Service-Learning stands out as a teaching approach that connects theory and practice by giving students the opportunity both to participate in a service that meets community needs and to reflect on ...the experience in class in order to gain a deeper understanding of the course content and an enhanced sense of civic engagement. The advantages of Service-Learning for inclusive education have recently been underpinned by studies, in which pre-service teachers are exposed to diverse population groups in schools or communities. Our study explores how Service-Learning is applied in teacher education in Austria. It is based on a series of semi-structured interviews with 13 teacher educators who apply this form of teaching in cooperative projects with schools. Our findings suggest that teacher educators distinguish between five orientations in Service-Learning (connecting theory and practice, engagement, community needs, job-related skills, learning outside the classroom), take on distinct expert and support roles, and see multiple benefits in Service-Learning. Our study underlines the importance of Service-Learning for inclusive education and the value of preparing pre-service teachers for dealing with diverse groups of pupils by allowing them to experience the real-world problems that confront schools.
Standard quantum computation is based on sequences of unitary quantum logic gates that process qubits. The one-way quantum computer proposed by Raussendorf and Briegel is entirely different. It has ...changed our understanding of the requirements for quantum computation and more generally how we think about quantum physics. This new model requires qubits to be initialized in a highly entangled cluster state. From this point, the quantum computation proceeds by a sequence of single-qubit measurements with classical feedforward of their outcomes. Because of the essential role of measurement, a one-way quantum computer is irreversible. In the one-way quantum computer, the order and choices of measurements determine the algorithm computed. We have experimentally realized four-qubit cluster states encoded into the polarization state of four photons. We characterize the quantum state fully by implementing experimental four-qubit quantum state tomography. Using this cluster state, we demonstrate the feasibility of one-way quantum computing through a universal set of one- and two-qubit operations. Finally, our implementation of Grover's search algorithm demonstrates that one-way quantum computation is ideally suited for such tasks.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A time lens, which can be used to reshape the spectral and temporal properties of light, requires the ultrafast manipulation of optical signals and presents a significant challenge for single-photon ...application. In this work, we construct a time lens based on dispersion and sum-frequency generation to spectrally engineer single photons from an entangled pair. The strong frequency anticorrelations between photons produced from spontaneous parametric down-conversion are converted to positive correlations after the time lens, consistent with a negative-magnification system. The temporal imaging of single photons enables new techniques for time-frequency quantum state engineering.
We demonstrate a new architecture for an optical entangling gate that is significantly simpler than previous realizations, using partially polarizing beam splitters so that only a single optical ...mode-matching condition is required. We demonstrate operation of a controlled-z gate in both continuous-wave and pulsed regimes of operation, fully characterizing it in each case using quantum process tomography. We also demonstrate a fully resolving, nondeterministic optical Bell-state analyzer based on this controlled-z gate. This new architecture is ideally suited to guided optics implementations of optical gates.
Photons are critical to quantum technologies because they can be used for virtually all quantum information tasks, for example, in quantum metrology, as the information carrier in photonic quantum ...computation, as a mediator in hybrid systems, and to establish long-distance networks. The physical characteristics of photons in these applications differ drastically; spectral bandwidths span 12 orders of magnitude from 50 THz (ref. 6) for quantum-optical coherence tomography to 50 Hz for certain quantum memories. Combining these technologies requires coherent interfaces that reversibly map centre frequencies and bandwidths of photons to avoid excessive loss. Here, we demonstrate bandwidth compression of single photons by a factor of 40 as well as tunability over a range 70 times that bandwidth via sum-frequency generation with chirped laser pulses. This constitutes a time-to-frequency interface for light capable of converting time-bin to colour entanglement, and enables ultrafast timing measurements. It is a step towards arbitrary waveform generation for single and entangled photons.
Many-particle entangled states and entanglement between continuous properties are valuable resources for quantum information, but are notoriously difficult to generate. An experiment by Shalm et al ...now entangles the energy and emission times of three photons, creating generalized Einstein-Podolsky-Rosen correlations.
We have performed the first experimental tomographic reconstruction of a three-photon polarization state. Quantum state tomography is a powerful tool for fully describing the density matrix of a ...quantum system. We measured 64 three-photon polarization correlations and used a "maximum-likelihood" reconstruction method to reconstruct the Greenberger-Horne-Zeilinger state. The entanglement class has been characterized using an entanglement witness operator and the maximum predicted values for the Mermin inequality were extracted.
