Wireless communication systems, i.e., systems transmitting information via electromagnetic (radio) or acoustic (sound) waves, have become ubiquitous. In many of these systems, the transmitter or the receiver is mobile. Even if both link ends are static, scatterers — i.e., objects that reflect, scatter, or diffract the propagating waves — may move with significant velocities. These situations gi...

Inaccurate identification of vertebral levels is the main cause of wrong-site spine surgery which is performed by nearly half of the spine surgeons. Unusual anatomy and failure to verify the surgical level on radiographs have been commonly reported. We aimed at investigating the variations in vertebral number in adolescent idiopathic scoliosis (AIS) patients and thus to raise awareness of the p...

Customer lifetime value (LTV, see e.g. Bauer et al. 2005 and Rosset et al. 2003), which measures the profit generating potential, or value, of a customer, is increasingly being considered a touchstone for administering the CRM (Customer relationship management) process. This in order to provide attractive benefits and retain high-value customers, while maximizing profits from a business standpo...

As is well known, the variational equations of nonlinear dynamic systems are linear time-varying (LTV) by nature. In the modal solutions for these LTV equations, the earlier introduced dynamic eigenvalues play a key role. They are closely related to the Lyapunovand Floquet-exponents of the corresponding nonlinear systems. In this contribution, we present some simple examples for which analytic ...

Spondylolisthesis merupakan kondisi adanya pergeseran ke depan suatu korpus vertebra dengan yang terletak dibawahnya. Umumnya terjadi pada pertemuan lumbosacral joint dimana L5 bergeser diatas S1 akan tetapi hal tersebut dapat tingkatan lebih tinggi . Pada pasien disertai dan tidak spondilosis menyebabkan radikulopati signifikan defisit neurologis progresif akibat kompresi akar saraf. Gangguan ...

DESCRIPTION A 28-year-old lady presented with weakness in both lower limbs for 4 months, urinary and fecal incontinence for 3 months along with sensory loss in the perianal region and below both knees for 3 months. Clinical examination revealed intact higher mental functions and normal cranial nerves. A small paramedian swelling, 10×12 cm in size, soft in consistency was noted in lumbosacral re...

BACKGROUND There are few studies about risk factors for poor outcomes from multi-level lumbar posterolateral fusion limited to three or four level lumbar posterolateral fusions. The purpose of this study was to analyze the outcomes of multi-level lumbar posterolateral fusion and to search for possible risk factors for poor surgical outcomes. METHODS We retrospectively analyzed 37 consecutive ...

Received March 5, 1984; accepted May 18, 1984. On physical examination, there was tenderness in the L 1 area. Neurologic examination was normal. Initial radiographs (fig. 1A) of the lumbosacral spine revealed a compression fracture of the L 1 vertebra; subsequent myelography demonstrated an extradural block at the same level. At surgery, a standard posterior exposure of the dorsal arches of T10...