Primary intracerebellar osteosarcoma arising within an epidermoid cyst

The authors report a case of a primary extraskeletal osteosarcoma arising within an epidermoid cyst in the parenchyma of the cerebellum in a 64-year-old woman. On initial presentation, the tumor involved the midline cerebellum without attachment to the surrounding dura mater or calvarium. Complete medical and radiologic evaluation failed to reveal a primary skeletal or other extraskeletal osteosarcoma. To our knowledge, this is the first reported case of a primary extraskeletal osteosarcoma within the cerebellum. Osteosarcoma as a primary brain tumor is exceedingly rare, and only three cases (all occurring within the cerebral hemispheres) have been reported previously. The histogenesis of primary sarcomas of the brain is not evident. The associated finding of an epidermoid cyst suggests the tumor originated from a teratoma.     

100-gb/s transmission using orthogonal frequency-division multiplexing

The possibility of 100-Gb/s transmission over 25-GHz bandwidth using orthogonal frequency-division multiplexing (OFDM) is demonstrated. It is shown that 100-Gb/s transmission over 3840 km can be achieved using single-sideband quadrature-phase-shift keying OFDM transmission and low-density parity-check codes.     

Capacity of channels with redundant multitrack (d,k) constraints:the k<d case

Run-length-limited or (d,k) recording codes are widely used in digital storage systems with peak detection. The channel capacities of the redundant multitrack (d,k) constraint are calculated and tabulated for k相似文献   

Cascaded holographic polymer reflection grating filters for optical-code-division multiple-access applications

We evaluate the use of edge-illuminated holographic Bragg filters formed in phenanthrenequinone-doped poly(methyl methacrylate) for optical-code-division multiple-access (OCDMA) coding and decoding applications. Experimental cascaded Bragg filters are formed to select two different wavelengths with a fixed distance between the gratings and are directly coupled to a fiber-measurement system. The configuration and tolerances of the cascaded gratings are shown to be practical for time-wavelength OCDMA applications.     

Love, marriage, and divorce: Newlyweds' stress hormones foreshadow relationship changes.

Neuroendocrine function, assessed in 90 couples during their first year of marriage (Time 1), was related to marital dissolution and satisfaction 10 years later. Compared to those who remained married, epinephrine levels of divorced couples were 34% higher during a Time 1 conflict discussion, 22% higher throughout the day, and both epinephrine and norepinephrine were 16% higher at night. Among couples who were still married, Time 1 conflict ACTH levels were twice as high among women whose marriages were troubled 10 years later than among women whose marriages were untroubled. Couples whose marriages were troubled at follow-up produced 34% more norepinephrine during conflict, 24% more norepinephrine during the daytime, and 17% more during nighttime hours at Time 1 than the untroubled. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Field-Effect Transistors Made by Functionalized Pentacene with Logic Gate Applications

Funtionalized pentacene, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene), field-effect transistors (FET) were made by thermal evaporation or solution deposition methods and the temperature dependent mobility was measured. The field-effect mobility (μ_FET) activation energy is gate voltage dependent. At low gate voltage, activated conduction is dominant with Ea ~ 0.27 eV, slightly smaller than the bulk value, and the activation energy decreases with increasing gate voltage. This is ascribed to traps in the film. A non-monotonic temperature dependence is observed at high gate voltage (V_G < −30 V) with Ea ~ 60 - 170 meV at lower temperatures below the mobility maximum. Realization of simple logic gate circuits such as NOT (inverter), NOR, and NAND is demonstrated.     

Multimodal interaction with a wearable augmented reality system

An augmented reality system enhances a mobile user's situational awareness and provides new visualization functionality. The custom-built multimodal interface provides access to information encountered in urban environments. In this article, we detail our experiences with various input devices and modalities and discuss their advantages and drawbacks in the context of interaction tasks in mobile computing. We show how we integrated the input channels to use the modalities beneficially and how this enhances the interface's overall usability.