d 12 ± 1 after ovulation). Blood samples and liver biopsies were obtained, and blood concentrations of E2, P4, insulin-like growth factor (IGF)-I, IGF-II, and GH were measured. In the liver biopsies, we determined mRNA expression of the estrogen receptor α (ERα), GHR, Janus kinase 2 (JAK2), signal transducer and activator of transcription 5B (STAT5B), suppressor of cytokine signaling (SOCS)2 and 3, IGF-I, and IGF-II by quantitative reverse transcription-PCR. The concentration of E2 was higher bOv than aOv and CLP, as expected. The concentrations of IGF-I and GH were higher bOv and aOv compared with CLP. In contrast, concentrations of IGF-II were lower aOv compared with bOv and CLP. The mRNA expression of GHR was higher in liver biopsies obtained bOv compared with aOv and CLP. Notably, the expression of SOCS2 was higher bOv than aOv and in the CLP. Increased hepatic expression of SOCS2 during estrus was detectable when IGF-I concentrations were high; this result might indicate that SOCS2 expression attenuates the GHR signal transduction pathway during the phase of increased pituitary GH release. In conclusion, hepatic GHR and SOCS2 mRNA expression appeared to be promptly and sensitively regulated by increased E2 levels before ovulation of dairy heifers.