29 research outputs found
Optimal control of circuit quantum electrodynamics in one and two dimensions
Optimal control can be used to significantly improve multi-qubit gates in
quantum information processing hardware architectures based on superconducting
circuit quantum electrodynamics. We apply this approach not only to dispersive
gates of two qubits inside a cavity, but, more generally, to architectures
based on two-dimensional arrays of cavities and qubits. For high-fidelity gate
operations, simultaneous evolutions of controls and couplings in the two
coupling dimensions of cavity grids are shown to be significantly faster than
conventional sequential implementations. Even under experimentally realistic
conditions speedups by a factor of three can be gained. The methods immediately
scale to large grids and indirect gates between arbitrary pairs of qubits on
the grid. They are anticipated to be paradigmatic for 2D arrays and lattices of
controllable qubits.Comment: Published version
Broadband Geodesic Pulses for Three Spin Systems: Time-Optimal Realization of Effective Trilinear Coupling Terms and Indirect SWAP Gates
Broadband implementations of time-optimal geodesic pulse elements are
introduced for the efficient creation of effective trilinear coupling terms for
spin systems consisting of three weakly coupled spins 1/2. Based on these pulse
elements, the time-optimal implementation of indirect SWAP operations is
demonstrated experimentally. The duration of indirect SWAP gates based on
broadband geodesic sequence is reduced by 42.3% compared to conventional
approaches.Comment: 22 pages, incl. 8 figure
Site-specific labeling of nucleotides for making RNA for high resolution NMR studies using an E. coli strain disabled in the oxidative pentose phosphate pathway
Escherichia coli (E. coli) is a versatile organism for making nucleotides labeled with stable isotopes (13C, 15N, and/or 2H) for structural and molecular dynamics characterizations. Growth of a mutant E. coli strain deficient in the pentose phosphate pathway enzyme glucose-6-phosphate dehydrogenase (K10-1516) on 2-13C-glycerol and 15N-ammonium sulfate in Studier minimal medium enables labeling at sites useful for NMR spectroscopy. However, 13C-sodium formate combined with 13C-2-glycerol in the growth media adds labels to new positions. In the absence of labeled formate, both C5 and C6 positions of the pyrimidine rings are labeled with minimal multiplet splitting due to 1JC5C6 scalar coupling. However, the C2/C8 sites within purine rings and the C1â˛/C3â˛/C5Ⲡpositions within the ribose rings have reduced labeling. Addition of 13C-labeled formate leads to increased labeling at the base C2/C8 and the ribose C1â˛/C3â˛/C5Ⲡpositions; these new specific labels result in two- to three-fold increase in the number of resolved resonances. This use of formate and 15N-ammonium sulfate promises to extend further the utility of these alternate site specific labels to make labeled RNA for downstream biophysical applications such as structural, dynamics and functional studies of interesting biologically relevant RNAs
Nerve growth factor: The central hub in the development of allergic asthma?: Review
Neurotrophins like nerve growth factor (NGF), originally described as nerve growth factors in neuronal development, have been implicated in many physiological processes in the last years. They are now regarded as important factors involved in the resolution of pathological conditions. NGF has profound effects on inflammation, repair and remodeling of tissues. However, in the lung these beneficial effects can transact into disease promoting actions, e.g., in allergic inflammation or respiratory syncytial virus (RSV) infection. Overproduction of NGF then enhances inflammation, and promotes (neuronal) airway hyperreactivity and neurogenic inflammation. We hypothesize that NGF overexpression in certain vulnerable time windows during infancy could be a major risk factor for the development of asthma symptoms
Neurotrophic factors - a tool for therapeutic strategies in neurological, neuropsychiatric and neuroimmunological diseases?
Nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) belong to the protein family of neurotrophins. They both display profound neuromodulatory functions and are essentially involved in the survival and homeostatic maintenance of central and peripheral neurons during development and adulthood. Moreover, NGF and BDNF are known to modulate immune cell function and thus serve as mediators in the reciprocal cross talk between neurons and immune cells. Neurotrophic factors have been implicated in pathophysiological mechanisms of many diseases of the nervous and the immune system, such as amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), neuropathy, pain, allergic bronchial asthma (BA) and neurotrophic keratitis. For all these diseases research has reached the point of creating strategies for therapeutic intervention with neurotrophins. In this review, we present an overview of the pathophysiology, therapeutic interventions and strategies concerning NGF and BDNF in the mentioned diseases
A bibliometric analysis of bipolar affective disorders using density-equalizing mapping and output benchmarking
Serum neurotrophins: A study on the time course and influencing factors in a large old age sample
Synthesising bushmeat research effort in West and Central Africa: A new regional database
Unsustainable hunting threatens both biodiversity and local livelihoods. Despite high levels of research effort focused on understanding the dynamics of bushmeat trade and consumption, current research is largely site specific. Without synthesis and quantitative analysis of available case studies, the national and regional characteristics of bushmeat trade and consumption remain largely speculative, impeding efforts to inform national and regional policy on bushmeat trade. Here we describe the structure and content of the West and Central African bushmeat database which holds quantitative data on bushmeat sales, consumption and offtake for 177 species from 275 sites across 11 countries in two regions, spanning three decades of research. Despite this wealth of available data, we found important biases in research effort. The majority of studies in West and Central Africa have collected market data, which although providing a useful record of bushmeat sales, are limited in their ability to track changes in hunting offtake. In addition, few data exist for West Africa, and few studies have tracked changes over time, using repeat sampling. With new initiatives in the regions to track bushmeat hunting, this database represents an opportunity to synthesise current and future data on bushmeat hunting, consumption and trade in West and Central Africa, identify gaps in current understanding, and systematically target future monitoring efforts