Charge-state conditional operation of a spin qubit.

We report coherent operation of a singlet-triplet qubit controlled by the spatial arrangement of two confined electrons in an adjacent double quantum dot that is electrostatically coupled to the qubit. This four-dot system is the specific device geometry needed for two-qubit operations of a two-electron spin qubit. We extract the strength of the capacitive coupling between qubit and adjacent double quantum dot and show that the present geometry allows fast conditional gate operation, opening pathways toward implementation of a universal set of gates for singlet-triplet spin qubits.

Impaired nerve regeneration and enhanced neuroinflammatory response in mice lacking pituitary adenylyl cyclase activating peptide.

Peripheral nerve injury models are used to investigate processes that can potentially be exploited in CNS injury. A consistent change that occurs in injured peripheral neurons is an induction in expression of pituitary adenylyl cyclase activating peptide (PACAP), a neuropeptide with putative neuroprotective and neuritogenic actions. PACAP-deficient mice were used here to investigate actions of endogenous PACAP after facial nerve injury. Although motor neuron survival after axotomy was not significantly different in PACAP deficient vs. wild type mice, recovery of axon regeneration after crush injury was significantly delayed. The impaired regeneration was associated with 8- to 12-fold increases in gene expression of proinflammatory cytokines tumor necrosis factor-alpha, interferon-gamma, interleukin (IL) -6, and a 90% decrease in the anti-inflammatory cytokine IL-4 at the injury site. Similar cytokine changes and an increased microglial response were observed in the brainstem facial motor nucleus. Because immunocompromised animals such as SCID mice are known to exhibit peripheral nerve regeneration defects, the observations raise the novel hypothesis that PACAP is critically involved in a carefully controlled immune response that is necessary for proper nerve regeneration after injury.

Induction of neuropeptide gene expression and blockade of retrograde transport in facial motor neurons following local peripheral nerve inflammation in severe combined immunodeficiency and BALB/C mice.

Peripheral nerve inflammation is a common clinical problem that accompanies nerve injury and several diseases including Guillain-Barre syndrome and acute and chronic inflammatory demyelinating polyneuropathy. To determine if neuropeptides are induced in motor neurons after inflammation and to study the mechanisms involved, a nerve cuff soaked in complete Freund's adjuvant (CFA) was applied locally to the facial nerve of Balb/C mice. This procedure resulted in an influx of lymphocytes and macrophages to the affected area and a blockade of retrograde axonal transport distal, but not proximal, to the site of application. The same treatment resulted in a strong ipsilateral induction of pituitary adenylyl cyclase activating peptide (PACAP) gene expression in motor neurons in the facial motor nucleus. Because the changes could have occurred due to the loss of target-derived factors or to the production of new factors by immune cells, we studied the effect of the inflammatory stimulus on PACAP mRNA in mice with severe combined immunodeficiency (SCID). As expected, SCID mice showed a severely reduced influx of T-lymphocytes but not macrophages to the peripheral nerve. Moreover, although retrograde transport distal to the inflammation site was blocked similarly in control and SCID mice, the number of motor neurons expressing PACAP mRNA after CFA application was significantly reduced in SCID mice. The data indicate that the induction of PACAP mRNA during nerve inflammation requires the involvement of lymphocytes. However, because the induction of PACAP gene expression was only partially blocked in SCID mice, macrophages, loss of target-derived factors, or other mechanisms may also contribute to the upregulation of PACAP gene expression in motor neurons after nerve inflammation.

Lacerations of the mouth.

Soft-tissue and bony injuries of the face and oral cavity constitute much of the trauma seen in the emergency department. These types of wounds can be frightening for patients. The management of patients with oral lacerations, including those of the oral mucosa, gingiva, tongue, and lip, is addressed.

Efficacy of lasalocid sodium against coccidiosis (Eimeria zuernii and Eimeria bovis) in calves.

Calves experimentally infected with Eimeria bovis and E zuernii were used in a controlled experiment to determine the anticoccidial activity of lasalocid sodium. Eleven-week-old Holstein calves were given an inoculum of 300,000 E bovis and 200,000 E zuernii oocysts; medication was initiated on the day of inoculation and continued for a 4-week period. The progress of parasitic infection was monitored with quantitative fecal oocyst examinations for the 6 weeks before calves were inoculated, and then in the 4-week treatment period and a 3-week observation period. The calves were given different doses of lasalocid sodium (0.5, 0.75, 1.0, and 3.0 mg/kg) and were compared with both nonmedicated inoculated calves and controls (nonmedicated, noninoculated calves). There were overall numerical reductions of oocysts produced in the medicated groups when compared with the nonmedicated inoculated controls.

Erythema infectiosum: an outbreak of "slapped cheek" disease in north Devon.

An outbreak of erythema infectiosum (fifth disease; megalerythema epidemicum) which occurred in a small north Devon town (population 3600) during the spring of 1975 is reported. All fifty-eight cases displayed the diagnostic "slapped cheek" appearance. Virological studies gave disappointingly negative results.

Responses in the inferior olive to stimulation of the cerebellar and cerebral cortices in the cat.

1. Extracellular field potentials and single unit responses have been recorded from the inferior olive of the cat following stimulation of the surface of the contralateral paramedian lobule of the cerebellum, and of the ipsilateral cerebral cortex. 2. Cerebellar stimulation results in antidromic invasion of inferior olivary neurones via the climbing fibres. These responses are followed by synaptic discharges which may be generated through climbing fibre recurrent collaterals. 3. Precise histological controls have shown that these responses to stimulation of the paramedian lobule are located in the ventral lamella of the principal olive. 4. Unifocal stimulation of the sensori-motor cortex with surface-anodal pulses evokes synaptically generated discharges of neurones in the central lamella, with a latency of 8-9 msec. The area of cortex yielding responses has been mapped at chosen stimulus intensities and the limitations of the maps have been discussed. 5. It has been shown that the initial excitatory responses obtained from either cortex are followed by an inhibition which lasts about 100 msec, and gives way to a period of recovery or facilitation. This, in turn, is succeeded by a further period of inhibition. Possible neural substrates for these changes have been discussed.