The "Black Turbinate" sign: An early MR imaging finding of nasal mucormycosis.

Rhinocerebral mucormycosis is a rare angioinvasive fungal infection that has a strong predilection for patients with poorly controlled diabetes and immunosuppression. Initial presenting symptoms are nonspecific and frequently are attributed to more mundane sinonasal and orbital pathologies. Early diagnosis and treatment are essential for survival and minimizing neurologic sequelae. CT and MR imaging are often used in the diagnostic work-up; however, CT findings are nonspecific.

Red picosecond pulses generated by frequency doubling a Raman amplified widely tunable 1.3 microm fiber ring laser.

We generated 0.66 microm picosecond pulses by second-harmonic generation of the Raman amplified output of a 1.3 microm actively mode-locked fiber ring laser in a periodically poled potassium titanyl phosphate (PPKTP) waveguide. The ring laser produced 9 ps pulses at a 20 GHz repetition frequency, was tunable over 1284-1330 nm, and was based on a semiconductor optical amplifier and a Mach-Zehnder amplitude modulator. The Raman amplifier served both to amplify the ring laser and to compress the pulses as solitons. The spectral flexibility of the amplifiers and the modulator should enable similar configurations to be made at other wavelengths and facilitate efficient frequency doubling in waveguides to other visible wavelengths.

Discretized learning automata solutions to the capacity assignment problem for prioritized networks.

We present a discretized learning automaton (LA) solution to the capacity assignment (CA) problem which focuses on finding the best possible set of capacities for the links that satisfy the traffic requirements in a prioritized network while minimizing the cost. Most approaches consider a single class of packets flowing through the network, but in reality, different classes of packets with different average packet lengths and different priorities are transmitted over the networks. This generalized model is the focus of this paper. Although the problem is inherently NP-hard, a few approximate solutions have been proposed in the literature. Marayuma and Tang (1977) proposed a single algorithm composed of several elementary heuristic procedures. Other solutions tackle the problem by using modern-day artificial intelligence (AI) paradigms such as simulated annealing and genetic algorithms (GAs). In 2000, we introduced a new method, superior to these, that uses continuous LA. In this paper, we present a discretized LA solution to the problem. This solution uses a meta-action philosophy new to the field of LA, and is probably the best available solution to this extremely complex problem.

From single- to multiple-pPhoton decoherence in an atom interferometer.

We measure the decoherence of a spatially separated atomic superposition due to spontaneous photon scattering. We observe a qualitative change in decoherence versus separation as the number of scattered photons increases, and verify quantitatively the decoherence rate constant in the many-photon limit. Our results illustrate an evolution of decoherence consistent with general models developed for a broad class of decoherence phenomena.

Asymmetric tonic labyrinth reflexes and their interaction with neck reflexes in the decerebrate cat.

1. Tonic labyrinth and neck reflexes were studied separately and in combination in the decerebrate cat with C1 and C2 spinal roots cut. Reflex effects were observed as changes in length of the isotonically loaded medial head of triceps. 2. The tonic labyrinth reflexes acted asymmetrically on the medial head of triceps. Side-down rotation of the head produced shortening in medial triceps, whereas side-up rotations of the head resulted in a lengthening. 3. The tonic neck reflexes acted asymmetrically on the medial head of triceps. Side-down rotations of the neck produced a lengthening of medial triceps, whereas side-up rotations of the neck resulted in shortening. 4. Labyrinth and neck reflexes produce opposite effects on the same limb extensor muscle so that, if the neck innervation is intact, head tilting produces no change in muscle length. 5. It is suggested that the interaction between the labyrinth and neck reflexes contributes to the stability of the trunk, allowing the head to move freely on the body without affecting this stability. Labyrinth and neck reflexes need therefore to be considered together as a single system.

Reflex contributions to the assessment of the vertical.

On the ground the vertical directions "up" and "down" have significance in relation to the strategy for avoiding collision of the skull with the planet. Voluntary acts to this end may be based on the experienced result of reflexly generated motor commands. Relevant receptors lie in the otolith organs of the labyrinth, but the head is seldom steady in waking life. A revised scheme of labyrinth reflexes on the limbs--"downhill limbs extend"--replaces the classical scheme of Magnus. Interactions with neck reflexes according to this scheme serve to stabilize the trunk. In an orbiting spacecraft the pattern of afferent signals from the labyrinth differs from that on the ground, and predictions based on the new scheme are to be tested in the project "Operation Push-Pull" proposed for ESRO's Spacelab. Other activities of the Council of Europe's Working Party on Aerospace Physiology and Medicine are briefly described.