95 research outputs found

    Multimode ion-photon entanglement over 101 kilometers of optical fiber

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    A three-qubit quantum network node based on trapped atomic ions is presented. The ability to establish entanglement between each of the qubits in the node and a separate photon that has travelled over a 101km-long optical fiber is demonstrated. By sending those photons through the fiber in close succession, a remote entanglement rate is achieved that is greater than when using only a single qubit in the node. Once extended to more qubits, this multimode approach can be a useful technique to boost entanglement distribution rates in future long-distance quantum networks of light and matter.Comment: 9 pages, 3 figure

    Operation of a planar-electrode ion-trap array with adjustable RF electrodes

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    One path to realizing systems of trapped atomic ions suitable for large-scale quantum computing and simulation is to create a two-dimensional (2D) array of ion traps. Interactions between nearest-neighbouring ions could then be turned on and off by tuning the ions’ relative positions and frequencies. We demonstrate and characterize the operation of a planar-electrode ion-trap array. By driving the trap with a network of phase-locked radio-frequency resonators which provide independently variable voltage amplitudes we vary the position and motional frequency of a Ca ion in two-dimensions within the trap array. Work on fabricating a miniaturised form of this 2D trap array is also described, which could ultimately provide a viable architecture for large-scale quantum simulations.published_or_final_versio

    The EORTC emotional functioning computerized adaptive test:phases I-III of a cross-cultural item bank development

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    Background: The European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group is currently developing computerized adaptive testing measures for the Quality of Life Questionnaire Core-30 (QLQ-C30) scales. The work presented here describes the development of an EORTC item bank for emotional functioning (EF), which is one of the core domains of the QLQ-C30. Methods: According to the EORTC guidelines on module development, the development of the EF item bank comprised four phases, of which the phases I-III are reported in the present paper. Phase I involved defining the theoretical framework for the EF item bank and a literature search. Phase II included pre-defined item selection steps and a multi-stage expert review process. In phase III, feedback from cancer patients from different countries was obtained. Results: On the basis of literature search in phase I, a list of 1750 items was generated. These were reviewed and further developed in phase II with a focus on relevance, redundancy, clarity, and difficulty. The development and selection steps led to a preliminary list of 41 items. In phase III, patient interviews (N = 41; Austria, Denmark, Italy, and the UK) were conducted with the preliminary item list, resulting in some minor changes to item wording. The final list comprised 38 items. Discussion: The phases I-III of the developmental process have resulted in an EF item list that was well accepted by patients in several countries. The items will be subjected to larger-scale field testing in order to establish their psychometric characteristics and their fit to an item response theory model

    Monitoring physical and psychosocial symptom trajectories in ovarian cancer patients receiving chemotherapy

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    <p>Abstract</p> <p>Background</p> <p>Diagnosis and treatment of ovarian cancer (OC) entail severe symptom burden and a significant loss of quality of life (QOL). Somatic and psychological impairments may persist well beyond active therapy. Although essential for optimal symptom management as well as for the interpretation of treatment outcomes, knowledge on the course of QOL-related issues is scarce. This study aimed at assessing the course of depressive symptoms, anxiety, fatigue and QOL in patients with OC over the course of chemotherapy until early after-care.</p> <p>Methods</p> <p>23 patients were assessed longitudinally (eight time points) with regard to symptom burden (depression, anxiety, fatigue, and QOL) by means of patient-reported outcome instruments (HADS, MFI-20, EORTC QLQ-C30/-OV28) and clinician ratings (HAMA/D) at each chemotherapy cycle and at the first two aftercare visits.</p> <p>Results</p> <p>Statistically significant decrease over time was found for depressive symptoms and anxiety as well as for all fatigue scales. With regard to QOL, results indicated significant increase for 11 of 15 QOL scales, best for Social (effect size = 1.95; <it>p </it>< 0.001), Emotional (e.s. = 1.62; <it>p </it>< 0.001) and Physical Functioning (e.s. = 1.47; <it>p </it>< 0.001). Abdominal Symptoms (e.s. = 1.01; <it>p </it>= 0.009) decreased, Attitudes towards Disease and Treatment (e.s. = 1.80; <it>p </it>< 0.001) improved significantly over time. Analysis of Sexual Functioning was not possible due to a high percentage of missing responses (61.9%).</p> <p>Conclusions</p> <p>The present study underlines the importance of longitudinal assessment of QOL in order to facilitate the identification of symptom burden in OC patients. We found that patients show high levels of fatigue, anxiety and depressive symptoms and severely impaired QOL post-surgery (i.e. at start of chemotherapy) but condition improves considerably throughout chemotherapy reaching nearly general population symptoms levels until aftercare.</p

