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The local immune response to influenza virus infection was characterized by determining cytokine and chemokine levels in serial nasal lavage fluid samples from 15 volunteers experimentally infected with influenza A/Texas/36/91 (H1N1). The study was part of a randomized double-blind placebo-controlled trial to determine the prophylactic effect of intravenous zanamivir (600 mg 2x/day for 5 days), a highly selective inhibitor of influenza A and B virus neuraminidases, on the clinical symptoms of influenza infection. Nasal lavage fluid levels of interleukin (IL)-6, tumor necrosis factor-alpha, interferon-gamma, IL-10, monocyte chemotactic protein-1, and macrophage inflammatory protein-1alpha and -1beta increased in response to influenza virus infection and correlated statistically with the magnitude and time course of the symptoms. Treatment with zanamivir prevented the infection and abrogated the local cytokine and chemokine responses. These results reveal a complex interplay of cytokines and chemokines in the development of symptoms and resolution of influenza.

We propose a scheme to unconditionally entangle the internal states of atoms trapped in separate high-finesse optical cavities. The scheme uses the technique of quantum reservoir engineering in a cascaded cavity-QED setting, and for ideal (lossless) coupling between the cavities generates an entangled pure state. Highly entangled states are also shown to be possible for realizable cavity-QED parameters and with nonideal coupling.

Zanamivir is a potent inhibitor of influenza A and B virus neuraminidases and is active topically in experimental and natural human influenza. We conducted this double-blinded, placebo-controlled study to evaluate the safety and efficacy of intravenously administered zanamivir. Susceptible volunteers were randomized to receive either saline or zanamivir (600 mg) intravenously twice daily for 5 days beginning 4 h prior to intranasal inoculation with ∼105 50% tissue culture infectious doses (TCID50) of influenza A/Texas/36/91 (H1N1) virus. Reductions in the frequency of viral shedding (0% versus 100% in placebo, P < 0.005) and seroconversion (14% versus 100% in placebo, P < 0.005) and decreases in viral titer areas under the curve (0 versus 11.6 [median] log10 TCID50 · day/ml in placebo,P < 0.005) were observed in the zanamivir group, as were reductions in fever (14% versus 88% in placebo,P < 0.05), upper respiratory tract illness (0% versus 100% in placebo, P < 0.005), total symptom scores (1 versus 44 [median] in placebo, P < 0.005), and nasal-discharge weight (3.9 g versus 17.5 g [median] in placebo, P < 0.005). Zanamivir was detectable in nasal lavage samples collected on days 2 and 4 (unadjusted median concentrations, 10.5 and 12.0 ng/ml of nasal wash, respectively). This study demonstrates that intravenously administered zanamivir is distributed to the respiratory mucosa and is protective against infection and illness following experimental human influenza A virus inoculation.

Synaptic vesicle exo- and endocytosis are usually driven by neuronal activity but can also occur spontaneously. The identity and differences between vesicles supporting evoked and spontaneous neurotransmission remain highly debated. Here we combined nanometer-resolution imaging with a transient motion analysis approach to examine the dynamics of individual synaptic vesicles in hippocampal terminals under physiological conditions. We found that vesicles undergoing spontaneous and stimulated endocytosis differ in their dynamic behavior, particularly in the ability to engage in directed motion. Our data indicate that such motional differences depend on the myosin family of motor proteins, particularly myosin II. Analysis of synaptic transmission in the presence of myosin II inhibitor confirmed a specific role for myosin II in evoked, but not spontaneous, neurotransmission and also suggested a functional role of myosin II-mediated vesicle motion in supporting vesicle mobilization during neural activity.

We present a quantum multimodal treatment describing electromagnetically induced transparency ͑EIT͒ as a mechanism for storing continuous-variable quantum information in light fields. Taking into account the atomic noise and decoherences of realistic experiments, we numerically model the propagation, storage, and readout of signals contained in the sideband amplitude and phase quadratures of a light pulse using phase space methods. An analytical treatment of the effects predicted by this model is then presented. Finally, we use quantum information benchmarks to examine the properties of the EIT-based memory and show the parameters needed to operate beyond the quantum limit.

We examine the interaction of a weak probe with N atoms in a lambda-level configuration under the conditions of electromagnetically induced transparency (EIT). In contrast to previous works on EIT, we calculate the output state of the resultant slowly propagating light field while taking into account the effects of ground state dephasing and atomic noise for a more realistic model. In particular, we propose two experiments using slow light with a nonclassical probe field and show that two properties of the probe, entanglement and squeezing, characterizing the quantum state of the probe field, can be well-preserved throughout the passage.PACS numbers: 42.50.Gy, 03.67.-aThe coherent and reversible storage of the quantum state of a light field is an important issue for the realization of many protocols in quantum information processing. Recently much work has been done to address this issue by utilizing the phenomenon of electromagnetically induced transparency (EIT) [1,2,3,4,5,6,7,8,9, 10]. In this paper, we demonstrate that under the conditions of EIT, the quantum state of the stored light field can be well preserved even in the presence of dephasing and noise.In a conventional EIT setup, a strong, coherent field ("control field") is used to make an otherwise opaque medium transparent near an atomic resonance. A second, weak field ("probe") with a restricted bandwidth about this resonance can then propagate without absorption and with a substantially reduced group velocity compared to a pulse in vacuum, thus delaying (or effectively "storing") the light field within the atomic cloud for a duration equal to the delay time of the light pulse caused by the EIT medium.In this paper we concentrate on two representative quantities characterizing the amount of quantum information of a light field: squeezing, representing a subquantum noise level of fluctuation in the observable of one beam; and entanglement, where the sub-quantum noise fluctuation occurs in the correlation between two beams. We calculate the effect of the atom-light interaction on each quantity and show that the slowing of the light need not significantly degrade the information carried. Previous works on photon storage have indicated that in the absence of dephasing between the two ground states of the lambda system, and ignoring the Langevin noise operators arising from atomic coupling to a vacuum reservoir, the quantum state of light field is well preserved after traversing the EIT medium [2, 3, 11]. Here we further highlight the robustness of storage using EIT and show that even with dephasing and noise taken into account, entanglement and squeezing of the pulse at the exit of the medium need not differ significantly from that of the input pulse under experimentally realizable parameter regimes.We follow the model outlined in [2] and use a quasi one-dimensional model, consisting of two co-propagating beams passing through an optically thick medium of length L consisting of three-level atoms. The atoms have two metastable lower states |b and |c inter...