An entirely plasmid-based reverse genetics (RG) system was recently developed for rotavirus (RV), opening new avenues for in-depth molecular dissection of RV biology, immunology, and pathogenesis. ...Several improvements to further optimize the RG efficiency have now been described. However, only a small number of individual RV strains have been recovered to date. None of the current methods have supported the recovery of murine RV, impeding the study of RV replication and pathogenesis in an
suckling mouse model. Here, we describe useful modifications to the RG system that significantly improve rescue efficiency of multiple RV strains. In addition to the 11 group A RV segment-specific (+)RNAs (+)ssRNAs, a chimeric plasmid was transfected, from which the capping enzyme NP868R of African swine fever virus (ASFV) and the T7 RNA polymerase were expressed. Second, a genetically modified MA104 cell line was used in which several components of the innate immunity were degraded. Using this RG system, we successfully recovered the simian RV RRV strain, the human RV CDC-9 strain, a reassortant between murine RV D6/2 and simian RV SA11 strains, and several reassortants and reporter RVs. All these recombinant RVs were rescued at a high efficiency (≥80% success rate) and could not be reliably rescued using several recently published RG strategies (<20%). This improved system represents an important tool and great potential for the rescue of other hard-to-recover RV strains such as low-replicating attenuated vaccine candidates or low-cell culture passage clinical isolates from humans or animals.
Group A rotavirus (RV) remains as the single most important cause of severe acute gastroenteritis among infants and young children worldwide. An entirely plasmid-based reverse genetics (RG) system was recently developed, opening new ways for in-depth molecular study of RV. Despite several improvements to further optimize the RG efficiency, it has been reported that current strategies do not enable the rescue of all cultivatable RV strains. Here, we described a helpful modification to the current strategies and established a tractable RG system for the rescue of the simian RRV strain, the human CDC-9 strain, and a murine-like RV strain, which is suitable for both
and
studies. This improved RV reverse genetics system will facilitate study of RV biology in both
and
systems that will facilitate the improved design of RV vaccines, better antiviral therapies, and expression vectors.
A huge clinical research database on adjuvant cancer treatment has verified improvements in breast cancer outcomes such as recurrence and mortality rates. On the other hand, adjuvant therapy with ...agents such as hormone therapy, chemotherapy and radiotherapy impacts on quality of life due to substantial short- and long-term side effects.
To assess the effect of aerobic or resistance exercise interventions during adjuvant treatment for breast cancer on treatment-related side effects such as physical deterioration, fatigue, psychosocial distress and physiological, morphological and biological changes.
We searched the Cochrane Breast Cancer Specialised Register (16 July 2004) and the following electronic databases: MEDLINE (1966 to 2006), EMBASE (1988 to 2004), CINAHL (1982 to 2004), SPORTDiscus (1975 to 2004), PsycINFO (1872 to 2003), SIGLE (1880 to 2004), ProQuest Digital Dissertations (1861 to 2004) and Conference Papers Index (1973 to 2004). Furthermore, we screened references in relevant reviews and clinical trials and handsearched relevant journals.
We included randomised and non-randomised controlled trials that examined aerobic or resistance exercise, or both, in women undergoing adjuvant treatment for breast cancer.
Two authors independently extracted data and assessed methodological quality and adequacy of the training stimulus following a set of standardised criteria. Meta-analyses were performed for physical fitness, fatigue and weight gain using a random-effects model.
Nine trials involving 452 women met the inclusion criteria. Meta-analysis for cardiorespiratory fitness (involving 207 participants) suggested that exercise improves cardiorespiratory fitness (SMD 0.66, 95% CI 0.20 to 1.12). Meta-analysis for fatigue (317 participants) found statistically non-significant improvements for participants in the exercise intervention groups compared to control (non-exercising) groups (SMD -0.12, 95% CI -0.37 to 0.13); the same applied for the meta-analysis of weight gain (147 participants) (SMD -1.11, 95% CI -2.44 to 0.22). Evidence for other outcomes remains limited. Adverse effects (lymphedema and shoulder tendonitis) were observed in two trials. The results from non-randomised controlled trials are similar to those of randomised controlled trials and do not appear to produce any bias. This review is based on a small number of trials with a considerable degree of clinical heterogeneity regarding adjuvant cancer treatments and exercise interventions.
Exercise during adjuvant treatment for breast cancer can be regarded as a supportive self-care intervention which results in improved physical fitness and thus the capacity for performing activities of daily life, which may otherwise be impaired due to inactivity during treatment. Improvements in fatigue were ambiguous and there was a lack of evidence for improvement with exercise for other treatment-related side effects. Since exercise interventions (for sedentary participants) require behaviour change, strategies for behaviour change should underpin these interventions. Furthermore, long-term evaluation is required due to possible long-term side effects.
PDF