    OR14I1 is a receptor for the human cytomegalovirus pentameric complex and defines viral epithelial cell tropism

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    A human cytomegalovirus (HCMV) pentameric glycoprotein complex (PC), gH-gL-UL128-UL130-UL131A, is necessary for viral infection of clinically relevant cell types, including epithelial cells, which are important for interhost transmission and disease. We performed genome-wide CRISPR/Cas9 screens of different cell types in parallel to identify host genes specifically required for HCMV infection of epithelial cells. This effort identified a multipass membrane protein, OR14I1, as a receptor for HCMV infection. This olfactory receptor family member is required for HCMV attachment, entry, and infection of epithelial cells and is dependent on the presence of viral PC. OR14I1 is required for AKT activation and mediates endocytosis entry of HCMV. We further found that HCMV infection of epithelial cells is blocked by a synthetic OR14I1 peptide and inhibitors of adenylate cyclase and protein kinase A (PKA) signaling. Identification of OR14I1 as a PC-dependent HCMV host receptor associated with epithelial tropism and the role of the adenylate cyclase/PKA/AKT-mediated signaling pathway in HCMV infection reveal previously unappreciated targets for the development of vaccines and antiviral therapies

    Entanglement of trapped-ion qubits separated by 230 meters

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    We report on an elementary quantum network of two atomic ions separated by 230 m. The ions are trapped in different buildings and connected with 520(2) m of optical fiber. At each network node, the electronic state of an ion is entangled with the polarization state of a single cavity photon; subsequent to interference of the photons at a beamsplitter, photon detection heralds entanglement between the two ions. Fidelities of up to (88.2+2.36.0)%(88.2+2.3-6.0)\% are achieved with respect to a maximally entangled Bell state, with a success probability of 4×1054 \times 10^{-5}. We analyze the routes to improve these metrics, paving the way for long-distance networks of entangled quantum processors

    Cell cycle-dependent acetylation of Rb2/p130 in NIH3T3 cells

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    The retinoblastoma protein (pRb) and the pRb-related proteins, p130 and p107, form the ‘pocket protein' family of cell cycle regulatory factors. A well characterized function of these proteins is the cell cycle-dependent regulation of E2F-responsive genes. The biological activity of pocket proteins is regulated by phosphorylation and for the founding member pRb it has been shown that acetylation also has an important role in modulating its function during the cell cycle. Here, we show that hyperphosphorylated retinoblastoma 2 (Rb2)/p130 also exists in an acetylated form in NIH3T3 cells. Acetylated p130 is present in the nucleus but not in the cytoplasm. Acetylation is cell cycle dependent, starting in S-phase and persisting until late G2-period. Using recombinant p130 and truncated forms for in vitro acetylation by the acetyltransferase p300, we could identify K1079 in the C-terminal part as the major acetylation site by mass spectrometry. Minor acetylation sites were pinpointed to K1068 and K1111 in the C-terminus, and K128 and K130 in the N-terminus. The human papilloma virus 16 protein-E7 preferentially binds to acetylated p130 and significantly increases in vitro p130 acetylation by p300

    The Effect of Recurrent Floods on Genetic Composition of Marble Trout Populations

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    A changing global climate can threaten the diversity of species and ecosystems. We explore the consequences of catastrophic disturbances in determining the evolutionary and demographic histories of secluded marble trout populations in Slovenian streams subjected to weather extremes, in particular recurrent flash floods and debris flows causing massive mortalities. Using microsatellite data, a pattern of extreme genetic differentiation was found among populations (global FST of 0.716), which exceeds the highest values reported in freshwater fish. All locations showed low levels of genetic diversity as evidenced by low heterozygosities and a mean of only 2 alleles per locus, with few or no rare alleles. Many loci showed a discontinuous allele distribution, with missing alleles across the allele size range, suggestive of a population contraction. Accordingly, bottleneck episodes were inferred for all samples with a reduction in population size of 3–4 orders of magnitude. The reduced level of genetic diversity observed in all populations implies a strong impact of genetic drift, and suggests that along with limited gene flow, genetic differentiation might have been exacerbated by recurrent mortalities likely caused by flash flood and debris flows. Due to its low evolutionary potential the species might fail to cope with an intensification and altered frequency of flash flood events predicted to occur with climate change
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