9,051 research outputs found
Quantum Algorithmic Readout in Multi-Ion Clocks
Optical clocks based on ensembles of trapped ions offer the perspective of
record frequency uncertainty with good short-term stability. Most suitable
atomic species lack closed transitions for fast detection such that the clock
signal has to be read out indirectly through transferring the quantum state of
clock ions to co-trapped logic ions by means of quantum logic operations. For
ensembles of clock ions existing methods for quantum logic readout require a
linear overhead in either time or the number of logic ions. Here we report a
quantum algorithmic readout whose overhead scales logarithmically with the
number of clock ions in both of these respects. We show that the readout
algorithm can be implemented with a single application of a multi-species
quantum gate, which we describe in detail for a crystal of Aluminum and Calcium
ions.Comment: 4 pages + 7 pages appendix; 5 figures; v3: published versio
A New Agro-Meteorological Simulation Model for Predicting Daily Grass Growth Rates Across Ireland
Grass growth rates and herbage yields depend on weather conditions, soil characteristics and grassland management and differ from year to year and from site to site. In the past, grass growth has been predicted using both mechanistic and statistical models. The accuracy of mechanistic models is commonly insufficient for practical application, while statistical models generally apply to one test site only (e.g. Han et al., 2003). In this paper a semi-empirical grass growth model is presented which is numerically accurate, but which can be applied to contrasting sites across Ireland at the same time
Beam-beam instability driven by wakefield effects in linear colliders
The vertical beam profile distortions induced by wakefield effects in linear colliders (the so-called ``banana effect'') generate a beam-beam instability at the collision point when the vertical disruption parameter is large. We illustrate this effect in the case of the TESLA linear collider project. We specify the tolerance on the associated emittance growth, which translates into tolerances on injection jitter and, for a given tuning procedure, on structure misalignments. We look for possible cures based on fast orbit correction at the interaction point and using a fast luminosity monitor
Requirement for the NF-kappa B family member Re1A in the development of secondary lymphoid organs
The transcription factor nuclear factor (NF)-kappaB has been suggested to be a key mediator of the development of lymph nodes and Peyer's patches. However, targeted deletion of NF-kappaB/ Rel family members has not yet corroborated such a function. Here we report that when mice lacking the RelA subunit of NF-kappaB are brought to term by breeding onto a tumor necrosis factor receptor (TNFR)1-deficient background, the trice that are born lack lymph nodes, foyer's patches, and an organized splenic microarchitecture, and have a profound defect in T cell-dependent antigen responses. Analyses of TNFR1/1RelA-deficient embryonic tissues and of radiation chimeras suggest that the dependence on RelA is manifest not in hematopoietic cells but rather in radioresistant stromal cells needed for the development of secondary lymphoid organs
Margin Protection Program: Educating Dairy Producers on the 2014 Farm Bill Programs
Seven meetings in northeast Iowa and one meeting in northwest Iowa were held to educate producers on the 2014 Farm Bill dairy program, Margin Protection Program (MPP). Programs were held to provide an explanation of the MPP program, analysis on how the program could impact producers, and considerations on how producers can make the decision for their operation. The eight meetings held reached 182 producers and ag professionals
- …